National Library of Energy BETA

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. Doppler radar flowmeter

    DOE Patents [OSTI]

    Petlevich, Walter J. (Uniontown, PA); Sverdrup, Edward F. (Adamsburg, PA)

    1978-01-01

    A Doppler radar flowmeter comprises a transceiver which produces an audio frequency output related to the Doppler shift in frequency between radio waves backscattered from particulate matter carried in a fluid and the radiated radio waves. A variable gain amplifier and low pass filter are provided for amplifying and filtering the transceiver output. A frequency counter having a variable triggering level is also provided to determine the magnitude of the Doppler shift. A calibration method is disclosed wherein the amplifier gain and frequency counter trigger level are adjusted to achieve plateaus in the output of the frequency counter and thereby allow calibration without the necessity of being able to visually observe the flow.

  4. Sandia Energy - TTU Advanced Doppler Radar

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

    TTU Advanced Doppler Radar Home Stationary Power Energy Conversion Efficiency Wind Energy SWiFT Facility & Testing TTU Advanced Doppler Radar TTU Advanced Doppler...

  5. On Deriving Vertical Air Motions from Cloud Radar Doppler Spectra MATTHEW D. SHUPE

    E-Print Network [OSTI]

    multiple ground-based remote sensors. Corrections for Doppler spectrum broadening due to turbulence, wind the Department of Energy (DOE) Atmospheric Radiation Measurement Program's (ARM) site in Barrow, Alaska, during

  6. 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)

    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 Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 OutreachProductswsicloudwsiclouddenDVA N C E D BGene NetworkNuclearDNP 20082 P r o j eCommittee offrom Doppler

  7. Doppler weather radar based nowcasting of cyclone Ogni Soma Sen Roy1,

    E-Print Network [OSTI]

    Lakshmanan, Valliappa

    Doppler weather radar based nowcasting of cyclone Ogni Soma Sen Roy1, , V Lakshmanan2 , S K Roy@yahoo.com In this paper, we describe offline analysis of Indian Doppler Weather Radar (DWR) data from cyclone Ogni using). Processing of Indian Doppler Weather Radar (DWR) data for nowcasting application under the sub-project Local

  8. Comments on: Texas Tech University mobile doppler radars provide unique

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

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  9. 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

  10. Signal Processing Algorithms for the Terminal Doppler Weather Radar: Build 2

    E-Print Network [OSTI]

    Cho, John Y. N.

    Signal Processing Algorithms for the Terminal Doppler Weather Radar: Build 2 February 21, 2010 John to the public through the National Technical Information Service, Springfield, VA 22161 Signal Processing) was developed for the Terminal Doppler Weather Radar (TDWR), enhanced signal processing algorithms taking

  11. Low-Cost Differential Front-End for Doppler Radar Vital Sign Monitoring

    E-Print Network [OSTI]

    Fletcher, Richard Ribon

    We present a differential front end design for improving the performance of short-range low-cost Doppler radars for vital sign detection with application to automotive driver safety systems, health monitoring, and security ...

  12. Wearable Doppler radar with integrated antenna for patient vital sign monitoring

    E-Print Network [OSTI]

    Fletcher, Richard Ribon

    A 2.45 GHz wearable Doppler radar unit with radio data link is presented for use in portable patient monitoring and emergency response. Unlike portable Electrocardiograms (ECG) or Photoplethysmography (PPG), the near-field ...

  13. 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

  14. Single data set detection for multistatic doppler radar 

    E-Print Network [OSTI]

    Shtarkalev, Bogomil Iliev

    2015-06-29

    The aim of this thesis is to develop and analyse single data set (SDS) detection algorithms that can utilise the advantages of widely-spaced (statistical) multiple-input multiple-output (MIMO) radar to increase their ...

  15. Local and global statistics of clear-air Doppler radar Andreas Muschinski

    E-Print Network [OSTI]

    Muschinski, Andreas

    Local and global statistics of clear-air Doppler radar signals Andreas Muschinski CIRES, University 6 October 2003; accepted 30 October 2003; published 27 January 2004. [1] A refined theoretical statistics like locally averaged velocities, local velocity variances, local dissipation rates, and local

  16. ASSIMILATION OF DOPPLER RADAR DATA INTO NUMERICAL WEATHER MODELS

    SciTech Connect (OSTI)

    Chiswell, S.; Buckley, R.

    2009-01-15

    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.

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

    SciTech Connect (OSTI)

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

    2014-03-02

    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.

