Sample records for radar doppler spectra

  1. Cloud radar Doppler spectra in drizzling stratiform clouds: 2. Observations and microphysical modeling of drizzle evolution

    E-Print Network [OSTI]

    Cloud radar Doppler spectra in drizzling stratiform clouds: 2. Observations and microphysical I, the influence of cloud microphysics and dynamics on the shape of cloud radar Doppler spectra in warm stratiform clouds was discussed. The traditional analysis of radar Doppler moments was extended

  2. Cloud radar Doppler spectra in drizzling stratiform clouds: 1. Forward modeling and remote sensing applications

    E-Print Network [OSTI]

    Cloud radar Doppler spectra in drizzling stratiform clouds: 1. Forward modeling and remote sensing broadening and drizzle growth in shallow liquid clouds remain not well understood. Detailed, cloudscale. Profiling, millimeterwavelength (cloud) radars can provide such observations. In particular, the first three

  3. A High Resolution Hydrometer Phase Classifier Based on Analysis of Cloud Radar Doppler Spectra.

    SciTech Connect (OSTI)

    Luke,E.; Kollias, P.

    2007-08-06T23:59:59.000Z

    The lifecycle and radiative properties of clouds are highly sensitive to the phase of their hydrometeors (i.e., liquid or ice). Knowledge of cloud phase is essential for specifying the optical properties of clouds, or else, large errors can be introduced in the calculation of the cloud radiative fluxes. Current parameterizations of cloud water partition in liquid and ice based on temperature are characterized by large uncertainty (Curry et al., 1996; Hobbs and Rangno, 1998; Intriery et al., 2002). This is particularly important in high geographical latitudes and temperature ranges where both liquid droplets and ice crystal phases can exist (mixed-phase cloud). The mixture of phases has a large effect on cloud radiative properties, and the parameterization of mixed-phase clouds has a large impact on climate simulations (e.g., Gregory and Morris, 1996). Furthermore, the presence of both ice and liquid affects the macroscopic properties of clouds, including their propensity to precipitate. Despite their importance, mixed-phase clouds are severely understudied compared to the arguably simpler single-phase clouds. In-situ measurements in mixed-phase clouds are hindered due to aircraft icing, difficulties distinguishing hydrometeor phase, and discrepancies in methods for deriving physical quantities (Wendisch et al. 1996, Lawson et al. 2001). Satellite-based retrievals of cloud phase in high latitudes are often hindered by the highly reflecting ice-covered ground and persistent temperature inversions. From the ground, the retrieval of mixed-phase cloud properties has been the subject of extensive research over the past 20 years using polarization lidars (e.g., Sassen et al. 1990), dual radar wavelengths (e.g., Gosset and Sauvageot 1992; Sekelsky and McIntosh, 1996), and recently radar Doppler spectra (Shupe et al. 2004). Millimeter-wavelength radars have substantially improved our ability to observe non-precipitating clouds (Kollias et al., 2007) due to their excellent sensitivity that enables the detection of thin cloud layers and their ability to penetrate several non-precipitating cloud layers. However, in mixed-phase clouds conditions, the observed Doppler moments are dominated by the highly reflecting ice crystals and thus can not be used to identify the cloud phase. This limits our ability to identify the spatial distribution of cloud phase and our ability to identify the conditions under which mixed-phase clouds form.

  4. Cloud Properties from Doppler Radar Spectra - a Growing Suite of Information Extraction Algorithms

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  5. Sandia National Laboratories: TTU Advanced Doppler Radar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    rotor sweep. Doppler radar technologies and techniques developed at TTU have the potential to revolutionize wind energy generation by providing comprehensive information...

  6. Doppler Radar Wind Profiles Iwan Holleman

    E-Print Network [OSTI]

    Stoffelen, Ad

    ). The potential impact of a network of boundary layer wind profilers and sodars for mesoscale wind analysisDoppler Radar Wind Profiles Iwan Holleman Scientific Report, KNMI WR-2003-02, 2003 #12;2 #12 Strategy 18 3 Methods for Wind Profile Retrieval 25 3.1 Radial Velocity from Local Wind Model 25 3

  7. 2138 IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 52, NO. 4, APRIL 2014 HF Bistatic Ocean Doppler Spectra: Simulation

    E-Print Network [OSTI]

    with in situ buoy measurements. Experimental and simulated Doppler spectra agree generally well, except Terms--Bistatic high-frequency surface wave radar (HFSWR), Doppler spectrum [power spectral density (PSD

  8. Using doppler radar images to estimate aircraft navigational heading error

    DOE Patents [OSTI]

    Doerry, Armin W. (Albuquerque, NM); Jordan, Jay D. (Albuquerque, NM); Kim, Theodore J. (Albuquerque, NM)

    2012-07-03T23:59:59.000Z

    A yaw angle error of a motion measurement system carried on an aircraft for navigation is estimated from Doppler radar images captured using the aircraft. At least two radar pulses aimed at respectively different physical locations in a targeted area are transmitted from a radar antenna carried on the aircraft. At least two Doppler radar images that respectively correspond to the at least two transmitted radar pulses are produced. These images are used to produce an estimate of the yaw angle error.

  9. Sandia Energy - TTU Advanced Doppler Radar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    radar technologies and techniques developed at TTU have the potential to revolutionize wind energy generation by providing comprehensive information about the modulated flows...

  10. 2 1 APPLICATION GALLERY 1.1 Tracking ``Fuzzy'' Storms in Doppler Radar Images

    E-Print Network [OSTI]

    Barron, John

    and tornadoes. The Doppler radar generates intensity and radial velocity images, examples of which are shown Doppler radar radial and velocity image (a) (b) (c) (d) Figure 1.2: The storm tracks for the (a) 5 th , (b2 1 APPLICATION GALLERY 1.1 Tracking ``Fuzzy'' Storms in Doppler Radar Images J. L. Barron 1 , R. E

  11. The Accuracy of Radar Estimates of Ice Terminal Fall Speed from Vertically Pointing Doppler Radar Measurements

    E-Print Network [OSTI]

    Protat, Alain

    The Accuracy of Radar Estimates of Ice Terminal Fall Speed from Vertically Pointing Doppler Radar and 2835 MHz) are used to characterize the terminal fall speed of hydrometeors and the vertical air motion air velocity in ice clouds is small on average, as is assumed in terminal fall speed retrieval methods

  12. Using Doppler spectra to separate hydrometeor populations and analyze ice precipitation in multilayered mixed-phase clouds

    SciTech Connect (OSTI)

    Rambukkange, Mahlon P.; Verlinde, J.; Eloranta, E. W.; Flynn, Connor J.; Clothiaux, Eugene E.

    2011-01-31T23:59:59.000Z

    Multimodality of cloud radar Doppler spectra is used to partition cloud particle phases and to separate distinct ice populations in the radar sample volume, thereby facilitating analysis of individual ice showers in multilayered mixed-phase clouds. A 35-GHz cloud radar located at Barrow, Alaska, during the Mixed-Phase Arctic Cloud Experiment collected the Doppler spectra. Data from a pair of collocated depolarization lidars confirmed the presence of two liquid cloud layers reported in this study. Surprisingly, both of these cloud layers were embedded in ice precipitation yet maintained their liquid. Our spectral separation of the ice precipitation yielded two distinct ice populations: ice initiated within the two liquid cloud layers and ice precipitation formed in higher cloud layers. Comparisons of ice fall velocity versus radar reflectivity relationships derived for distinct showers reveal that a single relationship might not properly represent the ice showers during this period.

  13. MECHANICAL VIBRATION SENSING FOR STRUCTURAL HEALTH MONITORING USING A MILLIMETER-WAVE DOPPLER RADAR SENSOR

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    MECHANICAL VIBRATION SENSING FOR STRUCTURAL HEALTH MONITORING USING A MILLIMETER-WAVE DOPPLER RADAR of structural health monitoring (SHM). In this paper, we report on a millimeter-wave Doppler radar sensor sensing, millimeter-waves, structural health monitoring. INTRODUCTION Structural health monitoring based

  14. Performance comparison of pulse-pair and wavelets methods for the pulse Doppler weather radar

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    - eters. The radar reflectivity (Z), the radial velocity (Vr) and the spectral width of velocities (W). [1). Generally, the meteorological targets move with speeds lower than 50 m/secs. The Doppler Effect wouldPerformance comparison of pulse-pair and wavelets methods for the pulse Doppler weather radar

  15. Characterization of Doppler Effects in the Context of Over-the-Horizon Radar

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Characterization of Doppler Effects in the Context of Over-the-Horizon Radar Cornel Ioana Grenoble addresses the problem of the characterization of Doppler effect of maneuvering targets in the context reveals the Doppler effects characterizing the target's trajectory. Analysis of such signals

  16. Radar echo, Doppler Effect and Radar detection in the uniformly accelerated reference frame

    E-Print Network [OSTI]

    Bernhard Rothenstein; Stefan Popescu

    2006-09-14T23:59:59.000Z

    The uniformly accelerated reference frame described by Hamilton, Desloge and Philpott involves the observers who perform the hyperbolic motion with constant proper acceleration gi. They start to move from different distances measured from the origin O of the inertial reference frame K(XOY), along its OX axis with zero initial velocity. Equipped with clocks and light sources they are engaged with each other in Radar echo, Doppler Effect and Radar detection experiments. They are also engaged in the same experiments with an inertial observer at rest in K(XOY) and located at its origin O. We derive formulas that account for the experiments mentioned above. We study also the landing conditions of the accelerating observers on a uniformly moving platform.

  17. The effect of smoothing the Doppler radar derived wind field on perturbation pressure retrieval

    E-Print Network [OSTI]

    Rosser, George Philip

    1986-01-01T23:59:59.000Z

    THE EFFECT OF SMOOTHING THE DOPPLER RADAR DERIVED WIND FIELD ON PERTURBATION PRESSURE RETRIEVAL A Thesis by GEORGE PHILIP ROSSER, JR. Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE May 1986 Major Subject: Meteorology THE EFFECT OF SMOOTHING THE DOPPLER RADAR DERIVED WIND FIELD ON PERTURBATION PRESSURE RETRIEVAL A Thesis by GEORGE PHILIP ROSSER, JR. Approved as to style and content by...

  18. Ensemble Kalman Filter Assimilation of Doppler Radar Data with a Compressible Nonhydrostatic Model: OSS Experiments

    E-Print Network [OSTI]

    Xue, Ming

    Ensemble Kalman Filter Assimilation of Doppler Radar Data with a Compressible Nonhydrostatic Model on an ensemble Kalman filter (EnKF) method and tested with simulated radar data from a supercell storm for at least 2 h. 1. Introduction Since its introduction by Evensen (1994), the en- semble Kalman filter (En

  19. Wind Profiling by Doppler Weather Radar Iwan Holleman (holleman@knmi.nl)

    E-Print Network [OSTI]

    Stoffelen, Ad

    Wind Profiling by Doppler Weather Radar Iwan Holleman (holleman@knmi.nl) Royal Netherlands wind profiles at a high temporal resolution. Several algorithms and quality ensuring procedures for the extraction of wind profiles from radar volume data have been published. A comparison and verification

  20. VOLUME 78, NUMBER 5 P H Y S I C A L R E V I E W L E T T E R S 3 FEBRUARY 1997 Multifrequency Doppler Radar Observations of Electron Gyroharmonic Effects

    E-Print Network [OSTI]

    Doppler Radar Observations of Electron Gyroharmonic Effects during Electromagnetic Pumping the first detailed mul- tifrequency HF Doppler radar (MDR) studies of elec- tron gyroharmonic effects) Experimental results of multifrequency HF Doppler radar studies during electromagnetic pumping

  1. A newsletter for non-scientists (and scientists) interested in MAGIC The last two updates discussed how the Doppler effect can be used by radars to provide

    E-Print Network [OSTI]

    updates discussed how the Doppler effect can be used by radars to provide information on the sizes-pointing radar using the Doppler effect is equal to the speed of the surrounding air, i.e., the speed of raindrops falling in still air: an upward-pointing radar measures the Doppler shifts from falling raindrops

  2. ASSIMILATION OF DOPPLER RADAR DATA INTO NUMERICAL WEATHER MODELS

    SciTech Connect (OSTI)

    Chiswell, S.; Buckley, R.

    2009-01-15T23:59:59.000Z

    During the year 2008, the United States National Weather Service (NWS) completed an eight fold increase in sampling capability for weather radars to 250 m resolution. This increase is expected to improve warning lead times by detecting small scale features sooner with increased reliability; however, current NWS operational model domains utilize grid spacing an order of magnitude larger than the radar data resolution, and therefore the added resolution of radar data is not fully exploited. The assimilation of radar reflectivity and velocity data into high resolution numerical weather model forecasts where grid spacing is comparable to the radar data resolution was investigated under a Laboratory Directed Research and Development (LDRD) 'quick hit' grant to determine the impact of improved data resolution on model predictions with specific initial proof of concept application to daily Savannah River Site operations and emergency response. Development of software to process NWS radar reflectivity and radial velocity data was undertaken for assimilation of observations into numerical models. Data values within the radar data volume undergo automated quality control (QC) analysis routines developed in support of this project to eliminate empty/missing data points, decrease anomalous propagation values, and determine error thresholds by utilizing the calculated variances among data values. The Weather Research and Forecasting model (WRF) three dimensional variational data assimilation package (WRF-3DVAR) was used to incorporate the QC'ed radar data into input and boundary conditions. The lack of observational data in the vicinity of SRS available to NWS operational models signifies an important data void where radar observations can provide significant input. These observations greatly enhance the knowledge of storm structures and the environmental conditions which influence their development. As the increase in computational power and availability has made higher resolution real-time model simulations possible, the need to obtain observations to both initialize numerical models and verify their output has become increasingly important. The assimilation of high resolution radar observations therefore provides a vital component in the development and utility of numerical model forecasts for both weather forecasting and contaminant transport, including future opportunities to improve wet deposition computations explicitly.

  3. Noise correction of turbulent spectra obtained from Acoustic Doppler Velocimeters

    SciTech Connect (OSTI)

    Durgesh, Vibhav; Thomson, Jim; Richmond, Marshall C.; Polagye, Brian

    2014-03-02T23:59:59.000Z

    Accurately estimated auto-spectral density functions are essential for characterization of turbulent flows, and they also have applications in computational fluid dynamics modeling, site and inflow characterization for hydrokinetic turbines, and inflow turbulence generation. The Acoustic Doppler Velocimeter (ADV) provides single-point temporally resolved data, that are used to characterize turbulent flows in rivers, seas, and oceans. However, ADV data are susceptible to contamination from various sources, including instrument noise, which is the intrinsic limit to the accuracy of acoustic velocity measurements. Due to the presence of instrument noise, the spectra obtained are altered at high frequencies. The focus of this study is to develop a robust and effective method for accurately estimating auto-spectral density functions from ADV data by reducing or removing the spectral contribution derived from instrument noise. For this purpose, the “Noise Auto-Correlation” (NAC) approach was developed, which exploits the correlation properties of instrument noise to identify and remove its contribution from spectra. The spectra estimated using the NAC approach exhibit increased fidelity and a slope of -5/3 in the inertial range, which is typically observed for turbulent flows. Finally, this study also compares the effectiveness of low-pass Gaussian filters in removing instrument noise with that of the NAC approach. For the data used in this study, both the NAC and Gaussian filter approaches are observed to be capable of removing instrument noise at higher frequencies from the spectra. However, the NAC results are closer to the expected frequency power of -5/3 in the inertial sub-range.

  4. A newsletter for non-scientists (and scientists) interested in MAGIC The last update discussed how an upward-pointing radar can utilize the Doppler effect to

    E-Print Network [OSTI]

    discussed how an upward-pointing radar can utilize the Doppler effect to determine the downdraft (or updraft the Doppler signal from a vertically pointing radar can be used to determine sizes and numbers of raindrops, the frequency shifts in the Doppler signal corresponds directly to speeds of the drops relative to the ground

  5. Impacts of Beam Broadening and Earth Curvature on Storm-Scale 3D Variational Data Assimilation of Radial Velocity with Two Doppler Radars

    E-Print Network [OSTI]

    Gao, Jidong

    of Radial Velocity with Two Doppler Radars GUOQING GE Center for Analysis and Prediction of Storms assimilation. This study examines the effects of simplifying ray path and ray broadening calculations. Introduction The operational Weather Surveillance Radar-1988 Doppler (WSR-88D) Next Generation Weather Radar

  6. Mixed-Phase Cloud Retrievals Using Doppler Radar Spectra

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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  7. On the measurement of wind speeds in tornadoes with a portable CW/FM-CW Doppler radar

    SciTech Connect (OSTI)

    Bluestein, H.B. (Oklahoma Univ., Norman, OK (USA). School of Meteorology); Unruh, W.P. (Los Alamos National Lab., NM (USA))

    1991-01-01T23:59:59.000Z

    Both the formation mechanism and structure of tornadoes are not yet well understood. The Doppler radar is probably the best remote-sensing instrument at present for determining the wind field in tornadoes. Although much has been learned about the non-supercell tornado from relatively close range using Doppler radars at fixed sites, close-range measurements in supercell tornadoes are relatively few. Doppler radar can increase significantly the number of high-resolution, sub-cloud base measurements of both the tornado vortex and its parent vortex in supercells, with simultaneous visual documentation. The design details and operation of the CW/FM-CW Doppler radar developed at the Los Alamos National Laboratory and used by storm-intercept teams at the Univ. of Oklahoma are described elsewhere. The radar transmits 1 W at 3 cm, and can be switched back and forth between CW and FM-CW modes. In the FM-CW mode the sweep repetition frequency is 15.575 kHz and the sweep width 1.9 MHz; the corresponding maximum unambiguous range and velocity, and range resolution are 5 km, {plus minus} 115 m s{sup {minus}1}, and 78 m respectively. The bistatic antennas, which have half-power beamwidths of 5{degree}, are easily pointed wit the aid of a boresighted VCR. FM-CW Data are recorded on the VCR, while voice documentation is recorded on the audio tape; video is recorded on another VCR. The radar and antennas are easily mounted on a tripod, and can be set up by three people in a minute or two. The purpose of this paper is to describe the signal processing techniques used to determine the Doppler spectrum in the FM-CW mode and a method of its interpretation in real time, and to present data gathered in a tornadic storm in 1990. 15 refs., 7 figs.

  8. Relativistic Doppler effect: universal spectra and zeptosecond pulses

    E-Print Network [OSTI]

    S. Gordienko; A. Pukhov; O. Shorokhov; T. Baeva

    2004-05-10T23:59:59.000Z

    We report on a numerical observation of the train of zeptosecond pulses produced by reflection of a relativistically intense femtosecond laser pulse from the oscillating boundary of an overdense plasma because of the Doppler effect. These pulses promise to become a unique experimental and technological tool since their length is of the order of the Bohr radius and the intensity is extremely high $\\propto 10^{19}$ W/cm$^2$. We present the physical mechanism, analytical theory, and direct particle-in-cell simulations. We show that the harmonic spectrum is universal: the intensity of $n$th harmonic scales as $1/n^{p}$ for $n < 4\\gamma^2$, where $\\gamma$ is the largest $\\gamma$--factor of the electron fluid boundary, $p=3$ and $p=5/2$ for the broadband and quasimonochromatic laser pulses respectively.

  9. Doppler Lidar (DL) Handbook

    SciTech Connect (OSTI)

    Newsom, RK

    2012-02-13T23:59:59.000Z

    The Doppler lidar (DL) is an active remote sensing instrument that provides range- and time-resolved measurements of radial velocity and attenuated backscatter. The principle of operation is similar to radar in that pulses of energy are transmitted into the atmosphere; the energy scattered back to the transceiver is collected and measured as a time-resolved signal. From the time delay between each outgoing transmitted pulse and the backscattered signal, the distance to the scatterer is inferred. The radial or line-of-sight velocity of the scatterers is determined from the Doppler frequency shift of the backscattered radiation. The DL uses a heterodyne detection technique in which the return signal is mixed with a reference laser beam (i.e., local oscillator) of known frequency. An onboard signal processing computer then determines the Doppler frequency shift from the spectra of the heterodyne signal. The energy content of the Doppler spectra can also be used to determine attenuated backscatter.

  10. ON THE IMPACT OF SUPER RESOLUTION WSR-88D DOPPLER RADAR DATA ASSIMILATION ON HIGH RESOLUTION NUMERICAL MODEL FORECASTS

    SciTech Connect (OSTI)

    Chiswell, S

    2009-01-11T23:59:59.000Z

    Assimilation of radar velocity and precipitation fields into high-resolution model simulations can improve precipitation forecasts with decreased 'spin-up' time and improve short-term simulation of boundary layer winds (Benjamin, 2004 & 2007; Xiao, 2008) which is critical to improving plume transport forecasts. Accurate description of wind and turbulence fields is essential to useful atmospheric transport and dispersion results, and any improvement in the accuracy of these fields will make consequence assessment more valuable during both routine operation as well as potential emergency situations. During 2008, the United States National Weather Service (NWS) radars implemented a significant upgrade which increased the real-time level II data resolution to 8 times their previous 'legacy' resolution, from 1 km range gate and 1.0 degree azimuthal resolution to 'super resolution' 250 m range gate and 0.5 degree azimuthal resolution (Fig 1). These radar observations provide reflectivity, velocity and returned power spectra measurements at a range of up to 300 km (460 km for reflectivity) at a frequency of 4-5 minutes and yield up to 13.5 million point observations per level in super-resolution mode. The migration of National Weather Service (NWS) WSR-88D radars to super resolution is expected to improve warning lead times by detecting small scale features sooner with increased reliability; however, current operational mesoscale model domains utilize grid spacing several times larger than the legacy data resolution, and therefore the added resolution of radar data is not fully exploited. The assimilation of super resolution reflectivity and velocity data into high resolution numerical weather model forecasts where grid spacing is comparable to the radar data resolution is investigated here to determine the impact of the improved data resolution on model predictions.

  11. Deconvolution of positron annihilation coincidence Doppler broadening spectra using iterative projected Newton method with non-negativity

    E-Print Network [OSTI]

    Soatto, Stefano

    accumulation rate, suffers from the poor intrinsic resolution of HP(Ge) gamma ray spectroscopy systems of the 514 keV gamma ray line of 85 Sr where photons from the source are observed in pseudo-coincidence [71 Deconvolution of positron annihilation coincidence Doppler broadening spectra using iterative

  12. Evaluation of Single-Doppler Radar Wind Retrievals in Flat and Complex Terrain

    SciTech Connect (OSTI)

    Newsom, Rob K.; Berg, Larry K.; Pekour, Mikhail S.; Fast, Jerome D.; Xu, Qin; Zhang, Pengfei; Yang, Qing; Shaw, William J.; Flaherty, Julia E.

    2014-08-01T23:59:59.000Z

    The accuracy of winds derived from NEXRAD level II data is assessed by comparison with independent observations from 915 MHz radar wind profilers. The evaluation is carried out at two locations with very different terrain characteristics. One site is located in an area of complex terrain within the State Line Wind Energy Center in northeast Oregon. The other site is located in an area of flat terrain on the east-central Florida coast. The National Severe Storm Laboratory’s 2DVar algorithm is used to retrieve wind fields from the KPDT (Pendleton OR) and KMLB (Melbourne FL) NEXRAD radars. Comparisons between the 2DVar retrievals and the radar profilers were conducted over a period of about 6 months and at multiple height levels at each of the profiler sites. Wind speed correlations at most observation height levels fell in the range from 0.7 to 0.8, indicating that the retrieved winds followed temporal fluctuations in the profiler-observed winds reasonably well. The retrieved winds, however, consistently exhibited slow biases in the range of1 to 2 ms-1. Wind speed difference distributions were broad with standard deviations in the range from 3 to 4 ms-1. Results from the Florida site showed little change in the wind speed correlations and difference standard deviations with altitude between about 300 and 1400 m AGL. Over this same height range, results from the Oregon site showed a monotonic increase in the wind speed correlation and a monotonic decrease in the wind speed difference standard deviation with increasing altitude. The poorest overall agreement occurred at the lowest observable level (~300 m AGL) at the Oregon site, where the effects of the complex terrain were greatest.

  13. Detection of supercooled liquid in mixedphase clouds using radar Doppler spectra

    E-Print Network [OSTI]

    Shupe, Matthew

    in the temperature range from 0 to -40°C, where both liquid and ice hydrometeor phases are sustainable of their hydrometeors (i.e., liquid or ice). Current cloud parameterizations that parti- tion water into liquid and ice 2010; published 1 October 2010. [1] Cloud phase identification from active remote sensors

  14. ARM - Measurement - Radar Doppler

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625govInstrumentstdmadap Documentation TDMADAP : XDCnarrowband upwelling

  15. Doppler tomography of the Little Homunculus: High resolution spectra of [Fe II] 16435 around Eta Carinae

    E-Print Network [OSTI]

    Nathan Smith

    2004-12-21T23:59:59.000Z

    High-resolution spectra of [Fe II] 16435 around eta Carinae provide powerful diagnostics of the geometry and kinematics of the ``Little Homunculus'' (LH) growing inside the larger Homunculus nebula. The LH expansion is not perfectly homologous: while low-latitudes are consistent with linear expansion since 1910, the polar caps imply ejection dates around 1920--1930. However, the expansion speed of the LH is slower than the post-eruption wind, so the star's powerful wind may accelerate it. With an initial ejection speed of 200 km/s in 1890, the LH would have been accelerated to its present speed if the mass is roughly 0.1 Msun. This agrees with an independent estimate of the LH mass based on its density and volume. In any case, an ejection after 1930 is ruled out. Using the LH as a probe of the 1890 event, then, it is evident that its most basic physical parameters (total mass and kinetic energy; 0.1 Msun and 10^46.9 ergs, respectively) are orders of magnitude less than during the giant eruption in the 1840s. Thus, the ultimate energy sources were different for these two events -- yet their ejecta have the same bipolar geometry. This clue may point toward a collimation mechanism separate from the underlying causes of the outbursts.

  16. Vibrational spectra of nanowires measured using laser doppler vibrometry and STM studies of epitaxial graphene : an LDRD fellowship report.

    SciTech Connect (OSTI)

    Biedermann, Laura Butler

    2009-09-01T23:59:59.000Z

    A few of the many applications for nanowires are high-aspect ratio conductive atomic force microscope (AFM) cantilever tips, force and mass sensors, and high-frequency resonators. Reliable estimates for the elastic modulus of nanowires and the quality factor of their oscillations are of interest to help enable these applications. Furthermore, a real-time, non-destructive technique to measure the vibrational spectra of nanowires will help enable sensor applications based on nanowires and the use of nanowires as AFM cantilevers (rather than as tips for AFM cantilevers). Laser Doppler vibrometry is used to measure the vibration spectra of individual cantilevered nanowires, specifically multiwalled carbon nanotubes (MWNTs) and silver gallium nanoneedles. Since the entire vibration spectrum is measured with high frequency resolution (100 Hz for a 10 MHz frequency scan), the resonant frequencies and quality factors of the nanowires are accurately determined. Using Euler-Bernoulli beam theory, the elastic modulus and spring constant can be calculated from the resonance frequencies of the oscillation spectrum and the dimensions of the nanowires, which are obtained from parallel SEM studies. Because the diameters of the nanowires studied are smaller than the wavelength of the vibrometer's laser, Mie scattering is used to estimate the lower diameter limit for nanowires whose vibration can be measured in this way. The techniques developed in this thesis can be used to measure the vibrational spectra of any suspended nanowire with high frequency resolution Two different nanowires were measured - MWNTs and Ag{sub 2}Ga nanoneedles. Measurements of the thermal vibration spectra of MWNTs under ambient conditions showed that the elastic modulus, E, of plasma-enhanced chemical vapor deposition (PECVD) MWNTs is 37 {+-} 26 GPa, well within the range of E previously reported for CVD-grown MWNTs. Since the Ag{sub 2}Ga nanoneedles have a greater optical scattering efficiency than MWNTs, their vibration spectra was more extensively studied. The thermal vibration spectra of Ag{sub 2}Ga nanoneedles was measured under both ambient and low-vacuum conditions. The operational deflection shapes of the vibrating Ag{sub 2}Ga nanoneedles was also measured, allowing confirmation of the eigenmodes of vibration. The modulus of the crystalline nanoneedles was 84.3 {+-} 1.0 GPa. Gas damping is the dominate mechanism of energy loss for nanowires oscillating under ambient conditions. The measured quality factors, Q, of oscillation are in line with theoretical predictions of air damping in the free molecular gas damping regime. In the free molecular regime, Q{sub gas} is linearly proportional to the density and diameter of the nanowire and inversely proportional to the air pressure. Since the density of the Ag{sub 2}Ga nanoneedles is three times that of the MWNTs, the Ag{sub 2}Ga nanoneedles have greater Q at atmospheric pressures. Our initial measurements of Q for Ag{sub 2}Ga nanoneedles in low-vacuum (10 Torr) suggest that the intrinsic Q of these nanoneedles may be on the order of 1000. The epitaxial carbon that grows after heating (000{bar 1}) silicon carbide (SiC) to high temperatures (1450-1600) in vacuum was also studied. At these high temperatures, the surface Si atoms sublime and the remaining C atoms reconstruct to form graphene. X-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM) were used to characterize the quality of the few-layer graphene (FLG) surface. The XPS studies were useful in confirming the graphitic composition and measuring the thickness of the FLG samples. STM studies revealed a wide variety of nanometer-scale features that include sharp carbon-rich ridges, moire superlattices, one-dimensional line defects, and grain boundaries. By imaging these features with atomic scale resolution, considerable insight into the growth mechanisms of FLG on the carbon-face of SiC is obtained.

  17. Measuring surface ocean wave height and directional spectra using an Acoustic Doppler Current Profiler from an autonomous underwater vehicle

    E-Print Network [OSTI]

    Haven, Scott

    2012-01-01T23:59:59.000Z

    The Acoustic Doppler Current Profiler (ADCP) is a proven technology which is capable of measuring surface wave height and directional information, however it is generally limited to rigid, bottom mounted applications which ...

  18. Doppler characteristics of sea clutter.

    SciTech Connect (OSTI)

    Raynal, Ann Marie; Doerry, Armin Walter

    2010-06-01T23:59:59.000Z

    Doppler radars can distinguish targets from clutter if the target's velocity along the radar line of sight is beyond that of the clutter. Some targets of interest may have a Doppler shift similar to that of clutter. The nature of sea clutter is different in the clutter and exo-clutter regions. This behavior requires special consideration regarding where a radar can expect to find sea-clutter returns in Doppler space and what detection algorithms are most appropriate to help mitigate false alarms and increase probability of detection of a target. This paper studies the existing state-of-the-art in the understanding of Doppler characteristics of sea clutter and scattering from the ocean to better understand the design and performance choices of a radar in differentiating targets from clutter under prevailing sea conditions.

  19. Transverse and Longitudinal Doppler Effects of the Sunbeam Spectra and Earth-Self Rotation and Orbital Velocities, the Mass of the Sun and Others

    E-Print Network [OSTI]

    Sang Boo Nam

    2009-11-21T23:59:59.000Z

    The transverse and longitudinal Doppler effects of the sunbeam spectra are shown to result in the earth parameters such as the earth-self rotation and revolution velocities, the earth orbit semi-major axis, the earth orbital angular momentum, the earth axial tilt, the earth orbit eccentricity, the local latitude and the mass of the sun. The sunbeam global positioning scheme is realized, including the earth orbital position. PACS numbers: 91.10.Fc, 95.10.Km, 91.10.Da, 91.10.Jf.

  20. Tangential velocity measurement using interferometric MTI radar

    DOE Patents [OSTI]

    Doerry, Armin W.; Mileshosky, Brian P.; Bickel, Douglas L.

    2006-01-03T23:59:59.000Z

    Radar systems use time delay measurements between a transmitted signal and its echo to calculate range to a target. Ranges that change with time cause a Doppler offset in phase and frequency of the echo. Consequently, the closing velocity between target and radar can be measured by measuring the Doppler offset of the echo. The closing velocity is also known as radial velocity, or line-of-sight velocity. Doppler frequency is measured in a pulse-Doppler radar as a linear phase shift over a set of radar pulses during some Coherent Processing Interval (CPI). An Interferometric Moving Target Indicator (MTI) radar can be used to measure the tangential velocity component of a moving target. Multiple baselines, along with the conventional radial velocity measurement, allow estimating the true 3-D velocity of a target.

  1. Thunderstorm characteristics of cloud-to-ground lightning at the Kennedy Space Center, Florida: a study of lightning initiation signatures as indicated by Doppler radar

    E-Print Network [OSTI]

    Gremillion, Michael Shane

    1998-01-01T23:59:59.000Z

    , except for 1806-1824 UTC 58 29 Same as Fig. 27, except for 1830-1847 UTC 59 30 Radar echo tops for all categories of storms 95 31 Scatter diagram of mixed-phase reflectivity lapse rate and maximum reflectivity at the freezing level for all storms... Mexico. Taylor (1978) also found the center of activity to be associated with the supercooled cloud layer between the regions of ? 5'C and ? 20'C. One theory of thunderstorm electrification supports the idea of an ice-related precipitation...

  2. 32nd Conf. Radar Meteorology Albuquerque, NM, 2005

    E-Print Network [OSTI]

    Xue, Ming

    32nd Conf. Radar Meteorology Albuquerque, NM, 2005 J1J.4 MULTIPLE DOPPLER WIND ANALYSIS and smoothness constraints by incorporating them into a cost function yielding the 3-D wind. In this study, this 3DVAR analysis method is adapted to perform multiple Doppler wind analysis for CASA radars, together

  3. Sub-Doppler Spectra of Infrared Hyperfine Transitions of Nitric Oxide Using a Pulse Modulated Quantum Cascade Laser: Rapid Passage, Free Induction Decay and the AC Stark Effect

    SciTech Connect (OSTI)

    Duxbury, Geoffrey; Kelly, James F.; Blake, Thomas A.; Langford, Nigel

    2012-05-07T23:59:59.000Z

    Using a low power, rapid (nsec) pulse-modulated quantum cascade (QC) laser, collective coherent effects in the 5 {micro}m spectrum of nitric oxide have been demonstrated by the observation of sub-Doppler hyperfine splitting and also Autler-Townes splitting of Doppler broadened lines. For nitrous oxide, experiments and model calculations have demonstrated that two main effects occur with ulsemodulated (chirped) quantum cascade lasers: free induction decay signals, and signals induced by rapid passage during the laser chirp. In the open shell molecule, NO, in which both {Lambda}-doubling splitting and hyperfine structure occur, laser field-induced coupling between the hyperfine levels of the two {Lambda}-doublet components can induce a large AC Stark effect. This may be observed as sub-Doppler structure, field-induced splittings, or Autler-Townes splitting of a Doppler broadened line. These represent an extension of the types of behaviour observed in the closed shell molecule nitrous oxide, using the same apparatus, when probed with an 8 {micro}m QC laser.

  4. Doppler Tomography

    E-Print Network [OSTI]

    T. R. Marsh

    2000-11-01T23:59:59.000Z

    I review the method of Doppler tomography which translates binary-star line profiles taken at a series of orbital phases into a distribution of emission over the binary. I begin with a discussion of the basic principles behind Doppler tomography, including a comparison of the relative merits of maximum entropy regularisation versus filtered back-projection for implementing the inversion. Following this I discuss the issue of noise in Doppler images and possible methods for coping with it. Then I move on to look at the results of Doppler Tomography applied to cataclysmic variable stars. Outstanding successes to date are the discovery of two-arm spiral shocks in cataclysmic variable accretion discs and the probing of the stream/magnetospheric interaction in magnetic cataclysmic variable stars. Doppler tomography has also told us much about the stream/disc interaction in non-magnetic systems and the irradiation of the secondary star in all systems. The latter indirectly reveals such effects as shadowing by the accretion disc or stream. I discuss all of these and finish with some musings on possible future directions for the method. At the end I include a tabulation of Doppler maps published in refereed journals.

  5. 3D Velocity from 3D Doppler Radial Velocity J. L. Barron,1

    E-Print Network [OSTI]

    Barron, John

    to compute local 3D velocity (local 3D optical flow). Radial velocity (measured by the Doppler effect3D Velocity from 3D Doppler Radial Velocity J. L. Barron,1 R. E. Mercer,1 X. Chen,1 P. Joe2 1 velocity data and qualitatively on real radial velocity data, obtained from the Doppler radar at Kurnell

  6. Sandia Energy - TTU Advanced Doppler Radar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del Sol Home Distribution GridDocumentsInstitute ofSitingStaffSunshine toSystemsTTU

  7. Doppler flowmeter

    DOE Patents [OSTI]

    Karplus, H.H.B.; Raptis, A.C.

    1981-11-13T23:59:59.000Z

    A Doppler flowmeter impulses an ultrasonic fixed-frequency signal obliquely into a slurry flowing in a pipe and a reflected signal is detected after having been scattered off of the slurry particles, whereby the shift in frequencies between the signals is proportional to the slurry velocity and hence slurry flow rate. This flowmeter filters the Doppler frequency-shift signal, compares the filtered and unfiltered shift signals in a divider to obtain a ratio, and then further compares this ratio against a preset fractional ratio. The flowmeter utilizes a voltage-to-frequency convertor to generate a pulsed signal having a determinable rate of repetition precisely proportional to the divergence of the ratios. The pulsed signal serves as the input control for a frequency-controlled low-pass filter, which provides thereby that the cutoff frequency of the filtered signal is known. The flowmeter provides a feedback control by minimizing the divergence. With the cutoff frequency and preset fractional ratio known, the slurry velocity and hence flow will also be determinable.

  8. 3D Least Squares Velocity from 3D Doppler Radial X. Chen, J.L. Barron, R.E. Mercer

    E-Print Network [OSTI]

    Barron, John

    neighbourhoods to compute local 3D velocity. Radial velocity (measured by the Doppler effect) is the component3D Least Squares Velocity from 3D Doppler Radial Velocity X. Chen, J.L. Barron, R.E. Mercer Dept. Radial velocity can be used to predict the motion of storms in sequences of Doppler radar datasets

  9. Imaging synthetic aperture radar

    DOE Patents [OSTI]

    Burns, Bryan L. (Tijeras, NM); Cordaro, J. Thomas (Albuquerque, NM)

    1997-01-01T23:59:59.000Z

    A linear-FM SAR imaging radar method and apparatus to produce a real-time image by first arranging the returned signals into a plurality of subaperture arrays, the columns of each subaperture array having samples of dechirped baseband pulses, and further including a processing of each subaperture array to obtain coarse-resolution in azimuth, then fine-resolution in range, and lastly, to combine the processed subapertures to obtain the final fine-resolution in azimuth. Greater efficiency is achieved because both the transmitted signal and a local oscillator signal mixed with the returned signal can be varied on a pulse-to-pulse basis as a function of radar motion. Moreover, a novel circuit can adjust the sampling location and the A/D sample rate of the combined dechirped baseband signal which greatly reduces processing time and hardware. The processing steps include implementing a window function, stabilizing either a central reference point and/or all other points of a subaperture with respect to doppler frequency and/or range as a function of radar motion, sorting and compressing the signals using a standard fourier transforms. The stabilization of each processing part is accomplished with vector multiplication using waveforms generated as a function of radar motion wherein these waveforms may be synthesized in integrated circuits. Stabilization of range migration as a function of doppler frequency by simple vector multiplication is a particularly useful feature of the invention; as is stabilization of azimuth migration by correcting for spatially varying phase errors prior to the application of an autofocus process.

  10. A radar study of the interaction between lightning and precipitation

    SciTech Connect (OSTI)

    Holden, D.N.; Ulbrich, C.W.

    1988-01-01T23:59:59.000Z

    A radar study was made of the interaction between lightning and precipitation with the 430 MHz Doppler radar at the Arecibo Observatory in Puerto Rico. On one occasion, the spectral power at Doppler velocities near that corresponding to the updraft increased substantially within a fraction of a second after a discharge was detected in the beam. Calculations were made to simulate the effect of an electric field change on mean Doppler velocity for a distribution of droplets in a thunderstorm. 13 refs., 4 figs.

  11. Merged and corrected 915 MHz Radar Wind Profiler moments

    SciTech Connect (OSTI)

    Jonathan Helmus,Virendra Ghate, Frederic Tridon

    2014-06-25T23:59:59.000Z

    The radar wind profiler (RWP) present at the SGP central facility operates at 915 MHz and was reconfigured in early 2011, to collect key sets of measurements for precipitation and boundary layer studies. The RWP is configured to run in two main operating modes: a precipitation (PR) mode with frequent vertical observations and a boundary layer (BL) mode that is similar to what has been traditionally applied to RWPs. To address issues regarding saturation of the radar signal, range resolution and maximum range, the RWP PR mode is set to operate with two different pulse lengths, termed as short pulse (SP) and long pulse (LP). Please refer to the RWP handbook (Coulter, 2012) for further information. Data from the RWP PR-SP and PR-LP modes have been extensively used to study deep precipitating clouds, especially their dynamical structure as the RWP data does not suffer from signal attenuation during these conditions (Giangrande et al., 2013). Tridon et al. (2013) used the data collected during the Mid-latitude Continental Convective Cloud Experiment (MC3E) to improve the estimation of noise floor of the RWP recorded Doppler spectra.

  12. Merged and corrected 915 MHz Radar Wind Profiler moments

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Jonathan Helmus,Virendra Ghate, Frederic Tridon

    The radar wind profiler (RWP) present at the SGP central facility operates at 915 MHz and was reconfigured in early 2011, to collect key sets of measurements for precipitation and boundary layer studies. The RWP is configured to run in two main operating modes: a precipitation (PR) mode with frequent vertical observations and a boundary layer (BL) mode that is similar to what has been traditionally applied to RWPs. To address issues regarding saturation of the radar signal, range resolution and maximum range, the RWP PR mode is set to operate with two different pulse lengths, termed as short pulse (SP) and long pulse (LP). Please refer to the RWP handbook (Coulter, 2012) for further information. Data from the RWP PR-SP and PR-LP modes have been extensively used to study deep precipitating clouds, especially their dynamical structure as the RWP data does not suffer from signal attenuation during these conditions (Giangrande et al., 2013). Tridon et al. (2013) used the data collected during the Mid-latitude Continental Convective Cloud Experiment (MC3E) to improve the estimation of noise floor of the RWP recorded Doppler spectra.

  13. EFFICIENT ASSIMILATION OF RADAR DATA AT HIGH RESOLUTION FOR SHORT-RANGE NUMERICAL WEATHER PREDICTION

    E-Print Network [OSTI]

    Xue, Ming

    system must assimilate Doppler radar data including radial velocity and reflectivity, and combine and also con- tain the hydrometeors and latent heating effects that eliminate the need for spinning up

  14. Laser radar VI; Proceedings of the Meeting, Los Angeles, CA, Jan. 23-25, 1991

    SciTech Connect (OSTI)

    Becherer, R.J.

    1991-01-01T23:59:59.000Z

    Topics presented include lidar wind shear detection for commercial aircraft, centroid tracking of range-Doppler images, an analytic approach to centroid performance analysis, simultaneous active/passive IR vehicle detection, and resolution limits for high-resolution imaging lidar. Also presented are laser velocimetry applications, the application of laser radar to autonomous spacecraft landing, 3D laser radar simulation for autonomous spacecraft landing, and ground based CW atmospheric Doppler lidar performamce modeling.

  15. High frequency radar and its application to fresh water Lorelle A. Meadows a,

    E-Print Network [OSTI]

    Ruf, Christopher

    ) at a Doppler shift corresponding very nearly to the phase velocity of the radially ad- vancing and receding frequency of the radar, c is the radial velocity of the Bragg resonant waves and cem is the speed of light average radiated powers, respectively. The effective offshore range for these radars was found to be 18 km

  16. Rotational Doppler effect in x-ray photoionization

    SciTech Connect (OSTI)

    Sun Yuping; Wang Chuankui [College of Physics and Electronics, Shandong Normal University, 250014 Jinan (China); Theoretical Chemistry, Roslagstullsbacken 15, Royal Institute of Technology, S-106 91 Stockholm (Sweden); Gel'mukhanov, Faris [Theoretical Chemistry, Roslagstullsbacken 15, Royal Institute of Technology, S-106 91 Stockholm (Sweden)

    2010-11-15T23:59:59.000Z

    The energy of the photoelectron experiences a red or blue Doppler shift when the molecule recedes from the detector or approaches him. This results in a broadening of the photoelectron line due to the translational thermal motion. However, the molecules also have rotational degrees of freedom and we show that the translational Doppler effect has its rotational counterpart. This rotational Doppler effect leads to an additional broadening of the spectral line of the same magnitude as the Doppler broadening caused by translational thermal motion. The rotational Doppler broadening as well as the rotational recoil broadening is sensitive to the molecular orbital from which the photoelectron is ejected. This broadening should be taken into account in analysis of x-ray photoemission spectra of super-high resolution and it can be directly observed using x-ray pump-probe spectroscopy.

  17. Optics -Laser Doppler Imaging. As the name suggests,LDI,Laser Doppler Imaging exploits the Doppler

    E-Print Network [OSTI]

    Floreano, Dario

    Optics - Laser Doppler Imaging. As the name suggests,LDI,Laser Doppler Imaging exploits the Doppler effect to generate images,in this case of red blood cells moving within the microcirculatory system the Doppler shifted light we obtain information on all the red cells moving in the illuminated tissue,hence we

  18. Acoustic Doppler Current Profiler Principles of Operation

    E-Print Network [OSTI]

    deYoung, Brad

    .............................................................................................................................2 2. The Doppler Effect and Radial Current Velocity..................................................................................................................................................4 The Doppler Effect.............................................................6 The Doppler Effect Measures Relative, Radial Motion

  19. Radar-cross-section reduction of wind turbines. part 1.

    SciTech Connect (OSTI)

    Brock, Billy C.; Loui, Hung; McDonald, Jacob J.; Paquette, Joshua A.; Calkins, David A.; Miller, William K.; Allen, Steven E.; Clem, Paul Gilbert; Patitz, Ward E.

    2012-03-05T23:59:59.000Z

    In recent years, increasing deployment of large wind-turbine farms has become an issue of growing concern for the radar community. The large radar cross section (RCS) presented by wind turbines interferes with radar operation, and the Doppler shift caused by blade rotation causes problems identifying and tracking moving targets. Each new wind-turbine farm installation must be carefully evaluated for potential disruption of radar operation for air defense, air traffic control, weather sensing, and other applications. Several approaches currently exist to minimize conflict between wind-turbine farms and radar installations, including procedural adjustments, radar upgrades, and proper choice of low-impact wind-farm sites, but each has problems with limited effectiveness or prohibitive cost. An alternative approach, heretofore not technically feasible, is to reduce the RCS of wind turbines to the extent that they can be installed near existing radar installations. This report summarizes efforts to reduce wind-turbine RCS, with a particular emphasis on the blades. The report begins with a survey of the wind-turbine RCS-reduction literature to establish a baseline for comparison. The following topics are then addressed: electromagnetic model development and validation, novel material development, integration into wind-turbine fabrication processes, integrated-absorber design, and wind-turbine RCS modeling. Related topics of interest, including alternative mitigation techniques (procedural, at-the-radar, etc.), an introduction to RCS and electromagnetic scattering, and RCS-reduction modeling techniques, can be found in a previous report.

  20. Automatic Fall Detection Based on Doppler Radar Motion Signature

    E-Print Network [OSTI]

    He, Zhihai "Henry"

    than one third of adults 65 and older fall each year in the United States. To address the problem, we above age 65 [2]. The death rate caused by falls among elders is increasing quickly over the past decade classification; SVM; kNN I. INTRODUCTION Falls are the leading causes of accidental death in the US population

  1. Constructing a Merged CloudPrecipitation Radar Dataset for Tropical Convective Clouds during the DYNAMO/AMIE Experiment at Addu Atoll

    E-Print Network [OSTI]

    of observations from three radars--the S-band dual-polarization Doppler radar (S-Pol), the C-band Shared Mobile, and radiative heating rate retrievals. With this dataset the full spectrum of tropical convective clouds during, U.S. Department of Energy, Washington, D.C. Corresponding author address: Dr. Zhe Feng, Pacific

  2. Assimilation of Simulated Polarimetric Radar Data for a Convective Storm Using the Ensemble Kalman Filter. Part I: Observation Operators for Reflectivity and

    E-Print Network [OSTI]

    Xue, Ming

    the Weather Sur- veillance Radar-1988 Doppler (WSR-88D), the radial velocity and equivalent radar reflectivity and reflectivity link the model velocity compo- nents to the observed radial velocity and the model hydrometeor melting model that defines the water fraction in the melting snow or hail. The effect of varying density

  3. Analysis and Prediction of 8 May 2003 Oklahoma City Tornadic Thunderstorm and Embedded Tornado using ARPS with Assimilation of WSR-88D Radar Data

    E-Print Network [OSTI]

    Xue, Ming

    dimensional variational (3DVAR) analysis (Gao et al. 2002; 2004) to analyze the radar radial velocity data the environment that guarantees tornado formation. To include the effect of tornado parent mesocyclone and study storms, the WSR-88D Doppler radar network of the United States provides a key information for storm

  4. MEMS BASED DOPPLER VELOCITY MEASUREMENT SYSTEM

    E-Print Network [OSTI]

    White, Robert D.

    .2 Doppler Effect...................................................................................10 2MEMS BASED DOPPLER VELOCITY MEASUREMENT SYSTEM A dissertation submitted by Minchul Shin IN PARTIAL micromachined ultrasonic transducer (cMUT) based in-air Doppler velocity measurement system using a 1 cm2 planar

  5. Dual-Doppler analysis of the 17 June 1997 bow echo over southeast Texas

    E-Print Network [OSTI]

    Moncla, Kerry Louis

    2001-01-01T23:59:59.000Z

    , 1996: Role of gust front circulations in long-track severe straight-line winds. Preprints, 18' Conf. on Severe Local Storms, San Francisco, CA, Amer. Meteor. Soc. , 504-508. Biggerstaff, M. I. , J. Guynes, S. Hristova-Veleva, E-K Seo, B. Karl, Z... and Lightening Experiment ? TEXACAL 97. Preprints, 28th Conf. on Radar Meteor. , Austin, TX, Amer. Meteor. Soc. , 588-589. Burgess, D. W. , and B. F. Smull, 1990: Doppler radar observation of a bow echo associated with a long-track severe windstorm. Preprints...

  6. Dual-Doppler analysis of the 17 June 1997 bow echo over southeast Texas 

    E-Print Network [OSTI]

    Moncla, Kerry Louis

    2001-01-01T23:59:59.000Z

    , 1996: Role of gust front circulations in long-track severe straight-line winds. Preprints, 18' Conf. on Severe Local Storms, San Francisco, CA, Amer. Meteor. Soc. , 504-508. Biggerstaff, M. I. , J. Guynes, S. Hristova-Veleva, E-K Seo, B. Karl, Z... and Lightening Experiment ? TEXACAL 97. Preprints, 28th Conf. on Radar Meteor. , Austin, TX, Amer. Meteor. Soc. , 588-589. Burgess, D. W. , and B. F. Smull, 1990: Doppler radar observation of a bow echo associated with a long-track severe windstorm. Preprints...

  7. Evaluating radial component current measurements from CODAR high frequency radars and moored in situ current meters

    E-Print Network [OSTI]

    California at Santa Barbara, University of

    error of 19o . The effects of bearing errors on total velocity vector estimates were evaluated usingEvaluating radial component current measurements from CODAR high frequency radars and moored of the moorings carried vector measuring current meters (VMCM's), the ninth an upward-looking acoustic Doppler

  8. Short-term forecasting through intermittent assimilation of data from Taiwan and mainland China coastal radars

    E-Print Network [OSTI]

    Xue, Ming

    ; published 29 March 2012. [1] Radial velocity (Vr) and reflectivity (Z) data from eight coastal operational, but the benefit is mostly lost within the first hour of forecast. Assimilating data from a single Doppler radar with a good coverage of the typhoon inner core region is also quite effective, but it takes one more cycle

  9. Frequency domain phase-resolved optical Doppler and Doppler variance tomography

    E-Print Network [OSTI]

    Chen, Zhongping

    ), is capable of measuring micro- flows using the optical Doppler effect [1,2]. Early ODT systems were unableFrequency domain phase-resolved optical Doppler and Doppler variance tomography Lei Wang a phase-resolved optical Doppler tomography (ODT) was developed with Doppler variance imag- ing capability

  10. Sandia National Laboratories: Radar Friendly Blades

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    MitigationRadar Friendly Blades Radar Friendly Blades Some wind farms have the potential to cause interference with the normal operation of radar systems used for security, weather...

  11. "DERIVATION" OF THE DE BROGLIE RELATION FROM THE DOPPLER EFFECT

    E-Print Network [OSTI]

    Crawford, Frank S.

    2013-01-01T23:59:59.000Z

    BROGLIE RELATION FROM THE DOPPLER EFFECT Frank S. Crawfordusual derivation of the Doppler effect gives Eq. (l). (The

  12. Demonstrations: sound source for Doppler shift

    E-Print Network [OSTI]

    Boal, David

    of the Universe Doppler effect The technique for measuring the velocities of very remote galaxies is based uponDemonstrations: ·sound source for Doppler shift ·big balloon and labels Text: Mod. Phys. 8.A, 8.B, 8.C Problems: 1, 3, 6, 7 from Ch. 8 What's important: ·Doppler shift ·Hubble's law ·age

  13. RADAR OBSERVATIONS OF COMET 103P/HARTLEY 2

    SciTech Connect (OSTI)

    Harmon, John K.; Nolan, Michael C.; Howell, Ellen S.; Taylor, Patrick A. [Arecibo Observatory, National Astronomy and Ionosphere Center, HC3 Box 53995, Arecibo, Puerto Rico 00612 (Puerto Rico); Giorgini, Jon D., E-mail: harmon@naic.edu [Jet Propulsion Laboratory, California Institute of Technology, MS 301-150, 4800 Oak Grove Dr., Pasadena, California 91109 (United States)

    2011-06-10T23:59:59.000Z

    Comets rarely come close enough to be studied intensively with Earth-based radar. The most recent such occurrence was when Comet 103P/Hartley 2 passed within 0.12 AU in late 2010 October, less than two weeks before the EPOXI flyby. This offered a unique opportunity to improve pre-encounter trajectory knowledge and obtain complementary physical data for a spacecraft-targeted comet. 103P/Hartley 2 is only the fourth comet nucleus to be imaged with radar and already the second to be identified as an elongated, bilobate object based on its delay-Doppler signature. The images show the dominant spin mode to be a rotation about the short axis with a period of 18.2 hr. The nucleus has a low radar albedo consistent with a surface density of 0.5-1.0 g cm{sup -3}. A separate echo component was detected from large (>cm) grains ejected anisotropically with velocities of several to tens of meters per second. Radar shows that, in terms of large-grain production, 103P/Hartley 2 is an unusually active comet for its size.

  14. X-band Scanning ARM Precipitation Radar (X-SAPR) Instrument Handbook

    SciTech Connect (OSTI)

    Widener, K; Bharadwaj, N

    2012-10-29T23:59:59.000Z

    The X-band scanning ARM cloud radar (X-SAPR) is a full-hemispherical scanning polarimetric Doppler radar transmitting simultaneously in both H and V polarizations. With a 200 kW magnetron transmitter, this puts 100 kW of transmitted power for each polarization. The receiver for the X-SAPR is a Vaisala Sigmet RVP-900 operating in a coherent-on-receive mode. Three X-SAPRs are deployed around the Southern Great Plains (SGP) Central Facility in a triangular array. A fourth X-SAPR is deployed near Barrow, Alaska on top of the Barrow Arctic Research Center.

  15. Doppler effect in Schwarzschild geometry

    E-Print Network [OSTI]

    A. Radosz; A. T. Augousti; K. Ostasiewicz

    2007-12-13T23:59:59.000Z

    The Doppler shift considered in general relativity involves mixed contributions of distinct, gravitational and kinematical origins and for most metrics or trajectories it takes a complex form. The expression for the Doppler shift may simplify due to particular symmetries. In Schwarzschild spacetime it factorizes in the case of radial fall for an observer and radial null geodesic. The resulting expression is composed of factors that can be identified with contributions arising from classical, special relativistic and general relativistic origins. This result turns out to be more general: it holds for the whole class of observers travelling parallel to the spatial path of null geodesics when receiving the signal. It also holds for a particular type of in-fall in the case of a Kerr metric.

  16. Impulse radar studfinder

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1995-01-01T23:59:59.000Z

    An impulse radar studfinder propagates electromagnetic pulses and detects reflected pulses from a fixed range. Unmodulated pulses, about 200 ps wide, are emitted. A large number of reflected pulses are sampled and averaged. Background reflections are subtracted. Reflections from wall studs or other hidden objects are detected and displayed using light emitting diodes.

  17. Performance degradation of OFDM systems due to Doppler spreading

    E-Print Network [OSTI]

    Wang, T J; Proakis, J G; Masry, E; Zeidler, James R

    2006-01-01T23:59:59.000Z

    on Jakes’ model for the Doppler effects, and an exponentialand S. Kaiser, “The effects of Doppler spreads in OFDM (A)In particular, the effect of Doppler spreading destroys the

  18. Development of the doppler electron velocimeter: theory.

    SciTech Connect (OSTI)

    Reu, Phillip L.

    2007-03-01T23:59:59.000Z

    Measurement of dynamic events at the nano-scale is currently impossible. This paper presents the theoretical underpinnings of a method for making these measurements using electron microscopes. Building on the work of Moellenstedt and Lichte who demonstrated Doppler shifting of an electron beam with a moving electron mirror, further work is proposed to perfect and utilize this concept in dynamic measurements. Specifically, using the concept of ''fringe-counting'' with the current principles of transmission electron holography, an extension of these methods to dynamic measurements is proposed. A presentation of the theory of Doppler electron wave shifting is given, starting from the development of the de Broglie wave, up through the equations describing interference effects and Doppler shifting in electron waves. A mathematical demonstration that Doppler shifting is identical to the conceptually easier to understand idea of counting moving fringes is given by analogy to optical interferometry. Finally, potential developmental experiments and uses of a Doppler electron microscope are discussed.

  19. AMS Annual Meeting, Symposium on Recent Developments in Atmospheric Applications of Radar and Lidar. 20-24 January 2008, New Orleans, LA

    E-Print Network [OSTI]

    Xue, Ming

    the evolution of the MCV. The impact of assimilating radial velocity and reflectivity from CASA in addition of four x-band dual-polarization Doppler radars in southwest Oklahoma. During the spring of 2007 2006b. Previous work found that 3DVAR reflectivity assimilation is most effective when combined

  20. An OSSE Framework Based on the Ensemble Square Root Kalman Filter for Evaluating the Impact of Data from Radar Networks on Thunderstorm Analysis

    E-Print Network [OSTI]

    Droegemeier, Kelvin K.

    by assimilating simulated radial velocity and reflectivity data from a Weather Surveillance Radar-1988 Doppler. The generally good analysis compared to earlier work indicates that the filter can effectively handle the non, significant errors develop in the analysis that cannot be effectively corrected. The combination of three CASA

  1. Long-term variation of radar-auroral backscatter and the interplanetary sector structure

    SciTech Connect (OSTI)

    Yeoman, T.K.; Burrage, M.D.; Lester, M.; Robinson, T.R.; Jones, T.B. (Univ. of Leicester (England))

    1990-12-01T23:59:59.000Z

    Recurrent variation of geomagnetic activity at the {approximately}27-day solar rotation period and higher harmonics is a well-documented phenomenon. Auroral radar backscatter data from the Sweden and Britain Radar-Auroral Experiment (SABRE) radar provide a continuous time series from 1981 to the present which is a highly sensitive monitor of geomagnetic activity. In this study, Maximum Entropy Method (MEM) dynamic power spectra of SABRE backscatter data from 1981 to 1989, concurrent interplanetary magnetic field (IMF) and solar wind parameters from 1981 to 1987, and the Kp index since 1932 are examined. Data since 1977 are compared with previously published heliospheric current sheet measurements mapped out from the solar photosphere. Stong periodic behavior is observed in the radar backscatter during the declining phase of solar cycle 21, but this periodicity disappears at the start of solar cycle 22. Similar behavior is observed in earlier solar cycles in the Kp spectra. Details of the radar backscatter, IMF, and solar wind spectra indicate that the solar wind momentum density is the dominant parameter in determining the backscatter periodicity. The temporal evolution of two- and four-sector structures, as predicted by SABRE backscatter spectra, throughout solar cycle 21 generally still agree well with heliospheric current sheet measurements. For one interval, however, there is evidence that evolution of the current sheet has occurred between the photospheric source surface and the Earth.

  2. Radar | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to:Ezfeedflag JumpID-f < RAPID‎ | Roadmap Jump to:b <RGS Development BV JumpRTEV IncRadar

  3. ARM Scanning Radar

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041cloth DocumentationProducts (VAP) VAP Update Information on new,Scanning Radar Azores Graciosa

  4. Range Sidelobe Suppression in a Desired Doppler Interval

    E-Print Network [OSTI]

    Pezeshki, Ali

    is sensitive to Doppler effect. Off the zero- Doppler axis the ambiguity function of Golay pairs of phase codedRange Sidelobe Suppression in a Desired Doppler Interval Yuejie Chi,1 Ali Pezeshki,2 Robert--We present a novel method of constructing a Doppler resilient pulse train of Golay complementary waveforms

  5. Human action categorization using ultrasound micro-Doppler signatures

    E-Print Network [OSTI]

    Wennekers, Thomas

    of a wave radiated or scattered by the object. This is known as the Doppler effect. If the object frequency shift, known as the micro-Doppler effect. The micro-Doppler signature enables to determineHuman action categorization using ultrasound micro-Doppler signatures Salvador Dura-Bernal1

  6. This article has been accepted for inclusion in a future issue of this journal. Content is final as presented, with the exception of pagination. IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    a preliminary validation with in situ buoy measurements. Experimental and simulated Doppler spectra agree [power spectral density (PSD)], ocean wave spectum, radar equation. I. INTRODUCTION TODAY, high

  7. ARM Climate Research Facility Radar Operations Plan

    SciTech Connect (OSTI)

    Voyles, JW

    2012-05-18T23:59:59.000Z

    Roles, responsibilities, and processes associated with Atmospheric Radiation Measurement (ARM) Radar Operations.

  8. High resolution ion Doppler spectroscopy at Prairie View Rotamak

    SciTech Connect (OSTI)

    Houshmandyar, Saeid; Yang Xiaokang [Solar Observatory Department, Prairie View A and M University, Prairie View, Texas 77446 (United States); Magee, Richard [Department of Physics, West Virginia University, Morgantown, West Virginia 26506 (United States)

    2012-10-15T23:59:59.000Z

    A fast ion Doppler spectroscopy (IDS) diagnostic system is installed on the Prairie View Rotamak to measure ion temperature and plasma flow. The diagnostic employs a single channel photomultiplier tube and a Jarrell-Ash 50 monochromator with a diffraction grating line density of 1180 lines/mm, which allows for first order spectra of 200-600 nm. The motorized gear of the monochromator allows spectral resolution of 0.01 nm. Equal IDS measurements are observed for various impurity emission lines of which carbon lines exhibit stronger intensities. Furthermore, the diagnostics is examined in an experiment where plasma experiences sudden disruption and quick recovery. In this case, the IDS measurements show {approx}130% increase in ion temperature. Flow measurements are shown to be consistent with plasma rotation.

  9. Doppler reflectometer system in the stellarator TJ-II

    SciTech Connect (OSTI)

    Happel, T.; Estrada, T.; Blanco, E.; Tribaldos, V.; Cappa, A.; Bustos, A. [Laboratorio Nacional de Fusion, Asociacion Euratom-CIEMAT, 28040 Madrid (Spain)

    2009-07-15T23:59:59.000Z

    A Doppler reflectometer system has recently been installed in the stellarator TJ-II. The system is optimized for the Q-band (33-50 GHz) and the high-curvature plasmas produced in TJ-II. The launch angle of the microwave beam can be controlled by a steerable mirror to obtain angles between {+-}20 deg. enabling the measurement of perpendicular wave numbers in the range of 3-15 cm{sup -1}. The available angular range allows for comparisons between positive and negative values and additionally for calibration of the system. Localization and k{sub perpendicular}-estimation is done via the three-dimensional ray/beam-tracing code TRUBA. First measured spectra and radial profiles of the perpendicular velocity of plasma density fluctuations are presented.

  10. Radar polarimetry for geoscience applications

    SciTech Connect (OSTI)

    Elachi, C.; Kuga, Y.; McDonald, K.; Sarabandi, K.; Ulaby, F.T.; Whitt, M.; Zebker, H.; van Zyl, J.J.

    1990-01-01T23:59:59.000Z

    A source book for remote sensing and radar design engineers, this text covers wave polarization, polarization synthesis, scattering matrices, SAR polarization systems, and an array of applications It covers: an introduction to the different mathematical representations used to describe scattering properties, a review of scatterometer system design and calibration techniques for use in polarimetric measurements, a study of specific polarimetric radar systems, such as the shuttle imaging radar C (SIR-C), that includes calibration and compression techniques, data processing guidelines, and design approaches.

  11. 915-MHz Radar Wind Profiler (915RWP) Handbook

    SciTech Connect (OSTI)

    Coulter, R

    2005-01-01T23:59:59.000Z

    The 915 MHz radar wind profiler/radio acoustic sounding system (RWP/RASS) measures wind profiles and backscattered signal strength between (nominally) 0.1 km and 5 km and virtual temperature profiles between 0.1 km and 2.5 km. It operates by transmitting electromagnetic energy into the atmosphere and measuring the strength and frequency of backscattered energy. Virtual temperatures are recovered by transmitting an acoustic signal vertically and measuring the electromagnetic energy scattered from the acoustic wavefront. Because the propagation speed of the acoustic wave is proportional to the square root of the virtual temperature of the air, the virtual temperature can be recovered by measuring the Doppler shift of the scattered electromagnetic wave.

  12. Digital hf radar observations of equatorial spread-F

    SciTech Connect (OSTI)

    Argo, P.E.

    1984-01-01T23:59:59.000Z

    Modern digital ionosondes, with both direction finding and doppler capabilities can provide large scale pictures of the Spread-F irregularity regions. A morphological framework has been developed that allows interpretation of the hf radar data. A large scale irregularity structure is found to be nightward of the dusk terminator, stationary in the solar reference frame. As the plasma moves through this foehn-wall-like structure it descends, and irregularities may be generated. Localized upwellings, or bubbles, may be produced, and they drift with the background plasma. The spread-F irregularity region is found to be best characterized as a partly cloudy sky, due to the patchiness of the substructures. 13 references, 16 figures.

  13. Ground Penetrating Radar, Barrow, Alaska

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    John Peterson

    This is 500 MHz Ground Penetrating Radar collected along the AB Line in Intensive Site 1 beginning in October 2012 and collected along L2 in Intensive Site 0 beginning in September 2011. Both continue to the present.

  14. Sub-Doppler resonances in the back-scattered light from random porous media infused with Rb vapor

    E-Print Network [OSTI]

    Villalba, S; Lenci, L; Bloch, D; Lezama, A; Failache, H

    2013-01-01T23:59:59.000Z

    We report on the observation of sub-Doppler resonances on the back-scattered light from a random porous glass medium with rubidium vapor filling its interstices. The sub-Doppler spectral lines are the consequence of saturated absorption where the incident laser beam saturates the atomic medium and the back-scattered light probes it. Some specificities of the observed spectra reflect the transient atomic evolution under confinement inside the pores. Simplicity, robustness and potential miniaturization are appealing features of this system as a spectroscopic reference.

  15. C-Band Scanning ARM Precipitation Radar (C-SAPR) Handbook

    SciTech Connect (OSTI)

    Widener, K; Bharadwaj, N

    2012-11-13T23:59:59.000Z

    The C-band scanning ARM precipitation radar (C-SAPR) is a scanning polarimetric Doppler radar transmitting simultaneously in both H and V polarizations. With a 350-kW magnetron transmitter, this puts 125 kW of transmitted power for each polarization. The receiver for the C-SAPR is a National Center for Atmospheric Research (NCAR) -developed Hi-Q system operating in a coherent-on-receive mode. The ARM Climate Research Facility operates two C-SAPRs; one of them is deployed near the Southern Great Plains (SGP) Central Facility near the triangular array of X-SAPRs, and the second C-SAPR is deployed at ARM’s Tropical Western Pacific (TWP) site on Manus Island in Papua New Guinea.

  16. Signal processing for airborne bistatic radar 

    E-Print Network [OSTI]

    Ong, Kian P

    The major problem encountered by an airborne bistatic radar is the suppression of bistatic clutter. Unlike clutter echoes for a sidelooking airborne monostatic radar, bistatic clutter echoes are range dependent. Using ...

  17. Obstacle penetrating dynamic radar imaging system

    DOE Patents [OSTI]

    Romero, Carlos E. (Livermore, CA); Zumstein, James E. (Livermore, CA); Chang, John T. (Danville, CA); Leach, Jr.. Richard R. (Castro Valley, CA)

    2006-12-12T23:59:59.000Z

    An obstacle penetrating dynamic radar imaging system for the detection, tracking, and imaging of an individual, animal, or object comprising a multiplicity of low power ultra wideband radar units that produce a set of return radar signals from the individual, animal, or object, and a processing system for said set of return radar signals for detection, tracking, and imaging of the individual, animal, or object. The system provides a radar video system for detecting and tracking an individual, animal, or object by producing a set of return radar signals from the individual, animal, or object with a multiplicity of low power ultra wideband radar units, and processing said set of return radar signals for detecting and tracking of the individual, animal, or object.

  18. Antarctic Mapping Project ACTIVE RADAR CALIBRATOR

    E-Print Network [OSTI]

    Howat, Ian M.

    RADARSAT Antarctic Mapping Project ACTIVE RADAR CALIBRATOR INSTALLATION DOCUMENT October, 1999 ENVIRONMENTAL RESEARCH INSTITUTE OF MICHIGAN CENTER FOR EARTH SCIENCES ALASKA SAR FACILITY BYRD POLAR RESEARCH...................................................................................................................................................3 Active Radar Calibrator Testing

  19. The use of Doppler radar to predict cloud-to-ground lightning

    E-Print Network [OSTI]

    Aclin, Keith Andrew

    1995-01-01T23:59:59.000Z

    during the spring of 1993 for squall line activity. These data will then be combined with the cloud-to-ground lightning that occurred within the six minutes of the scan time. Three sets of linear correlations will be generated. The first...

  20. Retrieving stratocumulus drizzle parameters using Doppler radar and lidar EWAN J. O'CONNOR

    E-Print Network [OSTI]

    Hogan, Robin

    types globally with a profound effect on the Earth's radiation budget, and the drizzle process-layer clouds are one of the most signifi- cant components of the shortwave radiation budget of the Earth. The drizzle process may also have implications for the radiative properties of such clouds (Feingold et al

  1. Scanning ARM Cloud Radars Part II: Data Quality Control and Processing

    SciTech Connect (OSTI)

    Kollias, Pavlos; Jo, Ieng; Borque, Paloma; Tatarevic, Aleksandra; Lamer, Katia; Bharadwaj, Nitin; Widener, Kevin B.; Johnson, Karen; Clothiaux, Eugene E.

    2014-03-01T23:59:59.000Z

    The Scanning ARM Cloud Radars (SACR’s) are the primary instruments for documenting the four-dimensional structure and evolution of clouds within a 20-30 km radius from the ARM fixed and mobile sites. Here, the post-processing of the calibrated SACR measurements is discussed. First, a feature mask algorithm that objectively determines the presence of significant radar returns is described. The feature mask algorithm is based on the statistical properties of radar receiver noise. It accounts for atmospheric emission and is applicable even for SACR profiles with few or no signal-free range gates. Using the nearest-in-time atmospheric sounding, the SACR radar reflectivities are corrected for gaseous attenuation (water vapor and oxygen) using a line-by-line absorption model. Despite having a high pulse repetition frequency, the SACR has a narrow Nyquist velocity limit and thus Doppler velocity folding is commonly observed. An unfolding algorithm that makes use of a first guess for the true Doppler velocity using horizontal wind measurements from the nearest sounding is described. The retrieval of the horizontal wind profile from the Hemispherical Sky – Range Height Indicator SACR scan observations and/or nearest sounding is described. The retrieved horizontal wind profile can be used to adaptively configure SACR scan strategies that depend on wind direction. Several remaining challenges are discussed, including the removal of insect and second-trip echoes. The described algorithms significantly enhance SACR data quality and constitute an important step towards the utilization of SACR measurements for cloud research.

  2. GMTI radar minimum detectable velocity.

    SciTech Connect (OSTI)

    Richards, John Alfred

    2011-04-01T23:59:59.000Z

    Minimum detectable velocity (MDV) is a fundamental consideration for the design, implementation, and exploitation of ground moving-target indication (GMTI) radar imaging modes. All single-phase-center air-to-ground radars are characterized by an MDV, or a minimum radial velocity below which motion of a discrete nonstationary target is indistinguishable from the relative motion between the platform and the ground. Targets with radial velocities less than MDV are typically overwhelmed by endoclutter ground returns, and are thus not generally detectable. Targets with radial velocities greater than MDV typically produce distinct returns falling outside of the endoclutter ground returns, and are thus generally discernible using straightforward detection algorithms. This document provides a straightforward derivation of MDV for an air-to-ground single-phase-center GMTI radar operating in an arbitrary geometry.

  3. Spectroscopic observation of the rotational Doppler effect

    E-Print Network [OSTI]

    S. Barreiro; J. W. R. Tabosa; H. Failache; A. Lezama

    2006-07-26T23:59:59.000Z

    We report on the first spectroscopic observation of the rotational Doppler shift associated with light beams carrying orbital angular momentum. The effect is evidenced as the broadening of a Hanle/EIT coherence resonance on Rb vapor when the two incident Laguerre-Gaussian laser beams have opposite topological charges. The observations closely agree with theoretical predictions.

  4. Microwave emissions from police radar

    E-Print Network [OSTI]

    Fink, John Michael

    1994-01-01T23:59:59.000Z

    MICROWAVE EMISSIONS FROM POLICE RADAR A Thesis by JOHN MICHAEL FINK Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1994 Major Subject...: Industrial Hygiene MICROWAVE EMISSIONS FROM POLICE RADAR A Thesis by JOHN MICHAEL FINK Submitted to Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE John P. Wag (Chair of Committee) Jero e J. C...

  5. A MAGNETIC CALIBRATION OF PHOTOSPHERIC DOPPLER VELOCITIES

    SciTech Connect (OSTI)

    Welsch, Brian T.; Fisher, George H. [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States); Sun, Xudong [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States)

    2013-03-10T23:59:59.000Z

    The zero point of measured photospheric Doppler shifts is uncertain for at least two reasons: instrumental variations (from, e.g., thermal drifts); and the convective blueshift, a known correlation between intensity and upflows. Accurate knowledge of the zero point is, however, useful for (1) improving estimates of the Poynting flux of magnetic energy across the photosphere, and (2) constraining processes underlying flux cancellation, the mutual apparent loss of magnetic flux in closely spaced, opposite-polarity magnetogram features. We present a method to absolutely calibrate line-of-sight (LOS) velocities in solar active regions (ARs) near disk center using three successive vector magnetograms and one Dopplergram coincident with the central magnetogram. It exploits the fact that Doppler shifts measured along polarity inversion lines (PILs) of the LOS magnetic field determine one component of the velocity perpendicular to the magnetic field, and optimizes consistency between changes in LOS flux near PILs and the transport of transverse magnetic flux by LOS velocities, assuming that ideal electric fields govern the magnetic evolution. Previous calibrations fitted the center-to-limb variation of Doppler velocities, but this approach cannot, by itself, account for residual convective shifts at the limb. We apply our method to vector magnetograms of AR 11158, observed by the Helioseismic and Magnetic Imager aboard the Solar Dynamics Observatory, and find clear evidence of offsets in the Doppler zero point in the range of 50-550 m s{sup -1}. In addition, we note that a simpler calibration can be determined from an LOS magnetogram and Dopplergram pair from the median Doppler velocity among all near-disk-center PIL pixels. We briefly discuss shortcomings in our initial implementation, and suggest ways to address these. In addition, as a step in our data reduction, we discuss the use of temporal continuity in the transverse magnetic field direction to correct apparently spurious fluctuations in resolution of the 180 Degree-Sign ambiguity.

  6. ROTATIONAL DOPPLER BEAMING IN ECLIPSING BINARIES

    SciTech Connect (OSTI)

    Groot, Paul J., E-mail: pgroot@astro.ru.nl [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States)

    2012-01-20T23:59:59.000Z

    In eclipsing binaries the stellar rotation of the two components will cause a rotational Doppler beaming during eclipse ingress and egress when only part of the eclipsed component is covered. For eclipsing binaries with fast spinning components this photometric analog of the well-known spectroscopic Rossiter-McLaughlin effect can exceed the strength of the orbital effect. Example light curves are shown for a detached double white dwarf binary, a massive O-star binary and a transiting exoplanet case, similar to WASP-33b. Inclusion of the rotational Doppler beaming in eclipsing systems is a prerequisite for deriving the correct stellar parameters from fitting high-quality photometric light curves and can be used to determine stellar obliquities as well as, e.g., an independent measure of the rotational velocity in those systems that may be expected to be fully synchronized.

  7. Design of a Doppler reflectometer for KSTAR

    SciTech Connect (OSTI)

    Lee, K. D., E-mail: kdlee@nfri.re.kr; Nam, Y. U.; Seo, Seong-Heon; Kim, Y. S. [National Fusion Research Institute, Yuseong, Daejeon 305-333 (Korea, Republic of)

    2014-11-15T23:59:59.000Z

    A Doppler reflectometer has been designed to measure the poloidal propagation velocity on the Korea Superconducting Tokamak Advanced Research (KSTAR) tokamak. It has the operating frequency range of V-band (50-75 GHz) and the monostatic antenna configuration with extraordinary mode (X-mode). The single sideband modulation with an intermediate frequency of 50 MHz is used for the heterodyne measurement with the 200 MHz in-phase and quadrature (I/Q) phase detector. The corrugated conical horn antenna is used to approximate the Gaussian beam propagation and it is installed together with the oversized rectangular waveguides in the vacuum vessel. The first commissioning test of the Doppler reflectometer system on the KSTAR tokamak is planned in the 2014 KSTAR experimental campaign.

  8. On Doppler tracking in cosmological spacetimes

    E-Print Network [OSTI]

    Matteo Carrera; Domenico Giulini

    2006-11-20T23:59:59.000Z

    We give a rigorous derivation of the general-relativistic formula for the two-way Doppler tracking of a spacecraft in Friedmann-Lemaitre-Robertson-Walker and in McVittie spacetimes. The leading order corrections of the so-determined acceleration to the Newtonian acceleration are due to special-relativistic effects and cosmological expansion. The latter, although linear in the Hubble constant, is negligible in typical applications within the Solar System.

  9. Sub-Doppler Stark Spectroscopy in the A?X (1,0) Band of CN

    SciTech Connect (OSTI)

    Hall, G.E.; Hause, M.L.; Sears, T.J.

    2009-11-26T23:59:59.000Z

    The effect of external electric fields has been measured in hyperfine-resolved sub-Doppler transitions in the A {sup 2}{Pi}-X {sup 2}{Sigma} (1,0) band of the CN radical near 10900 cm{sup -1}. Static electric fields less than 1 kV/cm are sufficient to mix the most closely spaced {Lambda}-dpublets in the A state, leading to Stark spectra with both new and shifted resonances. Simulations of the saturation-dip Stark spectral line profiles allow extraction of the A-state permanent electric dipole moment with a magnitude of 0.06 {+-} 0.02 D.

  10. Two terminal micropower radar sensor

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1995-01-01T23:59:59.000Z

    A simple, low power ultra-wideband radar motion sensor/switch configuration connects a power source and load to ground. The switch is connected to and controlled by the signal output of a radar motion sensor. The power input of the motion sensor is connected to the load through a diode which conducts power to the motion sensor when the switch is open. A storage capacitor or rechargeable battery is connected to the power input of the motion sensor. The storage capacitor or battery is charged when the switch is open and powers the motion sensor when the switch is closed. The motion sensor and switch are connected between the same two terminals between the source/load and ground.

  11. Two terminal micropower radar sensor

    DOE Patents [OSTI]

    McEwan, T.E.

    1995-11-07T23:59:59.000Z

    A simple, low power ultra-wideband radar motion sensor/switch configuration connects a power source and load to ground. The switch is connected to and controlled by the signal output of a radar motion sensor. The power input of the motion sensor is connected to the load through a diode which conducts power to the motion sensor when the switch is open. A storage capacitor or rechargeable battery is connected to the power input of the motion sensor. The storage capacitor or battery is charged when the switch is open and powers the motion sensor when the switch is closed. The motion sensor and switch are connected between the same two terminals between the source/load and ground. 3 figs.

  12. Minimizing Biases in Radar Precipitation Estimates

    E-Print Network [OSTI]

    McRoberts, Douglas B

    2014-12-08T23:59:59.000Z

    ................................................................................................. 57 3.4 The same as Fig. 3.3b, but with HRAP grid cells detected by the flagging algorithm (gray diamonds) in the 90 km – 100 km annulus in the KABR radar domain .......................................................................... 62 3.5... ...................... 163 xiii FIGURE Page 5.1 Same as Fig. 3.1, but without radar locations or boundaries for radar domains ................................................................................................... 169 5.2 (a) Stage IV 1-month Po...

  13. A land based radar polarimeter processing system

    E-Print Network [OSTI]

    Kronke, Chester William

    1984-01-01T23:59:59.000Z

    Assignments 4 Indicator Circuit Read Port Assignments. 5 Interpretation of Indicator Circuit Data . 6 RF Head Common Control Port Signal Assignments . 7 iSBC-80/24 Parallel I/O Summary. 8 iSBX-311 Analog Input Signal Assignments 9 Memory Map... Polarimeter Antennas 2 Azimuthal Angle of Radar Polarimeter Boom. 3 Block Diagram of the Radar Polarimeter System. 4 Block Diagram of Radar Hardware. 10 5 Microwave Transceiver Circuit Transfer Switches Controlled by RDADS. 12 6 Block Diagram...

  14. Radar range measurements in the atmosphere.

    SciTech Connect (OSTI)

    Doerry, Armin Walter

    2013-02-01T23:59:59.000Z

    The earth's atmosphere affects the velocity of propagation of microwave signals. This imparts a range error to radar range measurements that assume the typical simplistic model for propagation velocity. This range error is a function of atmospheric constituents, such as water vapor, as well as the geometry of the radar data collection, notably altitude and range. Models are presented for calculating atmospheric effects on radar range measurements, and compared against more elaborate atmospheric models.

  15. Radar network communication through sensing of frequency hopping

    DOE Patents [OSTI]

    Dowla, Farid; Nekoogar, Faranak

    2013-05-28T23:59:59.000Z

    In one embodiment, a radar communication system includes a plurality of radars having a communication range and being capable of operating at a sensing frequency and a reporting frequency, wherein the reporting frequency is different than the sensing frequency, each radar is adapted for operating at the sensing frequency until an event is detected, each radar in the plurality of radars has an identification/location frequency for reporting information different from the sensing frequency, a first radar of the radars which senses the event sends a reporting frequency corresponding to its identification/location frequency when the event is detected, and all other radars in the plurality of radars switch their reporting frequencies to match the reporting frequency of the first radar upon detecting the reporting frequency switch of a radar within the communication range. In another embodiment, a method is presented for communicating information in a radar system.

  16. Radar investigation of the Hockley salt dome

    E-Print Network [OSTI]

    Hluchanek, James Andrew

    1973-01-01T23:59:59.000Z

    : Geophysics RADAR INVESTIGATION OF THE HOCKLEY SALT DOME A Thesis by UAMES ANDREW HLUCHANEK A'pproved as to style and content by: (Head of Departme t ? Member) May 1. 973 ABSTRACT Radar investigation of the Hockley Salt Dome. . (Nay, 1973) James... Andrew Hluchanek, B. S. , Texas A&M University Directed by: Dr. Robert R. Unterberger Radar probing through salt was accomplished at 17 radar stations established in the United Salt Company mine at Hockley, Texas. The top of the salt dom is mapped...

  17. Doppler-induced dynamics of fields in FabryPerot cavities with suspended mirrors

    E-Print Network [OSTI]

    Florida, University of

    The Doppler effect in Fabry­Perot cavities with suspended mirrors is analyzed. The Doppler shift, which by the Doppler effect that appears in a Fabry­Perot cavity with moving mirrors. The Doppler shift, whichDoppler-induced dynamics of fields in Fabry­Perot cavities with suspended mirrors Malik Rakhmanov

  18. Time-resolved fuel injector flow characterisation based on 3D laser Doppler vibrometry

    E-Print Network [OSTI]

    Crua, Cyril

    2015-01-01T23:59:59.000Z

    In order to enable investigations of the fuel flow inside unmodified injectors, we have developed a new experimental approach to measure time-resolved vibration spectra of diesel nozzles using a three dimensional laser vibrometer. The technique we propose is based on the triangulation of the vibrometer and fuel pressure transducer signals, and enables the quantitative characterisation of quasi-cyclic internal flows without requiring modifications to the injector, the working fluid, or limiting the fuel injection pressure. The vibrometer, which uses the Doppler effect to measure the velocity of a vibrating object, was used to scan injector nozzle tips during the injection event. The data were processed using a discrete Fourier transform to provide time-resolved spectra for valve-closed-orifice, minisac and microsac nozzle geometries, and injection pressures ranging from 60 to 160MPa, hence offering unprecedented insight into cyclic cavitation and internal mechanical dynamic processes. A peak was consistently f...

  19. PRECISE DOPPLER MONITORING OF BARNARD'S STAR

    SciTech Connect (OSTI)

    Choi, Jieun; Marcy, Geoffrey W.; Howard, Andrew W.; Isaacson, Howard [Department of Astronomy, University of California, Berkeley, CA 94720 (United States)] [Department of Astronomy, University of California, Berkeley, CA 94720 (United States); McCarthy, Chris [Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 (United States)] [Department of Physics and Astronomy, San Francisco State University, San Francisco, CA 94132 (United States); Fischer, Debra A. [Department of Astronomy, Yale University, New Haven, CT 06520-8101 (United States)] [Department of Astronomy, Yale University, New Haven, CT 06520-8101 (United States); Johnson, John A. [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States)] [Department of Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States); Wright, Jason T., E-mail: jieun_eb@berkeley.edu [Department of Astronomy, The Pennsylvania State University, University Park, PA 16802 (United States)

    2013-02-20T23:59:59.000Z

    We present 248 precise Doppler measurements of Barnard's Star (Gl 699), the second nearest star system to Earth, obtained from Lick and Keck Observatories during the 25 years between 1987 and 2012. The early precision was 20 m s{sup -1} but was 2 m s{sup -1} during the last 8 years, constituting the most extensive and sensitive search for Doppler signatures of planets around this stellar neighbor. We carefully analyze the 136 Keck radial velocities spanning 8 years by first applying a periodogram analysis to search for nearly circular orbits. We find no significant periodic Doppler signals with amplitudes above {approx}2 m s{sup -1}, setting firm upper limits on the minimum mass (Msin i) of any planets with orbital periods from 0.1 to 1000 days. Using a Monte Carlo analysis for circular orbits, we determine that planetary companions to Barnard's Star with masses above 2 M {sub Circled-Plus} and periods below 10 days would have been detected. Planets with periods up to 2 years and masses above 10 M {sub Circled-Plus} (0.03 M {sub Jup}) are also ruled out. A similar analysis allowing for eccentric orbits yields comparable mass limits. The habitable zone of Barnard's Star appears to be devoid of roughly Earth-mass planets or larger, save for face-on orbits. Previous claims of planets around the star by van de Kamp are strongly refuted. The radial velocity of Barnard's Star increases with time at 4.515 {+-} 0.002 m s{sup -1} yr{sup -1}, consistent with the predicted geometrical effect, secular acceleration, that exchanges transverse for radial components of velocity.

  20. Doppler effect of time and space

    E-Print Network [OSTI]

    Giovanni Zanella

    2012-08-30T23:59:59.000Z

    This paper shows as the relativistic Doppler effect can be extended also to time and space associated to moving bodies. This extension derives from the analysis of the wave-fronts of the light emitted by a moving source in inertial motion in the empty space, as viewed from the stationary reference. Indeed, time and space can be represented by the same vector quantities, which appear asymmetrical in forward and back direction along the path of the moving body. Consequently, the whole size of the moving bodies dilates along the direction of their motion, as their path. Thought experiments and real facts demonstrate this issue.

  1. Sandia National Laboratories: National Air Space radar system

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Air Space radar system Sandia Develops Tool to Evaluate Wind-TurbineRadar Impacts On December 3, 2014, in Computational Modeling & Simulation, Energy, News, News & Events,...

  2. Technical Note: Improved implementation of doppler broadening in MCNP5

    SciTech Connect (OSTI)

    Bartol, Laura J.; DeWerd, Larry A. [University of Wisconsin-Madison, Department of Medical Physics, Madison, Wisconsin 53705 (United States)

    2012-09-15T23:59:59.000Z

    Purpose: Incoherent scattering has a substantial effect on spectroscopic measurements and simulations. Many general-purpose Monte Carlo codes include models that account for the effects of bound electrons on incoherent scattering, including Doppler broadening (DB). This work investigates the DB model used in the Monte Carlo N-particle transport code (MCNP5). Methods: Simulations were run with three versions of MCNP5: v1.51, v1.60, and a modified form of v1.60 (v1.60m). All simulations used the MCPLIB04 photon data library, which presents the electron subshell data for incoherent scattering in the form of a probability density function. In v1.60m, the source code was altered to sample the electron subshell from a cumulative density function instead. Each version of the code was tested using an identical set of simulations that investigated DB in a slab of silicon at scattering angles of 15 Degree-Sign , 30 Degree-Sign , and 45 Degree-Sign . For each angle, simulations were run for multiple energies between 200 keV and 800 keV. The spectrum of singly-scattered photons at the exit of the slab was scored. Spectra were analytically calculated for comparison. Results: In v1.51, DB was modeled for incident photon energies below 760 keV, 384 keV, and 260 keV at scattering angles of 15 Degree-Sign , 30 Degree-Sign , and 45 Degree-Sign , respectively. Above these energy thresholds, v1.51 did not model DB. The spectra calculated using v1.60 and v1.60m exhibited DB for all energy-angle combinations; however, v1.60m, exhibited more energy broadening than did v1.60. The spectra calculated with v1.60m agreed with the analytical calculations. Conclusions: MCNP5 v1.51 and v1.60 model partial broadening when used with the MCPLIB04 data library. MCNP5 v1.60m models DB more accurately due to the form of the electron subshell data. In response to these results, Los Alamos National Laboratory has released a new photon data library, MCPLIB84, that presents the electron subshell data in cumulative distribution form. MCNP5 v1.60 should be used with this library when incoherent scattering has a significant impact on simulation results.

  3. Radar MeteorologyRadar Meteorology Feb 20, 1941 10 cm (S-band) radar used to track rain showers (Ligda)

    E-Print Network [OSTI]

    Rutledge, Steven

    (Ligda) Possibility of such observations was predicted by Ryde (1941) MIT Radiation Laboratory made in 1943 First operational weather radar, Panama, 1943 Science of radar meteorology born from WWII research fluctuations at 1/2 the wavelength of the incident radiation (a few meters in this case). Power returned from

  4. Comparison of Triature Doppler Velocimetry and VISAR

    SciTech Connect (OSTI)

    Cenobio H Gallegos, Bruce Marshall, Matthew Teel, Vincent T Romero, Abel Diaz, and Michael Berninger

    2010-01-01T23:59:59.000Z

    Triature Photonic Doppler Velocimetry (TDV) is an adaptation of Photonic Doppler Velocimetry (PDV) that rejects common-mode data noise after splitting PDV three ways, with each signal 120° out of phase from each other. Testing has demonstrated that TDV also improves temporal resolution from the typical five nanoseconds of PDV to a subnanosecond range. This paper compares the temporal response of TDV with that of PDV and VISAR [velocity interferometer system for any reflector] in an experiment with a subnanosecond (~120-picosecond rise time) shock source. Laboratory tests were performed using a high-power laser on targets of copper and aluminum. A Buce Marshall fast VISAR with a single-point PDV and a prototype TDV were used. A special probe that combined PDV, TDV, and fast VISAR made simultaneous velocity measurements. Breakout velocities of 1.3 km/second on copper and 2.5 km/second on aluminum were observed, where TDV resolved rise times of ~200 ps. This resolution was better than that of a fast VISAR, which can achieve ~500 ps temporal resolution. Test methods and results are presented.

  5. Ultra-wideband radar sensors and networks

    DOE Patents [OSTI]

    Leach, Jr., Richard R; Nekoogar, Faranak; Haugen, Peter C

    2013-08-06T23:59:59.000Z

    Ultra wideband radar motion sensors strategically placed in an area of interest communicate with a wireless ad hoc network to provide remote area surveillance. Swept range impulse radar and a heart and respiration monitor combined with the motion sensor further improves discrimination.

  6. Nuclear Spectra from Skyrmions

    SciTech Connect (OSTI)

    Manton, N. S. [DAMTP, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

    2009-08-26T23:59:59.000Z

    The structures of Skyrmions, especially for baryon numbers 4, 8 and 12, are reviewed. The quantized Skyrmion states are compared with nuclear spectra.

  7. Sandia Energy - Radar Friendly Blades

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of ScienceandMesa del Sol Home Distribution Grid IntegrationOffshoreLiveSustainablePriceRadar

  8. Doppler cooling to the Quantum limit M. Chalony,1

    E-Print Network [OSTI]

    Boyer, Edmond

    Doppler cooling to the Quantum limit M. Chalony,1 A. Kastberg,2 B. Klappauf,3 and D. Wilkowski1, 4 637371, Singapore (Dated: December 16, 2011) Doppler cooling on a narrow transition is limited by the noise of single scattering events. It shows novel features, which are in sharp contrast with cooling

  9. "An analysis of the classical Doppler Effect"[1] revisited

    E-Print Network [OSTI]

    Bernhard Rothenstein; Corina Nafornita

    2004-03-26T23:59:59.000Z

    After having shown that the formula which describes the Doppler effect in the general case holds only in the case of the "very high" frequency assumption, we derive free of assumptions Doppler formulas for two scenarios presented in the revisited paper.

  10. Imaging doppler velocimeter with downward heterodyning in the optical domain

    DOE Patents [OSTI]

    Reu, Phillip L; Hansche, Bruce D

    2013-05-21T23:59:59.000Z

    In a Doppler velocimeter, the incoming Doppler-shifted beams are heterodyned to reduce their frequencies into the bandwidth of a digital camera. This permits the digital camera to produce at every sampling interval a complete two-dimensional array of pixel values. This sequence of pixel value arrays provides a velocity image of the target.

  11. A laser Doppler method for noninvasive measurement of flow velocity

    SciTech Connect (OSTI)

    Biggs, G.L.

    1986-11-25T23:59:59.000Z

    Laser Doppler velocimetry is a powerful optical technique for noninvasively obtaining experimental flow-velocity data. This paper describes the principle of operation and various optical configurations of the laser Doppler velocimeter. As a sample application, we describe an experimental apparatus for measuring the velocity flow field around a cylinder, and give our experimental results.

  12. Computing the apparent centroid of radar targets

    SciTech Connect (OSTI)

    Lee, C.E.

    1996-12-31T23:59:59.000Z

    A high-frequency multibounce radar scattering code was used as a simulation platform for demonstrating an algorithm to compute the ARC of specific radar targets. To illustrate this simulation process, several targets models were used. Simulation results for a sphere model were used to determine the errors of approximation associated with the simulation; verifying the process. The severity of glint induced tracking errors was also illustrated using a model of an F-15 aircraft. It was shown, in a deterministic manner, that the ARC of a target can fall well outside its physical extent. Finally, the apparent radar centroid simulation based on a ray casting procedure is well suited for use on most massively parallel computing platforms and could lead to the development of a near real-time radar tracking simulation for applications such as endgame fuzing, survivability, and vulnerability analyses using specific radar targets and fuze algorithms.

  13. Magneto-Radar Hidden Metal Detector

    DOE Patents [OSTI]

    McEwan, Thomas E. (Las Vegas, NV)

    2005-07-05T23:59:59.000Z

    A varying magnetic field excites slight vibrations in an object and a radar sensor detects the vibrations at a harmonic of the excitation frequency. The synergy of the magnetic excitation and radar detection provides increased detection range compared to conventional magnetic metal detectors. The radar rejects background clutter by responding only to reflecting objects that are vibrating at a harmonic excitation field, thereby significantly improving detection reliability. As an exemplary arrangement, an ultra-wideband micropower impulse radar (MIR) is capable of being employed to provide superior materials penetration while providing range information. The magneto-radar may be applied to pre-screening magnetic resonance imaging (MRI) patients, landmine detection and finding hidden treasures.