  18. Vibrational spectra of nanowires measured using laser doppler...

    Office of Scientific and Technical Information (OSTI)

    of nanowires measured using laser doppler vibrometry and STM studies of epitaxial graphene : an LDRD fellowship report. Citation Details In-Document Search Title: Vibrational...

  19. 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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  20. Ka-Band ARM Zenith Radar (KAZR) Instrument Handbook

    SciTech Connect (OSTI)

    Widener, K; Bharadwaj, N; Johnson, K

    2012-03-06

    The Ka-band ARM zenith radar (KAZR) is a zenith-pointing Doppler cloud radar operating at approximately 35 GHz. The KAZR is an evolutionary follow-on radar to ARM's widely successful millimeter-wavelength cloud radar (MMCR). The main purpose of the KAZR is to provide vertical profiles of clouds by measuring the first three Doppler moments: reflectivity, radial Doppler velocity, and spectra width. At the sites where the dual-polarization measurements are made, the Doppler moments for the cross-polarization channel are also available. In addition to the moments, velocity spectra are also continuously recorded for each range gate.

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

    SciTech Connect (OSTI)

    Bluestein, H.B. . School of Meteorology); Unruh, W.P. )

    1991-01-01

    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.

  2. VALIDATION OF A RADAR DOPPLER SPECTRA SIMULATOR USING MEASUREMENTS FROM THE ARM CLOUD RADARS

    E-Print Network [OSTI]

    components and sub-grid turbulent kinetic energy). Libraries for spherical and non-spherical particles of Brookhaven Science Associates, LLC under Contract No. DE-AC02- 98CH10886 with the U.S. Department of Energy a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form

  3. Doppler Lidar (DL) Handbook

    SciTech Connect (OSTI)

    Newsom, RK

    2012-02-13

    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.

  4. 660 VOLUME 21J O U R N A L O F A T M O S P H E R I C A N D O C E A N I C T E C H N O L O G Y Deriving Mixed-Phase Cloud Properties from Doppler Radar Spectra

    E-Print Network [OSTI]

    Shupe, Matthew

    the vertical air motion and to correct estimates of ice particle fall speeds. A mixed-phase cloud case study properties are such that they produce a bimodal Doppler velocity spectrum. Under these conditions, the Doppler spectrum moments of the distinct liquid and ice spectral modes may be computed independently

  5. Predicting Millimeter Wave Radar Spectra for Autonomous Navigation

    E-Print Network [OSTI]

    Jose, Ebi

    Millimeter Wave (MMW) radars are currently used as range measuring devices in applications such as automotive driving aids (Langer and Jochem, 1996), (Rohling and Mende, 1996), the mapping of mines (Brooker et al., 2005) ...

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

    SciTech Connect (OSTI)

    Chiswell, S

    2009-01-11

    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.

  7. Abstract--Enabled by a dense network of Doppler weather radars with overlapping coverage, Distributed Collaborative

    E-Print Network [OSTI]

    Kurose, Jim

    for high accuracy wind field retrieval. This paper describes the multi- user, multi-attribute utilities are very large size (28 foot diameter antenna) and very high power (half megawatt). At approximately $10-numbers of high-power, high-cost, long-range radars with a paradigm based on Distributed Collaborative Adaptive

  8. Observations of a tornadic supercell over Oxfordshire using a pair of Doppler radars

    E-Print Network [OSTI]

    Reading, University of

    the Cotswolds and Oxfordshire, and on into the home counties. There have been few previous detailed observations to determine whether the Oxfordshire tornado was associated with the presence of a `supercell' - a long-lived of the basic principles of weather radar may be found in the Met Office's Fact Sheet number 15 (UK Met Office

  9. 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.

    2014-08-01

    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.

  10. Digital Doppler radial velocity data compared objectively with digital reflectivity radar data 

    E-Print Network [OSTI]

    Beaver, Thomas Foster

    1980-01-01

    . , few components toward or away from the radar greater than -1 5 m s . However at 3 km and 4 km a def1n1te area of convergence is noted (Figs. 9 and 10). Although neither the ref lect1vity nor radial veloc1ty analyses at th1s time ind1cate any def1... I N 4 N CLI ILI IL O J ILI 6 0 ) Id CC OE IC + ILI IC I Vl ?T T W 0 0 0 LLI 0 Z 4( W 3 C- 7: LLI ri 4 4 I I N 0' 0 \\L III gQ ~ 4 N NZ WO 8 I 4l zj WN ~4I III W I- g I 0 R 0 O. I 0 0 ~ N 0 0 LI 0 0...

  11. ARM - Measurement - Radar Doppler

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

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  12. Multi-PRI Signal Processing for the Terminal Doppler Weather Radar. Part II: RangeVelocity Ambiguity Mitigation

    E-Print Network [OSTI]

    Cho, John Y. N.