  14. Real-time bulk-motion-correction free Doppler variance optical coherence tomography for choroidal capillary vasculature imaging

    E-Print Network [OSTI]

    Liu, Gangjun; Qi, Wenjuan; Yu, Lingfeng; Chen, Zhongping

    2011-01-01T23:59:59.000Z

    The effect of sample movement on the color Doppler andmotion effect can be neglected here. The Doppler variance

  15. Observations of colocated optical and radar aurora H. Bahcivan,1

    E-Print Network [OSTI]

    Lummerzheim, Dirk

    Observations of colocated optical and radar aurora H. Bahcivan,1 D. L. Hysell,2 D. Lummerzheim,3 M of the E region radar aurora obtained with a 30 MHz imaging radar and the optical aurora (green line, the radar aurora in the vicinity of a stable evening auroral arc arises because of the arc's polarization

  16. Widefield laser doppler velocimeter: development and theory.

    SciTech Connect (OSTI)

    Hansche, Bruce David; Reu, Phillip L.; Massad, Jordan Elias

    2007-03-01T23:59:59.000Z

    The widefield laser Doppler velocimeter is a new measurement technique that significantly expands the functionality of a traditional scanning system. This new technique allows full-field velocity measurements without scanning, a drawback of traditional measurement techniques. This is particularly important for tests in which the sample is destroyed or the motion of the sample is non-repetitive. The goal of creating ''velocity movies'' was accomplished during the research, and this report describes the current functionality and operation of the system. The mathematical underpinnings and system setup are thoroughly described. Two prototype experiments are then presented to show the practical use of the current system. Details of the corresponding hardware used to collect the data and the associated software to analyze the data are presented.

  17. IMPROVED CAPABILITIES FOR SITING WIND FARMS AND MITIGATING IMPACTS ON RADAR OBSERVATIONS

    SciTech Connect (OSTI)

    Chiswell, S.

    2010-01-15T23:59:59.000Z

    The development of efficient wind energy production involves challenges in technology and interoperability with other systems critical to the national mission. Wind turbines impact radar measurements as a result of their large reflectivity cross section as well as through the Doppler phase shift of their rotating blades. Wind farms can interfere with operational radar in multiple contexts, with degradation impacts on: weather detection such as tornado location, wind shear, and precipitation monitoring; tracking of airplanes where air traffic control software can lose the tracks of aircraft; and in identification of other low flying targets where a wind farm located close to a border might create a dead zone for detecting intruding objects. Objects in the path of an electromagnetic wave affect its propagation characteristics. This includes actual blockage of wave propagation by large individual objects and interference in wave continuity due to diffraction of the beam by individual or multiple objects. As an evolving industry, and the fastest growing segment of the energy sector, wind power is poised to make significant contributions in future energy generation requirements. The ability to develop comprehensive strategies for designing wind turbine locations that are mutually beneficial to both the wind industry that is dependent on production, and radar sites which the nation relies on, is critical to establishing reliable and secure wind energy. The mission needs of the Department of Homeland Security (DHS), Department of Defense (DOD), Federal Aviation Administration (FAA), and National Oceanographic and Atmospheric Administration (NOAA) dictate that the nation's radar systems remain uninhibited, to the maximum extent possible, by man-made obstructions; however, wind turbines can and do impact the surveillance footprint for monitoring airspace both for national defense as well as critical weather conditions which can impact life and property. As a result, a number of potential wind power locations have been contested on the basis of radar line of site. Radar line of site is dependent on local topography, and varies with atmospheric refractive index which is affected by weather and geographic conditions.

  18. Development of the Solid State X-band Radar and the Phased Array Radar System in Japan

    E-Print Network [OSTI]

    Droegemeier, Kelvin K.

    Development of the Solid State X-band Radar and the Phased Array Radar System in Japan By DR. TOMOO array radar system have been developed. Toshiba has developed the latest model of weather radar of precipitation and to achieve drastic reduction of its size and life cycle cost. It is now well known

  19. Relativistic formulation for the Doppler-broadened line profile

    SciTech Connect (OSTI)

    Huang, Young-Sea; Chiue, Juang-Han; Huang, Yi-Chi; Hsiung, Te-Chih [Department of Physics, Soochow University, Shih-Lin, Taipei, Taiwan (China); Department of Physics, National Central University, Chung-Li, Taiwan (China)

    2010-07-15T23:59:59.000Z

    Profiles of spectral lines due to the thermal motion of light-emitting particles are formulated based on the classical and the relativistic Doppler effects, respectively. For the classical case, the well-known Doppler-broadened line profile is reproduced. For the relativistic case, the line profile obtained is asymmetrically broadened with increasing temperature. However, the peak frequency remains unshifted, in contrast to blueshifted, as has been predicted in the current literature. Reasoning is given as to why the relativistic Doppler-broadened line profile currently accepted is probably invalid.

  20. Doppler Simulation and the Leslie Julius O. Smith III Stefania Serafin Jonathan Abel Dave Berners

    E-Print Network [OSTI]

    Smith III, Julius Orion

    for simulating the Doppler effect using interpolating and de-interpolating delay lines is described. The Doppler-dependent, frequency response of the rotating horn. 1 #12;Contents 1 Introduction 3 2 The Doppler Effect 3 2.1 Vector The Doppler effect causes the pitch of a sound source to appear to rise or fall due to motion of the source

  1. Doppler Optomechanics of a Photonic Crystal K. Karrai,1,* I. Favero,1,2,

    E-Print Network [OSTI]

    Ludwig-Maximilians-Universität, München

    mechanical motion by the Doppler effect. For a normal mirror the efficiency of this radiative Doppler]. This veloc- ity dependent force is due to the Doppler effect and to illustrate it they imagined a perfectly effects oppose each other. The larger the laser power, the larger the Doppler damping of the mirror

  2. Almost Linear Complexity Methods for Delay-Doppler Channel Alexander Fish and Shamgar Gurevich

    E-Print Network [OSTI]

    Sydney, University of

    provide a striking improvement over current methods in the presence of a substantial Doppler effect1 Almost Linear Complexity Methods for Delay-Doppler Channel Estimation Alexander Fish and Shamgar of delay-Doppler channel, i.e., a signal undergoes only delay and Doppler shifts, a widely used method

  3. SoundWave: Using the Doppler Effect to Sense Gestures Sidhant Gupta1,2

    E-Print Network [OSTI]

    Anderson, Richard

    SoundWave: Using the Doppler Effect to Sense Gestures Sidhant Gupta1,2 , Dan Morris1 , Shwetak N a well-understood phenomenon known as the "Doppler effect" or "Doppler shift", which characterizes to vision-based systems. We are not the first to use sonic techniques or the Doppler effect for gesture

  4. Radar echo signatures versus relative precipitation

    E-Print Network [OSTI]

    Huber, Terry Alvin

    1987-01-01T23:59:59.000Z

    the relationship between cell-echo signatures and precipitation characteristics, and to support the hypothesis that, during the lifespan of any particular isolated convective cell, the relative rainfall rate, as determined by radar for a given volume scan... Cooperative Program) field experiment of 1979. Four isolated cases, two rainshowers and two thundershowers, were selected for study. Profiles from volume scans taken 10 minutes before, during, and 10 minutes after the maximum radar-determined rainfall rate...

  5. Doppler optical coherence microscopy for studies of cochlear mechanics

    E-Print Network [OSTI]

    Hong, Stanley S.

    The possibility of measuring subnanometer motions with micron scale spatial resolution in the intact mammalian cochlea using Doppler optical coherence microscopy (DOCM) is demonstrated. A novel DOCM system is described ...

  6. Doppler electron velocimetry : notes on creating a practical tool.

    SciTech Connect (OSTI)

    Reu, Phillip L.; Milster, Tom (University of Arizona)

    2008-11-01T23:59:59.000Z

    The Doppler electron velocimeter (DEV) has been shown to be theoretically possible. This report attempts to answer the next logical question: Is it a practical instrument? The answer hinges upon whether enough electrons are available to create a time-varying Doppler current to be measured by a detector with enough sensitivity and bandwidth. The answer to both of these questions is a qualified yes. A target Doppler frequency of 1 MHz was set as a minimum rate of interest. At this target a theoretical beam current signal-to-noise ratio of 25-to-1 is shown for existing electron holography equipment. A detector is also demonstrated with a bandwidth of 1-MHz at a current of 10 pA. Additionally, a Linnik-type interferometer that would increase the available beam current is shown that would offer a more flexible arrangement for Doppler electron measurements over the traditional biprism.

  7. abdominal mediante doppler: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The time series analysis of Doppler velocity maps show enhanced power in the sunspot umbra at higher frequencies and in the penumbra at lower frequencies. We find that the peak...

  8. analyzing nexrad doppler: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The time series analysis of Doppler velocity maps show enhanced power in the sunspot umbra at higher frequencies and in the penumbra at lower frequencies. We find that the peak...

  9. artery doppler flow: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The time series analysis of Doppler velocity maps show enhanced power in the sunspot umbra at higher frequencies and in the penumbra at lower frequencies. We find that the peak...

  10. airborne pulse doppler: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The time series analysis of Doppler velocity maps show enhanced power in the sunspot umbra at higher frequencies and in the penumbra at lower frequencies. We find that the peak...

  11. artery doppler velocimetry: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The time series analysis of Doppler velocity maps show enhanced power in the sunspot umbra at higher frequencies and in the penumbra at lower frequencies. We find that the peak...

  12. acoustic doppler velocimeter: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The time series analysis of Doppler velocity maps show enhanced power in the sunspot umbra at higher frequencies and in the penumbra at lower frequencies. We find that the peak...

  13. al ecocardiograma doppler: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The time series analysis of Doppler velocity maps show enhanced power in the sunspot umbra at higher frequencies and in the penumbra at lower frequencies. We find that the peak...

  14. aplicaciones del doppler: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The time series analysis of Doppler velocity maps show enhanced power in the sunspot umbra at higher frequencies and in the penumbra at lower frequencies. We find that the peak...

  15. abnormal doppler enteral: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The time series analysis of Doppler velocity maps show enhanced power in the sunspot umbra at higher frequencies and in the penumbra at lower frequencies. We find that the peak...

  16. adaptive spectral doppler: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    The time series analysis of Doppler velocity maps show enhanced power in the sunspot umbra at higher frequencies and in the penumbra at lower frequencies. We find that the peak...

  17. An Ion Doppler Spectrometer Instrument for Ion Temperature and Flow Measurements on SSPX

    SciTech Connect (OSTI)

    King, J D; McLean, H S; Wood, R D; Romero-Talamas, C A; Moller, J M; Morse, E C

    2008-05-19T23:59:59.000Z

    A high-resolution ion Doppler spectrometer has been installed on the Sustained Spheromak Plasma Experiment to measure ion temperatures and plasma flow. The system is composed of a 1 meter focal length Czerny-Turner spectrometer with diffraction grating line density of 2400 lines/mm, which allows for first order spectra between 300 and 600 nm. A 16-channel photomultiplier tube detection assembly combined with output coupling optics provides a spectral resolution of 0.0126 nm per channel. We calculate in some detail the mapping of curved slit images onto the linear detector array elements. This is important in determining wavelength resolution and setting the optimum vertical extent of the slit. Also, because of the small wavelength window of the IDS, a miniature fiber optic survey spectrometer sensitive to a wavelength range 200 to 1100 nm and having resolution 0.2 nm, is used to obtain a time-integrated spectrum for each shot to verify specific impurity line radiation. Several measurements validate the systems operation. Doppler broadening of C III 464.72 nm line in the plasma shows time-resolved ion temperatures up to 250 eV for hydrogen discharges, which is consistent with neutral particle energy analyzer measurements. Flow measurements show a sub-Alfvenic plasma flow ranging from 5 to 45 km/s for helium discharges.

  18. Doppler-resolved kinetics of saturation recovery

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Forthomme, Damien; Hause, Michael L.; Yu, Hua-Gen; Dagdigian, Paul J.; Sears, Trevor J.; Hall, Gregory E.

    2015-04-08T23:59:59.000Z

    Frequency modulated laser transient absorption has been used to monitor the ground state rotational energy transfer rates of CN radicals in a double-resonance, depletion recovery experiment. When a pulsed laser is used to burn a hole in the equilibrium ground state population of one rotational state without velocity selection, the population recovery rate is found to depend strongly on the Doppler detuning of a narrow-band probe laser. Similar effects should be apparent for any relaxation rate process that competes effectively with velocity randomization. Alternative methods of extracting thermal rate constants in the presence of these non-thermal conditions are evaluated. Totalmore »recovery rate constants, analogous to total removal rate constants in an experiment preparing a single initial rotational level, are in good agreement with quantum scattering calculations, but are slower than previously reported experiments and show qualitatively different rotational state dependence between Ar and He collision partners. Quasi-classical trajectory studies confirm that the differing rotational state dependence is primarily a kinematic effect.« less

  19. Optimizing Doppler Surveys for Planet Yield

    E-Print Network [OSTI]

    Bottom, Michael; Johnson, John Asher; Blake, Cullen H

    2013-01-01T23:59:59.000Z

    One of the most promising methods of discovering nearby, low-mass planets in the habitable zones of stars is the precision radial velocity technique. However, there are many challenges that must be overcome to efficiently detect low-amplitude Doppler signals. This is both due to the required instrumental sensitivity and the limited amount of observing time. In this paper, we examine statistical and instrumental effects on precision radial velocity detection of extrasolar planets, an approach by which we maximize the planet yield in a fixed amount of observing time available on a given telescope. From this perspective, we show that G and K dwarfs observed at 400-600 nm are the best targets for surveys complete down to a given planet mass and out to a specified orbital period. Overall we find that M dwarfs observed at 700-800 nm are the best targets for habitable-zone planets, particularly when including the effects of systematic noise floors. Also, we give quantitative specifications of the instrumental stabil...

  20. Doppler-resolved kinetics of saturation recovery

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Forthomme, Damien [Brookhaven National Lab. (BNL), Upton, NY (United States); Hause, Michael L. [Brookhaven National Lab. (BNL), Upton, NY (United States); Yu, Hua-Gen [Brookhaven National Lab. (BNL), Upton, NY (United States); Dagdigian, Paul J. [John Hopkins Univ., Baltimore, MD (United States); Sears, Trevor J. [Brookhaven National Lab. (BNL), Upton, NY (United States); Stony Brook Univ., Stony Brook, NY (United States); Hall, Gregory E. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2015-04-08T23:59:59.000Z

    Frequency modulated laser transient absorption has been used to monitor the ground state rotational energy transfer rates of CN radicals in a double-resonance, depletion recovery experiment. When a pulsed laser is used to burn a hole in the equilibrium ground state population of one rotational state without velocity selection, the population recovery rate is found to depend strongly on the Doppler detuning of a narrow-band probe laser. Similar effects should be apparent for any relaxation rate process that competes effectively with velocity randomization. Alternative methods of extracting thermal rate constants in the presence of these non-thermal conditions are evaluated. Total recovery rate constants, analogous to total removal rate constants in an experiment preparing a single initial rotational level, are in good agreement with quantum scattering calculations, but are slower than previously reported experiments and show qualitatively different rotational state dependence between Ar and He collision partners. Quasi-classical trajectory studies confirm that the differing rotational state dependence is primarily a kinematic effect.

  1. Ground Penetrating Radar in Hydrogeophysics

    SciTech Connect (OSTI)

    Hubbard, Susan; Lambot, S.; Binley, A.; Slob, E.; Hubbard, S.

    2008-01-15T23:59:59.000Z

    To meet the needs of a growing population and to provide us with a higher quality of life, increasing pressures are being placed on our environment through the development of agriculture, industry, and infrastructures. Soil erosion, groundwater depletion, salinization, and pollution have been recognized for decades as major threats to ecosystems and human health. More recently, the progressive substitution of fossil fuels by biofuels for energy production and climate change have been recognized as potential threats to our water resources and sustained agricultural productivity. The vadose zone mediates many of the processes that govern water resources and quality, such as the partition of precipitation into infiltration and runoff , groundwater recharge, contaminant transport, plant growth, evaporation, and energy exchanges between the Earth's surface and its atmosphere. It also determines soil organic carbon sequestration and carbon-cycle feedbacks, which could substantially impact climate change. The vadose zone's inherent spatial variability and inaccessibility precludes direct observation of the important subsurface processes. In a societal context where the development of sustainable and optimal environmental management strategies has become a priority, there is a strong prerequisite for the development of noninvasive characterization and monitoring techniques of the vadose zone. In particular, hydrogeophysical approaches applied at relevant scales are required to appraise dynamic subsurface phenomena and to develop optimal sustainability, exploitation, and remediation strategies. Among existing geophysical techniques, ground penetrating radar (GPR) technology is of particular interest for providing high-resolution subsurface images and specifically addressing water-related questions. Ground penetrating radar is based on the transmission and reception of VHF-UHF (30-3000 MHz) electromagnetic waves into the ground, whose propagation is determined by the soil electromagnetic properties and their spatial distribution. As the dielectric permittivity of water overwhelms the permittivity of other soil components, the presence of water in the soil principally governs GPR wave propagation. Therefore, GPR-derived dielectric permittivity is usually used as surrogate measure for soil water content. In the areas of unsaturated zone hydrology and water resources, GPR has been used to identify soil stratigraphy, to locate water tables, to follow wetting front movement, to estimate soil water content, to assist in subsurface hydraulic parameter identification, to assess soil salinity, and to support the monitoring of contaminants. The purpose of this special section of the Vadose Zone Journal is to present recent research advances and applications of GPR in hydrogeophysics, with a particular emphasis on vadose zone investigations. This special section includes contributions presented at the European Geosciences Union General Assembly 2006 (EGU 2006, Vienna, Austria) and the 11th International Conference on Ground Penetrating Radar (GPR 2006, Columbus, OH). The studies presented here deal with a wide range of surface and borehole GPR applications, including GPR sensitivity to contaminant plumes, new methods for soil water content determination, three-dimensional imaging of the subsurface, time-lapse monitoring of hydrodynamic events and inversion techniques for soil hydraulic properties estimation, and joint interpretation of GPR and electric resistivity tomography (ERT) data.

  2. High resolution laser induced fluorescence Doppler velocimetry utilizing saturated absorption spectroscopy

    SciTech Connect (OSTI)

    Aramaki, Mitsutoshi [Department of Electrical Engineering and Computer Science, Nagoya University, Nagoya 464-8603 (Japan); Ogiwara, Kohei; Etoh, Shuzo [Interdisciplinary Graduate School of Engineering Sciences, Kyushu University, Kasuga 816-8580 (Japan); Yoshimura, Shinji [National Institute for Fusion Science, Toki 509-5292 (Japan); Tanaka, Masayoshi Y. [Department of Advanced Energy Engineering Science, Kyushu University, Kasuga 816-8580 (Japan)

    2009-05-15T23:59:59.000Z

    A high resolution laser induced fluorescence (LIF) system has been developed to measure the flow velocity field of neutral particles in an electron-cyclotron-resonance argon plasma. The flow velocity has been determined by the Doppler shift of the LIF spectrum, which is proportional to the velocity distribution function. Very high accuracy in velocity determination has been achieved by installing a saturated absorption spectroscopy unit into the LIF system, where the absolute value and scale of laser wavelength are determined by using the Lamb dip and the fringes of a Fabry-Perot interferometer. The minimum detectable flow velocity of a newly developed LIF system is {+-}2 m/s, and this performance remains unchanged in a long-time experiment. From the radial measurements of LIF spectra of argon metastable atoms, it is found that there exists an inward flow of neutral particles associated with neutral depletion.

  3. Stepped frequency ground penetrating radar

    DOE Patents [OSTI]

    Vadnais, Kenneth G. (Ojai, CA); Bashforth, Michael B. (Buellton, CA); Lewallen, Tricia S. (Ventura, CA); Nammath, Sharyn R. (Santa Barbara, CA)

    1994-01-01T23:59:59.000Z

    A stepped frequency ground penetrating radar system is described comprising an RF signal generating section capable of producing stepped frequency signals in spaced and equal increments of time and frequency over a preselected bandwidth which serves as a common RF signal source for both a transmit portion and a receive portion of the system. In the transmit portion of the system the signal is processed into in-phase and quadrature signals which are then amplified and then transmitted toward a target. The reflected signals from the target are then received by a receive antenna and mixed with a reference signal from the common RF signal source in a mixer whose output is then fed through a low pass filter. The DC output, after amplification and demodulation, is digitized and converted into a frequency domain signal by a Fast Fourier Transform. A plot of the frequency domain signals from all of the stepped frequencies broadcast toward and received from the target yields information concerning the range (distance) and cross section (size) of the target.

  4. DOPPLER SIGNATURES OF THE ATMOSPHERIC CIRCULATION ON HOT JUPITERS

    SciTech Connect (OSTI)

    Showman, Adam P.; Lewis, Nikole K. [Department of Planetary Sciences and Lunar and Planetary Laboratory, The University of Arizona, 1629 University Boulevard, Tucson, AZ 85721 (United States)] [Department of Planetary Sciences and Lunar and Planetary Laboratory, The University of Arizona, 1629 University Boulevard, Tucson, AZ 85721 (United States); Fortney, Jonathan J. [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States)] [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Shabram, Megan, E-mail: showman@lpl.arizona.edu [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611-2055 (United States)] [Department of Astronomy, University of Florida, 211 Bryant Space Science Center, Gainesville, FL 32611-2055 (United States)

    2013-01-01T23:59:59.000Z

    The meteorology of hot Jupiters has been characterized primarily with thermal measurements, but recent observations suggest the possibility of directly detecting the winds by observing the Doppler shift of spectral lines seen during transit. Motivated by these observations, we show how Doppler measurements can place powerful constraints on the meteorology. We show that the atmospheric circulation-and Doppler signature-of hot Jupiters splits into two regimes. Under weak stellar insolation, the day-night thermal forcing generates fast zonal jet streams from the interaction of atmospheric waves with the mean flow. In this regime, air along the terminator (as seen during transit) flows toward Earth in some regions and away from Earth in others, leading to a Doppler signature exhibiting superposed blueshifted and redshifted components. Under intense stellar insolation, however, the strong thermal forcing damps these planetary-scale waves, inhibiting their ability to generate jets. Strong frictional drag likewise damps these waves and inhibits jet formation. As a result, this second regime exhibits a circulation dominated by high-altitude, day-to-night airflow, leading to a predominantly blueshifted Doppler signature during transit. We present state-of-the-art circulation models including non-gray radiative transfer to quantify this regime shift and the resulting Doppler signatures; these models suggest that cool planets like GJ 436b lie in the first regime, HD 189733b is transitional, while planets hotter than HD 209458b lie in the second regime. Moreover, we show how the amplitude of the Doppler shifts constrains the strength of frictional drag in the upper atmospheres of hot Jupiters. If due to winds, the {approx}2 km s{sup -1} blueshift inferred on HD 209458b may require drag time constants as short as 10{sup 4}-10{sup 6} s, possibly the result of Lorentz-force braking on this planet's hot dayside.

  5. Doppler effect in the oscillator radiation process in the medium

    E-Print Network [OSTI]

    Lekdar Gevorgian; Valeri Vardanyan

    2011-10-15T23:59:59.000Z

    The purpose of this paper is to investigate the radiation process of the charged particle passing through an external periodic field in a dispersive medium. In the optical range of spectrum we will consider two cases: first, the source has not eigenfrequency, and second, the source has eigenfrequency. In the first case, when the Cherenkov radiation occurs, the non-zero eigenfrequency produces a paradox for Doppler effect. It is shown that the absence of the eigenfrequency solves the paradox known in the literature. The question whether the process is normal (i.e. hard photons are being radiated under the small angles) or anomalous depends on the law of the medium dispersion. When the source has an eigenfrequency the Doppler effects can be either normal or anomalous. In the X-ray range of the oscillator radiation spectrum we have two photons radiated under the same angle- soft and hard. In this case the radiation obeys to so-called complicated Doppler effect, i.e. in the soft photon region we have anomalous Doppler effect and in the hard photon region we have normal Doppler effect.

  6. Direct recovery of fluctuation spectra from tomographic shear spectra

    SciTech Connect (OSTI)

    Mezzetti, Marino; Bonometto, Silvio A.; Murante, Giuseppe [Department of Physics, Astronomy Unit, Trieste University, Via Tiepolo 11, I 34143 Trieste (Italy); Casarini, Luciano, E-mail: mezzetti@oats.inaf.it, E-mail: bonometto@oats.inaf.it, E-mail: casarini@mib.infn.it, E-mail: murante@oats.inaf.it [Departamento de Fisica, UFES, Avenida Fernando Ferrari 514, Vitória, Espírito Santo (Brazil)

    2012-06-01T23:59:59.000Z

    Forthcoming experiments will enable us to determine high precision tomographic shear spectra. Matter density fluctuation spectra, at various z, should then be recovered from them, in order to constrain the model and determine the DE state equation. Available analytical expressions, however, do the opposite, enabling us to derive shear spectra from fluctuation spectra. Here we find the inverse expression, yielding density fluctuation spectra from observational tomographic shear spectra. The procedure involves SVD techniques for matrix inversion. We show in detail how the approach works and provide a few examples.

  7. Tracking butterfly flight paths across the landscape with harmonic radar

    E-Print Network [OSTI]

    Northampton, University of

    Tracking butterfly flight paths across the landscape with harmonic radar E. T. Cant1,*, A. D. Smith of five butterfly species were successfully tracked using harmonic radar within an agricultural landscape. Keywords: butterfly flight; harmonic radar; linear landscape features; Aglais urticae; Inachis io 1

  8. Bias adjustment of radar-based 3-hour precipitation accumulations

    E-Print Network [OSTI]

    Stoffelen, Ad

    projection of KNMI radar images 55 4 #12;Chapter 1 Introduction Since June 2003 a daily gauge is generated at 1400 UTC when the majority of the manual gauge observations have been reported. The radar-gaugeBias adjustment of radar-based 3-hour precipitation accumulations Iwan Holleman Technical Report

  9. Climatology of extreme rainfall from rain gauges and weather radar

    E-Print Network [OSTI]

    Stoffelen, Ad

    by conventional rain gauge networks. A 10-year radar-based climatology of rainfall depths for durations of 15 minClimatology of extreme rainfall from rain gauges and weather radar Aart Overeem #12;Thesis:30 PM in the Aula #12;Aart Overeem Climatology of extreme rainfall from rain gauges and weather radar

  10. Soil-penetrating synthetic aperture radar

    SciTech Connect (OSTI)

    Boverie, B.; Brock, B.C.; Doerry, A.W.

    1994-12-01T23:59:59.000Z

    This report summarizes the results for the first year of a two year Laboratory Directed Research and Development (LDRD) effort. This effort included a system study, preliminary data acquisition, and preliminary algorithm development. The system study determined the optimum frequency and bandwidth, surveyed soil parameters and targets, and defined radar cross section in lossy media. The data acquisition imaged buried objects with a rail-SAR. Algorithm development included a radar echo model, three-dimensional processing, sidelobe optimization, phase history data interpolation, and clutter estimation/cancellation.

  11. Impact of Airborne Doppler Radar Data Assimilation on the Numerical Simulation of Intensity Changes of Hurricane Dennis near a Landfall

    E-Print Network [OSTI]

    Pu, Zhaoxia

    of Hurricane Dennis near a Landfall ZHAOXIA PU AND XUANLI LI Department of Atmospheric Sciences, University (Manuscript received 27 February 2009, in final form 15 May 2009) ABSTRACT Accurate forecasting of a hurricane's intensity changes near its landfall is of great importance in making an effective hurricane warning

  12. Analysis of 11 june 2003 mesoscale convective vortex genesis using weather surveillance radar ??88 doppler (wsr-88d) 

    E-Print Network [OSTI]

    Reynolds, Amber Elizabeth

    2009-05-15T23:59:59.000Z

    Mesoscale convective vortices (MCVs), which typically form within the stratiform rain of some mesoscale convective systems (MCSs), may persist for days, often regenerating convection daily. Long-lived MCVs can produce as much precipitation as a...

  13. Life Cycle of a Mesoscale Circular Gust Front Observed by a C-Band Doppler Radar in West Africa

    E-Print Network [OSTI]

    Lothon, Marie

    On 10 July 2006, during the Special Observation Period (SOP) of the African Monsoon Multidisciplinary Analysis (AMMA) campaign, a small convective system initiated over Niamey and propagated westward in the vicinity of ...

  14. Analysis of 11 june 2003 mesoscale convective vortex genesis using weather surveillance radar ??88 doppler (wsr-88d)

    E-Print Network [OSTI]

    Reynolds, Amber Elizabeth

    2009-05-15T23:59:59.000Z

    Mesoscale convective vortices (MCVs), which typically form within the stratiform rain of some mesoscale convective systems (MCSs), may persist for days, often regenerating convection daily. Long-lived MCVs can produce as much precipitation as a...

  15. Doppler-like effect and doubtful expansion of universe

    E-Print Network [OSTI]

    Edward Szaraniec

    2003-10-01T23:59:59.000Z

    The distance contraction, as observed in electrical soundings over horizontally stratified earth (static system), is identified as a counterpart of Doppler shift in dynamical systems. Identification of Doppler-like effect in a stock-still systems makes it possible to give an al-ternative answer to the question about an effective cause of the Doppler shift, which sounds: the inhomogeneities. This answer opens different static as well as kinematic possibilities, which challenge established theories of expanding universe and energizing big bang.The energy propagating in stratified universe of layers exhibits a shift which could be at-tributed not only to the expansion (Hubble's theory) but alternatively to fluctuations in material properties (inhomogeneities).

  16. Precision Measuring of Velocities via the Relativistic Doppler Effect

    E-Print Network [OSTI]

    Leonid M. Ozernoy

    1997-12-26T23:59:59.000Z

    Just as the ordinary Doppler effect serves as a tool to measure radial velocities of celestial objects, so can the relativistic Doppler effect be implemented to measure a combination of radial and transverse velocities by using recent improvements in observing techniques. A key element that makes a further use of this combination feasible is the periodicity in changes of the orbital velocity direction for the source. Two cases are considered: (i) a binary star; and (ii) a solitary star with the planetary companion. It is shown that, in case (i), several precision Doppler measurements employing the gas absorption cell technique would determine both the total orbital velocity and the inclination angle of the binary orbit disentangled from the peculiar velocity of the system. The necessary condition for that is the measured, at least with a modest precision, proper motion and distance to the system.

  17. Precision Measuring of Velocities via the Relativistic Doppler Effect

    E-Print Network [OSTI]

    Ozernoy, L M

    1997-01-01T23:59:59.000Z

    Just as the ordinary Doppler effect serves as a tool to measure radial velocities of celestial objects, so can the relativistic Doppler effect be implemented to measure a combination of radial and transverse velocities by using recent improvements in observing techniques. A key element that makes a further use of this combination feasible is the periodicity in changes of the orbital velocity direction for the source. Two cases are considered: (i) a binary star; and (ii) a solitary star with the planetary companion. It is shown that, in case (i), several precision Doppler measurements employing the gas absorption cell technique would determine both the total orbital velocity and the inclination angle of the binary orbit disentangled from the peculiar velocity of the system. The necessary condition for that is the measured, at least with a modest precision, proper motion and distance to the system.

  18. USAGE OF RADARS FOR WIND ENERGY APPICATIONS Determine the benefit of using radar observations for wind energy applications by

    E-Print Network [OSTI]

    USAGE OF RADARS FOR WIND ENERGY APPICATIONS TASK: Determine the benefit of using radar observations for wind energy applications by analyzing i) the resolution effects and ii) sensitivity effects of weather radar systems. MOTIVATION: Wind energy applications strongly focus high-resolution wind observations

  19. Doppler shifts in the coma of Comet P/Halley

    SciTech Connect (OSTI)

    Herbig, G.H. (Hawaii Univ., Honolulu (USA))

    1990-04-01T23:59:59.000Z

    The relative radial velocities across 70-100 arcsecs of the coma of Comet P/Halley were measured on four days in 1985-1986 on coude CCD spectrograms in order to search for detectable Doppler shifts. The measurements show a trend of positive velocity with respect to projected distance from the nucleus. The shifts are most clearly observed at r = 1.1 AU, where the relative velocity at 10000 km amounted to 3-4 km/s. The Doppler shifts represent an integration through the whole coma. It is suggested that a proper model of the comet is needed to convert the shifts into true outflow velocities. 14 refs.

  20. Some non-precipitation radar echoes as observed by CPS-9 radar

    E-Print Network [OSTI]

    Luckenbach, Guenther Edward

    1959-01-01T23:59:59.000Z

    . Solar Signal Lightning Metallic Objects Anomalous Propagation 23 23 25 25 1. 23 July 1958 5 August 1958 7 August 1958 13 August 1958 5. 8 September 1958. 9 September 1958 Cold Front 32 32 41 41 47 10. Lightning Layers - Radiosonde... artificially produced boundaries of temperature~ humidity, and turbulence but failed to detect angels on 3. 2 and 1. 25 cm radar. No means independent of the radar for measuring the inhomogenities was employed. In 1948, Baldwin [ 2 ] suggested that angels...

  1. Enhanced Doppler Effect in the Upper Hybrid Resonance Microwave Backscattering Experiment

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Enhanced Doppler Effect in the Upper Hybrid Resonance Microwave Backscattering Experiment A, Politekhnicheskaya 26, 194021 St.Petersburg, Russia Observations of enhanced Doppler frequency shift effect based on this effect is proposed. 1. INTRODUCTION Investigation of tokamak plasma poloidal rotation

  2. Motion Measurement for Synthetic Aperture Radar.

    SciTech Connect (OSTI)

    Doerry, Armin W.

    2015-01-01T23:59:59.000Z

    Synthetic Aperture Radar (SAR) measures radar soundings from a set of locations typically along the flight path of a radar platform vehicle. Optimal focusing requires precise knowledge of the sounding source locations in 3 - D space with respect to the target scene. Even data driven focusing techniques (i.e. autofocus) requires some degree of initial fidelity in the measurements of the motion of the radar. These requirements may be quite stringent especially for fine resolution, long ranges, and low velocities. The principal instrument for measuring motion is typically an Inertial Measurement Unit (IMU), but these instruments have inherent limi ted precision and accuracy. The question is %22How good does an IMU need to be for a SAR across its performance space?%22 This report analytically relates IMU specifications to parametric requirements for SAR. - 4 - Acknowledgements Th e preparation of this report is the result of a n unfunded research and development activity . Although this report is an independent effort, it draws heavily from limited - release documentation generated under a CRADA with General Atomics - Aeronautical System, Inc. (GA - ASI), and under the Joint DoD/DOE Munitions Program Memorandum of Understanding. Sandia National Laboratories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of En ergy's National Nuclear Security Administration under contract DE - AC04 - 94AL85000.

  3. Micropower impulse radar technology and applications

    SciTech Connect (OSTI)

    Mast, J., LLNL

    1998-04-15T23:59:59.000Z

    The LLNL-developed Micropower Impulse Radar (MIR) technology has quickly gone from laboratory concept to embedded circuitry in numerous government and commercial systems in the last few years[l]. The main ideas behind MIR, invented by T. McEwan in the Laser Program, are the generation and detection systems for extremely low- power ultra-wideband pulses in the gigaHertz regime using low-cost components. These ideas, coupled with new antenna systems, timing and radio-frequency (RF) circuitry, computer interfaces, and signal processing, have provided the catalyst for a new generation of compact radar systems. Over the past several years we have concentrated on a number of applications of MIR which address a number of remote-sensing applications relevant to emerging programs in defense, transportation, medical, and environmental research. Some of the past commercial successes have been widely publicized [2] and are only now starting to become available for market. Over 30 patents have been filed and over 15 licenses have been signed on various aspects of the MIR technology. In addition, higher performance systems are under development for specific laboratory programs and government reimbursables. The MIR is an ultra- wideband, range-gated radar system that provides the enabling hardware technology used in the research areas mentioned above. It has numerous performance parameters that can be Selected by careful design to fit the requirements. We have improved the baseline, short- range, MIR system to demonstrate its effectiveness. The radar operates over the hand from approximately I to 4 GHz with pulse repetition frequencies up to 10 MHz. It provides a potential range resolution of I cm at ranges of greater than 20 m. We have developed a suite of algorithms for using MIR for image formation. These algorithms currently support Synthetic aperture and multistate array geometries. This baseline MIR radar imaging system has been used for several programmatic applications.

  4. A Coupled Model for Radiative Transfer: Doppler Effects, Equilibrium and Non-Equilibrium Diffusion Asymptotics

    E-Print Network [OSTI]

    Goudon, Thierry

    A Coupled Model for Radiative Transfer: Doppler Effects, Equilibrium and Non-Equilibrium Diffusion. The interaction terms take into account both scattering and absorption/emission phenomena, as well as Doppler-diffusion equations. Key words. Hydrodynamic limits. Diffusion approximation. Radiative transfer. Doppler correction

  5. MOTION EFFECT MODELING IN MULTIPATH CONFIGURATION USING WARPING BASED LAG-DOPPLER FILTERING

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    MOTION EFFECT MODELING IN MULTIPATH CONFIGURATION USING WARPING BASED LAG-DOPPLER FILTERING Nicolas be defined for all possible velocities and time delays of the configuration [3]. Recently, the Doppler effect. Traditionally, the time delay and Doppler effects are analyzed by the ambiguity function. If the signal

  6. Reversed Doppler Effect in Photonic Crystals Evan J. Reed,* Marin Soljacic, and John D. Joannopoulos

    E-Print Network [OSTI]

    Soljaèiæ, Marin

    Reversed Doppler Effect in Photonic Crystals Evan J. Reed,* Marin Soljacic´, and John D, 42.79.Hp, 42.79.Jq, 47.40.Nm In 1843, Johann Christian Doppler proposed an effect whereby of extrasolar planets. The Doppler effect predicts that light shined by an ob- server onto an object moving

  7. Doppler Effect Associated with the Reflection of Light on a Moving Mirror

    E-Print Network [OSTI]

    Bernhard Rothenstein; Ioan Damian

    2005-08-18T23:59:59.000Z

    The Doppler Effect associated with the reflection on a moving mirror is reduced to two Doppler Effect experiments involving the incoming incident ray and the outgoing reflected ray or vice-versa. The dependence of the corresponding Doppler factors on the incidence angle on the stationary mirror.

  8. Doppler cooling to the Quantum limit M. Chalony,1

    E-Print Network [OSTI]

    is canceled. PACS numbers: 37.10.De, 37.10.Gh Laser cooling of atoms is a technique widely used, mainly of laser cooling and trapping techniques, in parallel with precise measure- ments of the momentumDoppler cooling to the Quantum limit M. Chalony,1 A. Kastberg,2 B. Klappauf,3 and D. Wilkowski1, 4

  9. Laser Locking with Doppler-free Saturated Absorption Spectroscopy

    E-Print Network [OSTI]

    Novikova, Irina

    - 1 - Laser Locking with Doppler-free Saturated Absorption Spectroscopy Paul L. Stubbs, Advisor the frequency of a 795 nm diode laser using a saturated absorption spectroscopy method. Laser locking in AMO physics is done to stabilize the frequency of lasers used in the laboratory in order to make results more

  10. Extracting Fish and Water Velocity from Doppler Profiler Data

    E-Print Network [OSTI]

    deYoung, Brad

    Extracting Fish and Water Velocity from Doppler Profiler Data ĺ Ð 1 ¸ Ö Ò ×¹ Ò ÝÖ¹Ê Ò 2 1 processing algo- rithms normally used to extract water velocity. We present an alternative method for velocity homogeneity precludes the extraction of fish velocities. Water velocities can sometimes still

  11. Doppler Ultrasound Driven Biomechanical Model of the Brain for

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Doppler Ultrasound Driven Biomechanical Model of the Brain for Intraoperative Brain of the target is essential to reduce mor- bidity during brain tumor removal interventions. Yet, image-guided neu- rosurgery faces an important issue for large skull openings where brain soft-tissues can exhibit large

  12. Research on Fast-Doppler-Broadening of neutron cross sections

    SciTech Connect (OSTI)

    Li, S.; Wang, K.; Yu, G. [Dept. of Engineering Physics, Tsinghua Univ., Beijing, 100084 (China)

    2012-07-01T23:59:59.000Z

    A Fast-Doppler-Broadening method is developed in this work to broaden Continuous Energy neutron cross-sections for Monte Carlo calculations. Gauss integration algorithm and parallel computing are implemented in this method, which is unprecedented in the history of cross section processing. Compared to the traditional code (NJOY, SIGMA1, etc.), the new Fast-Doppler-Broadening method shows a remarkable speedup with keeping accuracy. The purpose of using Gauss integration is to avoid complex derivation of traditional broadening formula and heavy load of computing complementary error function that slows down the Doppler broadening process. The OpenMP environment is utilized in parallel computing which can take full advantage of modern multi-processor computers. Combination of the two can reduce processing time of main actinides (such as {sup 238}U, {sup 235}U) to an order of magnitude of 1{approx}2 seconds. This new method is fast enough to be applied to Online Doppler broadening. It can be combined or coupled with Monte Carlo transport code to solve temperature dependent problems and neutronics-thermal hydraulics coupled scheme which is a big challenge for the conventional NJOY-MCNP system. Examples are shown to determine the efficiency and relative errors compared with the NJOY results. A Godiva Benchmark is also used in order to test the ACE libraries produced by the new method. (authors)

  13. Dual beam translator for use in Laser Doppler anemometry

    DOE Patents [OSTI]

    Brudnoy, D.M.

    1984-04-12T23:59:59.000Z

    A method and apparatus for selectively translating the path of at least one pair of light beams in a Laser Doppler anemometry device whereby the light paths are translated in a direction parallel to the original beam paths so as to enable attainment of spacial coincidence of the two intersection volumes and permit accurate measurements of Reynolds shear stress.

  14. Generalized Doppler effect in spaces with a transport along paths

    E-Print Network [OSTI]

    Bozhidar Z. Iliev

    2004-01-19T23:59:59.000Z

    An analog of the classical Doppler effect is investigated in spaces (manifolds) whose tangent bundle is endowed with a transport along paths, which, in particular, can be parallel one. The obtained results are valid irrespectively to the particles mass, i.e. they hold for massless particles (e.g. photons) as well as for massive ones.

  15. Complex Doppler effect in left-handed metamaterials

    E-Print Network [OSTI]

    Ziemkiewicz, David

    2014-01-01T23:59:59.000Z

    The Doppler shift is investigated in one-dimensional system with moving source. Theoretical findings are confirmed in numerical simulations of optical and acoustical waves propagation in simple metamaterial model, showing the reversed shift and the existence of multiple frequency modes. The properties of these waves are discussed. The effect of absorption on the phenomenon is outlined.

  16. Doppler optical mixing spectroscopy in multiparticle scattering fluids

    SciTech Connect (OSTI)

    Dubnishchev, Yu N [S S Kutateladze Institute of Thermophysics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation)

    2011-03-31T23:59:59.000Z

    We discuss the basic scheme of laser Doppler optical mixing spectroscopy for the analysis of media with multiparticle scattering. It is shown that the Rayleigh scheme, in contrast to the heterodyne and differential schemes, is insensitive to the effects of multiparticle scattering. (laser applications and other aspects of quantum electronics)

  17. Non-Gaussianity and CMB aberration and Doppler

    SciTech Connect (OSTI)

    Catena, Riccardo [Institut für Theoretische Physik, Friedrich-Hund-Platz 1, 37077 Göttingen (Germany); Liguori, Michele; Renzi, Alessandro [INFN, Sezione di Padova, Via Marzolo 8, 35131 Padova (Italy); Notari, Alessio, E-mail: riccardo.catena@theorie.physik.uni-goettingen.de, E-mail: michele.liguori@pd.infn.it, E-mail: notari@ffn.ub.es, E-mail: arenzi@pd.infn.it [Departament de Física Fondamental i Institut de Ciéncies del Cosmos, Universitat de Barcelona, Martí i Franqués 1, 08028 Barcelona (Spain)

    2013-09-01T23:59:59.000Z

    The peculiar motion of an observer with respect to the CMB rest frame induces a deflection in the arrival direction of the observed photons (also known as CMB aberration) and a Doppler shift in the measured photon frequencies. As a consequence, aberration and Doppler effects induce non trivial correlations between the harmonic coefficients of the observed CMB temperature maps. In this paper we investigate whether these correlations generate a bias on non-Gaussianity estimators f{sub NL}. We perform this analysis simulating a large number of temperature maps with Planck-like resolution (lmax = 2000) as different realizations of the same cosmological fiducial model (WMAP7yr). We then add to these maps aberration and Doppler effects employing a modified version of the HEALPix code. We finally evaluate a generalization of the Komatsu, Spergel and Wandelt non-Gaussianity estimator for all the simulated maps, both when peculiar velocity effects have been considered and when these phenomena have been neglected. Using the value v/c = 1.23 × 10{sup ?3} for our peculiar velocity, we found that the aberration/Doppler induced non-Gaussian signal is at most of about half of the cosmic variance ? for f{sub NL} both in a full-sky and in a cut-sky experimental configuration, for local, equilateral and orthogonal estimators. We conclude therefore that when estimating f{sub NL} it is safe to ignore aberration and Doppler effects if the primordial map is already Gaussian. More work is necessary however to assess whether a map which contains non-Gaussianity can be significantly distorted by a peculiar velocity.

  18. Reviewing Pulsar Spectra

    E-Print Network [OSTI]

    W. Sieber

    2002-08-30T23:59:59.000Z

    Problems solved? Pulsar research must be considered - 35 years after the detection of pulsars - a mature science, where the basic questions have been raised and discussed. One would hope that many if not all generic and important problems have found some kind of answer and that scientific work can concentrate now on specific details requiring more in depth investigation. We know, however, that this picture is not true. Even well studied areas did in the past not always lead to a general accepted model and some were investigated at the beginning with enthusiasm but left behind. This paper will concentrate on one narrow topic, pulsar radio spectra. It is the attempt to work out, what features are now generally accepted, but also what features are still in discussion after so many years of pulsar research. In this sense the paper will enlighten in a personal view those aspects which are still under discussion.

  19. Development of a Drillrod/Telemetry Radar

    SciTech Connect (OSTI)

    Raton Technology Research, Inc.

    1999-11-12T23:59:59.000Z

    Efficient extraction of deeply buried natural resources is dependent upon accurate geologic models. The model becomes the basis for developing plans for extraction of the resource. Geoscientists working in geothermal and hydrocarbon recovery have a great deal in common with fellow geoscientists working in the mining industry. They appreciate the intractable problem of increasing the depth of investigation to tens of meters from the wellbore. The goal of this project was to develop a borehole radar tool to acquire data within tens of meters from the wellbore. For geothermal and hydrocarbon applications, the tool was to acquire data for mapping fractures surrounding the wellbore. In mining of coal, the radar acquires data for determining coal seam thickness and detecting geologic anomalies ahead of mining.

  20. Digitized dual wavelength radar data from a Texas thunderstorm

    E-Print Network [OSTI]

    Radlein, Robin Ann

    1977-01-01T23:59:59.000Z

    DIGITIZED DUAL WAVL'LENGTH RADAR DATA FROM A TEXAS THUNDERSTORM A Thesis ROBIN ANN RADLEIN Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree ol MASTER OF SCIENCE December 1977... Wavelength Radar Data from a Texas Thunderstorm. (December 1977) Robin Ann Radlein~ B. S , Texas ASN University Chairman of Advisory Committee: Dr Vance Noyer Nulti-tilt digitized dual wavelength radar data collected during a Texas thunderstorm were...

  1. Long-term Observations of the Convective Boundary Layer Using Insect Radar Returns at the SGP ARM Climate Research Facility

    SciTech Connect (OSTI)

    Chandra, A S; Kollias, P; Giangrande, S E; Klein, S A

    2009-08-20T23:59:59.000Z

    A long-term study of the turbulent structure of the convective boundary layer (CBL) at the U.S. Department of Energy Atmospheric Radiation Measurement Program (ARM) Southern Great Plains (SGP) Climate Research Facility is presented. Doppler velocity measurements from insects occupying the lowest 2 km of the boundary layer during summer months are used to map the vertical velocity component in the CBL. The observations cover four summer periods (2004-08) and are classified into cloudy and clear boundary layer conditions. Profiles of vertical velocity variance, skewness, and mass flux are estimated to study the daytime evolution of the convective boundary layer during these conditions. A conditional sampling method is applied to the original Doppler velocity dataset to extract coherent vertical velocity structures and to examine plume dimension and contribution to the turbulent transport. Overall, the derived turbulent statistics are consistent with previous aircraft and lidar observations. The observations provide unique insight into the daytime evolution of the convective boundary layer and the role of increased cloudiness in the turbulent budget of the subcloud layer. Coherent structures (plumes-thermals) are found to be responsible for more than 80% of the total turbulent transport resolved by the cloud radar system. The extended dataset is suitable for evaluating boundary layer parameterizations and testing large-eddy simulations (LESs) for a variety of surface and cloud conditions.

  2. Raindrop size distributions and radar reflectivity-rain rate relationships for radar hydrology Hydrology and Earth System Sciences, 5(4), 615627 (2001) EGS

    E-Print Network [OSTI]

    Boyer, Edmond

    Raindrop size distributions and radar reflectivity-rain rate relationships for radar hydrology 615 Hydrology and Earth System Sciences, 5(4), 615­627 (2001) © EGS Raindrop size distributions and radar reflectivity­rain rate relationships for radar hydrology* Remko Uijlenhoet1 Sub-department Water Resources

  3. Applications of Radar Interferometry to Detect Surface Deformation...

    Open Energy Info (EERE)

    Valley in Southern California Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Applications of Radar Interferometry to Detect Surface...

  4. NNSA Completes its Critical Radar Arming and Fuzing Test for...

    National Nuclear Security Administration (NNSA)

    its Critical Radar Arming and Fuzing Test for the W88 ALT 370 | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile...

  5. Multipoint photonic doppler velocimetry using optical lens elements

    DOE Patents [OSTI]

    Frogget, Brent Copely; Romero, Vincent Todd

    2014-04-29T23:59:59.000Z

    A probe including a fisheye lens is disclosed to measure the velocity distribution of a moving surface along many lines of sight. Laser light, directed to the surface and then reflected back from the surface, is Doppler shifted by the moving surface, collected into fisheye lens, and then directed to detection equipment through optic fibers. The received light is mixed with reference laser light and using photonic Doppler velocimetry, a continuous time record of the surface movement is obtained. An array of single-mode optical fibers provides an optic signal to an index-matching lens and eventually to a fisheye lens. The fiber array flat polished and coupled to the index-matching lens using index-matching gel. Numerous fibers in a fiber array project numerous rays through the fisheye lens which in turn project many measurement points at numerous different locations to establish surface coverage over a hemispherical shape with very little crosstalk.

  6. Prospects for Doppler cooling of three-electronic-level molecules

    SciTech Connect (OSTI)

    Nguyen, J. H. V.; Odom, B. [Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, Illinois 60208 (United States)

    2011-05-15T23:59:59.000Z

    Analogous to the extension of laser cooling techniques from two-level to three-level atoms, Doppler cooling of molecules with an intermediate electronic state is considered. In particular, we use a rate-equation approach to simulate cooling of SiO{sup +}, in which population buildup in the intermediate state is prevented by its short lifetime. We determine that Doppler cooling of SiO{sup +} can be accomplished without optically repumping from the intermediate state, at the cost of causing undesirable parity flips and rotational diffusion. Since the necessary repumping would require a large number of continuous-wave lasers, optical pulse shaping of a femtosecond laser is proposed as an attractive alternative. Other candidate three-electron-level molecules are also discussed.

  7. Design and Development of Dual Polarized, Stacked Patch Antenna Element for S-Band Dual-Pol Weather Radar Array

    E-Print Network [OSTI]

    Bhardwaj, Shubhendu

    2012-01-01T23:59:59.000Z

    in Weather Detection . . . . . . . . . . . . . . . . . .for S-Band Weather Radar . . . . . . . . . . . . . Dual-polpatterns of polarimetric weather radars,” Journal of

  8. Doppler effect and frequency-shift in optics

    E-Print Network [OSTI]

    S C Tiwari

    2006-05-29T23:59:59.000Z

    A critical review of frequency-shift phenomena a la Doppler effect is presented. The importance of Fermi's theory of 1932 is pointed out, and it is argued that there exists a gap in our understanding of this phenomena at a fundamental level. Alternative mechanism in terms of photon number oscillations is suggested for polarization changing experiments. The physical reality of single photon is revisited, and a possible experimental scheme to test the alternative mechanism is suggested.

  9. Experimental investigation of velocity biasing in laser Doppler anemometry

    E-Print Network [OSTI]

    Wiedner, Brian Gregory

    1988-01-01T23:59:59.000Z

    Tech University; Chair of Advisory Commettee: Dr. Gerald L. Morrison The effects of several velocity bias reduction schemes were invest- igated using a 3-D laser Doppler anemometer and counter type (burst) signal processors. Amongst these schemes... of Sample Size on Effects of Sample Size on Effects of Sample Size on Effects of Sample Size on Velocity and Reynolds Stresses Axial Mean Velocity Radial Mean Velocity Axial Turbulence Intensity Radial Turbulence Intensity Axial/Radial Correlation...

  10. A Fisheye Lens as a Photonic Doppler Velocimetry Probe

    SciTech Connect (OSTI)

    Frogget, B. C.

    2012-08-16T23:59:59.000Z

    These presentation visuals report an instrument that, by use of a fish-eye lens, generates a beat signal using fiber mixing of unshifted light with Doppler-shifted light and measures the beat frequency. Ray trace diagrams are shown to illustrate advantages and disadvantages. The authors find their instrument has a long tracking distance, and large angle coverage. Index matching eases assembly, reduces return loss and flattens the field.

  11. Wide-open, high-resolution microwave/millimeter-wave Doppler frequency shift estimation using photonics technology

    E-Print Network [OSTI]

    Zou, Xihua; Lu, Bing; Pan, Wei; Yan, Lianshan; Shao, Liyang

    2014-01-01T23:59:59.000Z

    Today, wide-open, high-resolution Doppler frequency shift (DFS) estimation is essential for radar, microwave/millimeter-wave, and communication systems. Using photonics technology, an effective approach is proposed and experimentally demonstrated, providing a high-resolution and frequency-independent solution. In the approach consisting of two cascaded opto-electronic modulators, DFS between the transmitted microwave/ millimeter-wave signal and the received echo signal is mapped into a doubled spacing between two target optical sidebands. Subsequently, the DFS is then estimated through the spectrum analysis of a generated low-frequency electrical signal, with an improved resolution by a factor of 2. In experiments, DFSs from -90 to 90 KHz are successfully estimated for microwave/millimeter-wave signals at 10, 15, and 30 GHz, where estimation errors keep lower than +/- 5e-10 Hz. For radial velocity measurement, these results reveal a range from 0 to 900 m/s (0 to 450 m/s) and a resolution of 1e-11 m/s (5e-12 m...

  12. Doppler-Zeeman mapping of magnetic CP stars: The case of the CP star HD 215441

    E-Print Network [OSTI]

    V. L. Khokhlova; D. V. Vasilchenko; V. V. Stepanov; V. V. Tsymbal

    1998-05-07T23:59:59.000Z

    When using a recently developed method of Doppler-Zeeman mapping (Vasilchenko et al., 1996) for analysis of a real star and real observational data, we are confronted with limitations due to the model simplifications and unavoidable errors in observed spectra. We discuss the errors introduced by probable inaccurracies of the mathematical model: analytical fit of the local Stokes parameters, influence of magneto-optical effect, ignorance of the true atmosphere model to compute local Stokes profiles, non-uniform surface brightness. The magnetic field configuration is found in the form of arbitrarily shifted dipole and sum of dipole and quadrupole, along with the distribution of Si, Ti, Cr and Fe over the surface of the star. Lines of different elements lead to the same magnetic field configuration, which is reliably determined for the part of the stellar surface which faces the observer. This allows to compare the magnetic field and chemical maps of the surface of HD 215441. A large-scale ring structure with the magnetic pole at its center is clearly seen on the abundance maps. Si, Cr and Ti are highly deficient where the magnetic field lines are vertical (near the magnetic pole) while Fe is highly overabundant there.

  13. Greenland snow accumulation estimates from satellite radar scatterometer data

    E-Print Network [OSTI]

    Long, David G.

    Greenland snow accumulation estimates from satellite radar scatterometer data Mark R. Drinkwater accumulation on the Greenland ice sheet. Microwave radar backscatter images of Greenland are derived using (or decrease) in net snow accumulation on the polar ice caps. The net mass balance of the Greenland

  14. Weather Radar Control System Seidu Ibrahim; Advisor: Eric J. Knapp

    E-Print Network [OSTI]

    Mountziaris, T. J.

    Weather Radar Control System Seidu Ibrahim; Advisor: Eric J. Knapp Dept. of Electrical and Computer Engineering University of Massachusetts, Amherst Abstract Weather radar is an important part of the national infrastructure that is used in producing forecasts and issuing hazardous weather warnings. Traditional weather

  15. Cassini Radio Detection and Ranging (RADAR): Earth and Venus observations

    E-Print Network [OSTI]

    Lorenz, Ralph D.

    of operation is as a synthetic aperture radar (SAR) mapper at Titan, with the fan-shaped beam dragged across of incidence angles. During all of the active modes, SAR, altimeter, and scat- terometer, the microwave power but rather was operated to obtain calibration data and rehearse instrument operations. 2. Venus The RADAR

  16. Ultrawideband radar clutter measurements of forested terrain, 1991--1992

    SciTech Connect (OSTI)

    Sheen, D.M.; Severtsen, R.H.; Prince, J.M.; Davis, K.C.; Collins, H.D.

    1993-06-01T23:59:59.000Z

    The ultrawideband (UWB) radar clutter measurements project was conducted to provide radar clutter data for new ultrawideband radar systems which are currently under development. A particular goal of this project is to determine if conventional narrow band clutter data may be extrapolated to the UWB case. This report documents measurements conducted in 1991 and additional measurements conducted in 1992. The original project consisted of clutter measurements of forested terrain in the Olympic National Forest near Sequim, WA. The impulse radar system used a 30 kW peak impulse source with a 2 Gigasample/second digitizer to form a UHF (300--1000 MHz) ultrawideband impulse radar system. Additional measurements were conducted in parallel using a Systems Planning Corporation (SPC) step-chirp radar system. This system utilized pulse widths of 1330 nanoseconds over a bandwidth of 300--1000 MHz to obtain similar resolution to the impulse system. Due to the slow digitizer data throughput in the impulse radar system, data collection rates were significantly higher using the step-chirp system. Additional forest clutter measurements were undertaken in 1992 to increase the amount of data available, and especially to increase the amount of data from the impulse radar system.

  17. The spectra of accretion discs in low-mass X-ray binaries

    E-Print Network [OSTI]

    R. R. Ross; A. C. Fabian

    1995-11-14T23:59:59.000Z

    We present self-consistent models for the radiative transfer in Shakura-Sunyaev accretion discs in bright low-mass X-ray binaries (LMXB). Our calculations include the full effects of incoherent Compton scattering and the vertical temperature structure within the disc, as well as the effects of Doppler blurring and gravitational redshift. We find that the observed X-ray spectra are well fit by exponentially cutoff power-law models. The difference between the observed total spectrum and our calculated disc spectrum should reveal the spectrum of the disc/neutron star boundary layer and other emitting regions considered to be present in LMXB.

  18. Implementation of on-the-fly doppler broadening in MCNP

    SciTech Connect (OSTI)

    Martin, W. R.; Wilderman, S. [Department of Nuclear Engineering and Radiological Sciences, University of Michigan (United States); Brown, F. B. [Los Alamos National Laboratory (United States); Yesilyurt, G. [Argonne National Laboratory (United States)

    2013-07-01T23:59:59.000Z

    A new method to obtain Doppler broadened cross sections has been implemented into MCNP, removing the need to generate cross sections for isotopes at problem temperatures. When a neutron of energy E enters a material region that is at some temperature T, the cross sections for that material at temperature T are immediately obtained 'on-the-fly' (OTF) by interpolation using a high order functional expansion for the temperature dependence of the Doppler-broadened cross section for that isotope at the neutron energy E. The OTF cross sections agree with the NJOY-based cross sections for all neutron energies and all temperatures in the range specified by the user, e.g., 250 K - 3200 K. The OTF methodology has been successfully implemented into the MCNP Monte Carlo code and has been tested on several test problems by comparing MCNP with conventional ACE cross sections versus MCNP with OTF cross sections. The test problems include the Doppler defect reactivity benchmark suite and two full-core VHTR configurations, including one with multiphysics coupling using RELAP5-3D/ATHENA for the thermal-hydraulic analysis. The comparison has been excellent, verifying that the OTF libraries can be used in place of the conventional ACE libraries generated at problem temperatures. In addition, it has been found that the OTF methodology greatly reduces the complexity of the input for MCNP, resulting in an order of magnitude decrease in the number of input lines for full-core configurations. Finally, for full-core problems with multiphysics feedback, the memory required to store the cross section data is considerably reduced with OTF cross sections and the additional computational effort with OTF is modest, on the order of 10-15%. (authors)

  19. Radar transponder apparatus and signal processing technique

    DOE Patents [OSTI]

    Axline, Jr., Robert M. (Albuquerque, NM); Sloan, George R. (Albuquerque, NM); Spalding, Richard E. (Albuquerque, NM)

    1996-01-01T23:59:59.000Z

    An active, phase-coded, time-grating transponder and a synthetic-aperture radar (SAR) and signal processor means, in combination, allow the recognition and location of the transponder (tag) in the SAR image and allow communication of information messages from the transponder to the SAR. The SAR is an illuminating radar having special processing modifications in an image-formation processor to receive an echo from a remote transponder, after the transponder receives and retransmits the SAR illuminations, and to enhance the transponder's echo relative to surrounding ground clutter by recognizing special transponder modulations from phase-shifted from the transponder retransmissions. The remote radio-frequency tag also transmits information to the SAR through a single antenna that also serves to receive the SAR illuminations. Unique tag-modulation and SAR signal processing techniques, in combination, allow the detection and precise geographical location of the tag through the reduction of interfering signals from ground clutter, and allow communication of environmental and status information from said tag to be communicated to said SAR.

  20. Impulse radar with swept range gate

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1998-09-08T23:59:59.000Z

    A radar range finder and hidden object locator is based on ultra-wide band radar with a high resolution swept range gate. The device generates an equivalent time amplitude scan with a typical range of 4 inches to 20 feet, and an analog range resolution as limited by a jitter of on the order of 0.01 inches. A differential sampling receiver is employed to effectively eliminate ringing and other aberrations induced in the receiver by the near proximity of the transmit antenna (10), so a background subtraction is not needed, simplifying the circuitry while improving performance. Techniques are used to reduce clutter in the receive signal, such as decoupling the receive (24) and transmit cavities (22) by placing a space between them, using conductive or radiative damping elements on the cavities, and using terminating plates on the sides of the openings. The antennas can be arranged in a side-by-side parallel spaced apart configuration or in a coplanar opposed configuration which significantly reduces main bang coupling.

  1. Impulse radar with swept range gate

    DOE Patents [OSTI]

    McEwan, T.E.

    1998-09-08T23:59:59.000Z

    A radar range finder and hidden object locator is based on ultra-wide band radar with a high resolution swept range gate. The device generates an equivalent time amplitude scan with a typical range of 4 inches to 20 feet, and an analog range resolution as limited by a jitter of on the order of 0.01 inches. A differential sampling receiver is employed to effectively eliminate ringing and other aberrations induced in the receiver by the near proximity of the transmit antenna, so a background subtraction is not needed, simplifying the circuitry while improving performance. Techniques are used to reduce clutter in the receive signal, such as decoupling the receive and transmit cavities by placing a space between them, using conductive or radiative damping elements on the cavities, and using terminating plates on the sides of the openings. The antennas can be arranged in a side-by-side parallel spaced apart configuration or in a coplanar opposed configuration which significantly reduces main bang coupling. 25 figs.

  2. Assembly flow simulation of a radar

    SciTech Connect (OSTI)

    Rutherford, W.C.; Biggs, P.M.

    1993-10-01T23:59:59.000Z

    A discrete event simulation model has been developed to predict the assembly flow time of a new radar product. The simulation was the key tool employed to identify flow constraints. The radar, production facility, and equipment complement were designed, arranged, and selected to provide the most manufacturable assembly possible. A goal was to reduce the assembly and testing cycle time from twenty-six weeks to six weeks. A computer software simulation package (SLAM II) was utilized as the foundation a for simulating the assembly flow time. FORTRAN subroutines were incorporated into the software to deal with unique flow circumstances that were not accommodated by the software. Detailed information relating to the assembly operations was provided by a team selected from the engineering, manufacturing management, inspection, and production assembly staff. The simulation verified that it would be possible to achieve the cycle time goal of six weeks. Equipment and manpower constraints were identified during the simulation process and adjusted as required to achieve the flow with a given monthly production requirement. The simulation is being maintained as a planning tool to be used to identify constraints in the event that monthly output is increased. ``What-if`` studies have been conducted to identify the cost of reducing constraints caused by increases in output requirement.

  3. A novel photonic Doppler velocimetry for transverse velocity measurement

    SciTech Connect (OSTI)

    Chen Guanghua; Wang Detian; Liu Jun; Meng Jianhua; Liu Shouxian; Yang Qingguo [Institute of Fluid Physics, CAEP, P.O. Box 919-109, Mianyang, Sichuan 621900 (China)

    2013-01-15T23:59:59.000Z

    A fiber interferometry for transverse velocity measurement has been developed. This diagnostic is similar to photonic Doppler velocimetry in the way in which laser propagates and couples. The interferometer mainly consists of a fiber coupler, an emitting probe, and two receiving probes. A pair of scattered laser beams mix in the coupler and generates fringes with frequency proportional to transverse velocity. Measurement of transverse velocity is independent of longitudinal velocity. The feasibility of the technique has been verified by rotating wheel experiment and shock loading experiment.

  4. Holographic laser Doppler imaging of pulsatile blood flow

    E-Print Network [OSTI]

    Bencteux, Jeffrey; Kostas, Thomas; Bayat, Sam; Atlan, Michael

    2015-01-01T23:59:59.000Z

    We report on wide-field imaging of pulsatile motion induced by blood flow using heterodyne holographic interferometry on the thumb of a healthy volunteer, in real-time. Optical Doppler images were measured with green laser light by a frequency-shifted Mach-Zehnder interferometer in off-axis configuration. The recorded optical signal was linked to local instantaneous out-of-plane motion of the skin at velocities of a few hundreds of microns per second, and compared to blood pulse monitored by plethysmoraphy during an occlusion-reperfusion experiment.

  5. Improved Prediction of the Doppler Effect in TRISO Fuel

    SciTech Connect (OSTI)

    J. Ortensi; A.M. Ougouag

    2009-05-01T23:59:59.000Z

    The Doppler feedback mechanism is a major contributor to the passive safety of gas-cooled, graphite-moderated High Temperature Reactors that use fuel based on TRISO particles. It follows that the correct prediction of the magnitude and time-dependence of this feedback effect is essential to the conduct of safety analyses for these reactors. Since the effect is directly dependent on the actual temperature reached by the fuel during transients, the underlying phenomena of heat transfer and temperature rise must be correctly predicted. This paper presents an improved model for the TRISO particle and its thermal behavior during transients. The improved approach incorporates an explicit TRISO heat conduction model to better quantify the time dependence of the temperature in the various layers of the TRISO particle, including its fuel central zone. There follows a better treatment of the Doppler Effect within said fuel zone. The new model is based on a 1-D analytic solution for composite media using the Green’s function technique. The modeling improvement takes advantage of some of the physical behavior of TRISO fuel under irradiation and includes a distinctive look at the physics of the neutronic Doppler Effect. The new methodology has been implemented within the coupled R-Z nodal diffusion code CYNOD-THERMIX. The new model has been applied to the analysis of earthquakes (presented in a companion paper). In this paper, the model is applied to the control rod ejection event, as specified in the OECD PBMR-400 benchmark, but with temperature dependent thermal properties. The results obtained for this transient using the enhanced code are a considerable improvement over the predictions of the original code. The incorporation of the enhanced model shows that the Doppler Effect plays a more significant role than predicted by the original unenhanced model based on the THERMIX homogenized fuel region model. The new model shows that the overall energy generation during the rod ejection transient is significantly lower than predicted by the unenhanced model. The fuel temperature reaches a slightly higher maximum, but at no time does it approach the nominal allowable TRISO fuel temperature. The analyses with the enhanced model also show that the reactor period during the cool down is larger than previously predicted with the homogenous fuel region model.

  6. Numerical computation of doppler-broadening in the resonance domain

    SciTech Connect (OSTI)

    Sanchez, R. [Commissariat a l'Energie Atomique et aux Energies Alternatives, Service d'Etudes de Reacteurs et de Mathematiques Appliquees, CEA DEN DM2S/SERMA, 91191 Gif-sur-Yvette cedex (France); Hewko, C. [Commissariat a l'Energie Atomique et aux Energies Alternatives, Service d'Etudes de Reacteurs et de Mathematiques Appliquees, CEA DEN DM2S/SERMA, 91191 Gif-sur-Yvette cedex (France); AREVA NP/PEPDD-F, Tour Areva, Place J. Millier, 92084 La Defense (France); Santandrea, S. [Commissariat a l'Energie Atomique et aux Energies Alternatives, Service d'Etudes de Reacteurs et de Mathematiques Appliquees, CEA DEN DM2S/SERMA, 91191 Gif-sur-Yvette cedex (France)

    2013-07-01T23:59:59.000Z

    We have implemented an accurate and fast calculation of the Doppler-broadened kernel PT(E {yields} E') for neutron elastic scattering based on a gas model. An exponential cutoff which accounts for the asymptotic behavior of the error function helps limit the range of integration while eliminating difference effects. This allows for calculating a kernel library for {sup 238}U over a very fine energy grid covering the resonance range in only a few hours in a laptop. We give an example showing the impact of {sup 238}U elastic up-scattering on the values of self shielded cross sections. (authors)

  7. Effect of window reflections on photonic Doppler velocimetry measurements

    SciTech Connect (OSTI)

    Ao, T.; Dolan, D. H. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States)

    2011-02-15T23:59:59.000Z

    Photonic Doppler velocimetry (PDV) has rapidly become a standard diagnostic for measuring velocities in dynamic compression research. While free surface velocity measurements are fairly straightforward, complications occur when PDV is used to measure a dynamically loaded sample through a window. Fresnel reflections can severely affect the velocity and time resolution of PDV measurements, especially for low-velocity transients. Shock experiments of quartz compressed between two sapphire plates demonstrate how optical window reflections cause ringing in the extracted PDV velocity profile. Velocity ringing is significantly reduced by using either a wedge window or an antireflective coating.

  8. SIRHEN : a data reduction program for photonic Doppler velocimetry measurements.

    SciTech Connect (OSTI)

    Dolan, Daniel H., III; Ao, Tommy

    2010-06-01T23:59:59.000Z

    SIRHEN (Sandia InfraRed HEtrodyne aNalysis) is a program for reducing data from photonic Doppler velocimetry (PDV) measurements. SIRHEN uses the short-time Fourier transform method to extract velocity information. The program can be run in MATLAB (2008b or later) or as a Windows executable. This report describes the new Sandia InfraRed HEtrodyne aNalysis program (SIRHEN; pronounced 'siren') that has been developed for efficient and robust analysis of PDV data. The program was designed for easy use within Sandia's dynamic compression community.

  9. Orderly Spectra from Random Interactions

    SciTech Connect (OSTI)

    Johnson, C.W. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803-4001 (United States)] [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803-4001 (United States); Bertsch, G.F. [Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States)] [Department of Physics, FM-15, University of Washington, Seattle, Washington 98195 (United States); Dean, D.J.; Dean, D.J. [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 (United States) [Department of Physics and Astronomy, University of Tennessee, Knoxville, Tennessee 37996 (United States); Department of Physics and Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803-4001 (United States)

    1998-03-01T23:59:59.000Z

    We investigate the low-lying spectra of many-body systems with random two-body interactions, specifying that the ensemble be invariant under particle-hole conjugation. Surprisingly we find patterns reminiscent of more orderly interactions, such as a predominance of J=0 ground states separated by a gap from the excited states, and evidence of phonon vibrations in the low-lying spectra. {copyright} {ital 1998} {ital The American Physical Society}

  10. Calibration of the groundbased radars during CLARE'98 Robin J. Hogan

    E-Print Network [OSTI]

    Hogan, Robin

    Calibration of the ground­based radars during CLARE'98 Robin J. Hogan Department of Meteorology. The approach used to calibrate the radars is to start with the absolute calibration provided by the Rabelais radar in Rayleigh­scattering light rain or cloud. Finally the W­band radars are calibrated

  11. A 10-year radar-based climatology of rainfall Aart Overeem, Iwan Holleman, Adri Buishand

    E-Print Network [OSTI]

    Stoffelen, Ad

    the derivation of a 10- year radar-based precipitation climatology for the Netherlands. Using rain gauges of the radar-based accumulations with an independent gauge network confirms the quality of the data set. Finally, the radar data are used to obtain exceedance probabilities and maximum rainfall depths. II. RADAR

  12. ELEVATION-DEPENDENT TRENDS IN PRECIPITATION OBSERVED BY THE NAME RADAR NETWORK

    E-Print Network [OSTI]

    Rutledge, Steven

    i THESIS ELEVATION-DEPENDENT TRENDS IN PRECIPITATION OBSERVED BY THE NAME RADAR NETWORK Submitted BY ANGELA K. ROWE ENTITLED ELEVATION- DEPENDENT TRENDS IN PRECIPITATION OBSERVED BY THE NAME RADAR NETWORK BY THE NAME RADAR NETWORK Radar data from the 2004 North American Monsoon Experiment (NAME) Enhanced Observing

  13. Considerations for the use of radar-derived precipitation estimates in determining return intervals for extreme

    E-Print Network [OSTI]

    Allen, Robert J.

    to those based on traditional rain gauge networks. For both the radar and gauge data, increasing, considerable differences between radar ARF and gauge ARF exist. Radar ARF decays at a faster rate (with increasing area) than gauge ARF. For a basin size of 20,000 km2 , the percent difference between radar ARF

  14. On the Doppler effect for photons in rotating systems

    E-Print Network [OSTI]

    Giuliani, Giuseppe

    2015-01-01T23:59:59.000Z

    The analysis of the Doppler effect for photons in rotating systems, studied using the M\\"ossbauer effect, confirms the general conclusions of a previous paper dedicated to experiments with photons emitted/absorbed by atoms/nuclei in inertial flight. The wave theory of light is so deeply rooted that it has been--and currently is--applied to describe phenomena in which the fundamental entities at work are discrete (photons). The fact that the wave theory of light can describe one aspect of these phenomena can not overshadow two issues: the corpuscular theory of light, firstly applied to the Doppler effect for photons by Schr\\"odinger in 1922, is by far more complete since it describes all the features of the studied phenomena; the wave theory can be used only when the number of photons at work is statistically significant. The disregard of basic methodological criteria may appear as a minor fault. However, the historical development of quantum physics shows that the predominance of the wave theory of radiation,...

  15. Design, Assembly, and Testing of a Photon Doppler Velocimetry Probe

    SciTech Connect (OSTI)

    Malone, Robert M; Cox, Brian C; Daykin, Edward P; DeVore, Douglas O; Esquibel, David L; Frayer, Daniel K; Frogget, Brent C; Gallegos, Cenobio H; Kaufman, Morris I; McGillivray, Kevin D; Romero, Vincent T; Briggs, Matthew E; Furlanetto, Michael R; Holtkamp, David B; Pazuchanics, Peter; Primas, Lori E; Shinas, Michael A

    2011-08-21T23:59:59.000Z

    A novel fiber-optic probe measures the velocity distribution of an imploding surface along many lines of sight. Reflected light from each spot on the moving surface is Doppler shifted with a small portion of this light propagating backwards through the launching fiber. The reflected light is mixed with a reference laser in a technique called photon Doppler velocimetry, providing continuous time records. Within the probe, a matrix array of 56 single-mode fibers sends light through an optical relay consisting of three types of lenses. Seven sets of these relay lenses are grouped into a close-packed array allowing the interrogation of seven regions of interest. A six-faceted prism with a hole drilled into its center directs the light beams to the different regions. Several types of relay lens systems have been evaluated, including doublets and molded aspheric singlets. The optical design minimizes beam diameters and also provides excellent imaging capabilities. One of the fiber matrix arrays can be replaced by an imaging coherent bundle. This close-packed array of seven relay systems provides up to 476 beam trajectories. The pyramid prism has its six facets polished at two different angles that will vary the density of surface point coverage. Fibers in the matrix arrays are angle polished at 8{sup o} to minimize back reflections. This causes the minimum beam waist to vary along different trajectories. Precision metrology on the direction cosine trajectories is measured to satisfy environmental requirements for vibration and temperature.

  16. A Fisheye Lens as a Photonic Doppler Velocimetry Probe

    SciTech Connect (OSTI)

    Frogget, B C; Cox, B C; DeVore, D O; Esquibel, D L; Frayer, D K; Furlanetto, M R; Holtkamp, D B; Kaufman, M I; Malone, R M

    2012-09-01T23:59:59.000Z

    A new fisheye lens design is used as a miniature probe to measure the velocity distribution of an imploding surface along many lines of sight. Laser light, directed and scattered back along each beam on the surface, is Doppler shifted by the moving surface and collected into the launching fiber. The received light is mixed with reference laser light in each optical fiber in a technique called photonic Doppler velocimetry, providing a continuous time record. An array of single-mode optical fibers sends laser light through the fisheye lens. The lens consists of an index-matching positive element, two positive doublet groups, and two negative singlet elements. The optical design minimizes beam diameters, physical size, and back reflections for excellent signal collection. The fiber array projected through the fisheye lens provides many measurement points of surface coverage over a hemisphere with very little crosstalk. The probe measures surface movement with only a small encroachment into the center of the cavity. The fiber array is coupled to the index-matching element using index-matching gel. The array is bonded and sealed into a blast tube for ease of assembly and focusing. This configuration also allows the fiber array to be flat polished at a common object plane. In areas where increased measurement point density is desired, the fibers can be close packed. To further increase surface density coverage, smaller-diameter cladding optical fibers may be used.

  17. Automatic signal processing of front monitor radar for tunneling machines

    SciTech Connect (OSTI)

    Sato, Toru [Kyoto Univ. (Japan). Dept. of Electronics and Communication] [Kyoto Univ. (Japan). Dept. of Electronics and Communication; Takeda, Kenya [NTT Co. Ltd., Chiba (Japan)] [NTT Co. Ltd., Chiba (Japan); Nagamatsu, Takashi [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan)] [Mitsubishi Heavy Industries, Ltd., Tokyo (Japan); Wakayama, Toshio [Mitsubishi Electric Corp., Kamakura, Kanagawa (Japan)] [Mitsubishi Electric Corp., Kamakura, Kanagawa (Japan); Kimura, Iwane [Osaka Inst. of Tech., Hirakata, Osaka (Japan)] [Osaka Inst. of Tech., Hirakata, Osaka (Japan); Shinbo, Tetsuya [Komatsu Co. Ltd., Kanagawa (Japan)] [Komatsu Co. Ltd., Kanagawa (Japan)

    1997-03-01T23:59:59.000Z

    It is planned to install a front monitoring impulse radar on the surface of the rotating drill of tunneling machines in order to detect obstacles such as casing pipes of vertical borings. The conventional aperture synthesis technique can no more be applied to such cases because the radar image of a pipe dies not constituent a hyperbola as is the case for linear scanning radars. The authors have developed a special purpose signal processing algorithm with the aid of the discrete model fitting method, which can be used for any pattern of scanning. The details of the algorithm are presented together with the results of numerical simulations and test site experiments.

  18. Development and characterization analysis of a radar polarimeter

    E-Print Network [OSTI]

    Bong, Soei Siang

    1984-01-01T23:59:59.000Z

    . OPERATIONAL ANALYSIS OF THE RPS Assembling the RPS. Theoretical Calculations. Losses in the RF Heads. 1. The L-Band Radar Head (1. 6 GHz). 2. The C-Band Radar Head (4. 75 GHz) 3. The X-Band Radar Head (10. 003 GHz) RF Head Stability as Measured... of the Components in the IF Section. List of Components in the L-Band RF Head. List of Components in the C-Band RF Head. List of Components in the X-Band RF Head. Detail List of Components in the L-Band RF Head . Specifications of the Components in the L...

  19. Development and characterization analysis of a radar polarimeter 

    E-Print Network [OSTI]

    Bong, Soei Siang

    1984-01-01T23:59:59.000Z

    . OPERATIONAL ANALYSIS OF THE RPS Assembling the RPS. Theoretical Calculations. Losses in the RF Heads. 1. The L-Band Radar Head (1. 6 GHz). 2. The C-Band Radar Head (4. 75 GHz) 3. The X-Band Radar Head (10. 003 GHz) RF Head Stability as Measured... of the Components in the IF Section. List of Components in the L-Band RF Head. List of Components in the C-Band RF Head. List of Components in the X-Band RF Head. Detail List of Components in the L-Band RF Head . Specifications of the Components in the L...

  20. Monitoring internal organ motion with continuous wave radar in CT

    SciTech Connect (OSTI)

    Pfanner, Florian [Institute of Medical Physics, University of Erlangen–Nürnberg, 91052 Erlangen, Germany and Siemens AG, Healthcare Sector, Siemensstr. 1, 91301 Forchheim (Germany)] [Institute of Medical Physics, University of Erlangen–Nürnberg, 91052 Erlangen, Germany and Siemens AG, Healthcare Sector, Siemensstr. 1, 91301 Forchheim (Germany); Maier, Joscha [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)] [Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany); Allmendinger, Thomas; Flohr, Thomas [Siemens AG, Healthcare Sector, Siemensstr. 1, 91301 Forchheim (Germany)] [Siemens AG, Healthcare Sector, Siemensstr. 1, 91301 Forchheim (Germany); Kachelrieß, Marc [Institute of Medical Physics, University of Erlangen–Nürnberg, 91052 Erlangen, Germany and Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)] [Institute of Medical Physics, University of Erlangen–Nürnberg, 91052 Erlangen, Germany and Medical Physics in Radiology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg (Germany)

    2013-09-15T23:59:59.000Z

    Purpose: To avoid motion artifacts in medical imaging or to minimize the exposure of healthy tissues in radiation therapy, medical devices are often synchronized with the patient's respiratory motion. Today's respiratory motion monitors require additional effort to prepare the patients, e.g., mounting a motion belt or placing an optical reflector on the patient's breast. Furthermore, they are not able to measure internal organ motion without implanting markers. An interesting alternative to assess the patient's organ motion is continuous wave radar. The aim of this work is to design, implement, and evaluate such a radar system focusing on application in CT.Methods: The authors designed a radar system operating in the 860 MHz band to monitor the patient motion. In the intended application of the radar system, the antennas are located close to the patient's body inside the table of a CT system. One receive and four transmitting antennas are used to avoid the requirement of exact patient positioning. The radar waves propagate into the patient's body and are reflected at tissue boundaries, for example at the borderline between muscle and adipose tissue, or at the boundaries of organs. At present, the authors focus on the detection of respiratory motion. The radar system consists of the hardware mentioned above as well as of dedicated signal processing software to extract the desired information from the radar signal. The system was evaluated using simulations and measurements. To simulate the radar system, a simulation model based on radar and wave field equations was designed and 4D respiratory-gated CT data sets were used as input. The simulated radar signals and the measured data were processed in the same way. The radar system hardware and the signal processing algorithms were tested with data from ten volunteers. As a reference, the respiratory motion signal was recorded using a breast belt simultaneously with the radar measurements.Results: Concerning the measurements of the test persons, there is a very good correlation (?= 0.917) between the respiratory motion phases received by the radar system and the external motion monitor. Our concept of using an array of transmitting antennas turned out to be widely insensitive to the positioning of the test persons. A time shift between the respiratory motion curves recorded with the radar system and the motion curves from the external respiratory monitor was observed which indicates a slight difference between internal organ motion and motion detected by the external respiratory monitor. The simulations were in good accordance with the measurements.Conclusions: A continuous wave radar operating in the near field of the antennas can be used to determine the respiratory motion of humans accurately. In contrast to trigger systems used today, the radar system is able to measure motion inside the body. If such a monitor was routinely available in clinical CT, it would be possible optimizing the scan start with respect to the respiratory state of the patient. Breathing commands would potentially widely be avoided, and as far as uncooperative patients or children are concerned, less sedation might be necessary. Further applications of the radar system could be in radiation therapy or interventional imaging for instance.

  1. Doppler cooling of calcium ions using a dipole-forbidden transition Richard J. Hendricks,1

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , a large variety of laser cooling techniques have been proposed and demonstrated 1,2 . These includeDoppler cooling of calcium ions using a dipole-forbidden transition Richard J. Hendricks,1 Jens L; published 4 February 2008 Doppler cooling of calcium ions has been experimentally demonstrated using the S1

  2. A Transect of Glacier Bay Ocean Currents Measured by Acoustic Doppler Current Profiler (ADCP)

    E-Print Network [OSTI]

    that the tidal flow accelerates over Glacier Bay's shallow entrance sill to speeds of 180 cm/s and then slowsA Transect of Glacier Bay Ocean Currents Measured by Acoustic Doppler Current Profiler (ADCP shipboard acoustic Doppler current profiler (ADCP) transects of ocean current in Glacier Bay and Muir Inlet

  3. Use of a Vertical Vorticity Equation in Variational Dual-Doppler Wind Analysis ALAN SHAPIRO

    E-Print Network [OSTI]

    Gao, Jidong

    is explored. The analysis winds are obtained by minimizing a cost function accounting for the discrepanciesUse of a Vertical Vorticity Equation in Variational Dual-Doppler Wind Analysis ALAN SHAPIRO School equation in a weak-constraint (least squares error) variational dual-Doppler wind analysis procedure

  4. Doppler effects in a left-handed material: a first-principle theoretical study

    E-Print Network [OSTI]

    Sanshui Xiao; Min Qiu

    2005-09-01T23:59:59.000Z

    The Doppler effects for the reflected wave from a moving media are systemically analyzed in this paper. The theoretical formula for the Doppler shift in the left-handed material, which is described by Drude's dispersion model, is presented. This formula is examined by first-principles numerical experiments, which are in agreement with the theoretical results.

  5. Qualitative interpretation of galaxy spectra

    E-Print Network [OSTI]

    Almeida, J Sanchez; Terlevich, E; Fernandes, R Cid; Morales-Luis, A B

    2012-01-01T23:59:59.000Z

    We describe a simple step-by-step guide to qualitative interpretation of galaxy spectra. Rather than an alternative to existing automated tools, it is put forward as an instrument for quick-look analysis, and for gaining physical insight when interpreting the outputs provided by automated tools. Though the recipe is of general application, it was developed for understanding the nature of the Automatic Spectroscopic K-means based (ASK) template spectra. They resulted from the classification of all the galaxy spectra in the Sloan Digital Sky Survey data release 7 (SDSS-DR7), thus being a comprehensive representation of the galaxy spectra in the local universe. Using the recipe, we give a description of the properties of the gas and the stars that characterize the ASK classes, from those corresponding to passively evolving galaxies, to HII galaxies undergoing a galaxy-wide starburst. The qualitative analysis is found to be in excellent agreement with quantitative analyses of the same spectra. A number of byprodu...

  6. Wide band stepped frequency ground penetrating radar

    DOE Patents [OSTI]

    Bashforth, M.B.; Gardner, D.; Patrick, D.; Lewallen, T.A.; Nammath, S.R.; Painter, K.D.; Vadnais, K.G.

    1996-03-12T23:59:59.000Z

    A wide band ground penetrating radar system is described embodying a method wherein a series of radio frequency signals is produced by a single radio frequency source and provided to a transmit antenna for transmission to a target and reflection therefrom to a receive antenna. A phase modulator modulates those portions of the radio frequency signals to be transmitted and the reflected modulated signal is combined in a mixer with the original radio frequency signal to produce a resultant signal which is demodulated to produce a series of direct current voltage signals, the envelope of which forms a cosine wave shaped plot which is processed by a Fast Fourier Transform Unit 44 into frequency domain data wherein the position of a preponderant frequency is indicative of distance to the target and magnitude is indicative of the signature of the target. 6 figs.

  7. Wide band stepped frequency ground penetrating radar

    DOE Patents [OSTI]

    Bashforth, Michael B. (Buellton, CA); Gardner, Duane (Santa Maria, CA); Patrick, Douglas (Santa Maria, CA); Lewallen, Tricia A. (Ventura, CA); Nammath, Sharyn R. (Santa Barbara, CA); Painter, Kelly D. (Goleta, CA); Vadnais, Kenneth G. (Alexandria, VA)

    1996-01-01T23:59:59.000Z

    A wide band ground penetrating radar system (10) embodying a method wherein a series of radio frequency signals (60) is produced by a single radio frequency source (16) and provided to a transmit antenna (26) for transmission to a target (54) and reflection therefrom to a receive antenna (28). A phase modulator (18) modulates those portion of the radio frequency signals (62) to be transmitted and the reflected modulated signal (62) is combined in a mixer (34) with the original radio frequency signal (60) to produce a resultant signal (53) which is demodulated to produce a series of direct current voltage signals (66) the envelope of which forms a cosine wave shaped plot (68) which is processed by a Fast Fourier Transform unit 44 into frequency domain data (70) wherein the position of a preponderant frequency is indicative of distance to the target (54) and magnitude is indicative of the signature of the target (54).

  8. Collapse and revival of the Doppler-Rabi oscillations of a moving atom in a cavity

    SciTech Connect (OSTI)

    Kozlovskii, A. V. [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation)], E-mail: kozlovsk@sci.lebedev.ru

    2008-11-15T23:59:59.000Z

    Collapse and revival of the Doppler-Rabi oscillations of a two-level atom moving in a cavity electromagnetic field are analyzed. The coupled atom-field dynamics are predicted accurately by numerical calculation and approximately by using the stationary phase approximation combined with the Poisson summation formula. The collapse and revival patterns are shown to be qualitatively different in the cases of moving atom and atom at rest. In particular, quantum revivals of Doppler-Rabi oscillations occur with a period determined by the Doppler shift of the atomic transition frequency. This regime of Doppler-Rabi oscillations requires that the Rabi frequency and the Doppler shift satisfy the condition {omega}{sub R} << {omega}{sub D}. Under the inverse relation, the collapse- revival phenomenon generally does not occur. It is shown that even a small amount of atom-cavity detuning eliminates collapse-revival behavior. The analysis is performed for both coherent and thermal cavity fields.

  9. Post-Newtonian Theory for Precision Doppler Measurements of Binary Star Orbits

    E-Print Network [OSTI]

    Kopeikin, S M

    1999-01-01T23:59:59.000Z

    The determination of velocities of stars from precise Doppler measurements is described here using relativistic theory of astronomical reference frames so as to determine the Keplerian and post-Keplerian parameters of binary systems. Seven appropriate reference frames are introduced and then we apply successive Lorentz transformations and the relativistic equation of light propagation to establish the exact treatment of Doppler effect in binary systems, both in special and general relativity theories. As a result, the Doppler shift is a sum of (1) linear in $c^{-1}$ terms, which include the ordinary Doppler effect and its variation due to the secular radial acceleration of the binary with respect to observer; (2) terms proportional to $c^{-2}$, which include the contributions from the quadratic Doppler effect caused by the relative motion of binary star with respect to the Solar system, motion of the particle emitting light and diurnal rotational motion of observer, orbital motion of the star around the binar...

  10. QUALITATIVE INTERPRETATION OF GALAXY SPECTRA

    SciTech Connect (OSTI)

    Sanchez Almeida, J.; Morales-Luis, A. B. [Instituto de Astrofisica de Canarias, E-38205 La Laguna, Tenerife (Spain); Terlevich, R.; Terlevich, E. [Instituto Nacional de Astrofisica, Optica y Electronica, Tonantzintla, Puebla (Mexico); Cid Fernandes, R., E-mail: jos@iac.es, E-mail: abml@iac.es, E-mail: rjt@ast.cam.ac.uk, E-mail: eterlevi@inaoep.mx, E-mail: cid@astro.ufsc.br [Departamento de Fisica-CFM, Universidade Federal de Santa Catarina, P.O. Box 476, 88040-900 Florianopolis, SC (Brazil)

    2012-09-10T23:59:59.000Z

    We describe a simple step-by-step guide to qualitative interpretation of galaxy spectra. Rather than an alternative to existing automated tools, it is put forward as an instrument for quick-look analysis and for gaining physical insight when interpreting the outputs provided by automated tools. Though the recipe is for general application, it was developed for understanding the nature of the Automatic Spectroscopic K-means-based (ASK) template spectra. They resulted from the classification of all the galaxy spectra in the Sloan Digital Sky Survey data release 7, thus being a comprehensive representation of the galaxy spectra in the local universe. Using the recipe, we give a description of the properties of the gas and the stars that characterize the ASK classes, from those corresponding to passively evolving galaxies, to H II galaxies undergoing a galaxy-wide starburst. The qualitative analysis is found to be in excellent agreement with quantitative analyses of the same spectra. We compare the mean ages of the stellar populations with those inferred using the code STARLIGHT. We also examine the estimated gas-phase metallicity with the metallicities obtained using electron-temperature-based methods. A number of byproducts follow from the analysis. There is a tight correlation between the age of the stellar population and the metallicity of the gas, which is stronger than the correlations between galaxy mass and stellar age, and galaxy mass and gas metallicity. The galaxy spectra are known to follow a one-dimensional sequence, and we identify the luminosity-weighted mean stellar age as the affine parameter that describes the sequence. All ASK classes happen to have a significant fraction of old stars, although spectrum-wise they are outshined by the youngest populations. Old stars are metal-rich or metal-poor depending on whether they reside in passive galaxies or in star-forming galaxies.

  11. Coherent radar ice thickness measurements over the Greenland ice sheet

    E-Print Network [OSTI]

    Gogineni, S. Prasad; Tammana, Dilip; Braaten, David A.; Leuschen, C.; Legarsky, J.; Kanagaratnam, P.; Stiles, J.; Allen, C.; Jezek, K.; Akins, T.

    2001-12-27T23:59:59.000Z

    We developed two 150-MHz coherent radar depth sounders for ice thickness measurements over the Greenland ice sheet. We developed one of these using connectorized components and the other using radio frequency integrated circuits (RFICs). Both...

  12. Sea surface wave reconstruction from marine radar images

    E-Print Network [OSTI]

    Qi, Yusheng, S.M. Massachusetts Institute of Technology

    2012-01-01T23:59:59.000Z

    The X-band marine radar is one type of remote sensing technology which is being increasingly used to measure sea surface waves nowadays. In this thesis, how to reconstruct sea surface wave elevation maps from X-band marine ...

  13. Inversion of synthetic aperture radar interferograms for sources...

    Open Energy Info (EERE)

    synthetic aperture radar interferograms for sources of production-related subsidence at the Dixie Valley geothermal field Jump to: navigation, search OpenEI Reference LibraryAdd to...

  14. Earth curvature and atmospheric refraction effects on radar signal propagation.

    SciTech Connect (OSTI)

    Doerry, Armin Walter

    2013-01-01T23:59:59.000Z

    The earth isn't flat, and radar beams don't travel straight. This becomes more noticeable as range increases, particularly at shallow depression/grazing angles. This report explores models for characterizing this behavior.

  15. Radar Vehicle Detection Within Four Quadrant Gate Crossings

    E-Print Network [OSTI]

    Illinois at Urbana-Champaign, University of

    of the exit gate · Less delay between entry and exit gate descent · Extends the exit gate delay only) Methodology 4) Results 5) Conclusions 6) Acknowledgments Exit Gate Operating Modes (EGOM) Radar Vehicle

  16. A spatial display for Ground-Penetrating Radar change detection

    E-Print Network [OSTI]

    Quimby, Paul W

    2013-01-01T23:59:59.000Z

    Ground-Penetrating Radar (GPR) enables the exploration and mapping of subterranean volumes for applications such as construction, humanitarian demining, archeology, and environmental science. In each of these applications, ...

  17. Sandia National Laboratories: evaluating wind-turbine/radar impacts

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Air Space (NAS) radar system, which has led to a blanket rejection of several wind-farm developments. To improve the siting and ... Last Updated: December 3, 2014 Go To...

  18. Optical Spectra of Dusty Starbursts

    E-Print Network [OSTI]

    B. M. Poggianti

    2000-11-23T23:59:59.000Z

    This contribution presents the optical spectral properties of FIR-luminous galaxies, whose distinctive feature is often the simultaneous presence in the spectra of a strong $\\rm H\\delta$ line in absorption and of emission lines (e(a) spectra). A discrepancy between the star formation rate estimated from the FIR luminosity and that derived from the $\\rm H\\alpha$ luminosity persists even after having corrected the $\\rm H\\alpha$ flux for dust according to the observed Balmer decrement. It is shown that the e(a) spectrum can be reproduced assuming a current starburst and dust extinction affecting the youngest stellar populations much more than the older stars.