    ­Velocity Ambiguity Mitigation JOHN Y. N. CHO Lincoln Laboratory, Massachusetts Institute of Technology, Lexington of the multi-PRI RV ambiguity mitigation scheme is demonstrated using simulated and real weather radar data, with excellent results. Combined with the adaptive clutter filter, this technique will be used within the larger

  13. Using a Low-Order Model to Detect and Characterize Tornadoes in Multiple-Doppler Radar Data

    E-Print Network [OSTI]

    Gao, Jidong

    , University of Oklahoma, Norman, Oklahoma TIAN-YOU YU School of Electrical and Computer Engineering the tornado path and radar-grid-scale features of the horizontal wind field in the vicinity of the tornado. Introduction A major focus in severe weather research for opera- tional applications is the development

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

    E-Print Network [OSTI]

    Nathan Smith

    2004-12-21

    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.

  15. Doppler characteristics of sea clutter.

    SciTech Connect (OSTI)

    Raynal, Ann Marie; Doerry, Armin Walter

    2010-06-01

    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.

  16. 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

    2009-11-21

    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.

  17. Doppler Tomography

    E-Print Network [OSTI]

    T. R. Marsh

    2000-11-01

    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.

  18. Radar channel balancing with commutation

    SciTech Connect (OSTI)

    Doerry, Armin Walter

    2014-02-01

    When multiple channels are employed in a pulse-Doppler radar, achieving and maintaining balance between the channels is problematic. In some circumstances the channels may be commutated to achieve adequate balance. Commutation is the switching, trading, toggling, or multiplexing of the channels between signal paths. Commutation allows modulating the imbalance energy away from the balanced energy in Doppler, where it can be mitigated with filtering.

  19. Doppler segmentation 

    E-Print Network [OSTI]

    Yeh, Chih-Ping

    1983-01-01

    OF CONTENTS ABSTRACT . ACKNOWLEDGEMENT TABLE OF CONTENTS LIST OF FIGURES CHAPTER I. INTRODUCTION . CHAPTER II. SYSTEM DEVELOPMENT 1. Range Imaging System 2. Range and Velocity Acquisition by Linear FM Pulse . 3. Infrared Range/Doppler Imaging System... . CHAPTER III. SYSTEM PARAMETERS DESIGN l. Angular Resolution and Aperture Size 2. Pulse Repetition Frequency and Detector Array for Compact Image . 3. Pulse Duration and Velocity Sensitivity . 4. Pulse Modulation Bandwidth and Range Resolution 5...

  20. ERADERAD 20062006Proceedings ofProceedings of Detecting weather radar clutter

    E-Print Network [OSTI]

    results from investigations into detection of weather radar clutter by data fusion with satellite-basedERADERAD 20062006Proceedings ofProceedings of Detecting weather radar clutter using satellite-based nowcasting products. Weather radar data from three C-band Doppler weather radars of the Danish Meteorological

  1. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II)GeothermalFuel Magnetization andStochastic HomeSunShot

  2. Doppler flowmeter

    DOE Patents [OSTI]

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

    1981-11-13

    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.

  3. 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.

    2011-04-01

    Sounding of nonprecipitating clouds with the 10-cm wavelength Weather Surveillance Radar-1988 Doppler (WSR-88D) is discussed. Readily available enhancements to signal processing and volume coverage patterns of the WSR-88D ...

  4. Imaging synthetic aperture radar

    DOE Patents [OSTI]

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

    1997-01-01

    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.

  5. Approximate Bayesian Inference for Reconstructing Velocities of Migrating Birds from Weather Radar

    E-Print Network [OSTI]

    radar data. 1 Introduction The National Weather Service operates the WSR-88D (Weather Surveillance Radar, weather, and even airborne dust. Consequently, data must be interpreted manually by a highly information collected by Doppler radar. Our model is based on wind profiling algorithms from the weather

  6. Scanning ARM Cloud Radar Handbook

    SciTech Connect (OSTI)

    Widener, K; Bharadwaj, N; Johnson, K

    2012-06-18

    The scanning ARM cloud radar (SACR) is a polarimetric Doppler radar consisting of three different radar designs based on operating frequency. These are designated as follows: (1) X-band SACR (X-SACR); (2) Ka-band SACR (Ka-SACR); and (3) W-band SACR (W-SACR). There are two SACRs on a single pedestal at each site where SACRs are deployed. The selection of the operating frequencies at each deployed site is predominantly determined by atmospheric attenuation at the site. Because RF attenuation increases with atmospheric water vapor content, ARM's Tropical Western Pacific (TWP) sites use the X-/Ka-band frequency pair. The Southern Great Plains (SGP) and North Slope of Alaska (NSA) sites field the Ka-/W-band frequency pair. One ARM Mobile Facility (AMF1) has a Ka/W-SACR and the other (AMF2) has a X/Ka-SACR.