  19. An airborne digital processor for radar scatterometer data

    E-Print Network [OSTI]

    Yeadon, David Steven

    1977-01-01T23:59:59.000Z

    AN AIRBORNE DIGITAL PROCESSOR FOR RADAR SCATTEROMETER DATA A Thesis by DAVID STEVEN YEADON Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1977... Major Subject: Electrical Engineering AN AIRBORNE DIGITAL PROCESSOR FOR RADAR SCATTEROMETER DATA A Thesis by DAVID STEVEN YEADON Approved as to style and content by: (Chairman o Committee) Head of epartment) ( (Member ) (Member) August 1977...

  20. Differences in radar derived rainfall amounts due to sampling intervals

    E-Print Network [OSTI]

    Zdenek, David James

    1986-01-01T23:59:59.000Z

    DIFFERENCES IN RADAR DERIVED RAINFALL AMOUNTS DUE TO SAMPLING INTERVALS A Thesis by DAVID JAMES ZDENEK Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... December 1986 Major Subject: Meteorology DIFFERENCES IN RADAR DERIVED RAINFALL AMOUNTS DUE TO SAMPLING INTERVALS A Thesis by DAVID JAMES ZDENEK Approved as to style and content by: eorge L. Huebner (Chairman of Committee) CP~ CG~& Robert C...

  1. Photoacoustic Doppler Effect from Flowing Small Light-Absorbing Particles Hui Fang, Konstantin Maslov, and Lihong V. Wang*

    E-Print Network [OSTI]

    Wang, Lihong

    Photoacoustic Doppler Effect from Flowing Small Light-Absorbing Particles Hui Fang, Konstantin.55.Kf, 87.80.ÿy Laser flowmetry and acoustic flowmetry based on the Doppler effect [1] have become physical phenomenon--the photoacoustic Doppler (PAD) effect from moving particles--and its application

  2. Adv. Studies Theor. Phys., Vol. 4, 2010, no. 2, 67 -90 Channel Models of the Doppler Effect

    E-Print Network [OSTI]

    Drakakis, Konstantinos

    Adv. Studies Theor. Phys., Vol. 4, 2010, no. 2, 67 - 90 Channel Models of the Doppler Effect.Rickard@ucd.ie Abstract We offer a pedagogical study of the Doppler effect as a channel, and derive a mathematical model. We infer from these two observations that there is essentially only one Doppler effect in different

  3. Laser Doppler flowmetry signals to quantify effects of isoflurane on the peripheral cardiovascular system of healthy rats

    E-Print Network [OSTI]

    Chapeau-Blondeau, François

    Laser Doppler flowmetry signals to quantify effects of isoflurane on the peripheral cardiovascular; published online 27 December 2007 The optical Doppler effect resulting from interactions between laser light increases. These findings demonstrate the usefulness of the optical Doppler effect in physiological

  4. Doppler-free intermodulated fluorescence spectroscopy of $^4He$ $2^3P-3^{1,3}D$ transitions at 588 nm with a one-watt compact laser system

    E-Print Network [OSTI]

    Luo, Pei-Ling; Feng, Yan; Wang, Li-Bang; Shy, Jow-Tsong

    2015-01-01T23:59:59.000Z

    We have demonstrated Doppler-free intermodulated fluorescence spectroscopy of helium $2^3P-3^{1,3}D$ transitions in an rf discharged sealed-off cell using a compact laser system at 588 nm. An external cavity diode laser at 1176 nm was constructed to seed a Raman fiber amplifier. Laser power of more than one watt at 588 nm was produced by frequency doubling of the fiber amplifier output using a MgO:PPLN crystal. A doubling efficiency of 23 % was achieved. The power-dependent spectra of the $2^3P-3^3D$ transitions were investigated. Furthermore, the Doppler-free spectrum of the spin-forbidden $2^3P-3^1D$ transitions was observed for the first time. Our results are crucial towards precision test of QED atomic calculations, especially for improving the determination of the helium $3^1D-3^3D$ separation.

  5. Conventional and synthetic aperature processing for airborne ground penetrating radar

    SciTech Connect (OSTI)

    Cameron, R.M. [Airborne Environmental Surveys, Santa Maria, CA (United States); Simkins, W.L.; Brown, R.D. [MSB Technologies, Inc., Rome, NY (United States)

    1994-12-31T23:59:59.000Z

    For the past four years Airborne Environmental Surveys (AES), a Division of Era Aviation, Inc. has used unique and patented airborne Frequency-Modulated, Continuous Wave (FM-CW) radars and processes for detecting and mapping subsurface phenomena. Primary application has focused on the detection of man-made objects in landfills, hazardous waste sites (some of which contain unexploded ordinance), and subsurface plumes of refined free-floating hydrocarbons. Recently, MSB Technologies, Inc. (MSB) has developed a form of synthetic aperture radar processing (SAR), called GPSAR{trademark}, that is tailored especially for the AES radars. Used as an adjunct to more conventional airborne ground-penetrating radar data processing techniques, GPSAR takes advantage of the radars` coherent transmission and produces imagery that is better focused and more accurate in determining an object`s range and true depth. This paper describes the iterative stages of data processing and analysis used with the radars and shows the added advantages that GPSAR processing offers.

  6. Photonic Doppler Velocimetry Multiplexing Techniques: Evaluation of Photonic Techniques

    SciTech Connect (OSTI)

    Edward Daykin

    2012-05-24T23:59:59.000Z

    This poster reports progress related to photonic technologies. Specifically, the authors developed diagnostic system architecture for a Multiplexed Photonic Doppler Velocimetry (MPDV) that incorporates frequency and time-division multiplexing into existing PDV methodology to provide increased channel count. Current MPDV design increases number of data records per digitizer channel 8x, and also operates as a laser-safe (Class 3a) system. Further, they applied heterodyne interferometry to allow for direction-of-travel determination and enable high-velocity measurements (>10 km/s) via optical downshifting. They also leveraged commercially available, inexpensive and robust components originally developed for telecom applications. Proposed MPDV architectures employ only commercially available, fiber-coupled hardware.

  7. Doppler Effect of Nonlinear Waves and Superspirals in Oscillatory Media

    E-Print Network [OSTI]

    Lutz Brusch; Alessandro Torcini; Markus Baer

    2003-02-12T23:59:59.000Z

    Nonlinear waves emitted from a moving source are studied. A meandering spiral in a reaction-diffusion medium provides an example, where waves originate from a source exhibiting a back-and-forth movement in radial direction. The periodic motion of the source induces a Doppler effect that causes a modulation in wavelength and amplitude of the waves (``superspiral''). Using the complex Ginzburg-Landau equation, we show that waves subject to a convective Eckhaus instability can exhibit monotonous growth or decay as well as saturation of these modulations away from the source depending on the perturbation frequency. Our findings allow a consistent interpretation of recent experimental observations concerning superspirals and their decay to spatio-temporal chaos.

  8. Method and apparatus for ultrasonic doppler velocimetry using speed of sound and reflection mode pulsed wideband doppler

    DOE Patents [OSTI]

    Shekarriz, Alireza (Kennewick, WA); Sheen, David M. (Richland, WA)

    2000-01-01T23:59:59.000Z

    According to the present invention, a method and apparatus rely upon tomographic measurement of the speed of sound and fluid velocity in a pipe. The invention provides a more accurate profile of velocity within flow fields where the speed of sound varies within the cross-section of the pipe. This profile is obtained by reconstruction of the velocity profile from the local speed of sound measurement simultaneously with the flow velocity. The method of the present invention is real-time tomographic ultrasonic Doppler velocimetry utilizing a to plurality of ultrasonic transmission and reflection measurements along two orthogonal sets of parallel acoustic lines-of-sight. The fluid velocity profile and the acoustic velocity profile are determined by iteration between determining a fluid velocity profile and measuring local acoustic velocity until convergence is reached.

  9. Measuring soil moisture with imaging radars

    SciTech Connect (OSTI)

    Dubois, P.C.; Zyl, J. van [California Inst. of Tech., Pasadena, CA (United States). Jet Propulsion Lab.] [California Inst. of Tech., Pasadena, CA (United States). Jet Propulsion Lab.; Engman, T. [NASA Goddard Space Flight Center, Greenbelt, MD (United States)] [NASA Goddard Space Flight Center, Greenbelt, MD (United States)

    1995-07-01T23:59:59.000Z

    An empirical algorithm for the retrieval of soil moisture content and surface Root Mean Square (RMS) height from remotely sensed radar data was developed using scatterometer data. The algorithm is optimized for bare surfaces and requires two copolarized channels at a frequency between 1.5 and 11 GHz. It gives best results for kh {le} 2.5, {mu}{sub {upsilon}}{le}35%, and {theta}{ge}30{degree}. Omitting the usually weaker hv-polarized returns makes the algorithm less sensitive to system cross-talk and system noise, simplify the calibration process and adds robustness to the algorithm in the presence of vegetation. However, inversion results indicate that significant amounts of vegetation (NDVI>0.4) cause the algorithm to underestimate soil moisture and overestimate RMS height. A simple criteria based on the {sigma}{sub hv}{sup 0}/{sigma}{sub vv}{sup 0} ratio is developed to select the areas where the inversion is not impaired by the vegetation. The inversion accuracy is assessed on the original scatterometer data sets but also on several SAR data sets by comparing the derived soil moisture values with in-situ measurements collected over a variety of scenes between 1991 and 1994. Both spaceborne (SIR-C) and airborne (AIRSAR) data are used in the test. Over this large sample of conditions, the RMS error in the soil moisture estimate is found to be less than 4.2% soil moisture.

  10. Hierarchical analysis of molecular spectra

    SciTech Connect (OSTI)

    Davis, M.J.

    1996-03-01T23:59:59.000Z

    A novel representation of molecular spectra in terms of hierarchical trees has proven to be an important aid for the study of many significant problems in gas-phase chemical dynamics. Trees are generated from molecular spectra by monitoring the changes that occur in a spectrum as resolution is changed in a continuous manner. A tree defines a genealogy among all lines of a spectrum. This allows for a detailed understanding of the assignment of features of a spectrum that may be difficult to obtain any other way as well as an understanding of intramolecular energy transfer time scales, mechanisms, and pathways. The methodology has been applied to several problems: transition state spectroscopy, intramolecular energy transfer in highly excited molecules, high-resolution overtone spectroscopy, and the nature of the classical-quantum correspondence when there is classical chaos (``quantum chaos``).

  11. Graphene based tunable fractal Hilbert curve array broadband radar absorbing screen for radar cross section reduction

    SciTech Connect (OSTI)

    Huang, Xianjun, E-mail: xianjun.huang@manchester.ac.uk [School of Electrical and Electronic Engineering, University of Manchester, Manchester M13 9PL (United Kingdom); College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China); Hu, Zhirun [School of Electrical and Electronic Engineering, University of Manchester, Manchester M13 9PL (United Kingdom); Liu, Peiguo [College of Electronic Science and Engineering, National University of Defense Technology, Changsha 410073 (China)

    2014-11-15T23:59:59.000Z

    This paper proposes a new type of graphene based tunable radar absorbing screen. The absorbing screen consists of Hilbert curve metal strip array and chemical vapour deposition (CVD) graphene sheet. The graphene based screen is not only tunable when the chemical potential of the graphene changes, but also has broadband effective absorption. The absorption bandwidth is from 8.9GHz to 18.1GHz, ie., relative bandwidth of more than 68%, at chemical potential of 0eV, which is significantly wider than that if the graphene sheet had not been employed. As the chemical potential varies from 0 to 0.4eV, the central frequency of the screen can be tuned from 13.5GHz to 19.0GHz. In the proposed structure, Hilbert curve metal strip array was designed to provide multiple narrow band resonances, whereas the graphene sheet directly underneath the metal strip array provides tunability and averagely required surface resistance so to significantly extend the screen operation bandwidth by providing broadband impedance matching and absorption. In addition, the thickness of the screen has been optimized to achieve nearly the minimum thickness limitation for a nonmagnetic absorber. The working principle of this absorbing screen is studied in details, and performance under various incident angles is presented. This work extends applications of graphene into tunable microwave radar cross section (RCS) reduction applications.

  12. Design and implementation of a fiber optic doppler optical coherence microscopy system for cochlear imaging

    E-Print Network [OSTI]

    Williams, Logan P

    2014-01-01T23:59:59.000Z

    In this thesis, the design and implementation of a fiber optic Doppler optical coherence microscopy (FO-DOCM) system for cochlear imaging applications is presented. The use of a fiber optic design significantly reduces ...

  13. The Development of an Accuracy of a Doppler Global System for One Dimensional Velocity Measurement

    E-Print Network [OSTI]

    Karabacak, Mustafa

    2014-05-23T23:59:59.000Z

    shifting of the light frequency reflected by seeded particles or rotating disc surface speed. The relationship between the Doppler shift and the transmission ratio is a key part of the DGV system to calculate measured velocity. The absorption line filter...

  14. Incoherent scatter radar detection of enhanced plasma line in ionospheric E-region over Arecibo

    E-Print Network [OSTI]

    Pradipta, Rezy

    2006-01-01T23:59:59.000Z

    A series of incoherent scatter radar (ISR) observation were conducted at the Arecibo Observatory from December 27, 2005 until January 3, 2006. From plasma line measurements that were taken during this radar campaign, we ...

  15. Focused synthetic aperture radar processing of ice-sounder data collected over the Greenland ice sheet

    E-Print Network [OSTI]

    Legarsky, J.; Gogineni, Sivaprasad; Akins, T. L.

    2001-10-01T23:59:59.000Z

    We developed a synthetic aperture radar (SAR) processing algorithm for airborne/spaceborne ice-sounding radar systems and applied it to data collected in Greenland. By using focused SAR (phase-corrected coherent averaging), we improved along...

  16. Accuracy and resolution of shuttle radar topography mission data Bridget Smith and David Sandwell

    E-Print Network [OSTI]

    Sandwell, David T.

    Accuracy and resolution of shuttle radar topography mission data Bridget Smith and David Sandwell: General or miscellaneous. Citation: Smith, B., and D. Sandwell, Accuracy and resolution of shuttle radar

  17. Near real-time runoff estimation using spatially distributed radar rainfall data

    E-Print Network [OSTI]

    Hadley, Jennifer Lyn

    2004-09-30T23:59:59.000Z

    associated with rainfall. Radar networks, such as the Next Generation Weather Radar (NEXRAD) of the National Weather Service (NWS), which are widely available and continue to improve in quality and resolution, can accomplish these tasks. In general, a...

  18. Near Real-Time Runoff Estimation Using Spatially Distributed Radar Rainfall Data

    E-Print Network [OSTI]

    Hadley, Jennifer Lynn

    associated with rainfall. Radar networks, such as the Next Generation Weather Radar (NEXRAD) of the National Weather Service (NWS), which are widely available and continue to improve in quality and resolution, can accomplish these tasks. In general, a...

  19. Antarctica X-band MiniSAR crevasse detection radar : final report.

    SciTech Connect (OSTI)

    Sander, Grant J.; Bickel, Douglas Lloyd

    2007-09-01T23:59:59.000Z

    This document is the final report for the Antarctica Synthetic Aperture Radar (SAR) Project. The project involved the modification of a Sandia National Laboratories MiniSAR system to operate at X-band in order to assess the feasibility of an airborne radar to detect crevasses in Antarctica. This radar successfully detected known crevasses at various geometries. The best results were obtained for synthetic aperture radar resolutions of at most one foot and finer. In addition to the main goal of detecting crevasses, the radar was used to assess conops for a future operational radar. The radar scanned large areas to identify potential safe landing zones. In addition, the radar was used to investigate looking at objects on the surface and below the surface of the ice. This document includes discussion of the hardware development, system capabilities, and results from data collections in Antarctica.

  20. Analog FIR Filter Used for Range-Optimal Pulsed Radar Applications

    E-Print Network [OSTI]

    Su, Eric Chen

    2014-08-13T23:59:59.000Z

    Matched filter is one of the most critical block in radar applications. With different measured range and relative velocity of a target we will need different bandwidth of the matched filter to maximize the radar signal to noise ratio (SNR...

  1. On reconciling ground-based with spaceborne normalized radar cross section measurements

    E-Print Network [OSTI]

    Baumgartner, F.; Munk, J.; Jezek, K. C.; Gogineni, Sivaprasad

    2002-02-01T23:59:59.000Z

    This study examines differences in the normalized radar cross section, derived from ground-based versus spaceborne radar data. A simple homogeneous half-space model, indicates that agreement between the two improves as 1) ...

  2. Modification of the Doppler Effect due to the Helicity-Rotation Coupling

    E-Print Network [OSTI]

    Bahram Mashhoon

    2002-10-20T23:59:59.000Z

    The helicity-rotation coupling and its current empirical basis are examined. The modification of the Doppler effect due to the coupling of photon spin with the rotation of the observer is considered in detail in connection with its applications in the Doppler tracking of spacecraft. Further implications of this coupling and the possibility of searching for it in the intensity response of a rotating detector are briefly discussed.

  3. Doppler Boosting and Deboosting Effects in the Forward Relativistic Jets of AGNs and GRBs

    E-Print Network [OSTI]

    Jianfeng Zhou; Yan Su

    2006-10-15T23:59:59.000Z

    It is widely accepted that the Doppler deboosting effects exist in counter relativistic jets. However, people often neglect another important fact that both Doppler boosting and deboosting effects could happen in forward relativistic jets. Such effects might be used to explain some strange phenomena, such as the invisible gaps between the inner and outer jets of AGNs, and the rapid initial decays and re-brightening bumps in the light curves of GRBs.

  4. FMCW radars for snow research Hans-Peter Marshall a,b,, Gary Koh a

    E-Print Network [OSTI]

    Marshall, Hans-Peter

    -available impulse radars are currently used operationally in Scandinavia's deep snow packs (e.g. Sand and Bruland

  5. Characteristics of Magnetohydrodynamic Oscillations Observed with Michelson Doppler Imager

    E-Print Network [OSTI]

    Norton, A A; Bush, R I; Tarbell, T D

    1999-01-01T23:59:59.000Z

    We report on the spatial distribution of magnetogram oscillatory power and phase angles between velocity and magnetogram signals as observed with the Michelson Doppler Imager. The dataset is 151.25 arcsec times 151.25 arcsec containing sunspot from Dec 2, 1997 with a temporal sampling interval of 60 seconds and spatial sampling of 0.605 arcsec. Simultaneously observed continuum intensity and surface velocity accompany the magnetic information. We focus on three frequency regimes: 0.5-1.0, 3.0-3.5 and 5.5-6.0 mHz corresponding roughly to timescales of magnetic evolution, p-modes and the 3 minute resonant sunspot oscillation. Significant low frequency magnetogram power is found in lower flux pixels, 100-300 Gauss, in a striking ring with filamentary structure surrounding sunspot. Five minute magnetogram power peaks in extended regions of flux 600-800 Gauss. The 3 minute oscillation is observed in sunspot umbra in pixels whose flux measures 1300-1500 Gauss. Phase angles of approximately -90 degrees between veloc...

  6. Characteristics of Magnetohydrodynamic Oscillations Observed with Michelson Doppler Imager

    E-Print Network [OSTI]

    A. A. Norton; R. K. Ulrich; R. I. Bush; T. D. Tarbell

    1999-07-19T23:59:59.000Z

    We report on the spatial distribution of magnetogram oscillatory power and phase angles between velocity and magnetogram signals as observed with the Michelson Doppler Imager. The dataset is 151.25 arcsec times 151.25 arcsec containing sunspot from Dec 2, 1997 with a temporal sampling interval of 60 seconds and spatial sampling of 0.605 arcsec. Simultaneously observed continuum intensity and surface velocity accompany the magnetic information. We focus on three frequency regimes: 0.5-1.0, 3.0-3.5 and 5.5-6.0 mHz corresponding roughly to timescales of magnetic evolution, p-modes and the 3 minute resonant sunspot oscillation. Significant low frequency magnetogram power is found in lower flux pixels, 100-300 Gauss, in a striking ring with filamentary structure surrounding sunspot. Five minute magnetogram power peaks in extended regions of flux 600-800 Gauss. The 3 minute oscillation is observed in sunspot umbra in pixels whose flux measures 1300-1500 Gauss. Phase angles of approximately -90 degrees between velocity and magnetic flux in the 3.0-3.5 and 5.5-6.0 mHz regimes are found in regions of significant cross amplitude.

  7. OBSERVATIONS OF DOPPLER BOOSTING IN KEPLER LIGHT CURVES

    SciTech Connect (OSTI)

    Van Kerkwijk, Marten H.; Breton, Rene P.; Justham, Stephen [Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing (China); Rappaport, Saul A. [37-602B, MIT Department of Physics and Kavli Institute for Astrophysics and Space Research, 70 Vassar St., Cambridge, MA 02139 (United States); Podsiadlowski, Philipp [Sub-department of Astrophysics, University of Oxford, Keble Road, Oxford OX1 3RH (United Kingdom); Han, Zhanwen, E-mail: mhvk@astro.utoronto.ed [National Astronomical Observatories/Yunnan Observatory and Key Laboratory of the Structure and Evolution of Celestial Objects, Chinese Academy of Sciences, Kunming 650011 (China)

    2010-05-20T23:59:59.000Z

    Among the initial results from Kepler were two striking light curves, for KOI 74 and KOI 81, in which the relative depths of the primary and secondary eclipses showed that the more compact, less luminous object was hotter than its stellar host. That result became particularly intriguing because a substellar mass had been derived for the secondary in KOI 74, which would make the high temperature challenging to explain; in KOI 81, the mass range for the companion was also reported to be consistent with a substellar object. We re-analyze the Kepler data and demonstrate that both companions are likely to be white dwarfs. We also find that the photometric data for KOI 74 show a modulation in brightness as the more luminous star orbits, due to Doppler boosting. The magnitude of the effect is sufficiently large that we can use it to infer a radial velocity amplitude accurate to 1 km s{sup -1}. As far as we are aware, this is the first time a radial-velocity curve has been measured photometrically. Combining our velocity amplitude with the inclination and primary mass derived from the eclipses and primary spectral type, we infer a secondary mass of 0.22 {+-} 0.03 M{sub sun}. We use our estimates to consider the likely evolutionary paths and mass-transfer episodes of these binary systems.

  8. On the need for simultaneity between X-ray and radio observations in Doppler factor estimates

    E-Print Network [OSTI]

    Liodakis, I; Pavlidou, V

    2015-01-01T23:59:59.000Z

    We use archival X-ray and radio VLBA data to calculate inverse Compton Doppler factors for four high-power radio, $\\gamma$-loud Flat Spectrum Radio Quasars frequently monitored by the F-GAMMA project. We explore the effect of the non-simultaneity between X-ray and radio observations by calculating Doppler factors for simultaneous and non-simultaneous observations. By comparing the newly re-calculated values from this work and archival values with variability Doppler factors, we show that simultaneous/quasi-simultaneous X-ray and radio observations can provide a reliable estimate of the true Doppler factor in blazar jets. For the particular case of PKS0528+134 we find that a time-difference of up to 1 week provides inverse Compton Doppler factor estimates consistent with the variability Doppler factor of this source at the 19% percent level. In contrast, time differences of more than 30 days between radio and X-ray observations result to discrepancies from 100% to more than a factor of 4.

  9. Vertical Structure of Tropical Cyclone Rainbands as seen by the TRMM Precipitation Radar

    E-Print Network [OSTI]

    Houze Jr., Robert A.

    1 Vertical Structure of Tropical Cyclone Rainbands as seen by the TRMM Precipitation Radar Deanna A's Precipitation Radar (TRMM PR) show the vertical structure of tropical cyclone rainbands. Radar-echo statistics show that rainbands have a two-layered structure, with distinct modes separated by the melting layer

  10. Off-The-Grid X-band Weather Radar Network for the West

    E-Print Network [OSTI]

    Gilbes, Fernando

    and target. CayeyNWS radar Mayaguez The Problem #12;Puerto Rico Test Bed · Multi-level Research Team · Low · Relay Stations #12;Network Node · Weather Radar · Processing Computer · Wireless Link #12;X-Band Weather cost · Better Merging algorithms · More Radars.... #12;PR Test Bed Team #12;Questions · ??? #12;Live

  11. Radar Network Scanning Coordination Based on Ensemble Transform Kalman Filtering Variance

    E-Print Network [OSTI]

    White, Luther

    Radar Network Scanning Coordination Based on Ensemble Transform Kalman Filtering Variance an ensemble Kalman filter is used as a criterion with which to op- timize radar network scanning strategies, is a function of the retrieval scanning parameters. It is shown that the mapping from radar parameters

  12. SCANNING CLOUD RADAR OBSERVATIONS AT AZORES: PRELIMINARY 3D CLOUD PRODUCTS

    E-Print Network [OSTI]

    SCANNING CLOUD RADAR OBSERVATIONS AT AZORES: PRELIMINARY 3D CLOUD PRODUCTS P. Kollias, I. Jo, A, NY www.bnl.gov ABSTRACT The deployment of the Scanning W-Band ARM Cloud Radar (SWACR) during the AMF campaign at Azores signals the first deployment of an ARM Facility-owned scanning cloud radar and offers

  13. ERAD 2008 -THE FIFTH EUROPEAN CONFERENCE ON RADAR IN METEOROLOGYAND HYDROLOGY 1. Introduction

    E-Print Network [OSTI]

    Haak, Hein

    , and the enhancement of the radar processing with capabilities found in modern radar equipment. In the European tender receivers and all data processing equipment in the radar sensor was replaced with modern equipment. The short pulse mode (0.8 microseconds) is used for PRFs up to 1200 Hz. To enhance reliability the thyratron

  14. A New Coherent Radar for Ice Sounding in Greenland A. Moussessian

    E-Print Network [OSTI]

    Kansas, University of

    A New Coherent Radar for Ice Sounding in Greenland A. Moussessian 1 , R.L. Jordan 1 , E. Rodriguez of this radar on board a P-3 aircraft took place in May of 1999 over Greenland with successful results blanking. The first deployment of this radar took place in May of 1999 in Greenland. During this deployment

  15. Determining weather radar antenna pointing using signals detected from the sun at low antenna elevations

    E-Print Network [OSTI]

    Stoffelen, Ad

    Determining weather radar antenna pointing using signals detected from the sun at low antenna radiation of the sun for checking of the antenna alignment and of the sensitivity of the receiver chain is a well established method in weather radar maintenance, and radar manufacturers offer sun calibration

  16. Resultados obtidos com a utilizao de imagens de RADAR do satlite ALOS

    E-Print Network [OSTI]

    Resultados obtidos com a utilização de imagens de RADAR do satélite ALOS no combate ao desmatamento Documentos Indicativos de desmatamento com ALOS PALSAR #12;#12;INDICAR- Indicador de desmatamento por imagens de RADAR · Projeto desenvolvido pelo CSR/IBAMA · Utiliza imagens de RADAR do satélite Japonês ALOS

  17. Influence of small scale rainfall variability on standard comparison tools between radar and rain gauge data

    E-Print Network [OSTI]

    in revised form 18 October 2013 Accepted 8 November 2013 Rain gauges and weather radars do not measure some usual practice. © 2013 Elsevier B.V. All rights reserved. Keywords: Radar­rain gauge comparison are tipping bucket rain gauges, disdrometers, weather radars and (passive or active) sensors onboard

  18. Elements of a continuous-wave borehole radar. Final report

    SciTech Connect (OSTI)

    Caffey, T.W.H. [Sandia National Labs., Albuquerque, NM (United States). Geophysical Technology Dept.

    1997-08-01T23:59:59.000Z

    The theory is developed for the antenna array for a proposed continuous-wave, ground-penetrating radar for use in a borehole, and field measurements are presented. Accomplishments include the underground measurement of the transmitting beam in the azimuth plane, active azimuth-steering of the transmitting beam, and the development of a range-to-target algorithm. The excellent performance of the antenna array supports the concept of a continuous-wave borehole radar. A field-prototype should be developed for use in both geothermal zones and for the exploration and recovery of oil and gas.

  19. A newsletter for non-scientists (and scientists) interested in MAGIC Radars transmit pulses of radio waves of a given frequency and receive signals that are

    E-Print Network [OSTI]

    the Doppler effect, named after Christian Doppler, an Austrian physicist of the 19th century. Everyone sizes of raindrops. The Doppler effect pertains to the change in frequency of a wave emitted-- this is the Doppler effect in a nutshell. The amount by which the pitch is greater or lower, called the Doppler shift

  20. atomic spectra: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    spectra calculations and existing atlases of infrared spectra of Arcturus and Sunspot umbra. We present plots, which show the comparison of synthetic spectra and observed...

  1. atomic recoil spectra: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    spectra calculations and existing atlases of infrared spectra of Arcturus and Sunspot umbra. We present plots, which show the comparison of synthetic spectra and observed...

  2. Progress reports for October 1994 -- Joint UK/US Radar Program

    SciTech Connect (OSTI)

    Twogood, R.E.; Brase, J.M.; Mantrom, D.D.; Chambers, D.H.; Robey, H.F.

    1994-11-18T23:59:59.000Z

    This report gives the principle investigator, objectives, recent accomplishments, milestones for reporting period, expected milestones for ensuing period, other issues and planned expenditures for each of the following programs: airborne RAR/SAR; radar data processor; ground-based SAR signal processing workstation; static airborne radar; multi-aperture space-time array radar; radar field experiments; data analysis and detection theory; management; E-2C radar data analysis; modeling and analysis; current meter array; UCSB wave tank; stratified flow facility; and IR sensor system. Finally the budget status is given.

  3. High-resolution spectra of solar magnetic features. I. Analysis of penumbral fine structure

    SciTech Connect (OSTI)

    Lites, B.W.; Skumanich, A.; Scharmer, G.B. (High Altitude Observatory, Boulder, CO (USA) Kungliga Svenska Vetenskapsakademien, Stockholm (Sweden))

    1990-05-01T23:59:59.000Z

    The Swedish Vacuum Telescope on La Palma was used to obtain spectra of the magnetic-sensitive Fe I 630.25 nm line under conditions of exceptional angular resolution (0.32 arcsec) and high spectral resolution (FWHM 2.5 pm). Simultaneous 0.02 s CCD exposures of both the spectrum and the slit-jaw image effectively 'freeze' the atmospheric seeing motions and permit unambiguous identification of the spectra of the various penumbral structures. These spectra reveal the magnetic field strength in penumbral filaments through an intensity fit of the Zeeman splitting of this line. The observations show that: (1) the field strength varies from about 2100 G near the umbra-penumbra boundary to about 900 G at the outer edge of the penumbra, (2) the observed fluctuation of penumbral magnetic field is much less dramatic than the fluctuation in intensity, (3) there is a suggestion of a rapid change in field inclination between some light and dark filaments near the edge of the penumbra, and (4) there is no obvious correlation between Doppler shift (in part due to the Evershed flow) and filament intensity. 43 refs.

  4. Post-Newtonian Theory for Precision Doppler Measurements of Binary Star Orbits

    E-Print Network [OSTI]

    S. M. Kopeikin; L. M. Ozernoy

    1999-01-31T23:59:59.000Z

    The determination of velocities of stars from precise Doppler measurements is described here using relativistic theory of astronomical reference frames so as to determine the Keplerian and post-Keplerian parameters of binary systems. We apply successive Lorentz transformations and the relativistic equation of light propagation to establish the exact treatment of Doppler effect in binary systems both in special and general relativity theories. As a result, the Doppler shift is a sum of (1) linear in $c^{-1}$ terms, which include the ordinary Doppler effect and its variation due to the secular radial acceleration of the binary with respect to observer; (2) terms proportional to $c^{-2}$, which include the contributions from the quadratic Doppler effect caused by the relative motion of binary star with respect to the Solar system, motion of the particle emitting light and diurnal rotational motion of observer, orbital motion of the star around the binary's barycenter, and orbital motion of the Earth; and (3) terms proportional to $c^{-2}$, which include the contributions from redshifts due to gravitational fields of the star, star's companion, Galaxy, Solar system, and the Earth. After parameterization of the binary's orbit we find that the presence of periodically changing terms in the Doppler schift enables us disentangling different terms and measuring, along with the well known Keplerian parameters of the binary, four additional post-Keplerian parameters, including the inclination angle of the binary's orbit, $i$. We briefly discuss feasibility of practical implementation of these theoretical results, which crucially depends on further progress in the technique of precision Doppler measurements.

  5. TIDAL TURBULENCE SPECTRA FROM A COMPLIANT MOORING

    SciTech Connect (OSTI)

    Thomson, Jim; Kilcher, Levi; Richmond, Marshall C.; Talbert, Joe; deKlerk, Alex; Polagye, Brian; Guerra, Maricarmen; Cienfuegos, Rodrigo

    2013-06-13T23:59:59.000Z

    A compliant mooring to collect high frequency turbulence data at a tidal energy site is evaluated in a series of short demon- stration deployments. The Tidal Turbulence Mooring (TTM) improves upon recent bottom-mounted approaches by suspend- ing Acoustic Doppler Velocimeters (ADVs) at mid-water depths (which are more relevant to tidal turbines). The ADV turbulence data are superior to Acoustic Doppler Current Profiler (ADCP) data, but are subject to motion contamination when suspended on a mooring in strong currents. In this demonstration, passive stabilization is shown to be sufficient for acquiring bulk statistics of the turbulence, without motion correction. With motion cor- rection (post-processing), data quality is further improved; the relative merits of direct and spectral motion correction are dis- cussed.

  6. Gamma-ray burst prompt emission light curves and power density spectra in the ICMART model

    SciTech Connect (OSTI)

    Zhang, Bo [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Zhang, Bing, E-mail: bozhang@physics.unlv.edu, E-mail: zhang@physics.unlv.edu [Department of Physics and Astronomy, University of Nevada Las Vegas, Las Vegas, NV 89154 (United States)

    2014-02-20T23:59:59.000Z

    In this paper, we simulate the prompt emission light curves of gamma-ray bursts (GRBs) within the framework of the Internal-Collision-induced MAgnetic Reconnection and Turbulence (ICMART) model. This model applies to GRBs with a moderately high magnetization parameter ? in the emission region. We show that this model can produce highly variable light curves with both fast and slow components. The rapid variability is caused by many locally Doppler-boosted mini-emitters due to turbulent magnetic reconnection in a moderately high ? flow. The runaway growth and subsequent depletion of these mini-emitters as a function of time define a broad slow component for each ICMART event. A GRB light curve is usually composed of multiple ICMART events that are fundamentally driven by the erratic GRB central engine activity. Allowing variations of the model parameters, one is able to reproduce a variety of light curves and the power density spectra as observed.

  7. Gamma-Ray Burst Prompt Emission Light Curves and Power Density Spectra in the ICMART Model

    E-Print Network [OSTI]

    Zhang, Bo

    2013-01-01T23:59:59.000Z

    In this paper, we simulate the prompt emission light curves of gamma-ray bursts (GRBs) within the framework of the Internal-Collision-induced MAgnetic Reconnection and Turbulence (ICMART) model. This model applies to GRBs with a moderately-high magnetization parameter $\\sigma$ in the emission region. We show that this model can produce highly variable light curves with both fast and slow components. The rapid variability is caused by many locally Doppler-boosted mini-emitters due to turbulent magnetic reconnection in a moderately-high-$\\sigma$ flow. The run-away growth and subsequent depletion of these mini-emitters as a function time define a broad slow component for each ICMART event. A GRB light curve is usually composed of multiple ICMART events that are fundamentally driven by the erratic GRB central engine activity. Allowing variations of the model parameters, one is able to reproduce a variety of light curves and the power density spectra as observed.

  8. First observations of tracking clouds using scanning ARM cloud radars

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Borque, Paloma; Giangrande, Scott; Kollias, Pavlos

    2014-12-01T23:59:59.000Z

    Tracking clouds using scanning cloud radars can help to document the temporal evolution of cloud properties well before large drop formation (‘‘first echo’’). These measurements complement cloud and precipitation tracking using geostationary satellites and weather radars. Here, two-dimensional (2-D) Along-Wind Range Height Indicator (AW-RHI) observations of a population of shallow cumuli (with and without precipitation) from the 35-GHz scanning ARM cloud radar (SACR) at the DOE Atmospheric Radiation Measurements (ARM) program Southern Great Plains (SGP) site are presented. Observations from the ARM SGP network of scanning precipitation radars are used to provide the larger scale context of the cloud fieldmore »and to highlight the advantages of the SACR to detect the numerous, small, non-precipitating cloud elements. A new Cloud Identification and Tracking Algorithm (CITA) is developed to track cloud elements. In CITA, a cloud element is identified as a region having a contiguous set of pixels exceeding a preset reflectivity and size threshold. The high temporal resolution of the SACR 2-D observations (30 sec) allows for an area superposition criteria algorithm to match cloud elements at consecutive times. Following CITA, the temporal evolution of cloud element properties (number, size, and maximum reflectivity) is presented. The vast majority of the designated elements during this cumulus event were short-lived non-precipitating clouds having an apparent life cycle shorter than 15 minutes. The advantages and disadvantages of cloud tracking using an SACR are discussed.« less

  9. Assessment Of The Wind Farm Impact On The Radar

    E-Print Network [OSTI]

    Norman, Evgeny D

    2010-01-01T23:59:59.000Z

    This study shows the means to evaluate the wind farm impact on the radar. It proposes the set of tools, which can be used to realise this objective. The big part of report covers the study of complex pattern propagation factor as the critical issue of the Advanced Propagation Model (APM). Finally, the reader can find here the implementation of this algorithm - the real scenario in Inverness airport (the United Kingdom), where the ATC radar STAR 2000, developed by Thales Air Systems, operates in the presence of several wind farms. Basically, the project is based on terms of the department "Strategy Technology & Innovation", where it has been done. Also you can find here how the radar industry can act with the problem engendered by wind farms. The current strategies in this area are presented, such as a wind turbine production, improvements of air traffic handling procedures and the collaboration between developers of radars and wind turbines. The possible strategy for Thales as a main pioneer was given as ...

  10. Generating nonlinear FM chirp radar signals by multiple integrations

    DOE Patents [OSTI]

    Doerry, Armin W. (Albuquerque, NM)

    2011-02-01T23:59:59.000Z

    A phase component of a nonlinear frequency modulated (NLFM) chirp radar pulse can be produced by performing digital integration operations over a time interval defined by the pulse width. Each digital integration operation includes applying to a respectively corresponding input parameter value a respectively corresponding number of instances of digital integration.

  11. PAVEMENT OVERLAY THICKNESS EVALUATION USING GROUND PENTRATING RADAR (GPR)

    E-Print Network [OSTI]

    Shan, Jie

    PAVEMENT OVERLAY THICKNESS EVALUATION USING GROUND PENTRATING RADAR (GPR) Dwayne Harris, M.Sc., PG University, West Lafayette, IN 47907 jshan@ecn.purdue.edu ABSTRACT Accurate knowledge of pavement thickness is important information to have both at a network and project level. This information aids in pavement

  12. Automatic Radar Antenna Scan Type Recognition in Electronic

    E-Print Network [OSTI]

    Barshan, Billur

    Automatic Radar Antenna Scan Type Recognition in Electronic Warfare BILLUR BARSHAN BAHAEDDIN ERAVCI in electronic warfare (EW). The stages of the algorithm are scan period estimation, preprocessing (normalization Continuous-wave EW Electronic warfare EM Electromagnetic LFM Linear frequency modulation DTW Dynamic time

  13. First observations of tracking clouds using scanning ARM cloud radars

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Borque, Paloma [McGill Univ., Montreal, QC (Canada); Giangrande, Scott [Brookhaven National Lab. (BNL), Upton, NY (United States); Kollias, Pavlos [McGill Univ., Montreal, QC (Canada)

    2014-12-01T23:59:59.000Z

    Tracking clouds using scanning cloud radars can help to document the temporal evolution of cloud properties well before large drop formation (‘‘first echo’’). These measurements complement cloud and precipitation tracking using geostationary satellites and weather radars. Here, two-dimensional (2-D) Along-Wind Range Height Indicator (AW-RHI) observations of a population of shallow cumuli (with and without precipitation) from the 35-GHz scanning ARM cloud radar (SACR) at the DOE Atmospheric Radiation Measurements (ARM) program Southern Great Plains (SGP) site are presented. Observations from the ARM SGP network of scanning precipitation radars are used to provide the larger scale context of the cloud field and to highlight the advantages of the SACR to detect the numerous, small, non-precipitating cloud elements. A new Cloud Identification and Tracking Algorithm (CITA) is developed to track cloud elements. In CITA, a cloud element is identified as a region having a contiguous set of pixels exceeding a preset reflectivity and size threshold. The high temporal resolution of the SACR 2-D observations (30 sec) allows for an area superposition criteria algorithm to match cloud elements at consecutive times. Following CITA, the temporal evolution of cloud element properties (number, size, and maximum reflectivity) is presented. The vast majority of the designated elements during this cumulus event were short-lived non-precipitating clouds having an apparent life cycle shorter than 15 minutes. The advantages and disadvantages of cloud tracking using an SACR are discussed.

  14. Automated Target Recognition Using Passive Radar and Coordinated Flight Models

    E-Print Network [OSTI]

    Lanterman, Aaron

    of altitude and range. The Numerical Electromagnetic Code (NEC2) computes the antenna gain pattern, so Georgia Institute of Technology, Atlanta, GA 30332, USA ABSTRACT Rather than emitting pulses, passive system is in the transmitter, whereas designers of "hitchhiking" or "parasitic" radars have high

  15. The use of composite radar photographs in synoptic weather analysis

    E-Print Network [OSTI]

    Smith, G. D.

    1957-01-01T23:59:59.000Z

    of ursa. Velooity of line, figure K3 Xn addition t* th? foregoing infornacion, the bases and tope of leyscs end tops of convective echoes oan be ruporced. With certain radar installations, end under certain conditions, tha height of thu freeaing...

  16. Synthetic Aperture Radar Imaging with Motion Estimation and Liliana Borcea

    E-Print Network [OSTI]

    Papanicolaou, George C.

    Callaghan George Papanicolaou Abstract We introduce from first principles a synthetic aperture radar (SAR calibrated small apertures, (b) preliminary motion estimation from the data using the Wigner transform-band persistent surveillance SAR is a specific application that is covered by our analysis. Detailed numerical

  17. Synthetic aperture radar and interferometry development at Sandia National Laboratories

    SciTech Connect (OSTI)

    NONE

    1993-04-01T23:59:59.000Z

    Environmental monitoring, earth-resource mapping, and military systems require broad-area imaging at high resolutions. Many times the imagery must be acquired in inclement weather or during night as well as day. Synthetic aperture radar (SAR) provides such a capability. SAR systems take advantage of the long-range propagation characteristics of radar signals and the complex information processing capability of modern digital electronics to provide high resolution imagery. SAR complements photographic and other optical imaging capabilities because of the minimum constrains on time-of-day and atmospheric conditions and because of the unique responses of terrain and cultural targets to radar frequencies. Interferometry is a method for generating a three-dimensional image of terrain. The height projection is obtained by acquiring two SAR images from two slightly differing locations. It is different from the common method of stereoscopic imaging for topography. The latter relies on differing geometric projections for triangulation to define the surface geometry whereas interferometry relies on differences in radar propagation times between the two SAR locations. This paper presents the capabilities of SAR, explains how SAR works, describes a few SAR applications, provides an overview of SAR development at Sandia, and briefly describes the motion compensation subsystem.

  18. Quasioptical design of integrated Doppler backscattering and correlation electron cyclotron emission systems on the DIII-D tokamak

    E-Print Network [OSTI]

    Rhodes, T. L.

    The quasioptical design of a new integrated Doppler backscattering (DBS) and correlation electron cyclotron emission (CECE) system is presented. The design provides for simultaneous measurements of intermediate wavenumber ...

  19. Progress with On-The-Fly Neutron Doppler Broadening in MCNP

    SciTech Connect (OSTI)

    Brown, Forrest B. [Los Alamos National Laboratory; Martin, William R. [Los Alamos National Laboratory; Yesilyurt, Gokhan [Argonne National Laboratory; Wilderman, Scott [University of Michigan

    2012-06-18T23:59:59.000Z

    The University of Michigan, ANL, and LANL have been collaborating on a US-DOE-NE University Programs project 'Implementation of On-the-Fly Doppler Broadening in MCNP5 for Multiphysics Simulation of Nuclear Reactors.' This talk describes the project and provides results from the initial implementation of On-The-Fly Doppler broadening (OTF) in MCNP and testing. The OTF methodology involves high precision fitting of Doppler broadened cross-sections over a wide temperature range (the target for reactor calculations is 250-3200K). The temperature dependent fits are then used within MCNP during the neutron transport, for OTF broadening based on cell temperatures. It is straightforward to extend this capability to cover any temperature range of interest, allowing the Monte Carlo simulation to account for a continuous distribution of temperature ranges throughout the problem geometry.

  20. Doppler spectroscopy and D-alpha emission diagnostics for the C-2 FRC plasma

    SciTech Connect (OSTI)

    Gupta, Deepak K.; Paganini, E.; Bonelli, L.; Deng, B. H.; Gornostaeva, O.; Hayashi, R.; Knapp, K.; McKenzie, M.; Pousa-Hijos, R.; Primavera, S.; Schroeder, J.; Tuszewski, M. [Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688 (United States); Balvis, A.; Giammanco, F.; Marsili, P. [Department of Physics, University of Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy)

    2010-10-15T23:59:59.000Z

    Two Doppler spectroscopy diagnostics with complementary capabilities are developed to measure the ion temperatures and velocities of FRC plasmas in the C-2 device. First, the multichord ion doppler diagnostic can simultaneously measure 15 chords of the plasma using an image intensified camera. Second, a single-chord fast-response ion Doppler diagnostic provides much higher faster time response by using a 16-channel photo-multiplier tube array. To study the neutral density of deuterium under different wall and plasma conditions, a highly sensitive eight-channel D-alpha diagnostic has been developed and calibrated for absolute radiance measurements. These spectroscopic diagnostics capabilities, combined with other plasma diagnostics, are helping to understand and improve the field reversed configuration plasmas in the C-2 device.

  1. Effects of Doppler broadening on Autler-Townes splitting in six-wave mixing

    SciTech Connect (OSTI)

    Niu Jinyan [Laboratory of Optical Physics, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); School of Mathematics, Physics and Biological Engineering, Inner Mongolia University of Science and Technology, Baotou 014010 (China); Pei Liya; Lu Xiaogang; Wang Ruquan; Wu Lingan; Fu Panming [Laboratory of Optical Physics, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2011-09-15T23:59:59.000Z

    The effects of Doppler broadening on Autler-Townes (AT) splitting in six-wave mixing (SWM) are investigated by the dressed-state model. We analyze the velocities at which the atoms are in resonance with the dressed states through Doppler frequency shifting and find that, depending on the wave-number ratio, there may be two resonant velocities which can originate from resonance with one of the dressed states or from resonance with two different dressed states. Based on this model, we discuss a novel type of AT doublet in the SWM spectrum, where macroscopic effects play an important role. Specifically, the existence of resonant peaks requires polarization interference between atoms of different velocities in addition to a change in the number of resonant atoms involved. Our model can also be employed to analyze electromagnetically induced transparency resonance and other types of Doppler-free high-resolution AT spectroscopy.

  2. Intrinsic Lorentz violation in Doppler effect from a moving point light source

    E-Print Network [OSTI]

    Changbiao Wang

    2012-04-09T23:59:59.000Z

    Einstein's Doppler formula is not applicable when a moving point light source is close enough to the observer; for example, it may break down or cannot specify a determinate value when the point source and the observer overlap. In this paper, Doppler effect for a moving point light source is analyzed, and it is found that the principle of relativity allows the existence of intrinsic Lorentz violation. A conceptual scheme to experimentally test the point-source Doppler effect is proposed, and such a test could lead to an unexpected result that the frequency of a photon may change during propagation, which questions the constancy of Planck constant since the energy conservation in Einstein's light-quantum hypothesis must hold.

  3. Multi-line Doppler imaging of MR Ser in high-state

    E-Print Network [OSTI]

    Marcos Diaz; Deonisio Cieslinski

    2008-11-05T23:59:59.000Z

    Doppler images in Balmer, HeI, HeII and CII lines, and simultaneous I-band photometry of the polar MR Ser are presented and analyzed. The Balmer and Helium Doppler tomograms of this bright polar at high mass transfer state show the emission from the accretion flow and the heated surface of the companion star. As a result of a comparison between the Doppler tomograms the ionization structure of the flow could be constrained. The highest ionization region was found in the vicinity of the magnetospheric radius. Photoionization modeling of the accretion column indicates that the Balmer and Helium emission line production in this system can be explained by the central soft Xray illumination only. The orbital ephemeris of MR Ser has been revised.

  4. Methods And System Suppressing Clutter In A Gain-Block, Radar-Responsive Tag System

    DOE Patents [OSTI]

    Ormesher, Richard C. (Albuquerque, NM); Axline, Robert M. (Albuquerque, NM)

    2006-04-18T23:59:59.000Z

    Methods and systems reduce clutter interference in a radar-responsive tag system. A radar transmits a series of linear-frequency-modulated pulses and receives echo pulses from nearby terrain and from radar-responsive tags that may be in the imaged scene. Tags in the vicinity of the radar are activated by the radar's pulses. The tags receive and remodulate the radar pulses. Tag processing reverses the direction, in time, of the received waveform's linear frequency modulation. The tag retransmits the remodulated pulses. The radar uses a reversed-chirp de-ramp pulse to process the tag's echo. The invention applies to radar systems compatible with coherent gain-block tags. The invention provides a marked reduction in the strength of residual clutter echoes on each and every echo pulse received by the radar. SAR receiver processing effectively whitens passive-clutter signatures across the range dimension. Clutter suppression of approximately 14 dB is achievable for a typical radar system.

  5. Finding the mass-energy counterpart to the transverse Doppler shift: Avoiding de Broglie's paradox

    E-Print Network [OSTI]

    Steven M Taylor

    2005-09-30T23:59:59.000Z

    This paper identifies specific angles of emission and reception of light for which there exists a mass-energy counterpart to the well known transverse Doppler shift. At these angles, the relationship of proper and relative frequency is the same as that for proper and relative mass-energy of a source. Paradoxically, the transverse Doppler shift is often used to demonstrate that for specific angles of emission and reception the relationship of proper and relative frequency of light is the same as that for proper and relative time. But by carefully defining angles, this apparent paradox is resolved.

  6. Importance of the Doppler Effect to the Determination of the Deuteron Binding Energy

    E-Print Network [OSTI]

    Yongkyu Ko; Myung Ki Cheoun; Il-Tong Cheon

    1999-04-01T23:59:59.000Z

    The deuteron binding energy extracted from the reaction ${}^1H(n,\\gamma){}^2H$ is reviewed with the exact relativistic formula, where the initial kinetic energy and the Doppler effect are taken into account. We find that the negligible initial kinetic energy of the neutron could cause a significant uncertainty which is beyond the errors available up to now. Therefore, we suggest an experiment which should include the detailed informations about the initial kinetic energy and the detection angle. It could reduce discrepancies among the recently reported values about the deuteron binding energy and pin down the uncertainty due to the Doppler broadening of $\\gamma$ ray.

  7. Combined complex Doppler and Cherenkov effect in left-handed metamaterials

    E-Print Network [OSTI]

    Ziemkiewicz, David

    2015-01-01T23:59:59.000Z

    We derive the formula of the complex Doppler shift in a two-dimensional, dispersive metamaterial and we show that a moving, monochromatic radiation source generates multiple frequency modes. The role of the group velocity is stressed and the Doppler shifted radiation field exhibits features of the Cherenkov effect. The presented theory is also applicable to the case of a moving, nonoscillating charge and explains many peculiar characteristics of the Cherenkov radiation in lefthanded metamaterials such as the backward direction of power emission, the constant radiation angle and the lack of velocity threshold.

  8. Time delay and Doppler tests of the Lorentz symmetry of gravity

    SciTech Connect (OSTI)

    Bailey, Quentin G. [Physics Department, Embry-Riddle Aeronautical University, 3700 Willow Creek Road, Prescott, Arizona 86301 (United States)

    2009-08-15T23:59:59.000Z

    Modifications to the classic time-delay effect and Doppler shift in general relativity (GR) are studied in the context of the Lorentz-violating standard-model extension (SME). We derive the leading Lorentz-violating corrections to the time-delay and Doppler shift signals, for a light ray passing near a massive body. It is demonstrated that anisotropic coefficients for Lorentz violation control a time-dependent behavior of these signals that is qualitatively different from the conventional case in GR. Estimates of sensitivities to gravity-sector coefficients in the SME are given for current and future experiments, including the recent Cassini solar conjunction experiment.

  9. Radiative transfer effects on Doppler measurements as sources of surface effects in sunspot seismology

    E-Print Network [OSTI]

    S. P. Rajaguru; K. Sankarasubramanian; R. Wachter; P. H. Scherrer

    2006-11-29T23:59:59.000Z

    We show that the use of Doppler shifts of Zeeman sensitive spectral lines to observe wavesn in sunspots is subject to measurement specific phase shifts arising from, (i) altered height range of spectral line formation and the propagating character of p mode waves in penumbrae, and (ii) Zeeman broadening and splitting. We also show that these phase shifts depend on wave frequencies, strengths and line of sight inclination of magnetic field, and the polarization state used for Doppler measurements. We discuss how these phase shifts could contribute to local helioseismic measurements of 'surface effects' in sunspot seismology.

  10. Covariance Matrix of a Double-Differential Doppler-broadened Elastic Scattering Cross Section

    SciTech Connect (OSTI)

    Arbanas, Goran [ORNL; Becker, B. [Rensselaer Polytechnic Institute (RPI); Dagan, R [Institut fur Neutronenphysik und Reaktortechnik; Dunn, Michael E [ORNL; Larson, Nancy M [ORNL; Leal, Luiz C [ORNL; Williams, Mark L [ORNL

    2012-01-01T23:59:59.000Z

    Legendre moments of a double-differential Doppler-broadened elastic neutron scattering cross section on {sup 238}U are computed near the 6.67 eV resonance at temperature T = 10{sup 3} K up to angular order 14. A covariance matrix of these Legendre moments is computed as a functional of the covariance matrix of the elastic scattering cross section. A variance of double-differential Doppler-broadened elastic scattering cross section is computed from the covariance of Legendre moments.

  11. An Evaluation of Acoustic Doppler Velocimeters as Sensors to Obtain the Concentration of Suspended Mass in Water

    E-Print Network [OSTI]

    Boss, Emmanuel S.

    An Evaluation of Acoustic Doppler Velocimeters as Sensors to Obtain the Concentration of Suspended, acoustic Doppler velocimeters (ADVs) and other acoustic sensors have been used by researchers in the ocean than optical turbidity sensors, and the high-frequency velocity measurements allow for a direct

  12. Feasibility of a borehole VHF radar technique for fracture mapping

    SciTech Connect (OSTI)

    Chang, H.T.

    1984-01-01T23:59:59.000Z

    Experiments were conducted to establish the feasibility of a downhole high-frequency electromagnetic technique for location of fractures in the vicinity of boreholes. An existing flame-cut slot in granite was filled with salt water to simulate a brine-filled fracture. A transmitter consisting of a phased dual-dipole array arranged to provide a directional signal toward the fracture was installed in a borehole opposite the fracture. A receiver operated at 30 to 300 MHz was also located in the same borehole. The radar returns from the simulated fracture were detectable in boreholes located at distances of up to 12 meters from the fracture. These results indicate for the first time the feasibility of a downhole VHF radar for use in a single borehole for detection of fractures located away from the borehole.

  13. Forensic Application of FM-CW and Pulse Radar

    SciTech Connect (OSTI)

    S. K. Koppenjan; R. S. Freeland; M. L. Miller; R. E. Yoder

    2003-01-01T23:59:59.000Z

    Ground-penetrating radar (GPR) technology has supplied vital assistance in criminal investigations. However, law enforcement personnel desire further developments such that the technology is rapidly deployable, and that it provides both a simple user interface and sophisticated target identification. To assist in the development of target identification algorithms, our efforts involve gathering background GPR data for the various site conditions and circumstances that often typify clandestine burials. For this study, forensic anthropologists established shallow-grave plots at The University of Tennessee Anthropological Research Facility (ARF) that are specific to GPR research. These plots contain donated human cadavers lying in various configurations and depths, surrounded by assorted construction material and backfill debris. We scanned the plots using two GPR technologies: (1) a multi-frequency synthetic-aperture FM-CW radar (200-700 MHz) (GPR-X) developed by the U.S. Department of Energy's (DOE) Special Technologies Laboratory (STL), Bechtel Nevada (Koppenjan et al., 2000), and (2) a commercial pulse radar (SIR-20) manufactured by Geophysical Survey Systems, Inc. (400 and 900 MHz)(GSSI). The sweep-frequency data show the large biological mass decomposing within the torso as encircled ''hot spots.'' The 400-MHz pulse radar exhibit major horizontal reflectors above the body, with shadow reflectors (horizontal multiples) occurring beneath the body at 60 cm depth. The 400-MHz antenna was able to discern the grave walls and folded tarp covering the lower body. Under these moist, clay-rich conditions, the 900-MHz antenna was able to penetrate slightly beyond 30 cm beneath the concrete layer. However, neither system was able to penetrate beyond a one meter depth in the moist, clay-rich soil (fine, mixed, thermic Typic Paleudalf). Example scans from each system are provided, along with a discussion of the survey protocol and general performance.

  14. Radar antenna pointing for optimized signal to noise ratio.

    SciTech Connect (OSTI)

    Doerry, Armin Walter; Marquette, Brandeis [General Atomics Aeronautical Systems, Inc., San Diego, CA

    2013-01-01T23:59:59.000Z

    The Signal-to-Noise Ratio (SNR) of a radar echo signal will vary across a range swath, due to spherical wavefront spreading, atmospheric attenuation, and antenna beam illumination. The antenna beam illumination will depend on antenna pointing. Calculations of geometry are complicated by the curved earth, and atmospheric refraction. This report investigates optimizing antenna pointing to maximize the minimum SNR across the range swath.

  15. Laser Anemometry In Fluid Mechanics-IV Selected Papers from the Fourth Intl. Symp. On Appl. Of Laser-doppler Anemometry to Fluid Mechanics

    E-Print Network [OSTI]

    Instituto de Sistemas e Robotica

    . · Simultaneous Laser-Doppler-Velocimetry and particle sizing in the freeboard of a fluidised bed combustor. By K

  16. Digital meteorological radar data compared with digital infrared data from a geostationary meteorological satellite

    E-Print Network [OSTI]

    Henderson, Rodney Stuart

    1979-01-01T23:59:59.000Z

    OF CONTENTS Page ABSTRACT. ACKNOWLEDGMENTS. DEDICATION . iv vi TABLE OF CONTENTS . vii LIST OF TABLES. IX LIST OF FIGURES . LIST OF ACRONYMS CHAPTER xii I. INTRODUCTION 1. The Need for This Investigation 2. Present Status of Research Relating... to This Investigation 3. Objectives of the Investigation 4. Techniques and Scope of the Investigation. II. METEOROLOGICAL RADAR DATA . 10 1. Basic Radar Theory . 2. Earth Curvature Correction . 3. The TAMU Weather Radar System. 4. Data Reduction and Display 10...

  17. Simple Doppler Wind Lidar adaptive observation experiments with 3D-Var and an ensemble Kalman filter in a global primitive equations model

    E-Print Network [OSTI]

    Maryland at College Park, University of

    the next few years, the first Doppler Wind Lidar (DWL) will be deployed in space by the European Space1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Simple Doppler Wind Lidar adaptive Experiments, we compare several adaptive observation strategies designed to subsample Doppler Wind Lidar (DWL

  18. Impact Assessment of Simulated Doppler Wind Lidars with a Multivariate Variational Assimilation in the Tropics

    E-Print Network [OSTI]

    Stoffelen, Ad

    forecast errors of the European Centre for Medium-Range Weather Forecasts (ECMWF) model. Tropical mass­windImpact Assessment of Simulated Doppler Wind Lidars with a Multivariate Variational Assimilation, De Bilt, Netherlands CHRISTOPHE ACCADIA AND PETER SCHL�SSEL European Organisation

  19. Ensemble Kalman Filter Assimilation of Simulated HIWRAP Doppler Velocity Data in a Hurricane

    E-Print Network [OSTI]

    Ensemble Kalman Filter Assimilation of Simulated HIWRAP Doppler Velocity Data in a Hurricane JASON (Manuscript received 29 May 2012, in final form 16 January 2013) ABSTRACT This study utilizes ensemble Kalman Kalman filter (EnKF) assimilation of high-resolution observations from tropical cyclones can improve

  20. A Bistatic Phased-Array Doppler Sonar for WaveCurrent Research JEROME A. SMITH

    E-Print Network [OSTI]

    Buckingham, Michael

    A Bistatic Phased-Array Doppler Sonar for Wave­Current Research JEROME A. SMITH Scripps Institution; Smith 2006a). In this last case, a discrepancy was identified: the measured response at the surface given below, see Smith (2006a); for a discussion of the wave groups re- sponsible, see Smith

  1. Upstream Measurements of Wind Profiles with Doppler Lidar for Improved Wind Energy Integration

    SciTech Connect (OSTI)

    Rodney Frehlich

    2012-10-30T23:59:59.000Z

    New upstream measurements of wind profiles over the altitude range of wind turbines will be produced using a scanning Doppler lidar. These long range high quality measurements will provide improved wind power forecasts for wind energy integration into the power grid. The main goal of the project is to develop the optimal Doppler lidar operating parameters and data processing algorithms for improved wind energy integration by enhancing the wind power forecasts in the 30 to 60 minute time frame, especially for the large wind power ramps. Currently, there is very little upstream data at large wind farms, especially accurate wind profiles over the full height of the turbine blades. The potential of scanning Doppler lidar will be determined by rigorous computer modeling and evaluation of actual Doppler lidar data from the WindTracer system produced by Lockheed Martin Coherent Technologies, Inc. of Louisville, Colorado. Various data products will be investigated for input into numerical weather prediction models and statistically based nowcasting algorithms. Successful implementation of the proposed research will provide the required information for a full cost benefit analysis of the improved forecasts of wind power for energy integration as well as the added benefit of high quality wind and turbulence information for optimal control of the wind turbines at large wind farms.

  2. NATURE|Vol 441|18 May 2006 NEWS & VIEWS Doppler wobble. Second, the reduced stellar

    E-Print Network [OSTI]

    Cai, Long

    dimming of that star's light. By observing both Doppler signalsandtransits,boththemassandphysical size University, 60 Garden Street, Cambridge, Massachusetts 02138, USA. e-mail: dcharbonneau@cfa.harvard.edu 1 remains an open question. In the Solar System, the asteroid belt lies near 2.6 AU, between the orbits

  3. Lateral imaging of the superconducting vortex lattice using Doppler-modulated scanning tunneling microscopy

    E-Print Network [OSTI]

    Wei, John Y.T.

    Lateral imaging of the superconducting vortex lattice using Doppler-modulated scanning tunneling on the quasiparticle tunneling spectrum, we have laterally imaged the vortex lattice in superconducting 2H-NbSe2 that circulates along the sample edge. Above the lower critical field, field can penetrate into the superconductor

  4. The game of the "very small" and the "very big": The case of the Doppler Effect

    E-Print Network [OSTI]

    Bernhard Rothenstein; Albert Rothenstein

    2003-08-27T23:59:59.000Z

    In the study of the Doppler Effect, non-locality is not taken into account. We present two cases in which a continuous change in the receiver's speed and in the angle at which the successive wavecrests are received takes place. In each case the error committed by not taking into account the non-locality is evaluated.

  5. Periodic Flux Variability of Stars due to the Reflex Doppler Effect Induced by Planetary Companions

    E-Print Network [OSTI]

    Abraham Loeb; B. Scott Gaudi

    2003-03-28T23:59:59.000Z

    Upcoming space-based photometric satellites offer the possibility of detecting continuum flux variability at the micro-magnitude level. We show that the Doppler flux variability induced by the reflex motion of stars due to planetary companions has an amplitude of (3-alpha)K/c, where K is the reflex radial velocity amplitude and alpha is the logarithmic slope of source spectral flux in the observed frequency band. For many of the known close-in planetary systems with periods less than ~0.2 years, the periodic Doppler variability is of order a micromagnitude, and is significant relative to the variability caused by reflected light from the planetary companion. For companions with periods greater than ~0.2 years, the Doppler signal is larger than the reflected light signal. We show that the future photometric satellites should reach the sensitivity to detect this Doppler variability. In particular, the Kepler satellite should have the photon-noise sensitivity to detect at a signal-to-noise ratio > 5, all planets with minimum mass greater than 5 Jupiter masses, and periods less than 0.1 years around the 10,000 main-sequence stars with spectral types A through K and apparent magnitude V<12 in its field-of-view.

  6. Doppler effect in fragment autoionization following core-to-valence excitation in O{sub 2}

    SciTech Connect (OSTI)

    Guillemin, Renaud; Simon, Marc; Shigemasa, Eiji [Universite Pierre et Marie Curie, Laboratoire de Chimie Physique-Matiere et Rayonnement, UMR 7614, 11 rue Pierre et Marie Curie, F-75231 Paris Cedex 05, France and Centre National de la Recherche Scientifique, Laboratoire de Chimie Physique-Matiere et Rayonnement, UMR 7614, 11 rue Pierre et Marie Curie, F-75231 Paris Cedex 05 (France); Ultraviolet Synchrotron Orbital Radiation Facility, Institute for Molecular Science, Okazaki 444-8585 (Japan)

    2010-11-15T23:59:59.000Z

    Atomic autoionization following O 1s resonant excitation in O{sub 2} is studied using high-resolution electron spectroscopy. The resonant Auger spectrum showing evidence of ultrafast dissociation as well as the autoionization of oxygen atoms is measured and discussed. Evidence of the electronic Doppler effect is observed in both electronic decay mechanisms.

  7. The First Extrasolar Planet Discovered with a New Generation High Throughput Doppler Instrument

    E-Print Network [OSTI]

    Complutense de Madrid, Universidad

    was confirmed by radial velocity observations with the ET at the KPNO 2.1 m tele- scope and also at the 9 m is an effective method for planet detection. In addition, the ET concept is adaptable to multiple-object Doppler activity as the cause of the radial velocity variability. Our photometric observations rule out transits

  8. Flow Velocity Estimation in Optical Doppler Tomography and A Preliminary Study on Radiation Detection for Hybrid

    E-Print Network [OSTI]

    Piao, Daqing

    Tomography and A Preliminary Study on Radiation Detection for Hybrid Optical Coherence TomographyFlow Velocity Estimation in Optical Doppler Tomography and A Preliminary Study on Radiation Detection for Hybrid Optical Coherence Tomography/Scintigraphy Daqing Piao B.S., Tsinghua University, 1990 M

  9. Improving ISR Radar Utilization (How I quit blaming the user and made the radar easier to use).

    SciTech Connect (OSTI)

    Doerry, Armin W.

    2014-08-01T23:59:59.000Z

    In modern multi - sensor multi - mode Intelligence, Surveillance, and Reconnaissance ( ISR ) platforms, the plethora of options available to a sensor/payload operator are quite large, leading to an over - worked operator often down - selecting to favorite sensors an d modes. For example, Full Motion Video (FMV) is justifiably a favorite sensor at the expense of radar modes, even if radar modes can offer unique and advantageous information. The challenge is then to increase the utilization of the radar modes in a man ner attractive to the sensor/payload operator. We propose that this is best accomplished by combining sensor modes and displays into 'super - modes'. - 4 - Acknowledgements This report is the result of a n unfunded research and development activity . Sandia Natio nal Laboratories is a multi - program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE - AC04 - 94AL850 00.

  10. Phase control of probe response in a Doppler-broadened N-type four-level system

    SciTech Connect (OSTI)

    Fan Xijun; Liu Zhongbo; Liang Ying; Jia Kening [College of Physics and Electronics, Shandong Normal University, Jinan 250014 (China); Tong Dianmin [School of Physics, Shandong University, Jinan 250100 (China)

    2011-04-15T23:59:59.000Z

    In this paper, we investigate theoretically the effect of the relative phase ({phi}) between the probe and driving fields on gain (absorption) and dispersion of the probe field in a Doppler-broadened N-type four-level system with spontaneously generated coherence from different respects. It is shown that gain (absorption) and dispersion are very sensitive to variations in the relative phase, and changing the Doppler width also has an obvious effect on the phase-dependent gain (absorption) and dispersion. When the probe and driving fields have the same propagation directions (copropagating), for the same Doppler width, the dispersion curve with {phi}={alpha} is the same as the gain (absorption) curve with {phi}={alpha}+{pi}/2; however, when the probe and driving fields have opposite propagation directions (counterpropagating), the dispersion curve and gain (absorption) curve are different and the difference becomes more considerable with an increase in Doppler width. In the co- and counterpropagating cases, gain (absorption) and dispersion always vary periodically with varying {phi}, and the period is 2{pi}. By adjusting the value of {phi}, the largest gain (absorption) and dispersion can be obtained, and a large index of refraction without absorption can be realized. Generally speaking, gain decreases with an increase in Doppler width, but by adjusting value of {phi}, at some special values of Doppler width, a larger gain than that without Doppler broadening can be obtained. Our study also shows that gain in the copropagating case is much larger than that in the counterpropagating case.

  11. Null vector fields in spaces with affine connections and metrics. Doppler's effect, Hubble's effect, and aberration's effect

    E-Print Network [OSTI]

    Sawa Manoff

    2003-05-07T23:59:59.000Z

    The notion of null (isotropic) vector field is considered in spaces with affine connections and metrics as models of space or space-time. On its basis the propagation of signals in space-time is considered. The Doppler effect is generalized for these types of spaces. The notions of standard (longitudinal) Doppler effect and transversal Doppler effect are introduced. On their grounds, the Hubble effect and the aberration effect appear as Doppler effects with explicit forms of the centrifugal (centripetal) and Coriolis velocity vector fields in spaces with affine connections and metrics. The upper limit of the value of the general observed shift parameter z, generated by both the effects, based on the Doppler effects, is found to be z = 1.41. Doppler's effects, Hubble's effect, and aberration's effect could be used in mechanics of continuous media and in other classical field theories in the same way as the standard Doppler effect is used in classical and relativistic mechanics. PACS numbers: 04.20.Cv; 04.50.+h; 04.40.b; 04.90.+e; 83.10.Bb

  12. Power-law tailed spectra from equilibrium

    E-Print Network [OSTI]

    T. S. Biro; G. Purcsel; G. Gyorgyi; A. Jakovac; Zs. Schram

    2005-10-03T23:59:59.000Z

    We propose that power-law tailed hadron spectra may be viewed as stemming from a matter in an unconventional equilibrium state typical for non-extensive thermodynamics. A non-extensive Boltzmann equation, which is able to form such spectra as a stationary solution, is utilized as a rough model of quark matter hadronization. Basic ideas about non-extensive simulation of the QCD equation of state on the lattice are presented.

  13. ARM - Evaluation Product - Corrected Precipitation Radar Moments in Antenna

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006Datastreamstwrcam40m Documentation DataDatastreamsxsaprhsrhi1-min (NAVBE1M)Doppler Lidar

  14. Two-step Doppler cooling of a three-level ladder system with an intermediate metastable level

    E-Print Network [OSTI]

    Caroline Champenois; Gaetan Hagel; Martina Knoop; Marie Houssin; Cedric Zumsteg; Fernande Vedel; Michael Drewsen

    2008-02-14T23:59:59.000Z

    Doppler laser cooling of a three-level ladder system using two near-resonant laser fields is analyzed in the case of the intermediate level being metastable while the upper level is short-lived. Analytical as well as numerical results for e.g. obtainable scattering rates and achievable temperatures are presented. When appropriate, comparisons with two-level single photon Doppler laser cooling is made. These results are relevant to recent experimental Doppler laser cooling investigations addressing intercombination lines in alkali-earth metal atoms and quadrupole transitions in alkali-earth metal ions.

  15. Atomic lines in infrared spectra for ultracool dwarfs

    E-Print Network [OSTI]

    Yu. Lyubchik; H. R. A. Jones; Ya. V. Pavlenko; S. Viti; J. C. Pickering; R. Blackwell-Whitehead

    2003-12-22T23:59:59.000Z

    We provide a set of atomic lines which are suitable for the description of ultracool dwarf spectra from 10000 to 25000 \\AA. This atomic linelist was made using both synthetic spectra calculations and existing atlases of infrared spectra of Arcturus and Sunspot umbra. We present plots, which show the comparison of synthetic spectra and observed Arcturus and Sunspot umbral spectra for all atomic lines likely to be observable in high resolution infrared spectra.

  16. Incorporating WAAS Data Into an Ionospheric Model for Correcting Satellite Radar

    E-Print Network [OSTI]

    Toews, Carl

    at the Millstone Hill Satellite Tracking Radar. She currently holds a joint appointment with the Atmospheric corrections to radar measurements, incorporating data from a single receiver to generate TEC estimates that the GRIMS ionospheric model degenerates during times of sharp spatial TEC gradients, e.g. during geomagnetic

  17. Vertical Structure of Tropical Cyclone Rainbands as Seen by the TRMM Precipitation Radar

    E-Print Network [OSTI]

    Houze Jr., Robert A.

    Vertical Structure of Tropical Cyclone Rainbands as Seen by the TRMM Precipitation Radar DEANNA A Measurement Mission satellite's Precipitation Radar (TRMM PR) show the vertical structure of tropical cyclone separated by the melting layer. The ice layer is a combination of particles imported from the eyewall

  18. Vertical Structure of Tropical Cyclone Rainbands as seen by the TRMM Precipitation Radar

    E-Print Network [OSTI]

    Houze Jr., Robert A.

    1 Vertical Structure of Tropical Cyclone Rainbands as seen by the TRMM Precipitation Radar Deanna A (TRMM PR) show the vertical structure of tropical cyclone rainbands. Radar-echo2 statistics show that rainbands have a two-layered structure, with distinct modes separated by the3 melting layer. The ice layer

  19. Operational Monitoring of Weather Radar Receiving Chain Using the Sun IWAN HOLLEMAN

    E-Print Network [OSTI]

    Stoffelen, Ad

    Operational Monitoring of Weather Radar Receiving Chain Using the Sun IWAN HOLLEMAN Royal, is presented. The ``online'' method is entirely based on the analysis of sun signals in the polar volume data- termining the weather radar antenna pointing at low elevations using sun signals, and it is suited

  20. ERAD 2008 -THE FIFTH EUROPEAN CONFERENCE ON RADAR IN METEOROLOGY AND HYDROLOGY 1. Introduction

    E-Print Network [OSTI]

    Stoffelen, Ad

    , and the enhancement of the radar processing with capabilities found in modern radar equipment. In the European tender receivers and completely new data processing equipment. This modern equipment was integrated in the existing for PRFs up to 1200 Hz. To enhance reliability the thyratron powered switch unit, used to "fire

  1. Soil texture estimation over a semi-arid area using TERRASAR-X radar data

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Soil texture estimation over a semi-arid area using TERRASAR-X radar data M. Zribi1 , F. Kotti1 , Z Abstract In this paper, it is proposed to use TERRASAR-X data for analysis and estimation of soil surface. Simultaneously to TERRASAR-X radar acquisitions, ground measurements (texture, soil moisture and roughness) were

  2. Lagrangian Structures in Very High-Frequency Radar Data and Optimal Pollution Timing

    E-Print Network [OSTI]

    Marsden, Jerrold

    Lagrangian Structures in Very High-Frequency Radar Data and Optimal Pollution Timing Francois radar-based pollution release scheme using the hidden flow structure reduces the effect of industrial pollution in the coastal environment. INTRODUCTION The release of pollution in coastal areas [1, 2, 3] can

  3. Optimal Pollution Mitigation in Monterey Bay Based on Coastal Radar Data and Nonlinear

    E-Print Network [OSTI]

    Marsden, Jerrold

    Optimal Pollution Mitigation in Monterey Bay Based on Coastal Radar Data and Nonlinear Dynamics run-off which is a typical source of pollution in the bay. We show that a HF radar-based pollution release scheme using this flow structure reduces the impact of pollution on the coastal envi- ronment

  4. Radar Sounding of Glaciers in Greenland C. Allen, B, Wohletz, and S, Gogineni

    E-Print Network [OSTI]

    Kansas, University of

    Radar Sounding of Glaciers in Greenland C. Allen, B, Wohletz, and S, Gogineni The University on several flights over Greenland glaciers during the summer of 1995. The radar data were collected the theory and present results of the homomorphic deconvolution procedure. INTRODUCTION The Greenland

  5. FUSING MICROWAVE RADAR AND MICROWAVE-INDUCED THERMOACOUSTICS FOR BREAST CANCER DETECTION

    E-Print Network [OSTI]

    FUSING MICROWAVE RADAR AND MICROWAVE-INDUCED THERMOACOUSTICS FOR BREAST CANCER DETECTION Evgeny in the microwave range. Microwave-radar and microwave-induced thermoacoustic methods both struggle when-induced thermoacoustic (MIT) methods measure and process the acoustic signals induced by differential microwave heating

  6. Planning of Low-Cost 77-GHz Radar Transceivers for Automotive Applications

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    . Moghavvemi University ofMalaya INTRODUCTION The use of electronics in the automotive industry will reach (or the position and speed as with other components used in the automotive industry, radars will find widespreadPlanning of Low-Cost 77-GHz Radar Transceivers for Automotive Applications H. Ameri, A. Attaran & M

  7. "A Functional Design and System Architecture of a Control System for a Weather Radar"

    E-Print Network [OSTI]

    Mountziaris, T. J.

    "A Functional Design and System Architecture of a Control System for a Weather Radar" Seidu Ibrahim Faculty Mentor: Eric Knapp Weather radars operate by transmitting pulses of very high microwave energy antenna scan, a three dimensional view of the surrounding atmosphere is created. Traditional weather

  8. Reflectivity retrieval in a networked radar environment: Demonstration from the CASA IP1

    E-Print Network [OSTI]

    Jayasumana, Anura P.

    using data from the first Integration Project (IP1) radar network in Oklahoma. Electromagnetic waves, the lowest coverage altitude gets higher with range due to earth curvature [1]. A networked radar environment is capable of high spatial coverage and temporal resolution. The Engineering Research Center for CASA

  9. Thunderstorm lightning and radar characteristics: insights on electrification and severe weather forecasting

    E-Print Network [OSTI]

    Steiger, Scott Michael

    2007-04-25T23:59:59.000Z

    THUNDERSTORM LIGHTNING AND RADAR CHARACTERISTICS: INSIGHTS ON ELECTRIFICATION AND SEVERE WEATHER FORECASTING A Dissertation by SCOTT MICHAEL STEIGER Submitted to the Office of Graduate Studies of Texas A&M University in partial... fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY December 2005 Major Subject: Atmospheric Sciences THUNDERSTORM LIGHTNING AND RADAR CHARACTERISTICS: INSIGHTS ON ELECTRIFICATION AND SEVERE WEATHER...

  10. Design of X-Band FMCW Short Range Radar Dong-hun Shin*

    E-Print Network [OSTI]

    Park, Seong-Ook

    Proposed radar system is bi-static radar type. It is adopted for increasing the isolation between Tx and Rx of a power divider. A portion of the swept signal is coupled to the mixer as reference signal. The final transmitted power of the system is under 0dBm. Received echo signal from the Rx antenna is injected to mixer

  11. Comparison Between Mass Spectra of Individual Organic Particles...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Mass Spectra of Individual Organic Particles Generated by UV Laser Ablation and in the IRUV Two-Step Mode. Comparison Between Mass Spectra of Individual Organic Particles...

  12. Prospects of the WSR-88D Radar for Cloud Studies

    E-Print Network [OSTI]

    Melnikov, Valery M.; Zrni?, Dusan S.; Doviak, Richard J.; Chilson, Phillip B.; Mechem, David B.; Kogan, Yefim L.

    2011-04-01T23:59:59.000Z

    - flectivity field at 908 azimuth. APRIL 2011 M E L N I K O V E T A L . 863 compared measured solar radiation with model results. The Bird model (Bird and Hulstrom 1981) has been used to estimate the solar flux on the ground in the absence of clouds....S. Department of Commerce). REFERENCES Battan, L. J., 1973: Radar Observation of the Atmosphere. Uni- versity of Chicago, 324 pp. Bird, R. E., and R. L. Hulstrom, 1981: A simplified clear sky model for direct and diffuse insolation on horizontal surfaces. Solar...

  13. Compressive Radar with Off-Grid and Extended Targets

    E-Print Network [OSTI]

    Fannjiang, Albert

    2012-01-01T23:59:59.000Z

    Compressed sensing (CS) schemes are proposed for monostatic as well as synthetic aperture radar (SAR) imaging of sparse targets with chirps. In particular, a simple method is developed to improve performance with off-grid targets. Tomographic formulation of spotlight SAR is analyzed by CS methods with several bases and under various bandwidth constraints. Performance guarantees are established via coherence bound and the restricted isometry property. CS analysis provides a fresh and clear perspective on how to optimize temporal and angular samplings for spotlight SAR.

  14. Radar investigation of the Cote Blanche salt dome

    E-Print Network [OSTI]

    Stewart, Robert Donald

    1974-01-01T23:59:59.000Z

    THE COTE BLANCHE SALT DOME. Geology of the Cote Blanche Salt-Dome Azea. . Economic History of the Cote BLanche Salt-Dome Azea, Salt. . Oil and gas. III. ELECTROMAGNETIC WAVE PROPAGATION. . . Radar Speed in Air and in Salt. . . Velocity...' zznd i'r. mzznz 1959) . The east, south, end west flanks are nearly vertical. However, the north side oi the dome is characterised by a massive overhang. A well drilled by Shell Oil Company, Caffrey No. 1, confirmed the presence of a minimum of 3300...

  15. North and northeast Greenland ice discharge from satellite radar interferometry

    SciTech Connect (OSTI)

    Rignot, E.J. [California Institute of Technology, Pasadena, CA (United States)] [California Institute of Technology, Pasadena, CA (United States); Gogineni, S.P. [Univ. of Kansas, Lawrence, KS (United States)] [Univ. of Kansas, Lawrence, KS (United States); Krabill, W.B. [NASA Goddard Space Flight Center, Wallops Island, VA (United States)] [and others] [NASA Goddard Space Flight Center, Wallops Island, VA (United States); and others

    1997-05-09T23:59:59.000Z

    Ice discharge from north and northeast Greenland calculated from satellite radar interferometry data of 14 outlet glaciers is 3.5 times that estimated from iceberg production. The satellite estimates, obtained at the grounding line of the outlet glaciers, differ from those obtained at the glacier front, because basal melting is extensive at the underside of the floating glacier sections. The results suggest that the north and northeast parts of the Greenland ice sheet may be thinning and contributing positively to sea-level rise. 24 refs., 3 figs., 1 tab.

  16. Mitigating Wind-Radar Interference | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment3311,Official FileEnergyAERMOD-PRIME, UnitsMitigating Wind-Radar

  17. THE REGIONAL AND DIURNAL VARIABILITY OF THE VERTICAL STRUCTURE OF PRECIPITATION SYSTEMS IN AFRICA, BASED ON TRMM PRECIPITATION RADAR DATA

    E-Print Network [OSTI]

    Geerts, Bart

    IN AFRICA, BASED ON TRMM PRECIPITATION RADAR DATA Bart Geerts1 and Teferi Dejene University of Wyoming 1 microwave radiances (e.g. Kummerow and Giglio 1994), and 14 GHz radar reflectivities (e.g. Ferreira et al-based techniques are much inferior to radar-based techniques, in principle at least, because the anvil of large

  18. Deconvolution of Stark broadened spectra for multi-point density measurements in a flow Z-pinch

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Vogman, G. V. [Univ. of California, Berkeley, CA (United States); Shumlak, U. [Univ. of Washington, Seattle, WA (United States)

    2011-01-01T23:59:59.000Z

    Stark broadened emission spectra, once separated from other broadening effects, provide a convenient non-perturbing means of making plasma density measurements. A deconvolution technique has been developed to measure plasma densities in the ZaP flow Z-pinch experiment. The ZaP experiment uses sheared flow to mitigate MHD instabilities. The pinches exhibit Stark broadened emission spectra, which are captured at 20 locations using a multi-chord spectroscopic system. Spectra that are time- and chord-integrated are well approximated by a Voigt function. The proposed method simultaneously resolves plasma electron density and ion temperature by deconvolving the spectral Voigt profile into constituent functions: a Gaussian function associated with instrument effects and Doppler broadening by temperature; and a Lorentzian function associated with Stark broadening by electron density. The method uses analytic Fourier transforms of the constituent functions to fit the Voigt profile in the Fourier domain. The method is discussed and compared to a basic least-squares fit. The Fourier transform fitting routine requires fewer fitting parameters and shows promise in being less susceptible to instrumental noise and to contamination from neighboring spectral lines. The method is evaluated and tested using simulated lines and is applied to experimental data for the 229.69 nm C III line from multiple chords to determine plasma density and temperature across the diameter of the pinch. These measurements are used to gain a better understanding of Z-pinch equilibria.

  19. Laser Doppler velocimetry based on the optoacoustic effect in a RF-excited CO{sub 2} laser

    SciTech Connect (OSTI)

    Lee, Teaghee; Choi, Jong Woon [Department of Information and Communication, Honam University, Seobong-dong 59-1, Gwansan-gu, Gwangju 506-714 (Korea, Republic of); Kim, Yong Pyung [College of Electronics and Information, Kyunghee University, 1 Seocheon-dong, Giheung-gu, Yongin-si, Gyeonggi-do 446-701 (Korea, Republic of)

    2012-09-15T23:59:59.000Z

    We present a compact optoacoustic laser Doppler velocimetry method that utilizes the self-mixing effect in a RF-excited CO{sub 2} laser. A portion of a Doppler-shifted laser beam, produced by irradiating a single wavelength laser beam on a moving object, is mixed with an originally existing laser beam inside a laser cavity. The fine change of pressure in the laser cavity modulated by the Doppler-shifted frequency is detected by a condenser microphone in the laser tube. In our studies, the frequency of the Doppler signal due to the optoacoustic effect was detected as high as 50 kHz. Our measurements also confirmed that the signal varied linearly with the velocity of the external scatterer (the moving object) and the cosine of the angle between the laser beam and the velocity vector of the object.

  20. On the assessment of blood velocity and wall shear rate in arteries with Doppler ultrasound: a validation study 

    E-Print Network [OSTI]

    Blake, James R.

    2008-01-01T23:59:59.000Z

    Cardiovascular disease, mostly atherosclerosis, is responsible for one third of all deaths globally, rising to more than 50% in the Western World. Risk factors include smoking, diet, and familial history. Doppler ultrasound ...

  1. Comparing Pulsed Doppler LIDAR with SODAR and Direct Measurements for Wind Assessment

    SciTech Connect (OSTI)

    Kelley, N. D.; Jonkman, B. J.; Scott, G. N.; Pichugina, Y. L.

    2007-07-01T23:59:59.000Z

    There is a pressing need for good wind-speed measurements at greater and greater heights to assess the availability of the resource in terms of power production and to identify any frequently occurring atmospheric structural characteristics that may create turbulence that impacts the operational reliability and lifetime of wind turbines and their components. In this paper, we summarize the results of a short study that compares the relative accuracies of wind speeds derived from a high-resolution pulsed Doppler LIDAR operated by the National Oceanic and Atmospheric Administration (NOAA) and a midrange Doppler SODAR with wind speeds measured by four levels of tower-based sonic anemometry up to a height of 116 m.

  2. Method and system to measure temperature of gases using coherent anti-stokes doppler spectroscopy

    DOE Patents [OSTI]

    Rhodes, Mark

    2013-12-17T23:59:59.000Z

    A method of measuring a temperature of a noble gas in a chamber includes providing the noble gas in the chamber. The noble gas is characterized by a pressure and a temperature. The method also includes directing a first laser beam into the chamber and directing a second laser beam into the chamber. The first laser beam is characterized by a first frequency and the second laser beam is characterized by a second frequency. The method further includes converting at least a portion of the first laser beam and the second laser beam into a coherent anti-Stokes beam, measuring a Doppler broadening of the coherent anti-Stokes beam, and computing the temperature using the Doppler broadening.

  3. Gamma-ray induced Doppler broadening and the determination of lifetimes of excited nuclear states

    SciTech Connect (OSTI)

    Boerner, H.G.; Jolie, J.; Robinson, S.J. (Institut Laue-Langevin, 38 - Grenoble (France)); Kessler, E.G.; Dewey, S.M.; Greene, G.; Deslattes, R. (National Inst. of Standards and Technology, Gaithersburg, MD (USA)); Ulbig, S.; Lieb, K.P. (Goettingen Univ. (Germany, F.R.)); Casten, R.F. (Brookhaven National Lab., Upton, NY (USA)); Krusche, B. (Giessen Univ. (Germany, F.R.)); Cizewski, J.A. (Rutgers--the

    1990-01-01T23:59:59.000Z

    Measurements of lifetimes of excited states in nuclei yield crucial information for sensitive tests of nuclear models. Here a novel method will be discussed which involves the GRID (Gamma Ray Induced Doppler broadening) technique, in which Doppler broadening is observed in a transition from a nucleus recoiling from the emission of a previous gamma ray. As the recoil energy is extremely small, ultra-high energy resolving power has to be used. To date all such experiments have been carried out at ILL using the GAMS4 double flat crystal spectrometer which is operated in a NIST-ILL collaboration. The method can be used for all lifetimes below a few picoseconds. The wide range of applicability, together with the very exhaustive set of data often obtained, is an advantage with respect to many other methods. The characteristic features of GRID will be discussed using some selected examples. 21 refs., 8 figs.

  4. Analysis of photonic Doppler velocimetry data based on the continuous wavelet transform

    SciTech Connect (OSTI)

    Liu Shouxian; Wang Detian; Li Tao; Chen Guanghua; Li Zeren; Peng Qixian [Institute of Fluid Physics, China Academy of Engineering Physics, P.O. Box 919-109, Mianyang, Sichuan 621900 (China)

    2011-02-15T23:59:59.000Z

    The short time Fourier transform (STFT) cannot resolve rapid velocity changes in most photonic Doppler velocimetry (PDV) data. A practical analysis method based on the continuous wavelet transform (CWT) was presented to overcome this difficulty. The adaptability of the wavelet family predicates that the continuous wavelet transform uses an adaptive time window to estimate the instantaneous frequency of signals. The local frequencies of signal are accurately determined by finding the ridge in the spectrogram of the CWT and then are converted to target velocity according to the Doppler effects. A performance comparison between the CWT and STFT is demonstrated by a plate-impact experiment data. The results illustrate that the new method is automatic and adequate for analysis of PDV data.

  5. Cavity ring-down spectroscopy measurements of sub-Doppler hyperfine structure

    SciTech Connect (OSTI)

    Long, D. A.; Okumura, M. [Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125 (United States); Havey, D. K.; Hodges, J. T. [Process Measurements Division, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899 (United States); Miller, C. E. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California 91109 (United States)

    2010-06-15T23:59:59.000Z

    Frequency-stabilized cavity ring-down spectroscopy (FS-CRDS) was used to measure magnetic dipole transitions in the b {sup 1{Sigma}}{sub g}{sup +} (leftarrow) X {sup 3{Sigma}}{sub g}{sup -}(0,0) band of O{sub 2}. The {sup 17}O-containing isotopologues show unresolved hyperfine structure due to magnetic hyperfine splitting in the ground state. The sensitivity and stability of FS-CRDS allow for quantitative sub-Doppler measurements of the hyperfine constants, even when the hyperfine splittings are much smaller than the Doppler width. Unlike saturation spectroscopy, this linear absorption technique can be applied to weak transitions and employed to quantitatively measure intensities and line shapes. This method may be an attractive approach for measuring unresolved hyperfine structure in excited electronic states.

  6. Doppler- and recoil-free laser excitation of Rydberg states via three-photon transitions

    SciTech Connect (OSTI)

    Ryabtsev, I. I.; Beterov, I. I.; Tretyakov, D. B.; Entin, V. M.; Yakshina, E. A. [A. V. Rzhanov Institute of Semiconductor Physics SB RAS, Prospekt Lavrentyeva 13, 630090 Novosibirsk (Russian Federation)

    2011-11-15T23:59:59.000Z

    Three-photon laser excitation of Rydberg states by three different laser beams can be arranged in a starlike geometry that simultaneously eliminates the recoil effect and Doppler broadening. Our analytical and numerical calculations for a particular laser excitation scheme 5S{sub 1/2}{yields}5P{sub 3/2}{yields}6S{sub 1/2}{yields}nP in Rb atoms have shown that, compared to the one- and two-photon laser excitation, this approach provides much narrower linewidth and longer coherence time for both cold atom samples and hot vapors, if the intermediate one-photon resonances of the three-photon transition are detuned by more than respective single-photon Doppler widths. This method can be used to improve fidelity of Rydberg quantum gates and precision of spectroscopic measurements in Rydberg atoms.

  7. Doppler cooling with coherent trains of laser pulses and a tunable velocity comb

    SciTech Connect (OSTI)

    Ilinova, Ekaterina; Ahmad, Mahmoud; Derevianko, Andrei [Department of Physics, University of Nevada, Reno, Nevada 89557 (United States)

    2011-09-15T23:59:59.000Z

    We explore the possibility of decelerating and Doppler cooling an ensemble of two-level atoms by a coherent train of short, nonoverlapping laser pulses. We derive analytical expressions for mechanical force exerted by the train. In frequency space the force pattern reflects the underlying frequency comb structure. The pattern depends strongly on the ratio of the atomic lifetime to the repetition time between the pulses and pulse area. For example, in the limit of short lifetimes, the frequency-space peaks of the optical force wash out. We propose to tune the carrier-envelope offset frequency to follow the Doppler-shifted detuning as atoms decelerate; this leads to compression of atomic velocity distribution about comb teeth and results in a ''velocity comb''--a series of narrow equidistant peaks in the velocity space.

  8. On the role of spectral resolution in velocity shear layer measurements by Doppler reflectometry

    SciTech Connect (OSTI)

    Happel, T.; Blanco, E.; Estrada, T. [Laboratorio Nacional de Fusion, Association Euratom-Ciemat, 28040 Madrid (Spain)

    2010-10-15T23:59:59.000Z

    The signal quality of a Doppler reflectometer depends strongly on its spectral resolution, which is influenced by the microwave beam properties and the radius of curvature of the cutoff layer in the plasma. If measured close to a strong perpendicular velocity shear layer, the spectrum of the backscattered signal is influenced by different velocities. This can give rise to two Doppler shifted peaks in the spectrum as observed in TJ-II H-mode plasmas. It is shown by two-dimensional full wave simulations that the two peaks are separable provided the spectral resolution of the system is sufficient. However, if the spectral resolution is poor, the two peaks blend into one and yield an intermediate and incorrect velocity.

  9. Doppler Effects from Bending of Light Rays in Curved Space-Times

    E-Print Network [OSTI]

    Matteo Luca Ruggiero; Angelo Tartaglia; Lorenzo Iorio

    2006-05-06T23:59:59.000Z

    We study Doppler effects in curved space-time, i.e. the frequency shifts induced on electromagnetic signals propagating in the gravitational field. In particular, we focus on the frequency shift due to the bending of light rays in weak gravitational fields. We consider, using the PPN formalism, the gravitational field of an axially symmetric distribution of mass. The zeroth order, i.e. the sphere, is studied then passing to the contribution of the quadrupole moment, and finally to the case of a rotating source. We give numerical estimates for situations of physical interest, and by a very preliminary analysis, we argue that analyzing the Doppler effect could lead, in principle, in the foreseeable future, to the measurement of the quadrupole moment of the giant planets of the Solar System.

  10. Photoacoustics meets ultrasound: micro-Doppler photoacoustic effect and detection by ultrasound

    E-Print Network [OSTI]

    Gao, Fei; Zheng, Yuanjin; Ohl, Claus-Dieter

    2014-01-01T23:59:59.000Z

    In recent years, photoacoustics has attracted intensive research for both anatomical and functional biomedical imaging. However, the physical interaction between photoacoustic generated endogenous waves and an exogenous ultrasound wave is a largely unexplored area. Here, we report the initial results about the interaction of photoacoustic and external ultrasound waves leading to a micro-Doppler photoacoustic (mDPA) effect, which is experimentally observed and consistently modelled. It is based on a simultaneous excitation on the target with a pulsed laser and continuous wave (CW) ultrasound. The thermoelastically induced expansion will modulate the CW ultrasound and leads to transient Doppler frequency shift. The reported mDPA effect can be described as frequency modulation of the intense CW ultrasound carrier through photoacoustic vibrations. This technique may open the possibility to sensitively detect the photoacoustic vibration in deep optically and acoustically scattering medium, avoiding acoustic distor...