  7. Merged and corrected 915 MHz Radar Wind Profiler moments

    SciTech Connect (OSTI)

    Jonathan Helmus,Virendra Ghate, Frederic Tridon

    2014-06-25

    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.

  8. 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.

  9. A Method to Merge WSR-88D Data with ARM SGP Millimeter Cloud Radar Data by Studying Deep Convective Systems

    E-Print Network [OSTI]

    Dong, Xiquan

    A Method to Merge WSR-88D Data with ARM SGP Millimeter Cloud Radar Data by Studying Deep Convective A decade of collocated Atmospheric Radiation Measurement Program (ARM) 35-GHz Millimeter Cloud Radar (MMCR) and Weather Surveillance Radar-1988 Doppler (WSR-88D) data over the ARM Southern Great Plains (SGP) site have

  10. Inline Ultrasonic Rheometry by Pulsed Doppler

    SciTech Connect (OSTI)

    Pfund, David M.; Greenwood, Margaret S.; Bamberger, Judith A.; Pappas, Richard A.

    2006-12-22

    This will be a discussion of the non-invasive determination of the viscosity of a non-Newtonian fluid in laminar pipe flow over the range of shear rates present in the pipe. The procedure used requires knowledge of the flow profile in and the pressure drop along a long straight run of pipe. The profile is determined by using a pulsed ultrasonic Doppler velocimeter. This approach is ideal for making non-invasive, real-time measurements for monitoring and control. Rheograms of a shear thinning, thixotropic gel will be presented. The operating parameters and limitations of the Doppler-based instrument will be discussed. The most significant limitation is velocity gradient broadening of the Doppler spectra near the walls of the pipe. This limitation can be significant for strongly shear thinning fluids (depending also on the ratio of beam to pipe diameter and the transducer's insertion angle).

  11. Connectivity in a UAV Multi-static Radar Network David W. Casbeer

    E-Print Network [OSTI]

    Swindlehurst, A. Lee

    Connectivity in a UAV Multi-static Radar Network David W. Casbeer and A. Lee Swindlehurst This paper describes a multi-static radar network composed of multiple unmanned air vehicles (UAVs). Time-delay and Doppler measurements taken by the UAV team are passed to a centralized processor to determine optimal

  12. Signal Processing System for the CASA Integrated Project I Radars

    SciTech Connect (OSTI)

    Bharadwaj, Nitin; Chandrasekar, V.; Junyent, Francesc

    2010-09-01

    This paper describes the waveform design space and signal processing system for dual-polarization Doppler weather radar operating at X band. The performance of the waveforms is presented with ground clutter suppression capability and mitigation of range velocity ambiguity. The operational waveform is designed based on operational requirements and system/hardware requirements. A dual Pulse Repetition Frequency (PRF) waveform was developed and implemented for the first generation X-band radars deployed by the Center for Collaborative Adaptive Sensing of the Atmosphere (CASA). This paper presents an evaluation of the performance of the waveforms based on simulations and data collected by the first-generation CASA radars during operations.

  13. 32nd Conf. Radar Meteorology Albuquerque, NM, 2005

    E-Print Network [OSTI]

    Droegemeier, Kelvin K.

    and smoothness constraints by incorporating them into a cost function yielding the 3-D wind. In this study32nd Conf. Radar Meteorology Albuquerque, NM, 2005 J1J.4 MULTIPLE DOPPLER WIND ANALYSIS component of wind velocity. Thus, there is no direct measurement of the three-dimensional (3-D) wind field

  14. ECE/METR6613 Title: Weather Radar Polarimetry

    E-Print Network [OSTI]

    Zhang, Guifu

    ECE/METR6613 Title: Weather Radar Polarimetry (Wave Interactions with Geophysical Media) Class: 2 and Weather Observations, 2006, 1993, 1984 · Reference books 1. Akira Ishimaru: Wave Propagation and Scattering in Random Media, 1997, 1978 2. V. N. Bringi and V. Chandrasekar: Polarimetric Doppler Weather

  15. An Integrated Display and Analysis Methodology for Multivariable Radar Data BRENDA A. DOLAN AND STEVEN A. RUTLEDGE

    E-Print Network [OSTI]