  11. EXPLORING THE MORPHOLOGY OF RAVE STELLAR SPECTRA

    SciTech Connect (OSTI)

    Matijevic, G.; Zwitter, T. [Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana (Slovenia); Bienayme, O.; Siebert, A. [Observatoire de Strasbourg, Universite de Strasbourg, CNRS, 11 rue de l'universite, 67000 Strasbourg (France); Bland-Hawthorn, J. [Sydney Institute for Astronomy, University of Sydney, NSW 2006 (Australia); Boeche, C.; Grebel, E. K. [Astronomisches Rechen-Institut, Zentrum fuer Astronomie der Universitaet Heidelberg, Moenchhofstr. 12-14, 69120 Heidelberg (Germany); Freeman, K. C. [Research School of Astronomy and Astrophysics, Australia National University, Weston Creek, Canberra, ACT 2611 (Australia); Gibson, B. K. [Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 3TE (United Kingdom); Gilmore, G. [Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA (United Kingdom); Helmi, A. [Kapteyn Astronomical Institute, University of Groningen, P.O. Box 800, 9700 AV Groningen (Netherlands); Munari, U. [INAF Osservatorio Astronomico di Padova, 36012 Asiago (Italy); Navarro, J. [Department of Physics and Astronomy, University of Victoria, Victora, BC V8P 5C2 (Canada); Parker, Q. A.; Reid, W. [Department of Physics and Astronomy, Macquarie University, NSW 2109 (Australia); Seabroke, G. [Mullard Space Science Laboratory, University College London, Holmbury St. Mary, Dorking RH5 6NT (United Kingdom); Siviero, A. [Department of Astronomy, Padova University, Vicolo dell'Osservatorio 2, 35122 Padova (Italy); Steinmetz, M.; Williams, M. [Leibniz-Institut fuer Astrophysik Potsdam (AIP), An der Sternwarte 16, 14482 Potsdam (Germany); Watson, F. G., E-mail: gal.matijevic@fmf.uni-lj.si [Australian Astronomical Observatory, P.O. Box 296, Epping, NSW 2121 (Australia); and others

    2012-06-01T23:59:59.000Z

    The RAdial Velocity Experiment (RAVE) is a medium-resolution (R {approx} 7500) spectroscopic survey of the Milky Way that has already obtained over half a million stellar spectra. They present a randomly selected magnitude-limited sample, so it is important to use a reliable and automated classification scheme that identifies normal single stars and discovers different types of peculiar stars. To this end, we present a morphological classification of {approx}350, 000 RAVE survey stellar spectra using locally linear embedding, a dimensionality reduction method that enables representing the complex spectral morphology in a low-dimensional projected space while still preserving the properties of the local neighborhoods of spectra. We find that the majority of all spectra in the database ({approx} 90%-95%) belong to normal single stars, but there is also a significant population of several types of peculiars. Among them, the most populated groups are those of various types of spectroscopic binary and chromospherically active stars. Both of them include several thousands of spectra. Particularly the latter group offers significant further investigation opportunities since activity of stars is a known proxy of stellar ages. Applying the same classification procedure to the sample of normal single stars alone shows that the shape of the projected manifold in two-dimensional space correlates with stellar temperature, surface gravity, and metallicity.

  12. On the Doppler effect for light from orbiting sources in Kerr-type metrics

    E-Print Network [OSTI]

    S. Cisneros; G. Goedecke; C. Beetle; M. Engelhardt

    2015-01-23T23:59:59.000Z

    A formula is derived for the combined motional and gravitational Doppler effect in general stationary axisymmetric metrics for a photon emitted parallel or antiparallel to the assumed circular orbital motion of its source. The same formula is derived from eikonal approximation and Killing vector approaches to elucidate connections between observational astronomy and modern Relativity. The formula yields expected results in the limits of a moving or stationary source in the exterior Kerr and Schwarzschild metrics and a moving source in flat space.

  13. CONSTRAINING HIGH-SPEED WINDS IN EXOPLANET ATMOSPHERES THROUGH OBSERVATIONS OF ANOMALOUS DOPPLER SHIFTS DURING TRANSIT

    SciTech Connect (OSTI)

    Miller-Ricci Kempton, Eliza [Department of Astronomy and Astrophysics, University of California, Santa Cruz, CA 95064 (United States); Rauscher, Emily, E-mail: ekempton@ucolick.org [Lunar and Planetary Laboratory, University of Arizona, 1629 East University Boulevard, Tucson, AZ 85721 (United States)

    2012-06-01T23:59:59.000Z

    Three-dimensional (3D) dynamical models of hot Jupiter atmospheres predict very strong wind speeds. For tidally locked hot Jupiters, winds at high altitude in the planet's atmosphere advect heat from the day side to the cooler night side of the planet. Net wind speeds on the order of 1-10 km s{sup -1} directed towards the night side of the planet are predicted at mbar pressures, which is the approximate pressure level probed by transmission spectroscopy. These winds should result in an observed blueshift of spectral lines in transmission on the order of the wind speed. Indeed, Snellen et al. recently observed a 2 {+-} 1 km s{sup -1} blueshift of CO transmission features for HD 209458b, which has been interpreted as a detection of the day-to-night (substellar to anti-stellar) winds that have been predicted by 3D atmospheric dynamics modeling. Here, we present the results of a coupled 3D atmospheric dynamics and transmission spectrum model, which predicts the Doppler-shifted spectrum of a hot Jupiter during transit resulting from winds in the planet's atmosphere. We explore four different models for the hot Jupiter atmosphere using different prescriptions for atmospheric drag via interaction with planetary magnetic fields. We find that models with no magnetic drag produce net Doppler blueshifts in the transmission spectrum of {approx}2 km s{sup -1} and that lower Doppler shifts of {approx}1 km s{sup -1} are found for the higher drag cases, results consistent with-but not yet strongly constrained by-the Snellen et al. measurement. We additionally explore the possibility of recovering the average terminator wind speed as a function of altitude by measuring Doppler shifts of individual spectral lines and spatially resolving wind speeds across the leading and trailing terminators during ingress and egress.

  14. Doppler maps and surface differential rotation of EI Eri from the MUSICOS 1998 observations

    E-Print Network [OSTI]

    Zs. K?vári; A. Washuettl; B. H. Foing; K. Vida; J. Bartus; K. Oláh; the MUSICOS 98 team

    2008-11-03T23:59:59.000Z

    We present time-series Doppler images of the rapidly-rotating active binary star EI Eri from spectroscopic observations collected during the MUSICOS multi-site campaign in 1998, since the critical rotation period of 1.947 days makes it impossible to obtain time-resolved images from a single site. From the surface reconstructions a weak solar-type differential rotation, as well as a tiny poleward meridional flow are measured.

  15. Method and apparatus for optical Doppler tomographic imaging of fluid flow velocity in highly scattering media

    DOE Patents [OSTI]

    Nelson, John Stuart (Laguna Niguel, CA); Milner, Thomas Edward (Irvine, CA); Chen, Zhongping (Irvine, CA)

    1999-01-01T23:59:59.000Z

    Optical Doppler tomography permits imaging of fluid flow velocity in highly scattering media. The tomography system combines Doppler velocimetry with high spatial resolution of partially coherent optical interferometry to measure fluid flow velocity at discrete spatial locations. Noninvasive in vivo imaging of blood flow dynamics and tissue structures with high spatial resolutions of the order of 2 to 10 microns is achieved in biological systems. The backscattered interference signals derived from the interferometer may be analyzed either through power spectrum determination to obtain the position and velocity of each particle in the fluid flow sample at each pixel, or the interference spectral density may be analyzed at each frequency in the spectrum to obtain the positions and velocities of the particles in a cross-section to which the interference spectral density corresponds. The realized resolutions of optical Doppler tomography allows noninvasive in vivo imaging of both blood microcirculation and tissue structure surrounding the vessel which has significance for biomedical research and clinical applications.

  16. Linear and nonlinear light propagations in a Doppler-broadened medium via electromagnetically induced transparency

    SciTech Connect (OSTI)

    Li Liang; Huang Guoxiang [Department of Physics and Institute of Theoretical Physics, East China Normal University, Shanghai 200062 (China); State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200062, China and Institute of Nonlinear Physics, Zhejiang Normal University, Zhejiang 321004 (China)

    2010-08-15T23:59:59.000Z

    We present a systematic theoretical study to deal with linear and nonlinear light propagations in a Doppler-broadened three-level {Lambda} system via electromagnetically induced transparency (EIT), with incoherent population exchange between two lower energy levels taken into account. Through a careful analysis of base state and linear excitation, we show that the EIT condition of the system is given by |{Omega}{sub c}|{sup 2{gamma}}{sub 31}>>2{gamma}{sub 21{Delta}{omega}D}{sup 2}, where {Omega}{sub c} is half the Rabi frequency of the control field, {Delta}{omega}{sub D} is the Doppler width, and {gamma}{sub jl} is the decay rate of the coherence between states |j> and |l>. Under this condition, the effect of incoherent population exchange is insignificant, while dephasing dominates the decoherence of the system. This condition also ensures the validity of the weak nonlinear perturbation theory used in this work for solving the Maxwell-Bloch equations with inhomogeneous broadening. We then investigate the nonlinear propagation of the probe field and show that it is possible to form temporal optical solitons in the Doppler-broadened medium. Such solitons have ultraslow propagating velocity and can be generated in very low light power. The possibility of realizing (1+1)-dimensional and (2+1)-dimensional spatial optical solitons in the adiabatic regime of the system is also discussed.

  17. Mid-Infrared Spectra of Be Stars

    E-Print Network [OSTI]

    S. A. Rinehart; J. R. Houck; J. D. Smith

    1999-10-11T23:59:59.000Z

    We present the first medium-resolution ($R\\sim 600$) mid-infrared (8-13.3\\micron) spectra of 11 Be stars. A large number of lines are observed and identified in these spectra, including, as an example, 39 hydrogen recombination lines in the spectrum of $\\gamma$ Cas. In the majority of our spectra, all of the observed lines are attributable to hydrogen recombination. Two of the sources, $\\beta$ Lyr and MWC 349 also show emission from other species. Both of these objects show evidence of [Ne II] emission, and $\\beta$ Lyr also shows evidence of He I emission. We tabulate the effective line strength and line widths for the observed lines, and briefly discuss the physical implications of the observed line series. We also use a simple model of free-free emission to characterize the disks around these sources.

  18. Estimating the instantaneous velocity of randomly moving target swarms in a stratified ocean waveguide by Doppler analysis

    E-Print Network [OSTI]

    Bertsatos, Ioannis

    2011-01-01T23:59:59.000Z

    Doppleranalysis has been extensively used in active radar and sonar sensing to estimate the speed and direction of a single target within an imaging system resolution cell following deterministic theory. For target swarms, ...

  19. Power Spectra for Deterministic Chaotic Dynamical Systems

    E-Print Network [OSTI]

    Power Spectra for Deterministic Chaotic Dynamical Systems Ian Melbourne #3; Georg A. Gottwald y 8 observables. For slowly mixing systems such as Pomeau-Manneville intermittency maps, where the power spectrum done for mixing Axiom A systems [19] where the power spectrum is analytic apart from isolated

  20. Power Spectra for Deterministic Chaotic Dynamical Systems

    E-Print Network [OSTI]

    Gottwald, Georg A.

    Power Spectra for Deterministic Chaotic Dynamical Systems Ian Melbourne Georg A. Gottwald 23 July observables. For slowly mixing systems such as Pomeau-Manneville intermittency maps, where the power spectrum done for mixing Axiom A systems [19] where the power spectrum is analytic apart from isolated

  1. Ultra-wideband short-pulse radar with range accuracy for short range detection

    DOE Patents [OSTI]

    Rodenbeck, Christopher T; Pankonin, Jeffrey; Heintzleman, Richard E; Kinzie, Nicola Jean; Popovic, Zorana P

    2014-10-07T23:59:59.000Z

    An ultra-wideband (UWB) radar transmitter apparatus comprises a pulse generator configured to produce from a sinusoidal input signal a pulsed output signal having a series of baseband pulses with a first pulse repetition frequency (PRF). The pulse generator includes a plurality of components that each have a nonlinear electrical reactance. A signal converter is coupled to the pulse generator and configured to convert the pulsed output signal into a pulsed radar transmit signal having a series of radar transmit pulses with a second PRF that is less than the first PRF.

  2. Improved predictions of reactor antineutrino spectra

    SciTech Connect (OSTI)

    Mueller, Th. A.; Lhuillier, D.; Letourneau, A. [Commissariat a l'Energie Atomique et aux Energies Alternatives, Centre de Saclay, IRFU/SPhN, FR-91191 Gif-sur-Yvette (France); Fallot, M.; Cormon, S.; Giot, L.; Martino, J.; Porta, A.; Yermia, F. [Laboratoire SUBATECH, Ecole des Mines de Nantes, Universite de Nantes, CNRS/IN2P3, 4 rue Alfred Kastler, FR-44307 Nantes Cedex 3 (France); Fechner, M.; Lasserre, T.; Mention, G. [Commissariat a l'Energie Atomique et aux Energies Alternatives, Centre de Saclay, IRFU/SPP, FR-91191 Gif-sur-Yvette (France)

    2011-05-15T23:59:59.000Z

    Precise predictions of the antineutrino spectra emitted by nuclear reactors is a key ingredient in measurements of reactor neutrino oscillations as well as in recent applications to the surveillance of power plants in the context of nonproliferation of nuclear weapons. We report new calculations including the latest information from nuclear databases and a detailed error budget. The first part of this work is the so-called ab initio approach where the total antineutrino spectrum is built from the sum of all {beta} branches of all fission products predicted by an evolution code. Systematic effects and missing information in nuclear databases lead to final relative uncertainties in the 10-20% range. A prediction of the antineutrino spectrum associated with the fission of {sup 238}U is given based on this ab initio method. For the dominant isotopes we developed a more accurate approach combining information from nuclear databases and reference electron spectra associated with the fission of {sup 235}U, {sup 239}Pu, and {sup 241}Pu, measured at Institut Laue-Langevin (ILL) in the 1980s. We show how the anchor point of the measured total {beta} spectra can be used to suppress the uncertainty in nuclear databases while taking advantage of all the information they contain. We provide new reference antineutrino spectra for {sup 235}U, {sup 239}Pu, and {sup 241}Pu isotopes in the 2-8 MeV range. While the shapes of the spectra and their uncertainties are comparable to those of the previous analysis of the ILL data, the normalization is shifted by about +3% on average. In the perspective of the reanalysis of past experiments and direct use of these results by upcoming oscillation experiments, we discuss the various sources of errors and their correlations as well as the corrections induced by off-equilibrium effects.

  3. Iterative Self-Dual Reconstruction on Radar Image Recovery

    SciTech Connect (OSTI)

    Martins, Charles; Medeiros, Fatima; Ushizima, Daniela; Bezerra, Francisco; Marques, Regis; Mascarenhas, Nelson

    2010-05-21T23:59:59.000Z

    Imaging systems as ultrasound, sonar, laser and synthetic aperture radar (SAR) are subjected to speckle noise during image acquisition. Before analyzing these images, it is often necessary to remove the speckle noise using filters. We combine properties of two mathematical morphology filters with speckle statistics to propose a signal-dependent noise filter to multiplicative noise. We describe a multiscale scheme that preserves sharp edges while it smooths homogeneous areas, by combining local statistics with two mathematical morphology filters: the alternating sequential and the self-dual reconstruction algorithms. The experimental results show that the proposed approach is less sensitive to varying window sizes when applied to simulated and real SAR images in comparison with standard filters.

  4. Phase coded, micro-power impulse radar motion sensor

    DOE Patents [OSTI]

    McEwan, T.E.

    1996-05-21T23:59:59.000Z

    A motion sensing, micro-power impulse radar MIR impresses on the transmitted signal, or the received pulse timing signal, one or more frequencies lower than the pulse repetition frequency, that become intermediate frequencies in a ``IF homodyne`` receiver. Thus, many advantages of classical RF receivers can be thereby be realized with ultra-wide band radar. The sensor includes a transmitter which transmits a sequence of electromagnetic pulses in response to a transmit timing signal at a nominal pulse repetition frequency. A receiver samples echoes of the sequence of electromagnetic pulses from objects within the field with controlled timing, in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The relative timing of the transmit timing signal and the receive timing signal is modulated between a first relative delay and a second relative delay at an intermediate frequency, causing the receiver to sample the echoes such that the time between transmissions of pulses in the sequence and samples by the receiver is modulated at the intermediate frequency. Modulation may be executed by modulating the pulse repetition frequency which drives the transmitter, by modulating the delay circuitry which controls the relative timing of the sample strobe, or by modulating amplitude of the transmitted pulses. The electromagnetic pulses will have a nominal center frequency related to pulse width, and the first relative delay and the second relative delay between which the timing signals are modulated, differ by less than the nominal pulse width, and preferably by about one-quarter wavelength at the nominal center frequency of the transmitted pulses. 5 figs.

  5. Lightning and radar observations of hurricane Rita landfall

    SciTech Connect (OSTI)

    Henderson, Bradley G [Los Alamos National Laboratory; Suszcynsky, David M [Los Alamos National Laboratory; Hamlin, Timothy E [Los Alamos National Laboratory; Jeffery, C A [Los Alamos National Laboratory; Wiens, Kyle C [TEXAS TECH U.; Orville, R E [TEXAS A& M

    2009-01-01T23:59:59.000Z

    Los Alamos National Laboratory (LANL) owns and operates an array of Very-Low Frequency (VLF) sensors that measure the Radio-Frequency (RF) waveforms emitted by Cloud-to-Ground (CG) and InCloud (IC) lightning. This array, the Los Alamos Sferic Array (LASA), has approximately 15 sensors concentrated in the Great Plains and Florida, which detect electric field changes in a bandwidth from 200 Hz to 500 kHz (Smith et al., 2002). Recently, LANL has begun development of a new dual-band RF sensor array that includes the Very-High Frequency (VHF) band as well as the VLF. Whereas VLF lightning emissions can be used to deduce physical parameters such as lightning type and peak current, VHF emissions can be used to perform precise 3d mapping of individual radiation sources, which can number in the thousands for a typical CG flash. These new dual-band sensors will be used to monitor lightning activity in hurricanes in an effort to better predict intensification cycles. Although the new LANL dual-band array is not yet operational, we have begun initial work utilizing both VLF and VHF lightning data to monitor hurricane evolution. In this paper, we present the temporal evolution of Rita's landfall using VLF and VHF lightning data, and also WSR-88D radar. At landfall, Rita's northern eyewall experienced strong updrafts and significant lightning activity that appear to mark a transition between oceanic hurricane dynamics and continental thunderstorm dynamics. In section 2, we give a brief overview of Hurricane Rita, including its development as a hurricane and its lightning history. In the following section, we present WSR-88D data of Rita's landfall, including reflectivity images and temporal variation. In section 4, we present both VHF and VLF lightning data, overplotted on radar reflectivity images. Finally, we discuss our observations, including a comparison to previous studies and a brief conclusion.

  6. Phase coded, micro-power impulse radar motion sensor

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1996-01-01T23:59:59.000Z

    A motion sensing, micro-power impulse radar MIR impresses on the transmitted signal, or the received pulse timing signal, one or more frequencies lower than the pulse repetition frequency, that become intermediate frequencies in a "IF homodyne" receiver. Thus, many advantages of classical RF receivers can be thereby be realized with ultra-wide band radar. The sensor includes a transmitter which transmits a sequence of electromagnetic pulses in response to a transmit timing signal at a nominal pulse repetition frequency. A receiver samples echoes of the sequence of electromagnetic pulses from objects within the field with controlled timing, in response to a receive timing signal, and generates a sample signal in response to the samples. A timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The relative timing of the transmit timing signal and the receive timing signal is modulated between a first relative delay and a second relative delay at an intermediate frequency, causing the receiver to sample the echoes such that the time between transmissions of pulses in the sequence and samples by the receiver is modulated at the intermediate frequency. Modulation may be executed by modulating the pulse repetition frequency which drives the transmitter, by modulating the delay circuitry which controls the relative timing of the sample strobe, or by modulating amplitude of the transmitted pulses. The electromagnetic pulses will have a nominal center frequency related to pulse width, and the first relative delay and the second relative delay between which the timing signals are modulated, differ by less than the nominal pulse width, and preferably by about one-quarter wavelength at the nominal center frequency of the transmitted pulses.

  7. O{sub 2} rotational temperature measurements in an atmospheric air microdischarge by radar resonance-enhanced multiphoton ionization

    SciTech Connect (OSTI)

    Sawyer, Jordan; Wu, Yue; Zhang, Zhili [Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville Tennessee 37996 (United States)] [Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville Tennessee 37996 (United States); Adams, Steven F. [Air Force Research Laboratory (AFRL/RQQE), Wright-Patterson AFB, Ohio 45433-7919 (United States)] [Air Force Research Laboratory (AFRL/RQQE), Wright-Patterson AFB, Ohio 45433-7919 (United States)

    2013-06-21T23:59:59.000Z

    Nonintrusive spatially resolved rotational temperature measurements in an atmospheric air microdischarge are presented. The measurements were based on coherent microwave Rayleigh scattering (Radar) from resonance-enhanced multiphoton ionization of molecular oxygen. The open air DC microdischarge source operated in a stable 'normal-glow' mode and pin-to-pin electrodes spaced 1.3 mm apart. The second harmonic of a tunable dye laser beam was focused between the two electrodes and scanned between 286 and 288 nm. Coherent microwave Rayleigh scattering was used to collect the two-photon rotational spectra of O{sub 2} at C{sup 3}{Pi}(v = 2) Leftwards-Arrow X{sup 3}{Sigma}(v Prime = 0) transitions. The Boltzmann plots from analyses of the O{sub 2} rotational lines determined local rotational temperatures at various axial locations between the electrodes. The molecular oxygen rotational temperature varied from {approx}1150 K to {approx}1350 K within the discharge area. The measurements had an accuracy of {approx}{+-}50 K.

  8. INTERMITTENCY AND MULTIFRACTALITY SPECTRA OF THE MAGNETIC FIELD IN SOLAR ACTIVE REGIONS

    SciTech Connect (OSTI)

    Abramenko, Valentyna; Yurchyshyn, Vasyl [Big Bear Solar Observatory, 40386 North Shore Lane, Big Bear City, CA 92314 (United States)

    2010-10-10T23:59:59.000Z

    We present the results of a study of intermittency and multifractality of magnetic structures in solar active regions (ARs). Line-of-sight magnetograms for 214 ARs of different flare productivity observed at the center of the solar disk from 1997 January until 2006 December are utilized. Data from the Michelson Doppler Imager (MDI) instrument on board the Solar and Heliospheric Observatory operating in the high resolution mode, the Big Bear Solar Observatory digital magnetograph, and the Hinode SOT/SP instrument were used. Intermittency spectra were derived from high-order structure functions and flatness functions. The flatness function exponent is a measure of the degree of intermittency. We found that the flatness function exponent at scales below approximately 10 Mm is correlated with flare productivity (the correlation coefficient is -0.63). The Hinode data show that the intermittency regime is extended toward small scales (below 2 Mm) as compared to the MDI data. The spectra of multifractality, derived from the structure functions and flatness functions, are found to be broader for ARs of higher flare productivity as compared to those of low flare productivity. The magnetic structure of high-flaring ARs consists of a voluminous set of monofractals, and this set is much richer than that for low-flaring ARs. The results indicate the relevance of the multifractal organization of the photospheric magnetic fields to the flaring activity. The strong intermittency observed in complex and high-flaring ARs is a hint that we observe a photospheric imprint of enhanced sub-photospheric dynamics.

  9. The Design and Development of a Hybrid RF/Laser Radar System for Measuring Changes in

    E-Print Network [OSTI]

    Kansas, University of

    transmit power and higher PRF. RF pulse compression is used to improve system performance further. Receiver compression. Compared to laser radars like GLAS and MOLA, this sensor requires a lower peak transmit power Compression .......................................................... 14 2.6 Coherent Integration

  10. Joint anisotropy characterization and image formation in wide-angle synthetic aperture radar

    E-Print Network [OSTI]

    Varshney, Kush R. (Kush Raj)

    2006-01-01T23:59:59.000Z

    Imagery formed from wide-angle synthetic aperture radar (SAR) measurements has fine cross-range resolution in principle. However, conventional SAR image formation techniques assume isotropic scattering, which is not valid ...

  11. Ground penetrating radar technique to locate coal mining related features: case studies in Texas 

    E-Print Network [OSTI]

    Save, Neelambari R

    2006-04-12T23:59:59.000Z

    The goal of this research project is to identify the efficacy of the ground penetrating radar (GPR) technique in locating underground coal mine related subsidence features at Malakoff and Bastrop, Texas. The work at Malakoff ...

  12. Assessing and Analyzing Near-Surface Radar Snow Accumulation Layers at Summit, Greenland

    E-Print Network [OSTI]

    Overly, Thomas Buckmaster

    2010-04-28T23:59:59.000Z

    depth are compared to physical properties, age-depth relationships, and accumulation rates from ice cores near Summit. Having established the radar horizons as annual accumulation markers, a 350-year record of accumulation rate is derived and analyzed...

  13. A census of precipitation features in the tropics using TRMM: radar, ice scattering, and lightning observations

    E-Print Network [OSTI]

    Nesbitt, Stephen William

    1999-01-01T23:59:59.000Z

    and two ocean regions during August, September and October 1998, this study used radar retrievals and 85 GHz Polarization Corrected Temperatures (PCTs, which passively measure relative concentrations of precipitation-sized ice particles within a cloud...

  14. Radar signal pre-processing to suppress surface bounce and multipath

    DOE Patents [OSTI]

    Paglieroni, David W; Mast, Jeffrey E; Beer, N. Reginald

    2013-12-31T23:59:59.000Z

    A method and system for detecting the presence of subsurface objects within a medium is provided. In some embodiments, the imaging and detection system operates in a multistatic mode to collect radar return signals generated by an array of transceiver antenna pairs that is positioned across the surface and that travels down the surface. The imaging and detection system pre-processes that return signal to suppress certain undesirable effects. The imaging and detection system then generates synthetic aperture radar images from real aperture radar images generated from the pre-processed return signal. The imaging and detection system then post-processes the synthetic aperture radar images to improve detection of subsurface objects. The imaging and detection system identifies peaks in the energy levels of the post-processed image frame, which indicates the presence of a subsurface object.

  15. Development of an electronically tunable ultra-wideband radar imaging sensor and its components

    E-Print Network [OSTI]

    Han, Jeongwoo

    2006-08-16T23:59:59.000Z

    Novel microwave transmitter and receiver circuits have been developed for implementing UWB (Ultra-Wideband) impulse radar imaging sensor operating in frequency band 0.2 to 4 GHz. with tunable operating frequency band. The fundamental system design...

  16. Weather Radar and Hydrology 1 Influence of rainfall spatial variability on hydrological modelling: a

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Weather Radar and Hydrology 1 Influence of rainfall spatial variability on hydrological modelling variability as well as characteristics and hydrological behavior of catchments, we have proceeded simulator and a distributed hydrological model (with four production functions and a distributed transfer

  17. E-Print Network 3.0 - acquisition regime radar Sample Search...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    except the data acquisition system and the controller unit... A New Coherent Radar for Ice Sounding in Greenland A. Moussessian 1 , R.L. Jordan 1 , E. Rodriguez... : (818)...

  18. Radar-Based Vehicle Detection for Four-Quadrant Gate Crossing

    E-Print Network [OSTI]

    Illinois at Urbana-Champaign, University of

    · Work Crew Safety · Maximize Coverage · Longer Life · Immunity to Elements · Reliability · Potential Implementation #12;AREMA Compliance per Class C Equipment Environmental - Temperature, Humidity, Mechanical, EMI (Trackers) to Configuration Application Add Dual Radar Tracking Metrics Reliability Enhancements Accelerate

  19. 12B.4 2010 PHASEDARRAY RADAR INNOVATIVE SENSING EXPERIMENT Pam Heinselman 1

    E-Print Network [OSTI]

    Sensing Experiment (PARISE) via two components: radar data collection and National Weather Service (NWS." This sampling approach provides denser sampling at low altitudes, where it is needed most. In PARISE 2010

  20. Millimeter-wave radar sensor for automotive intelligent cruise control (ICC)

    SciTech Connect (OSTI)

    Russell, M.E.; Crain, A.; Curran, A.; Campbell, R.A.; Drubin, C.A.; Miccioli, W.F. [Raytheon, Tewksbury, MA (United States)] [Raytheon, Tewksbury, MA (United States)

    1997-12-01T23:59:59.000Z

    If automotive intelligent cruise-control (ICC) systems are to be successful in the marketplace, they must provide robust performance in a complex roadway environment. Inconveniences caused by reduced performance during inclement weather, interrupted performance due to dropped tracks, and annoying nuisance alarms will not be tolerated by the consumer, and would likely result in the rejection of this technology in the marketplace. An all-weather automotive millimeter-wave (MMW) radar sensor is described that uses a frequency-modulation coplanar-wave (FMCW) radar design capable of acquiring and tracking all obstacles in its field of view. Design tradeoffs are discussed and radar-sensor test results are presented along with the applicability of the radar to collision-warning systems.

  1. On the Feasibility of Precisely Measuring the Properties of a Precipitating Cloud with a Weather Radar

    E-Print Network [OSTI]

    Runnels, R.C.

    In this paper the results of an investigation are presented that are concerned with the feasibility of employing a weather radar to make precise measurements of the properties of a precipitating cloud. A schematic cloud is proposed as a model...

  2. Ground penetrating radar characterization of wood piles and the water table in Back Bay, Boston

    E-Print Network [OSTI]

    LeFrançois, Suzanne O'Neil, 1980-

    2003-01-01T23:59:59.000Z

    Ground penetrating radar (GPR) surveys are performed to determine the depth to the water table and the tops of wood piles beneath a residential structure at 122 Beacon Street in Back Bay, Boston. The area of Boston known ...

  3. A model for forming airborne synthetic aperture radar images of underground targets

    SciTech Connect (OSTI)

    Doerry, A.W.

    1994-01-01T23:59:59.000Z

    Synthetic Aperture Radar (SAR) from an airborne platform has been proposed for imaging targets beneath the earth`s surface. The propagation of the radar`s energy within the ground, however, is much different than in the earth`s atmosphere. The result is signal refraction, echo delay, propagation losses, dispersion, and volumetric scattering. These all combine to make SAR image formation from an airborne platform much more challenging than a surface imaging counterpart. This report treats the ground as a lossy dispersive half-space, and presents a model for the radar echo based on measurable parameters. The model is then used to explore various imaging schemes, and image properties. Dynamic range is discussed, as is the impact of loss on dynamic range. Modified window functions are proposed to mitigate effects of sidelobes of shallow targets overwhelming deeper targets.

  4. Radar and lightning analyses of gigantic jet-producing storms Tiffany C. Meyer,1,2

    E-Print Network [OSTI]

    Rutledge, Steven

    Radar and lightning analyses of gigantic jet-producing storms Tiffany C. Meyer,1,2 Timothy J. Lang of gigantic jets, similar to prior modeling studies. Citation: Meyer, T. C., T. J. Lang, S. A. Rutledge, W. A

  5. Multiple-scattering in radar systems: A review Alessandro Battaglia a,b,, Simone Tanelli c

    E-Print Network [OSTI]

    Hogan, Robin

    Review Multiple-scattering in radar systems: A review Alessandro Battaglia a,b,Ã, Simone Tanelli c. Tel.: +44 116 2709859. E-mail address: a.battaglia@le.ac.uk (A. Battaglia). Journal of Quantitative Spectroscopy & Radiative Transfer ] (

  6. Ground penetrating radar technique to locate coal mining related features: case studies in Texas

    E-Print Network [OSTI]

    Save, Neelambari R

    2006-04-12T23:59:59.000Z

    The goal of this research project is to identify the efficacy of the ground penetrating radar (GPR) technique in locating underground coal mine related subsidence features at Malakoff and Bastrop, Texas. The work at Malakoff has been done...

  7. Real-time 3-d localization using radar and passive surface acoustic wave transponders

    E-Print Network [OSTI]

    LaPenta, Jason Michael

    2007-01-01T23:59:59.000Z

    This thesis covers ongoing work into the design, fabrication, implementation, and characterization of novel passive transponders that allow range measurements at short range and at high update rates. Multiple RADAR measurement ...

  8. Simulations of Doppler Effects in Nuclear Reactions for AGATA Commissioning Experiments

    E-Print Network [OSTI]

    Ali Al-Adili

    2009-09-25T23:59:59.000Z

    The purpose of this master thesis is to simulate suitable nuclear reactions for a commissioning experiment, to be performed with the AGATA gamma-ray tracking spectrometer. The main aim of the work is to find a reaction, which gives large Doppler effects of the emitted gamma rays, with as small contribution as possible due to the energy and angular spread of the nuclei emitting the gamma rays. Inverse kinematics heavy-ion (HI) fusion reactions of the type (HI,gamma), (HI, n) on proton and deuteron targets have been studied. Target effects were investigated using the program TRIM in order to determine the impact on the Doppler effects caused by energy and angular straggling in the target material. The cross sections of a large number of reactions of protons and deuterons on nuclei with mass numbers in the range A=20-100 have been evaluated using the TALYS reaction code. The fusion-evaporation reactions, d(V-51,n)Cr-52 and d(Cl-37,n)Ar-38 were simulated in detail using the Monte Carlo code evapOR. The interactions in AGATA of the gamma rays emitted in these reactions were simulated using Geant4. The energy resolution of the gamma rays after gamma-ray tracking and Doppler correction were determined as a function of the interaction position resolution of the germanium detectors. The conclusion of this work is that of the two reactions d(V-51,n)Cr-52 is more suitable for an AGATA commissioning experiment.

  9. ACTIVE REGION MOSS: DOPPLER SHIFTS FROM HINODE/EXTREME-ULTRAVIOLET IMAGING SPECTROMETER OBSERVATIONS

    SciTech Connect (OSTI)

    Tripathi, Durgesh [Inter-University Centre for Astronomy and Astrophysics, Pune University Campus, Pune 411007 (India); Mason, Helen E. [Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Klimchuk, James A. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2012-07-01T23:59:59.000Z

    Studying the Doppler shifts and the temperature dependence of Doppler shifts in moss regions can help us understand the heating processes in the core of the active regions. In this paper, we have used an active region observation recorded by the Extreme-ultraviolet Imaging Spectrometer (EIS) on board Hinode on 2007 December 12 to measure the Doppler shifts in the moss regions. We have distinguished the moss regions from the rest of the active region by defining a low-density cutoff as derived by Tripathi et al. in 2010. We have carried out a very careful analysis of the EIS wavelength calibration based on the method described by Young et al. in 2012. For spectral lines having maximum sensitivity between log T = 5.85 and log T = 6.25 K, we find that the velocity distribution peaks at around 0 km s{sup -1} with an estimated error of 4-5 km s{sup -1}. The width of the distribution decreases with temperature. The mean of the distribution shows a blueshift which increases with increasing temperature and the distribution also shows asymmetries toward blueshift. Comparing these results with observables predicted from different coronal heating models, we find that these results are consistent with both steady and impulsive heating scenarios. However, the fact that there are a significant number of pixels showing velocity amplitudes that exceed the uncertainty of 5 km s{sup -1} is suggestive of impulsive heating. Clearly, further observational constraints are needed to distinguish between these two heating scenarios.

  10. EIS/Hinode observations of Doppler flow seen through the 40 arcsec wide slit

    E-Print Network [OSTI]

    D. E. Innes; R. Attie; H. Hara; M. S. Madjarska

    2008-07-08T23:59:59.000Z

    The Extreme ultraviolet Imaging Spectrometer (EIS) on board Hinode is the first solar telescope to obtain wide slit spectral images that can be used for detecting Doppler flows in transition region and coronal lines on the Sun and to relate them to their surrounding small scale dynamics. We select EIS lines covering the temperature range 6x10^4 K to 2x10^6 K that give spectrally pure images of the Sun with the 40 arcsec slit. In these images Doppler shifts are seen as horizontal brightenings. Inside the image it is difficult to distinguish shifts from horizontal structures but emission beyond the image edge can be unambiguously identified as a line shift in several lines separated from others on their blue or red side by more than the width of the spectrometer slit (40 pixels). In the blue wing of He II, we find a large number of events with properties (size and lifetime) similar to the well-studied explosive events seen in the ultraviolet spectral range. Comparison with X-Ray Telescope (XRT) images shows many Doppler shift events at the footpoints of small X-ray loops. The most spectacular event observed showed a strong blue shift in transition region and lower corona lines from a small X-ray spot that lasted less than 7 min. The emission appears to be near a cool coronal loop connecting an X-ray bright point to an adjacent region of quiet Sun. The width of the emission implies a line-of-sight velocity of 220 km/s. In addition, we show an example of an Fe XV shift with a velocity about 120 km/s, coming from what looks like a narrow loop leg connecting a small X-ray brightening to a larger region of X-ray emission.

  11. Inflation and Alternatives with Blue Tensor Spectra

    E-Print Network [OSTI]

    Yi Wang; Wei Xue

    2014-10-20T23:59:59.000Z

    We study the tilt of the primordial gravitational waves spectrum. A hint of blue tilt is shown from analyzing the BICEP2 and POLARBEAR data. Motivated by this, we explore the possibilities of blue tensor spectra from the very early universe cosmology models, including null energy condition violating inflation, inflation with general initial conditions, and string gas cosmology, etc. For the simplest G-inflation, blue tensor spectrum also implies blue scalar spectrum. In general, the inflation models with blue tensor spectra indicate large non-Gaussianities. On the other hand, string gas cosmology predicts blue tensor spectrum with highly Gaussian fluctuations. If further experiments do confirm the blue tensor spectrum, non-Gaussianity becomes a distinguishing test between inflation and alternatives.

  12. Adaptive Model-Based Mine Detection/Localization using Noisy Laser Doppler Vibration Measurements

    SciTech Connect (OSTI)

    Sullivan, E J; Xiang, N; Candy, J V

    2009-04-06T23:59:59.000Z

    The acoustic detection of buried mines is hampered by the fact that at the frequencies required for obtaining useful penetration, the energy is quickly absorbed by the ground. A recent approach which avoids this problem, is to excite the ground with a high-level low frequency sound, which excites low frequency resonances in the mine. These resonances cause a low-level vibration on the surface which can be detected by a Laser Doppler Vibrometer. This paper presents a method of quickly and efficiently detecting these vibrations by sensing a change in the statistics of the signal when the mine is present. Results based on real data are shown.

  13. Bragg cell laser intensity modulation: effect on laser Doppler velocimetry measurements

    SciTech Connect (OSTI)

    Mychkovsky, Alexander G.; Chang, Natasha A.; Ceccio, Steven L.

    2009-06-20T23:59:59.000Z

    In most laser Doppler velocimetry (LDV) systems, the frequency of one of the two laser beams that intersect to create the probe volume is shifted with an acousto-optic element. It is shown here that Bragg shifting can impose a problematic fluctuation in intensity on the frequency-shifted beam, producing spurious velocity measurements. This fluctuation occurs at twice the Bragg cell frequency, and its relative amplitude to the time average intensity is a function of the ratio of the laser beam diameter to the Bragg cell acoustic wavelength. A physical model and a configuration procedure to minimize adverse effects of the intensity modulations are presented.

  14. MEASUREMENTS OF ANISOTROPIC ION TEMPERATURES, NON-THERMAL VELOCITIES, AND DOPPLER SHIFTS IN A CORONAL HOLE

    SciTech Connect (OSTI)

    Hahn, M.; Savin, D. W. [Columbia Astrophysics Laboratory, Columbia University, MC 5247, 550 West 120th Street, New York, NY 10027 (United States)] [Columbia Astrophysics Laboratory, Columbia University, MC 5247, 550 West 120th Street, New York, NY 10027 (United States)

    2013-02-15T23:59:59.000Z

    We present a new diagnostic allowing one to measure the anisotropy of ion temperatures and non-thermal velocities, as well as Doppler shifts with respect to the ambient magnetic field. This method provides new results, as well as an independent test for previous measurements obtained with other techniques. Our spectral data come from observations of a low-latitude, on-disk coronal hole. A potential field source surface model was used to calculate the angle between the magnetic field lines and the line of sight for each spatial bin of the observation. A fit was performed to determine the line widths and Doppler shifts parallel and perpendicular to the magnetic field. For each line width component we derived ion temperatures T {sub i,} and T {sub i, Parallel-To} and non-thermal velocities v {sub nt,} and v {sub nt, Parallel-To }. T {sub i,} was cooler than off-limb polar coronal hole measurements, suggesting increasing collisional cooling with decreasing height. T {sub i, Parallel-To} is consistent with a uniform temperature of (1.8 {+-} 0.2) Multiplication-Sign 10{sup 6} K for each ion. Since parallel ion heating is expected to be weak, this ion temperature should reflect the proton temperature. A comparison between our results and others implies a large proton temperature gradient around 1.02 R {sub Sun }. The non-thermal velocities are thought to be proportional to the amplitudes of various waves. Our results for v {sub nt,} agree with Alfven wave amplitudes inferred from off-limb polar coronal hole line width measurements. Our v {sub nt, Parallel-To} results are consistent with slow magnetosonic wave amplitudes inferred from Fourier analysis of time-varying intensity fluctuations. Doppler shift measurements yield outflows of Almost-Equal-To 5 km s{sup -1} for ions formed over a broad temperature range. This differs from other studies that found a strong Doppler shift dependence on formation temperature.

  15. Lorentz transformation, time dilation, length contraction and Doppler Effect - all at once

    E-Print Network [OSTI]

    Bernhard Rothenstein; Stefan Popescu

    2007-12-04T23:59:59.000Z

    We present a simple derivation of the Lorentz transformations for the space-time coordinates of the same event. It is based on the relative character of length and time interval as measured by observes in relative motion. We begin by accepting that the relative motion modifies in some particular way the result of these measurements. However we do not postulate the character of this distortion i.e. whatever it is dilation or contraction. The formulas accounting for length contraction, time dilation and Doppler shift are a byproduct of this derivation.

  16. Convergence of Legendre Expansion of Doppler-Broadened Double Differential Elastic Scattering Cross Section

    SciTech Connect (OSTI)

    Arbanas, Goran [ORNL] [ORNL; Dunn, Michael E [ORNL] [ORNL; Larson, Nancy M [ORNL] [ORNL; Leal, Luiz C [ORNL] [ORNL; Williams, Mark L [ORNL] [ORNL

    2012-01-01T23:59:59.000Z

    Convergence properties of Legendre expansion of a Doppler-broadened double-differential elastic neutron scattering cross section of {sup 238}U near the 6.67 eV resonance at temperature 10{sup 3} K are studied. A variance of Legendre expansion from a reference Monte Carlo computation is used as a measure of convergence and is computed for as many as 15 terms in the Legendre expansion. When the outgoing energy equals the incoming energy, it is found that the Legendre expansion converges very slowly. Therefore, a supplementary method of computing many higher-order terms is suggested and employed for this special case.

  17. Supernovae Spectra (La Jolla Institute, 1980)

    SciTech Connect (OSTI)

    Meyerott, R.; Gillespie, G.H. (eds.)

    1980-01-01T23:59:59.000Z

    The workshop includes talks by invited speakers on observed supernova spectra, plasma conditions in supernova envelopes, on the present status and future requirements of atomic physics and spectroscopy that contribute to the solutions of the supernova problems. Of the 14 papers presented at the workshop, abstracts of two appeared previously in Energy Research Abstracts and abstracts of the remaining 12 were prepared separately for the data base. (GHT)

  18. Dynamical analysis of highly excited molecular spectra

    SciTech Connect (OSTI)

    Kellman, M.E. [Univ. of Oregon, Eugene (United States)

    1993-12-01T23:59:59.000Z

    The goal of this program is new methods for analysis of spectra and dynamics of highly excited vibrational states of molecules. In these systems, strong mode coupling and anharmonicity give rise to complicated classical dynamics, and make the simple normal modes analysis unsatisfactory. New methods of spectral analysis, pattern recognition, and assignment are sought using techniques of nonlinear dynamics including bifurcation theory, phase space classification, and quantization of phase space structures. The emphasis is chaotic systems and systems with many degrees of freedom.

  19. Thickness estimation of subsurface layers in asphalt pavement using monstatic ground penetrating radar

    E-Print Network [OSTI]

    Lau, Chun Lok

    1991-01-01T23:59:59.000Z

    for the degree of MASTER OF SCIENCE December 1991 Major Subject: Electrical Engineering THICKNESS ESTIMATION OF SUBSURFACE LAYERS IN ASPHALT PAVEMENT USING MONSTATIC GROUND PENETRATING RADAR A Thesis CHUN LOK LAU Approved as to style and content by... ACKNOWLEDGEMENTS. LIST OF FIGURES. . CHAPTER I INTRODUCTION. 1. 1 Importance of pavement profile data. 1. 2 Principle of Ground Penetrating Radar (GPR) . . . 1. 3 Subsurface layer thickness measurement method. . . . . . II GPR ANTENNA AND SYSTEM CALIBRATION...

  20. Assessing the capabilities of ground penetrating radar for applications in geologic and engineering subsurface studies

    E-Print Network [OSTI]

    Servos, Stacia Lynn

    1998-01-01T23:59:59.000Z

    of different display parameters from GSSI's RADAN software package . . . 21 (a) Unfiltered radar profile over an underground storage tank. (b) Profile (a) has been filtered wdth a horizontal high pass boxcar filter, removing the long horizontal reflector... and processed in the laboratory using RADAN, interpretation software developed by GSSI. The radar profile (or radargram) seen on the computer screen is a composition of paraUel series of amplitude versus time. The darkness or color displayed is proportional...

  1. IFP V4.0:a polar-reformatting image formation processor for synthetic aperture radar.

    SciTech Connect (OSTI)

    Eichel, Paul H.

    2005-09-01T23:59:59.000Z

    IFP V4.0 is the fourth generation of an extraordinarily powerful and flexible image formation processor for spotlight mode synthetic aperture radar. It has been successfully utilized in processing phase histories from numerous radars and has been instrumental in the development of many new capabilities for spotlight mode SAR. This document provides a brief history of the development of IFP, a full exposition of the signal processing steps involved, and a short user's manual for the software implementing this latest iteration.

  2. Radar cross section of triangular trihedral reflector with extended bottom plate.

    SciTech Connect (OSTI)

    Brock, Billy C.; Doerry, Armin Walter

    2009-05-01T23:59:59.000Z

    Trihedral corner reflectors are the preferred canonical target for SAR performance evaluation for many radar development programs. The conventional trihedrals have problems with substantially reduced Radar Cross Section (RCS) at low grazing angles, unless they are tilted forward, but in which case other problems arise. Consequently there is a need for better low grazing angle performance for trihedrals. This is facilitated by extending the bottom plate. A relevant analysis of RCS for an infinite ground plate is presented. Practical aspects are also discussed.

  3. Some effects of range upon AN/CPS-9 radar reflectivities in thunderstorms

    E-Print Network [OSTI]

    Sanford, Tom E

    1961-01-01T23:59:59.000Z

    SOMB BFFBCTS OF RANGE UPON AN/CPS-9 RADAR RBFLECTIVITIBS IN THUNDBRSTORMS A Thesis Tommy Eugene Sanford Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE January 1961 Major Subject: Meteorology SOME EFFECI'S OF RANGE UPON AN/CPS-9 RADAR REFLECTIVITIES IN THUNDERSTORMS A Thesis Tommy Eugene Sanford Approved as to style and content by: (Chairman of Committe ) 4~4 (Head...

  4. Computing High Accuracy Power Spectra with Pico

    E-Print Network [OSTI]

    William A. Fendt; Benjamin D. Wandelt

    2007-12-02T23:59:59.000Z

    This paper presents the second release of Pico (Parameters for the Impatient COsmologist). Pico is a general purpose machine learning code which we have applied to computing the CMB power spectra and the WMAP likelihood. For this release, we have made improvements to the algorithm as well as the data sets used to train Pico, leading to a significant improvement in accuracy. For the 9 parameter nonflat case presented here Pico can on average compute the TT, TE and EE spectra to better than 1% of cosmic standard deviation for nearly all $\\ell$ values over a large region of parameter space. Performing a cosmological parameter analysis of current CMB and large scale structure data, we show that these power spectra give very accurate 1 and 2 dimensional parameter posteriors. We have extended Pico to allow computation of the tensor power spectrum and the matter transfer function. Pico runs about 1500 times faster than CAMB at the default accuracy and about 250,000 times faster at high accuracy. Training Pico can be done using massively parallel computing resources, including distributed computing projects such as Cosmology@Home. On the homepage for Pico, located at http://cosmos.astro.uiuc.edu/pico, we provide new sets of regression coefficients and make the training code available for public use.