    Rutledge, Steven

    -depth analysis using radar products, such as Doppler-derived wind vectors and hydrometeor identification, has in real time. This study focuses on modifying and automating several radar- analysis and quality of intense rainfall, hail, strong updrafts, and other features such as mesocyclones and convergence lines

  16. Efficient Methods of Doppler Processing for Coexisting Land and Weather Clutter

    E-Print Network [OSTI]

    Candan, Cagatay

    Efficient Methods of Doppler Processing for Coexisting Land and Weather Clutter C¸ a~gatay Candan@metu.edu.tr, aoyilmaz@metu.edu.tr Abstract--The joint suppression of returns from land and weather clutter is required in many radar applications. Although the optimal method of land-weather clutter suppression is known

  17. 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

  18. Sandia Energy - Texas Tech University mobile doppler radars provide

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II)GeothermalFuel Magnetization andStochasticunique wind measurements to

  19. Sandia Energy - Radar Friendly Blades

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

    Radar Friendly Blades Home Stationary Power Energy Conversion Efficiency Wind Energy Siting and Barrier Mitigation Radar Friendly Blades Radar Friendly BladesTara...

  20. 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.

    2012-03-05

    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.

  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. Wideband Waveform Design principles for Solid-state Weather Radars

    SciTech Connect (OSTI)

    Bharadwaj, Nitin; Chandrasekar, V.

    2012-01-01

    The use of solid-state transmitter is becoming a key part of the strategy to realize a network of low cost electronically steered radars. However, solid-state transmitters have low peak powers and this necessitates the use of pulse compression waveforms. In this paper a frequency diversity wideband waveforms design is proposed to mitigate low sensitivity of solid-state transmitters. In addition, the waveforms mitigate the range eclipsing problem associated with long pulse compression. An analysis of the performance of pulse compression using mismatched compression filters designed to minimize side lobe levels is presented. The impact of range side lobe level on the retrieval of Doppler moments are presented. Realistic simulations are performed based on CSU-CHILL radar data and Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) Integrated Project I (IP1) radar data.

  3. Vibrational spectra of nanowires measured using laser doppler vibrometry

    Office of Scientific and Technical Information (OSTI)

    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 Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory of rare Kaonfor Direct Measurement(Journal Article)(Patent) |SciTechSciTechand

  4. Vibrational spectra of nanowires measured using laser doppler vibrometry

    Office of Scientific and Technical Information (OSTI)

    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 Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefieldSulfateSciTechtail.Theory of rare Kaonfor Direct Measurement(Journal Article)(Patent)

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

    SciTech Connect (OSTI)

    Widener, K; Bharadwaj, N

    2012-10-29

    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.

  6. Impulse radar studfinder

    DOE Patents [OSTI]

    McEwan, T.E.

    1995-10-10

    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. 9 figs.

  7. Impulse radar studfinder

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1995-01-01

    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.

  8. Laser- and Radar-based Mission Concepts for Suborbital and Spaceborne Monitoring of Seismic Surface Waves

    SciTech Connect (OSTI)

    Foxall, W; Schultz, C A; Tralli, D M

    2004-09-21

    The development of a suborbital or spaceborne system to monitor seismic waves poses an intriguing prospect for advancing the state of seismology. This capability would enable an unprecedented global mapping of the velocity structure of the earth's crust, understanding of earthquake rupture dynamics and wave propagation effects, and event source location, characterization and discrimination that are critical for both fundamental earthquake research and nuclear non-proliferation applications. As part of an ongoing collaboration between LLNL and JPL, an advanced mission concept study assessed architectural considerations and operational and data delivery requirements, extending two prior studies by each organization--a radar-based satellite system (JPL) for earthquake hazard assessment and a feasibility study of space- or UAV-based laser seismometer systems (LLNL) for seismic event monitoring. Seismic wave measurement requirements include lower bounds on detectability of specific seismic sources of interest and wave amplitude accuracy for different levels of analysis, such as source characterization, discrimination and tomography, with a 100 {micro}m wave amplitude resolution for waves nominally traveling 5 km/s, an upper frequency bound based on explosion and earthquake surface displacement spectra, and minimum horizontal resolution (1-5 km) and areal coverage, in general and for targeted observations. For a radar system, corresponding engineering and operational factors include: Radar frequency (dictated by required wave amplitude measurement accuracy and maximizing ranging, Doppler or interferometric sensitivity), time sampling (maximum seismic wave frequency and velocity), and overall system considerations such as mass, power and data rate. Technical challenges include characterization of, and compensation for, phase distortion resulting from atmospheric and ionospheric perturbations and turbulence, and effects of ground scattering characteristics and seismic ground motion on phase coherence over interferometric time intervals. Since the temporal sampling requirement may be finer than that possible for a high-altitude sensor to traverse a synthetic aperture length, a geostationary, real-aperture Ka-band system or constellation for equatorial and moderate-latitude global coverage is one option considered. The short wavelength would maximize interferometric sensitivity to small surface displacements and minimize required antenna area. Engineering issues include the design and deployment of a large ({approx} 100m) fixed aperture antenna; and fast electronic beam steering (entire aperture within nominal 1 s interferometric interval) with high-efficiency integrated transmit/receive modules. For a suborbital system, platform instability is an issue whereas at high earth orbit signal-to-noise and attendant power requirements dominate. Data delivery requirements include large-volume data storage and transmission; development of real-time, on-board event detection and processing algorithms, and data management structures for these very large data sets. A far-term roadmap would comprise a proof-of-concept demonstration using a laser or radar system mounted on a stratospheric balloon or UAV to image seismic wavefields from planned events (e.g. large mine blasts and/or purpose-designed explosions) and earthquake targets of opportunity. The technological challenges to developing any such seismic monitoring system, whether laser- or radar-based, are at this stage enormous. However, these concept studies suggest the long-term feasibility of such a system and drive the development of enabling technologies while fostering collaboration on meeting scientific and operational challenges of agencies such as NASA, DOE and DoD.

  9. Car-to-car radio channel measurements at 5 GHz: Pathloss, power-delay profile, and delay-Doppler

    E-Print Network [OSTI]

    Zemen, Thomas

    Car-to-car radio channel measurements at 5 GHz: Pathloss, power-delay profile, and delay Contact: apaier@nt.tuwien.ac.at Abstract-- We carried out a car­to­infrastructure (C2I) and car­to­car (C2­Doppler spectra in a C2C highway scenario, where both cars were traveling in opposite directions. A pathloss

  10. Effects of Radar Beam Shielding on Rainfall Estimation for the Polarimetric C-Band Radar

    E-Print Network [OSTI]

    Effects of Radar Beam Shielding on Rainfall Estimation for the Polarimetric C-Band Radar KATJA, polarimetric weather radar located in Trappes, France, were used to examine the effects of radar beam shielding-based rainfall estimates to beam shielding for C-band radar data during four typical rain events encountered

  11. ARM Climate Research Facility Radar Operations Plan

    SciTech Connect (OSTI)

    Voyles, JW

    2012-05-18

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

  12. 915-MHz Radar Wind Profiler (915RWP) Handbook

    SciTech Connect (OSTI)

    Coulter, R

    2005-01-01

    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.

  13. Stratiform and Convective Precipitation Observed by Multiple Radars during the DYNAMO/AMIE Experiment

    SciTech Connect (OSTI)

    Deng, Min; Kollias, Pavlos; Feng, Zhe; Zhang, Chidong; Long, Charles N.; Kalesse, Heike; Chandra, Arunchandra; Kumar, Vickal; Protat, Alain

    2014-11-01

    The motivation for this research is to develop a precipitation classification and rain rate estimation method using cloud radar-only measurements for Atmospheric Radiation Measurement (ARM) long-term cloud observation analysis, which are crucial and unique for studying cloud lifecycle and precipitation features under different weather and climate regimes. Based on simultaneous and collocated observations of the Ka-band ARM zenith radar (KAZR), two precipitation radars (NCAR S-PolKa and Texas A&M University SMART-R), and surface precipitation during the DYNAMO/AMIE field campaign, a new cloud radar-only based precipitation classification and rain rate estimation method has been developed and evaluated. The resulting precipitation classification is equivalent to those collocated SMART-R and S-PolKa observations. Both cloud and precipitation radars detected about 5% precipitation occurrence during this period. The convective (stratiform) precipitation fraction is about 18% (82%). The 2-day collocated disdrometer observations show an increased number concentration of large raindrops in convective rain compared to dominant concentration of small raindrops in stratiform rain. The composite distributions of KAZR reflectivity and Doppler velocity also show two distinct structures for convective and stratiform rain. These indicate that the method produces physically consistent results for two types of rain. The cloud radar-only rainfall estimation is developed based on the gradient of accumulative radar reflectivity below 1 km, near-surface Ze, and collocated surface rainfall (R) measurement. The parameterization is compared with the Z-R exponential relation. The relative difference between estimated and surface measured rainfall rate shows that the two-parameter relation can improve rainfall estimation.

  14. Ground Penetrating Radar, Barrow, Alaska

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

    John Peterson

    2015-03-06

    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.

  15. 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.