  5. THE THICKNESS DISTORTION OF Fe 57 BACKSCATTER MOSSBAUER SPECTRA

    E-Print Network [OSTI]

    Fultz, B.

    2013-01-01T23:59:59.000Z

    F. Weise, and P. Flinn, "Mossbauer Spectrometry for AnalysisOF Fe 57 BACKSCATTER MOSSBAUER SPECTRA B. Fultz and J. W.DISTORTION OF Fe BACKSCATTER MOSSBAUER SPECTRA B. Fultz and

  6. Infrared absorption spectra, radiative efficiencies, and global warming potentials

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    Infrared absorption spectra, radiative efficiencies, and global warming potentials absorption spectra, radiative efficiencies, and global warming potentials of perfluorocarbons: Comparison. (1995) and combined with atmospheric lifetimes from the literature to determine global warming

  7. Characteristics of profiles of gamma-ray burst pulses associated with the Doppler effect of fireballs

    E-Print Network [OSTI]

    Yi-Ping Qin; Zhi-Bin Zhang; Fu-Wen Zhang; Xiao-Hong Cui

    2004-08-31T23:59:59.000Z

    In this paper, we derive in a much detail the formula of count rates, in terms of the integral of time, of gamma-ray bursts in the framework of fireballs, where the Doppler effect of the expanding fireball surface is the key factor to be concerned. Effects arising from the limit of the time delay due to the limited regions of the emitting areas in the fireball surface and other factors are investigated. Our analysis shows that the formula of the count rate of fireballs can be expressed as a function of $\\tau $ which is the observation time scale relative to the dynamical time scale of the fireball. The profile of light curves of fireballs depends only on the relative time scale, entirely independent of the real time scale and the real size of the objects. It displays in detail how a cutoff tail, or a turn over, feature (called a cutoff tail problem) in the decay phase of a light curve can be formed. This feature is a consequence of a hot spot in the fireball surface, moving towards the observer, and was observed in a few cases previously. By performing fits to the count rate light curves of six sample sources, we show how to obtain some physical parameters from the observed profile of the count rate of GRBs. In addition, the analysis reveals that the Doppler effect of fireballs could lead to a power law relationship between the $FWHM$ of pulses and energy, which were observed previously by many authors.

  8. The chromospherically active binary star EI Eridani II. Long-term Doppler imaging

    E-Print Network [OSTI]

    A. Washuettl; K. G. Strassmeier; M. Weber

    2008-11-19T23:59:59.000Z

    Data from 11 years of continuous spectroscopic observations of the active RS CVn-type binary star EI Eridani - gained at NSO/McMath-Pierce, KPNO/Coude Feed and during the MUSICOS 98 campaign - were used to obtain 34 Doppler maps in three spectroscopic lines for 32 epochs, 28 of which are independent of each other. Various parameters are extracted from our Doppler maps: average temperature, fractional spottedness, and longitudinal and latitudinal spot-occurrence functions. We find that none of these parameters show a distinct variation nor a correlation with the proposed activity cycle as seen from photometric long-term observations. This suggests that the photometric brightness cycle may not necessarily be due to just a cool spot cycle. The general morphology of the spot pattern remains persistent over the whole period of 11 years. A large cap-like polar spot was recovered from all our images. A high degree of variable activity was noticed near latitudes of approx. 60-70 degrees where the appendages of the polar spot emerged and dissolved.

  9. Experiment and theory: the case of the Doppler effect for photons

    E-Print Network [OSTI]

    Giuliani, Giuseppe

    2015-01-01T23:59:59.000Z

    In 1907, Einstein suggested an experiment with flying atoms for corroborating time dilation. In that paper, the flying atom was conceived as a flying clock: the reference to the Doppler effect was only indirect (the experiments by Stark to the first order of $v/c$). In 1922, Schr\\"odinger showed that the emission of a light quantum by a (flying) atom is regulated by the conservation laws of energy and linear momentum. Therefore, the Doppler effect for photons is the consequence of the energy and momentum exchange between the atom and the photon: a central role is played by the quantum energy jump $\\Delta E$ of the transition (a relativistic invariant). The first realization of the experiment devised by Einstein is due to Ives and Stilwell (1938). Since then till nowadays experiments of this kind have been repeated in search of better precision and/or a deviation from the predictions of special relativity. The striking feature is that all the papers dealing with these experiments completely neglect Schr\\"oding...

  10. The effect of temperature anisotropy on observations of Doppler dimming and pumping in the inner corona

    E-Print Network [OSTI]

    Xing Li; Shadia Rifai Habbal; John Kohl; Giancarlo Noci

    1998-05-04T23:59:59.000Z

    Recent observations of the spectral line profiles and intensity ratio of the O VI 1032 {\\AA} and 1037.6 {\\AA} doublet by the Ultraviolet Coronagraph Spectrometer (UVCS) on the Solar and Heliospheric Observatory (SOHO), made in coronal holes below 3.5 $R_s$, provide evidence for Doppler dimming of the O VI 1037.6 {\\AA} line and pumping by the chromospheric C II 1037.0182 {\\AA} line. Evidence for a significant kinetic temperature anisotropy of O$^{5+}$ ions was also derived from these observations. We show in this Letter how the component of the kinetic temperature in the direction perpendicular to the magnetic field, for both isotropic and anisotropic temperature distributions, affects both the amount of Doppler dimming and pumping. Taking this component into account, we further show that the observation that the O VI doublet intensity ratio is less than unity can be accounted for only if pumping by C II 1036.3367 {\\AA} in addition to C II 1037.0182 {\\AA} is in effect. The inclusion of the C II 1036.3367 {\\AA} pumping implies that the speed of the O$^{5+}$ ions can reach 400 km/s around 3 $R_s$ which is significantly higher than the reported UVCS values for atomic hydrogen in polar coronal holes. These results imply that oxygen ions flow much faster than protons at that heliocentric distance.

  11. A High-Speed Optical Diagnostic that uses Interference Filters to Measure Doppler Shifts

    SciTech Connect (OSTI)

    S.F. Paul; C. Cates; M. Mauel; D. Maurer; G. Navratil; M. Shilov

    2004-08-09T23:59:59.000Z

    A high-speed, non-invasive velocity diagnostic has been developed for measuring plasma rotation. The Doppler shift is determined by employing two detectors that view line emission from the identical volume of plasma. Each detector views through an interference filter having a passband that varies linearly with wavelength. One detector views the plasma through a filter whose passband has a negative slope and the second detector views through one with a positive slope. Because each channel views the same volume of plasma, the ratio of the amplitudes is not sensitive to variations in plasma emission. With suitable knowledge of the filter characteristics and the relative gain, the Doppler shift is readily obtained in real time from the ratio of two channels without needing a low throughput spectrometer. The systematic errors--arising from temperature drifts, stability, and frequency response of the detectors and amplifiers, interference filter linearity, and ability to thoroughly homogenize the light from the fiber bundle--can be characterized well enough to obtain velocity data with + or - 1 km/sec with a time resolution of 0.3 msec.

  12. Linearly Organized Turbulence Structures Observed Over a Suburban Area by Dual-Doppler Lidar

    SciTech Connect (OSTI)

    Newsom, Rob K.; Calhoun, Ron; Ligon, David; Allwine, K Jerry

    2008-04-01T23:59:59.000Z

    Dual-Doppler lidar observations are used to investigate the structure and evolution of surface layer flow over a suburban area. The observations were made during the Joint Urban 2003 (JU2003) field experiment in Oklahoma City in the summer of 2003. This study focuses specifically on a 10-hour sequence of scan data beginning shortly after noon local time on July 7, 2003. During this period two coherent Doppler lidars performed overlapping low elevation angle sector scans upwind and south of Oklahoma City’s central business district (CBD). Radial velocity data from the two lidars are processed to reveal the structure and evolution of the horizontal velocity field in the surface layer throughout the afternoon and evening transition periods. The retrieved velocity fields clearly show a tendency for turbulence structures to be elongated in the direction of the mean flow throughout the entire 10-hour study period. As the stratification changed from unstable to weakly stable the turbulence structures became increasingly more linearly organized, and the cross-stream separation between high- and low-speed regoins decreased. The spatially resolved velocity fields are used to estimate streamwise and cross-stream turbulence length scales as functions of stability.

  13. Measurement of fluid-flow-velocity profile in turbid media by the use of optical Doppler tomography

    SciTech Connect (OSTI)

    Wang, Xiao-Jun; Milner, T.E.; Chen, Zhongping; Nelson, J.S. [Beckman Laser Institute and Medical Clinic, University of California-Irvine, Irvine, California 92715 (United States)]|[Department of Physics, Georgia Southern University, Statesboro, Georgia 30460 (United States)

    1997-01-01T23:59:59.000Z

    Optical Doppler tomography is demonstrated to be a simple, accurate, and noncontact method for measuring the fluid velocity of laminar flow in small-diameter ({approximately}0.5-mm) ducts. Studies are described that utilize circular (square) plastic (glass) ducts infused with a moving suspension of polymer micro-spheres in air and buried in an optically turbid medium. The measurement of Doppler-shifted frequencies of backscattered light from moving microspheres is used to construct a high-resolution spatial profile of fluid-flow velocity in the ducts. {copyright} 1997 Optical Society of America

  14. Correcting second-order contamination in low-resolution spectra

    E-Print Network [OSTI]

    V. Stanishev

    2007-05-23T23:59:59.000Z

    An empirical method for correcting low-resolution astronomical spectra for second-order contamination is presented. The method was developed for correcting spectra obtained with grism #4 of the ALFOSC spectrograph at the Nordic Optical Telescope and the performance is demonstrated on spectra of two nearby bright Type Ia supernovae.

  15. Infrared absorption spectra, radiative efficiencies, and global warming potentials

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    Infrared absorption spectra, radiative efficiencies, and global warming potentials of newly.mdpi.com/journal/atmosphere Article Infrared Absorption Spectra, Radiative Efficiencies, and Global Warming Potentials of Newly of 600­1730 cm-1 . These spectra are then used to calculate the radiative efficiencies and global warming

  16. ENDF/B-V, ENDF/B-VI, AND ENDF/B-VII.0 RESULTS FOR THE DOPPLER-DEFECT BENCHMARK (U)

    SciTech Connect (OSTI)

    MOSTELLER, RUSSELL D. [Los Alamos National Laboratory

    2007-02-09T23:59:59.000Z

    A set of computational benchmarks for the Doppler reactivity defect has been specified for an infinite array of identical fuel pin cells containing normal or enriched UO{sub 2} fuel, reactor-recycle mixed-oxide (MOX) fuel, or weapons-grade MOX fuel. The Doppler coefficient of reactivity, as well as the Doppler defect, can be computed for each of the cells. The MCNP5 Monte Carlo code was used to perform calculations for these benchmarks using cross sections derived from the ENDF/B-V, ENDF/B-VI, and ENDF/B-VII.0 nuclear data sets. The Doppler coefficients obtained from the three data sets exhibit very similar behavior. The Doppler coefficient for UO{sub 2} fuel becomes less negative with increasing enrichment, with a generally asymptotic shape. The Doppler coefficient for the reactor-recycle MOX becomes less negative with increasing PuO{sub 2} content but exhibits less curvature than that for UO{sub 2} fuel. The Doppler coefficient for weapons-grade MOX shows a pronounced shoulder between 1 wt.% and 2 wt.% PuO{sub 2}, with a nearly constant value thereafter. The Doppler coefficient for heavily loaded MOX fuel, whether reactor-recycle or weapons-grade, is significantly more negative than that for highly enriched UO{sub 2} fuel.

  17. hal-00182596,version2-14Feb2008 Two-step Doppler cooling of a three-level ladder system with an

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    hal-00182596,version2-14Feb2008 Two-step Doppler cooling of a three-level ladder system., Denmark (Dated: February 14, 2008) Abstract Doppler laser cooling of a three-level ladder system using two´er^ome, Case C21, 13397 Marseille Cedex 20, France M. Drewsen QUANTOP, Danish National Research foundation

  18. Uncertainty Quantification on Prompt Fission Neutrons Spectra

    SciTech Connect (OSTI)

    Talou, P. [T-16, Nuclear Physics Group, Los Alamos National Laboratory, NM 87545 (United States)], E-mail: talou@lanl.gov; Madland, D.G.; Kawano, T. [T-16, Nuclear Physics Group, Los Alamos National Laboratory, NM 87545 (United States)

    2008-12-15T23:59:59.000Z

    Uncertainties in the evaluated prompt fission neutrons spectra present in ENDF/B-VII.0 are assessed in the framework of the Los Alamos model. The methodology used to quantify the uncertainties on an evaluated spectrum is introduced. We also briefly review the Los Alamos model and single out the parameters that have the largest influence on the calculated results. Using a Kalman filter, experimental data and uncertainties are introduced to constrain model parameters, and construct an evaluated covariance matrix for the prompt neutrons spectrum. Preliminary results are shown in the case of neutron-induced fission of {sup 235}U from thermal up to 15 MeV incident energies.

  19. Nuclear reactor fissile isotopes antineutrino spectra

    E-Print Network [OSTI]

    V. Sinev

    2012-07-30T23:59:59.000Z

    Positron spectrum from inverse beta decay reaction on proton was measured in 1988-1990 as a result of neutrino exploration experiment. The measured spectrum has the largest statistics and lowest energy threshold between other neutrino experiments made that time at nuclear reactors. On base of the positron spectrum the standard antineutrino spectrum for typical reactor fuel composition was restored. In presented analysis the partial spectra forming this standard spectrum were extracted using specific method. They could be used for neutrino experiments data analysis made at any fuel composition of reactor core.

  20. Spectra Nova Technologies Inc | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro Industries Pvt LtdShawangunk,Southeast Colorado PowerSouthwesternCompaniesSES JumpSpectra Nova

  1. SpectraWatt | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere IRaghuraji Agro Industries Pvt LtdShawangunk,Southeast Colorado PowerSouthwesternCompaniesSES JumpSpectra

  2. Abstract--Synthetic aperture radar has become an important technique for generating high-resolution images of the ground,

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    velocity vector, because of the Doppler shift dependency on azimuthal position and radial velocity of the Doppler shift dependence on both azimuthal position and radial velocity of the moving target [15]. 2 is nowadays well mastered. If targets are moving, it induces a delocalization and a defocusing effect

  3. Power spectra of outflow-driven turbulence

    E-Print Network [OSTI]

    Moraghan, Anthony; Yoon, Suk-Jin

    2015-01-01T23:59:59.000Z

    We investigate the power spectra of outflow-driven turbulence through high-resolution three-dimensional isothermal numerical simulations where the turbulence is driven locally in real-space by a simple spherical outflow model. The resulting turbulent flow saturates at an average Mach number of ~2.5 and is analysed through density and velocity power spectra, including an investigation of the evolution of the solenoidal and compressional components. We obtain a shallow density power spectrum with a slope of ~-1.2 attributed to the presence of a network of localised dense filamentary structures formed by strong shock interactions. The total velocity power spectrum slope is found to be ~-2.0, representative of Burgers shock dominated turbulence model. The density weighted velocity power spectrum slope is measured as ~-1.6, slightly less than the expected Kolmogorov scaling value (slope of -5/3) found in previous works. The discrepancy may be caused by the nature of our real space driving model and we suggest ther...

  4. Micro-Doppler Effect Analysis and Feature Extraction in ISAR Imaging With Stepped-Frequency Chirp Signals

    E-Print Network [OSTI]

    Luo, Ying

    The micro-Doppler (m-D) effect induced by the rotating parts or vibrations of the target provides a new approach for target recognition. To obtain high range resolution for the extraction of the fine m-D signatures of an ...

  5. Outline Phonon spectra of graphene Raman spectra of graphene Crystal lattice dynamics

    E-Print Network [OSTI]

    Seminar Heng Wang University of Konstanz July 11, 2013 Heng Wang University of Konstanz () Crystal lattice Raman spectra of graphene What is Raman scattering Applications of Raman spectroscopy of graphene Heng (2013). Heng Wang University of Konstanz () Crystal lattice dynamics July 11, 2013 3 / 19 #12;Outline

  6. Prediction of buried mine-like target radar signatures using wideband electromagnetic modeling

    SciTech Connect (OSTI)

    Warrick, A.L.; Azevedo, S.G.; Mast, J.E.

    1998-04-06T23:59:59.000Z

    Current ground penetrating radars (GPR) have been tested for land mine detection, but they have generally been costly and have poor performance. Comprehensive modeling and experimentation must be done to predict the electromagnetic (EM) signatures of mines to access the effect of clutter on the EM signature of the mine, and to understand the merit and limitations of using radar for various mine detection scenarios. This modeling can provide a basis for advanced radar design and detection techniques leading to superior performance. Lawrence Livermore National Laboratory (LLNL) has developed a radar technology that when combined with comprehensive modeling and detection methodologies could be the basis of an advanced mine detection system. Micropower Impulse Radar (MIR) technology exhibits a combination of properties, including wideband operation, extremely low power consumption, extremely small size and low cost, array configurability, and noise encoded pulse generation. LLNL is in the process of developing an optimal processing algorithm to use with the MIR sensor. In this paper, we use classical numerical models to obtain the signature of mine-like targets and examine the effect of surface roughness on the reconstructed signals. These results are then qualitatively compared to experimental data.

  7. 13A.1 ASSIMILATION OF SIMULATED NETWORK RADAR DATA OF VARIED STORM TYPES USING ENSRF FOR CONVECTIVE STORM ANALYSES AND FORECASTS

    E-Print Network [OSTI]

    Xue, Ming

    installation costs down, the CASA radars will be placed on cell phone towers or other existing infras- tructure with large data transmission capabilities. Unlike the existing pre-programmed radar network, the collabo

  8. Multi-channel Doppler backscattering measurements in the C-2 field reversed configuration

    SciTech Connect (OSTI)

    Schmitz, L., E-mail: lschmitz@ucla.edu; Peebles, W. A. [Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095 (United States); Ruskov, E. [Department of Physics and Astronomy, University of California, Irvine, Irvine, California 92697 (United States); Deng, B. H.; Gota, H.; Gupta, D.; Tuszewski, M.; Douglass, J.; Binderbauer, M.; Tajima, T. [Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688 (United States)

    2014-11-15T23:59:59.000Z

    A versatile heterodyne Doppler Backscattering (DBS) system is used to measure density fluctuation levels (in the wavenumber range k?{sub s} ? 50), and the toroidal E × B flow velocity in the C-2 Field-Reversed Configuration (FRC). Six tunable frequencies in three waveguide bands (26 GHz ? f ? 90 GHz) are launched using monostatic beam optics, via a quasi-optical beam combiner/polarizer and an adjustable parabolic focusing mirror (inside the vacuum enclosure) achieving Gaussian beam spot sizes of 3–5.5 cm at the X/O-mode cutoff. The DBS system covers plasma densities of 0.8 × 10{sup 13} ? n{sub e} ? 1 × 10{sup 14} cm{sup ?3}, and provides access to the FRC core (up to the field null) and across the FRC separatrix into the scrape-off layer plasma.

  9. Scattering effects at near-wall flow measurements using Doppler global velocimetry

    SciTech Connect (OSTI)

    Fischer, Andreas; Haufe, Daniel; Buettner, Lars; Czarske, Juergen

    2011-07-20T23:59:59.000Z

    Doppler global velocimetry (DGV) is considered to be a useful optical measurement tool for acquiring flow velocity fields. Often near-wall measurements are required, which is still challenging due to errors resulting from background scattering and multiple-particle scattering. Since the magnitudes of both errors are unknown so far, they are investigated by scattering simulations and experiments. Multiple-particle scattering mainly causes a stochastic error, which can be reduced by averaging. Contrary to this, background scattering results in a relative systematic error, which is directly proportional to the ratio of the background scattered light power to the total scattered light power. After applying a correction method and optimizing the measurement arrangement, a subsonic flat plate boundary layer was successfully measured achieving a minimum wall distance of 100 {mu}m with a maximum relative error of 6%. The investigations reveal the current capabilities and perspectives of DGV for near-wall measurements.

  10. GR without SR: A gravitational-domain description of first-order Doppler effects

    E-Print Network [OSTI]

    Eric Baird

    1998-07-30T23:59:59.000Z

    Equivalence principles are a major part of modern relativity theory. Gravitational shifts can already be calculated within the time domain as motion shifts, and we examine the consequences of reversing this argument and describing motion shifts outside the time domain, as effects of curvature associated with relative velocity. This unusual "Doppler mass shift" approach appears to resolve some of Einstein's own criticisms of the "SR+GR" model and seems to remove some barriers to the reconciliation of classical and quantum theory. The disadvantage of this model is that constant-velocity problems no longer obey Euclidean geometry. By bypassing special relativity and the special theory's flat-space assumptions, the model also suggests an alternative non-transverse frequency-shift relationship. This difference should be testable.

  11. 2D full wave modeling for a synthetic Doppler backscattering diagnostic

    SciTech Connect (OSTI)

    Hillesheim, J. C.; Schmitz, L.; Kubota, S.; Rhodes, T. L.; Carter, T. A. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095 (United States); Holland, C. [University of California, San Diego, La Jolla, California 92093 (United States)

    2012-10-15T23:59:59.000Z

    Doppler backscattering (DBS) is a plasma diagnostic used in tokamaks and other magnetic confinement devices to measure the fluctuation level of intermediate wavenumber (k{sub {theta}}{rho}{sub s}{approx} 1) density fluctuations and the lab frame propagation velocity of turbulence. Here, a synthetic DBS diagnostic is described, which has been used for comparisons between measurements in the DIII-D tokamak and predictions from nonlinear gyrokinetic simulations. To estimate the wavenumber range to which a Gaussian beam would be sensitive, a ray tracing code and a 2D finite difference, time domain full wave code are used. Experimental density profiles and magnetic geometry are used along with the experimental antenna and beam characteristics. An example of the effect of the synthetic diagnostic on the output of a nonlinear gyrokinetic simulation is presented.

  12. Effect of net surface charge on particle sizing and material recognition by using phase Doppler anemometry

    SciTech Connect (OSTI)

    Zhou Jun; Xie Li

    2011-01-20T23:59:59.000Z

    By taking net surface charge into consideration, the scattering field of particles illuminated by dual laser beams of phase Doppler anemometry (PDA) is computed based on Mie's theory, and the effect of net surface charge on the phase-diameter relationship and the phase ratio is studied. It is found that the phase-diameter relationship and the relationship between the phase ratio and the refractive index of charged particles could be significantly different from those of uncharged particles, which would lead to errors in particle sizing and the measurement of refractive indices. A method of recognizing charged particles and determining the value of their surface conductivity, which is related to net surface charge, is proposed by utilizing the effect of net surface charge on the measurement of refractive indices using PDA.

  13. Doppler effect of gamma-ray bursts in the fireball framework

    E-Print Network [OSTI]

    Yi-Ping Qin; Fu-Wen Zhang

    2004-07-13T23:59:59.000Z

    The influence of the Doppler effect in the fireball framework on the spectrum of gamma-ray bursts is investigated. The study shows that the shape of the expected spectrum of an expanding fireball remains almost the same as that of the corresponding rest frame spectrum for constant radiations of the bremsstrahlung, Comptonized, and synchrotron mechanisms as well as for that of the GRB model. The peak flux spectrum and the peak frequency are obviously correlated. When the value of the Lorentz factor becomes 10 times larger, the flux of fireballs would be several orders of magnitude larger. The expansion speed of fireballs is a fundamental factor of the enhancement of the flux of gamma-ray bursts.

  14. Analysis of Doppler Lidar Data Acquired During the Pentagon Shield Field Campaign

    SciTech Connect (OSTI)

    Newsom, Rob K.

    2011-04-14T23:59:59.000Z

    Observations from two coherent Doppler lidars deployed during the Pentagon Shield field campaign are analyzed in conjunction with other sensors to characterize the overall boundary-layer structure, and identify the dominant flow characteristics during the entire two-week field campaign. Convective boundary layer (CBL) heights and cloud base heights (CBH) are estimated from an analysis of the lidar signal-to-noise-ratio (SNR), and mean wind profiles are computed using a modified velocity-azimuth-display (VAD) algorithm. Three-dimensional wind field retrievals are computed from coordinated overlapping volume scans, and the results are analyzed by visualizing the flow in horizontal and vertical cross sections. The VAD winds show that southerly flows dominate during the two-week field campaign. Low-level jets (LLJ) were evident on all but two of the nights during the field campaign. The LLJs tended to form a couple hours after sunset and reach maximum strength between 03 and 07 UTC. The surface friction velocities show distinct local maxima during four nights when strong LLJs formed. Estimates of the convective boundary layer height and residual layer height are obtained through an analysis of the vertical gradient of the lidar signal-to-noise-ratio (SNR). Strong minimum in the SNR gradient often develops just above the surface after sunrise. This minimum is associated with the developing CBL, and increases rapidly during the early portion of the daytime period. On several days, this minimum continues to increase until about sunset. Secondary minima in the SNR gradient were also observed at higher altitudes, and are believed to be remnants of the CBL height from previous days, i.e. the residual layer height. The dual-Doppler analysis technique used in this study makes use of hourly averaged radial velocity data to produce three-dimensional grids of the horizontal velocity components, and the horizontal velocity variance. Visualization of horizontal and vertical cross sections of the dual-Doppler wind retrievals often indicated a jet-like flow feature over the Potomac River under southerly flow conditions. This linear flow feature is roughly aligned with the Potomac River corridor to the south of the confluence with the Anatostia River, and is most apparent at low levels (i.e. below ~150 m MSL). It is believed that this flow arises due to reduced drag over the water surface and when the large scale flow aligns with the Potomac River corridor. A so-called area-constrained VAD analysis generally confirmed the observations from the dual-Doppler analysis. When the large scale flow is southerly, wind speeds over the Potomac River are consistently larger than the at a site just to the west of the river for altitudes less than 100 m MSL. Above this level, the trend is somewhat less obvious. The data suggest that the depth of the wind speed maximum may be reduced by strong directional shear aloft.

  15. Laser Doppler vibrometry for assessment of arteriosclerosis: A first step towards validation

    SciTech Connect (OSTI)

    Campo, Adriaan; Dirckx, Joris [University of Antwerp, Laboratory of Biomedical Physics, Groenenborgerlaan 171 2020 Antwerp (Belgium)

    2014-05-27T23:59:59.000Z

    It has been shown that in cardiovascular risk management, stiffness of large arteries has a very good predictive value for cardiovascular disease and mortality. This parameter can be estimated from the pulse wave velocity (PWV) measured between the common carotid artery (CCA) in the neck and femoral artery (FA) in the groin. However PWV can also be measured locally in the CCA, using non-invasive methods such as ultrasound (US) or laser Doppler vibrometry (LDV). Potential of the latter approach was already explored in previous research, and in this work a first step towards clinical validation is made. 50 hypertension II/III patients aged between 30 and 65 participate in the study. Patients were asked to remain sober for 4 hours prior to the measurements. The trajectory of the CCA in the neck was determined by a trained clinician guided by an US probe. 3 laser Doppler vibrometer (LDV) systems were aimed along the CCA. PWV was then calculated from the distance between beams and the time-shift between waveforms. Immediately after LDV measurements, PWV was measured with US. Additionally, carotid-femoral PWV was measured. As a validation, PWV results of the different techniques were compared with each other, and with medical background of the test subjects. Since data acquisition is still ongoing, data from only 20 patients will be discussed. No trends between measurement methods for PWV are apparent. However, a positive trend was detected between PWV as measured with LDV and blood pressure. More data, including additional experiments will be needed to verify this observation.

  16. ARM: Millimeter Wave Cloud Radar (MMCR), replaces mmcrcal and mmcrmoments datastreams following C-40 processor upgrade of 2003.09.09

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Widener, Kevin; Bharadwaj, Nitin; Johnson, Karen

    Millimeter Wave Cloud Radar (MMCR), replaces mmcrcal and mmcrmoments datastreams following C-40 processor upgrade of 2003.09.09

  17. Oxidation of carbynes: Signatures in infrared spectra

    SciTech Connect (OSTI)

    Cinquanta, E., E-mail: eugenio.cinquanta@mdm.imm.cnr.it, E-mail: p.rudolf@rug.nl [CIMAINA, University of Milan, Via Celoria 16, 20133 Milano (Italy); Department of Materials Science, University of Milan Bicocca, Via Cozzi 53, 20125 Milano (Italy); Manini, N.; Caramella, L.; Onida, G. [European Theoretical Spectroscopy Facility (ETSF), Via Celoria 16, 20133 Milano (Italy); Physics Department, University of Milan, Via Celoria 16, 20133 Milano (Italy); Ravagnan, L.; Milani, P. [CIMAINA, University of Milan, Via Celoria 16, 20133 Milano (Italy); Physics Department, University of Milan, Via Celoria 16, 20133 Milano (Italy); Rudolf, P., E-mail: eugenio.cinquanta@mdm.imm.cnr.it, E-mail: p.rudolf@rug.nl [Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen (Netherlands)

    2014-06-28T23:59:59.000Z

    We report and solidly interpret the infrared spectrum of both pristine and oxidized carbynes embedded in a pure-carbon matrix. The spectra probe separately the effects of oxidation on sp- and on sp{sup 2}-hybridized carbon, and provide information on the stability of the different structures in an oxidizing atmosphere. The final products are mostly short end-oxidized carbynes anchored with a double bond to sp{sup 2} fragments, plus an oxidized sp{sup 2} amorphous matrix. Our results have important implications for the realization of carbyne-based nano-electronics devices and highlight the active participation of carbynes in astrochemical reactions where they act as carbon source for the promotion of more complex organic species.

  18. Radioactive sample effects on EDXRF spectra

    SciTech Connect (OSTI)

    Worley, Christopher G [Los Alamos National Laboratory

    2008-01-01T23:59:59.000Z

    Energy dispersive X-ray fluorescence (EDXRF) is a rapid, straightforward method to determine sample elemental composition. A spectrum can be collected in a few minutes or less, and elemental content can be determined easily if there is adequate energy resolution. Radioactive alpha emitters, however, emit X-rays during the alpha decay process that complicate spectral interpretation. This is particularly noticeable when using a portable instrument where the detector is located in close proximity to the instrument analysis window held against the sample. A portable EDXRF instrument was used to collect spectra from specimens containing plutonium-239 (a moderate alpha emitter) and americium-241 (a heavy alpha emitter). These specimens were then analyzed with a wavelength dispersive XRF (WDXRF) instrument to demonstrate the differences to which sample radiation-induced X-ray emission affects the detectors on these two types of XRF instruments.

  19. UV spectra, bombs, and the solar atmosphere

    E-Print Network [OSTI]

    Judge, Philip G

    2015-01-01T23:59:59.000Z

    A recent analysis of UV data from the Interface Region Imaging Spectrograph {\\em IRIS} reports plasma "bombs" with temperatures near \\hot{} within the solar photosphere. This is a curious result, firstly because most bomb plasma pressures $p$ (the largest reported case exceeds $10^3$ dyn~cm$^{-2}$) fall well below photospheric pressures ($> 7\\times10^3$), and secondly, UV radiation cannot easily escape from the photosphere. In the present paper the {\\em IRIS} data is independently analyzed. I find that the bombs arise from plasma originally at pressures between $\\lta80$ and 800 dyne~cm$^{-2}$ before explosion, i.e. between $\\lta850$ and 550 km above $\\tau_{500}=1$. This places the phenomenon's origin in the low-mid chromosphere or above. I suggest that bomb spectra are more compatible with Alfv\\'enic turbulence than with bi-directional reconnection jets.

  20. Inflationary Spectra from Lorentz Violating Dissipative Models

    E-Print Network [OSTI]

    Adamek, Julian; Niemeyer, Jens C; Parentani, Renaud

    2008-01-01T23:59:59.000Z

    The sensitivity of inflationary spectra to initial conditions is addressed in the context of a phenomenological model that breaks Lorentz invariance by dissipative effects above some threshold energy $\\Lambda$. These effects are obtained dynamically by coupling the fluctuation modes to extra degrees of freedom which are unobservable below $\\Lambda$. Because of the strong dissipative effects in the early propagation, only the state of the extra degrees of freedom is relevant for the power spectrum. If this state is the ground state, and if $\\Lambda$ is much larger than the Hubble scale, the standard spectrum is recovered. Using analytical and numerical methods, we calculate the modifications induced by dissipation. We show that the leading modification is linear in the decay rate evaluated at horizon exit, and that superimposed oscillations are not generated significantly. Since the sign of this modification can be negative, a loss of power on the largest scales may be observable.

  1. Chemical and isotopic determination from complex spectra

    SciTech Connect (OSTI)

    Zardecki, A.; Strittmatter, R.B.

    1995-07-01T23:59:59.000Z

    Challenges for proliferation detection include remote, high- sensitivity detection of chemical effluents from suspect facilities and enhanced detection sensitivity for nuclear material. Both the identification of chemical effluents with lidar and enhanced nuclear material detection from radiation sensors involve determining constituents from complex spectra. In this paper, we extend techniques used to analyze time series to the analysis of spectral data. Pattern identification methods are applied to spectral data for domains where standard matrix inversion may not be suitable because of detection statistics. We use a feed-forward, back-propagation neural network in which the nodes of the input layer are fed with the observed spectral data. The nodes of the output layer contain the identification and concentration of the isotope or chemical effluent the sensor is to identify. We will discuss the neural network architecture, together with preliminary results obtained from the training process.

  2. THEORETICAL SPECTRA OF TERRESTRIAL EXOPLANET SURFACES

    SciTech Connect (OSTI)

    Hu Renyu; Seager, Sara [Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Ehlmann, Bethany L., E-mail: hury@mit.edu [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States)

    2012-06-10T23:59:59.000Z

    We investigate spectra of airless rocky exoplanets with a theoretical framework that self-consistently treats reflection and thermal emission. We find that a silicate surface on an exoplanet is spectroscopically detectable via prominent Si-O features in the thermal emission bands of 7-13 {mu}m and 15-25 {mu}m. The variation of brightness temperature due to the silicate features can be up to 20 K for an airless Earth analog, and the silicate features are wide enough to be distinguished from atmospheric features with relatively high resolution spectra. The surface characterization thus provides a method to unambiguously identify a rocky exoplanet. Furthermore, identification of specific rocky surface types is possible with the planet's reflectance spectrum in near-infrared broad bands. A key parameter to observe is the difference between K-band and J-band geometric albedos (A{sub g}(K) - A{sub g}(J)): A{sub g}(K) - A{sub g}(J) > 0.2 indicates that more than half of the planet's surface has abundant mafic minerals, such as olivine and pyroxene, in other words primary crust from a magma ocean or high-temperature lavas; A{sub g}(K) - A{sub g}(J) < -0.09 indicates that more than half of the planet's surface is covered or partially covered by water ice or hydrated silicates, implying extant or past water on its surface. Also, surface water ice can be specifically distinguished by an H-band geometric albedo lower than the J-band geometric albedo. The surface features can be distinguished from possible atmospheric features with molecule identification of atmospheric species by transmission spectroscopy. We therefore propose that mid-infrared spectroscopy of exoplanets may detect rocky surfaces, and near-infrared spectrophotometry may identify ultramafic surfaces, hydrated surfaces, and water ice.

  3. Dryline Characteristics near Lubbock, Texas, Based on Radar and West Texas Mesonet Data for May 2005 and May 2006

    E-Print Network [OSTI]

    Geerts, Bart

    Dryline Characteristics near Lubbock, Texas, Based on Radar and West Texas Mesonet Data for May, in final form 14 November 2007) ABSTRACT Two months of Lubbock, Texas, radar reflectivity data and West the spring" (Hane et al. 1993). Thus, forecasters from southwest Texas to west- ern Kansas routinely examine

  4. 500 IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, VOL. 3, NO. 4, OCTOBER 2006 ELF Radar System Proposed for Localized

    E-Print Network [OSTI]

    Simpson, Jamesina J.

    500 IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, VOL. 3, NO. 4, OCTOBER 2006 ELF Radar System frequency (ELF), finite difference time domain (FDTD), ionospheric disturbances, radar, remote sensing. I to be of sufficiently low power to have negligible heating or any other effects upon the ionospheric anomaly.) Employing

  5. J1.10 FAA SURVEILLANCE RADAR DATA AS A COMPLEMENT TO THE WSR-88D NETWORK *

    E-Print Network [OSTI]

    Droegemeier, Kelvin K.

    .S. Federal Aviation Administration (FAA) operates over 400 C- to L-band surveillance radars-- Airport realization of these benefits. This work was sponsored by the Federal Aviation Administration under Air ForceJ1.10 FAA SURVEILLANCE RADAR DATA AS A COMPLEMENT TO THE WSR-88D NETWORK * Mark E. Weber

  6. HumanWildlife Interactions 5(2):210217, Fall 2011 Using radar cross-section to enhance

    E-Print Network [OSTI]

    D; Brand 2010a) and the Federal Aviation Administration (FAA; FAA 2010, Herricks et al. 2010). The testing, airfield management, alert, aviation safety, BASH, bird strike, human­ wildlife conflicts, radar, radar cross-section, situational awareness, wildlife hazard Birds pose a threat to aviation safety and cost

  7. Telescope Array Radar (TARA) Observatory for Ultra-High Energy Cosmic Rays

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abbasi, R.; Takai, H.; Allen, C.; Beard, L.; Belz, J.; Besson, D.; Byrne, M.; Abou Bakr Othman, M.; Farhang-Boroujeny, B.; Gardner, A.; et al

    2014-12-01T23:59:59.000Z

    Construction was completed during summer 2013 on the Telescope Array RAdar (TARA) bi-static radar observatory for Ultra-High Energy Cosmic Rays (UHECR). TARA is co-located with the Telescope Array, the largest “conventional” cosmic ray detector in the Northern Hemisphere, in radio-quiet Western Utah. TARA employs an 8 MW Effective Radiated Power (ERP) VHF transmitter and smart receiver system based on a 250 MS/s data acquisition system in an effort to detect the scatter of sounding radiation by UHECR-induced atmospheric ionization. TARA seeks to demonstrate bi-static radar as a useful new remote sensing technique for UHECRs. In this report, we describe themore »design and performance of the TARA transmitter and receiver systems.« less

  8. Telescope Array Radar (TARA) Observatory for Ultra-High Energy Cosmic Rays

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Abbasi, R. [Univ. of Utah, Salt Lake City, UT (United States); Takai, H. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Allen, C. [Univ. of Kansas, Lawrence, KS (United States); Beard, L. [Purdue Univ., West Lafayette, IN (United States); Belz, J. [Univ. of Utah, Salt Lake City, UT (United States); Besson, D. [Univ. of Kansas, Lawrence, KS (United States). Moscow Engineering and Physics Inst. (Russian Federation); Byrne, M. [Univ. of Utah, Salt Lake City, UT (United States); Abou Bakr Othman, M. [Univ. of Utah, Salt Lake City, UT (United States); Farhang-Boroujeny, B. [Univ. of Utah, Salt Lake City, UT (United States); Gardner, A. [Univ. of Utah, Salt Lake City, UT (United States); Gillman, W.H. [Gillman and Associates, Salt Lake City, UT (United States); Hanlon, W. [Univ. of Utah, Salt Lake City, UT (United States); Hanson, J. [Univ. of Kansas, Lawrence, KS (United States); Jayanthmurthy, C. [Univ. of Utah, Salt Lake City, UT (United States); Kunwar, S. [Univ. of Kansas, Lawrence, KS (United States); Larson, S. L. [Utah State Univ., Logan, UT (United States); Myers, I. [Univ. of Utah, Salt Lake City, UT (United States); Prohira, S. [Univ. of Kansas, Lawrence, KS (United States); Ratzlaff, K. [Univ. of Kansas, Lawrence, KS (United States); Sokolsky, P. [Univ. of Utah, Salt Lake City, UT (United States); Thomson, G. B. [Univ. of Utah, Salt Lake City, UT (United States); Von Maluski, D. [Univ. of Utah, Salt Lake City, UT (United States)

    2014-12-01T23:59:59.000Z

    Construction was completed during summer 2013 on the Telescope Array RAdar (TARA) bi-static radar observatory for Ultra-High Energy Cosmic Rays (UHECR). TARA is co-located with the Telescope Array, the largest “conventional” cosmic ray detector in the Northern Hemisphere, in radio-quiet Western Utah. TARA employs an 8 MW Effective Radiated Power (ERP) VHF transmitter and smart receiver system based on a 250 MS/s data acquisition system in an effort to detect the scatter of sounding radiation by UHECR-induced atmospheric ionization. TARA seeks to demonstrate bi-static radar as a useful new remote sensing technique for UHECRs. In this report, we describe the design and performance of the TARA transmitter and receiver systems.

  9. Radar imagery interpretation to assess the hydrocarbon potential of four sites in the Philippines

    SciTech Connect (OSTI)

    Not Available

    1988-11-17T23:59:59.000Z

    The Republic of the Philippines is intensely interested in the identification, development, and conservation of natural resources. In keeping with this, the Government of the Philippines has recently completed a nationwide sedimentary basin evaluation program to assess hydrocarbon potential and assist in future exploration activities. This program of collection and interpretation of the radar imagery was designed to augment and complement the existing data base. The primary objective of the project was to further the goals of international energy development by aiding the Republic of the Philippines in the assessment of potential petroleum and geothermal prospects within the areas imaged. Secondary goals were to assist the Republic of the Philippines in utilizing state-of-the-art radar remote sensing technology for resource exploration, and to train key Philippines scientists in the use of imaging radar data. 29 refs., 30 figs., 14 tabs.

  10. Short range, ultra-wideband radar with high resolution swept range gate

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1998-05-26T23:59:59.000Z

    A radar range finder and hidden object locator is based on ultra-wide band radar with a high resolution swept range gate. The device generates an equivalent time amplitude scan with a typical range of 4 inches to 20 feet, and an analog range resolution as limited by a jitter of on the order of 0.01 inches. A differential sampling receiver is employed to effectively eliminate ringing and other aberrations induced in the receiver by the near proximity of the transmit antenna, so a background subtraction is not needed, simplifying the circuitry while improving performance. Uses of the invention include a replacement of ultrasound devices for fluid level sensing, automotive radar, such as cruise control and parking assistance, hidden object location, such as stud and rebar finding. Also, this technology can be used when positioned over a highway lane to collect vehicle count and speed data for traffic control.

  11. Short range, ultra-wideband radar with high resolution swept range gate

    DOE Patents [OSTI]

    McEwan, T.E.

    1998-05-26T23:59:59.000Z

    A radar range finder and hidden object locator is based on ultra-wide band radar with a high resolution swept range gate. The device generates an equivalent time amplitude scan with a typical range of 4 inches to 20 feet, and an analog range resolution as limited by a jitter of on the order of 0.01 inches. A differential sampling receiver is employed to effectively eliminate ringing and other aberrations induced in the receiver by the near proximity of the transmit antenna, so a background subtraction is not needed, simplifying the circuitry while improving performance. Uses of the invention include a replacement of ultrasound devices for fluid level sensing, automotive radar, such as cruise control and parking assistance, hidden object location, such as stud and rebar finding. Also, this technology can be used when positioned over a highway lane to collect vehicle count and speed data for traffic control. 14 figs.

  12. High-frequency scannerless imaging laser radar for industrial inspection and measurement applications

    SciTech Connect (OSTI)

    Schmitt, R.L.; Williams, R.J.; Matthews, J.D.

    1996-11-01T23:59:59.000Z

    This report describes the development and testing of a high-frequency scannerless imaging laser radar system to evaluate its viability as an industrial inspection and measurement sensor. We modified an existing 5.5-Mhz scannerless laser radar to operate at 150 Mhz, and measured its performance including its spatial resolution and range resolution. We also developed new algorithms that allow rapid data reduction with improved range resolution. The resulting 150-Mhz ladar system demonstrated a range resolution of better than 3 mm, which represents nearly a factor-of-100 improvement in range resolution over the existing scannerless laser radar system. Based on this work, we believe that a scannerless range imager with 1- to 2-mm range resolution is feasible. This work was performed as part of a small-business CRADA between Sandia National Laboratories and Perceptron, Inc.

  13. IFT&E Industry Report Wind Turbine-Radar Interference Test Summary.

    SciTech Connect (OSTI)

    Karlson, Benjamin; LeBlanc, Bruce Philip; Minster, David G; Estill, Milford; Miller, Bryan Edward; Busse, Franz (MIT LL); Keck, Chris (MIT LL); Sullivan, Jonathan (MIT LL); Brigada, David (MIT LL); Parker, Lorri (MIT LL); Younger, Richard (MIT LL); Biddle, Jason (MIT LL)

    2014-10-01T23:59:59.000Z

    Wind turbines have grown in size and capacity with today's average turbine having a power capacity of around 1.9 MW, reaching to heights of over 495 feet from ground to blade tip, and operating with speeds at the tip of the blade up to 200 knots. When these machines are installed within the line-of-sight of a radar system, they can cause significant clutter and interference, detrimentally impacting the primary surveillance radar (PSR) performance. The Massachusetts Institute of Technology's Lincoln Laboratory (MIT LL) and Sandia National Laboratories (SNL) were co-funded to conduct field tests and evaluations over two years in order to: I. Characterize the impact of wind turbines on existing Program-of-Record (POR) air surveillance radars; II. Assess near-term technologies proposed by industry that have the potential to mitigate the interference from wind turbines on radar systems; and III. Collect data and increase technical understanding of interference issues to advance development of long-term mitigation strategies. MIT LL and SNL managed the tests and evaluated resulting data from three flight campaigns to test eight mitigation technologies on terminal (short) and long-range (60 nmi and 250 nmi) radar systems. Combined across the three flight campaigns, more than 460 of hours of flight time were logged. This paper summarizes the Interagency Field Test & Evaluation (IFT&E) program and publicly- available results from the tests. It will also discuss the current wind turbine-radar interference evaluation process within the government and a proposed process to deploy mitigation technologies.

  14. Meteorological significance of frontal thin-line angel echoes observed by CPS-9 radar

    E-Print Network [OSTI]

    Miller, Donald Bradford

    1959-01-01T23:59:59.000Z

    METEOROLOGICAL SIGNIFICANCE OF FRONTAL THIN-LINE ANGEL ECHOES OBSERVED BY CPS-9 RADAR A Thesis By DONAID B. MILLER I/Lt USAF Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 1959 Ma]or Sub)ect Meteorology METEOROLOGICAL SIGNIFICANCE OF FRONTAL THIN-LINE ANGEL ECHOES OBSERVED BY CPS-9 RADAR A Thesi. s By DONALD B. MILLER I/Lt USAF Approved as to style and content by...

  15. Performance limits for exo-clutter Ground Moving Target Indicator (GMTI) radar.

    SciTech Connect (OSTI)

    Doerry, Armin Walter

    2010-09-01T23:59:59.000Z

    The performance of a Ground Moving Target Indicator (GMTI) radar system depends on a variety of factors, many which are interdependent in some manner. It is often difficult to 'get your arms around' the problem of ascertaining achievable performance limits, and yet those limits exist and are dictated by physics. This report identifies and explores those limits, and how they depend on hardware system parameters and environmental conditions. Ultimately, this leads to a characterization of parameters that offer optimum performance for the overall GMTI radar system. While the information herein is not new to the literature, its collection into a single report hopes to offer some value in reducing the 'seek time'.

  16. Excitation-emission spectra and fluorescence quantum yields for...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    vapor in air saturated with water vapor. Absorption and excitation-emission matrix (EEM) spectra of aqueous extracts of aged and control SOA samples were measured, and the...

  17. actinium gamma spectra: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    We discuss here constraints on the particle acceleration models from the observed gamma-ray bursts spectra. The standard synchrotron shock model assumes that some fraction of...

  18. SpectraMiner, an Interactive Data Mining and Visualization Software...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    we call SpectraMiner that makes it possible to handle hundreds of clusters without loss of information and thus overcome the limits set by traditional statistical data...

  19. auger decay spectra: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2008-01-01 44 Constraining Mass Spectra with Sterile Neutrinos from Neutrinoless Double Beta Decay, Tritium Beta Decay and Cosmology HEP - Experiment (arXiv) Summary: We...

  20. annihilation lifetime spectra: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    spectra from WIMP annihilation HEP - Theory (arXiv) Summary: If the present dark matter in the Universe annihilates into Standard Model particles, it must contribute to the...