  16. Multi-PRI Signal Processing for the Terminal Doppler Weather Radar. Part I: Clutter Filtering

    E-Print Network [OSTI]

    Cho, John Y. N.

    decision on clutter power estimated during an initial long-PRI surveillance scan. Simulations show system. 1. Introduction Range­velocity (RV) ambiguity is one of the most crucial data quality challenges (WSR- 88D). Thus, to mitigate RV ambiguity for the TDWR, a more aggressive approach must be taken

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

    E-Print Network [OSTI]

    Aclin, Keith Andrew

    1995-01-01

    If the National Weather Service could forecast the occurrences of cloud-toground lightning strikes, it would benefit the authorities that are served by the WSR-88Ds. In this thesis I will examine the WSR-88D level 11 archive ...

  18. DOPPLER RADAR MEASUREMENTS AND IMPLICATIONS FOR THE MICROPHYSICAL STUDY OF DRIZZLE FORMATION

    E-Print Network [OSTI]

    Division Brookhaven National Laboratory U.S. Department of Energy Office of Science ABSTRACT This poster10886 with the U.S. Department of Energy. The publisher by accepting the manuscript for publication-wide license to publish or reproduce the published form of this manuscript, or allow others to do so

  19. A Quality Control Concept for Radar Reflectivity, Polarimetric Parameters, and Doppler Velocity

    E-Print Network [OSTI]

    Raumfahrt, Oberpfaffenhofen, Wessling, Germany THOMAS EINFALT einfalt&hydrotec GbR, Lübeck, Germany non-weather-related objects, and attenuation of electromagnetic energy by hydrometeors on the quality in the Alpine foreland in southern Germany. 1. Introduction Quality characterization of observational data

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

    SciTech Connect (OSTI)

    Widener, K; Bharadwaj, N

    2012-11-13

    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.

  1. SPECTRA: A subroutine for response spectra generation

    SciTech Connect (OSTI)

    McCallen, D.B.

    1991-11-01

    A simple Fortran subroutine for generation of response spectra has been written and implemented on a Sun Sparc2 workstation. The routine generates absolute acceleration spectra, relative velocity spectra and relative displacement spectra for a given input acceleration time history. The subroutine will automatically set the period (i.e. the abscissa values of the spectra) at which spectral quantities are determined, and the user can select one of three options for determining the period values: Periods correspond to the periods utilized by the California Department of Mines and Geology strong motion instrumentation program (CSMIP) in generating the spectra which they distribute; periods correspond to the periods suggested by the American Society of Civil Engineers (ASCE) Seismic Analysis of Safety Related Nuclear Structures and Commentary on Standard for Seismic Analysis of Safety Related Nuclear Structures'' (ASCE 4-86) for in-structure spectra; periods correspond closely to the periods utilized by CSMIP, but a higher density of periods are utilized, resulting in a very high resolution spectra. To enable the use of the subroutine on any platform, simplicity has been maintained in the Fortran coding of the subroutine. The methodology utilized in generating the spectra, a discussion of the limitations of the spectra in the high frequency regime, and a listing of the subroutine are included in this report.

  2. SPECTRA: A subroutine for response spectra generation

    SciTech Connect (OSTI)

    McCallen, D.B.

    1991-11-01

    A simple Fortran subroutine for generation of response spectra has been written and implemented on a Sun Sparc2 workstation. The routine generates absolute acceleration spectra, relative velocity spectra and relative displacement spectra for a given input acceleration time history. The subroutine will automatically set the period (i.e. the abscissa values of the spectra) at which spectral quantities are determined, and the user can select one of three options for determining the period values: Periods correspond to the periods utilized by the California Department of Mines and Geology strong motion instrumentation program (CSMIP) in generating the spectra which they distribute; periods correspond to the periods suggested by the American Society of Civil Engineers (ASCE) ``Seismic Analysis of Safety Related Nuclear Structures and Commentary on Standard for Seismic Analysis of Safety Related Nuclear Structures`` (ASCE 4-86) for in-structure spectra; periods correspond closely to the periods utilized by CSMIP, but a higher density of periods are utilized, resulting in a very high resolution spectra. To enable the use of the subroutine on any platform, simplicity has been maintained in the Fortran coding of the subroutine. The methodology utilized in generating the spectra, a discussion of the limitations of the spectra in the high frequency regime, and a listing of the subroutine are included in this report.

  3. 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 ...

  4. 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)

    2006-12-12

    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.

  5. Radar operation in a hostile electromagnetic environment

    SciTech Connect (OSTI)

    Doerry, Armin Walter

    2014-03-01

    Radar ISR does not always involve cooperative or even friendly targets. An adversary has numerous techniques available to him to counter the effectiveness of a radar ISR sensor. These generally fall under the banner of jamming, spoofing, or otherwise interfering with the EM signals required by the radar sensor. Consequently mitigation techniques are prudent to retain efficacy of the radar sensor. We discuss in general terms a number of mitigation techniques.

  6. EISCAT Radar School, Kiruna, 2005 Outrigger in

    E-Print Network [OSTI]

    into regional fibre network, sharing costs with schools, health centres etc. #12;Bo Thidé EISCAT Radar School Thidé EISCAT Radar School, Kiruna,, 200515 LOFAR Phase 2 into Lower Saxony, Schleswig in innovative ways #12;Bo Thidé EISCAT Radar School, Kiruna,, 200524 LOFAR was conceived by the astrophysics

  7. Bachelor project: Ferromagnetische radar absorberende coatings

    E-Print Network [OSTI]

    Vuik, Kees

    Bachelor project: Ferromagnetische radar absorberende coatings Begeleider: D.R. van der Heul niet alleen een bijzondere vormgeving, maar zijn ook bedekt met radar absorbing coatings. De radar absorbing coatings (RAC) zetten de inkomende elektromagnetische golven om in warmte, die vervolgens naar de

  8. RADAR: THE CASSINI TITAN RADAR MAPPER C. ELACHI1,

    E-Print Network [OSTI]

    . SODERBLOM5 , S. VETRELLA11 , S. D. WALL1, , C. A. WOOD12 and H. A. ZEBKER13 1Jet Propulsion Laboratory rates, the data volumes, and power. This article describes the science objectives, operational modes at visible wave- lengths has been demonstrated most dramatically by the success of the Magellan radar

  9. Mon. Not. R. Astron. Soc. 000, 131 (2012) Printed 27 June 2012 (MN LATEX style file v2.2) Stokes IQUV Magnetic Doppler Imaging of Ap stars

    E-Print Network [OSTI]

    2012-01-01

    IQUV Magnetic Doppler Imaging of Ap stars I. ESPaDOnS and NARVAL Observations J. Silvester1,2 , G, corresponding to 297 individual polarised spectra, have been obtained for 7 bright Ap stars using the ESPa generation of surface maps of Ap stars, this study estab- lishes the performance and stability of the ESPa

  10. 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)

    2014-11-15

    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.

  11. Two terminal micropower radar sensor

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1995-01-01

    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.

  12. Two terminal micropower radar sensor

    DOE Patents [OSTI]

    McEwan, T.E.

    1995-11-07

    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.

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

    E-Print Network [OSTI]

    Crua, Cyril

    2015-01-01

    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...

  14. Observation of sub-Doppler absorption in the /Lambda-type three-level Doppler-broadened cesium system

    E-Print Network [OSTI]

    Junmin Wang; Yanhua Wang; Shubin Yan; Tao Liu; Tiancai Zhang

    2003-12-31

    Thanks to the atomic coherence in coupling laser driven atomic system, sub-Doppler absorption has been observed in Doppler-broadened cesium vapor cell via the /Lambda-type three-level scheme. The linewidth of the sub-Doppler absorption peak become narrower while the frequency detuning of coupling laser increases. The results are in agreement with the theoretical prediction by G. Vemuri et al.[PRA,Vol.53(1996) p.2842].

  15. Radar range measurements in the atmosphere.

    SciTech Connect (OSTI)

    Doerry, Armin Walter

    2013-02-01

    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.

  16. Ultra-wideband radar motion sensor

    DOE Patents [OSTI]

    McEwan, T.E.

    1994-11-01

    A motion sensor is based on ultra-wideband (UWB) radar. UWB radar range is determined by a pulse-echo interval. For motion detection, the sensors operate by staring at a fixed range and then sensing any change in the averaged radar reflectivity at that range. A sampling gate is opened at a fixed delay after the emission of a transmit pulse. The resultant sampling gate output is averaged over repeated pulses. Changes in the averaged sampling gate output represent changes in the radar reflectivity at a particular range, and thus motion. 15 figs.

  17. Radar network communication through sensing of frequency hopping

    DOE Patents [OSTI]

    Dowla, Farid; Nekoogar, Faranak

    2013-05-28

    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.

  18. Title: Shuttle Radar Topography Mission (SRTM) Data Creator /

    E-Print Network [OSTI]

    Title: Shuttle Radar Topography Mission (SRTM) Data Creator / Copyright Owner: National Aeronautics@yorku.ca Citation: National Aeronautics and Space Administration. "Shuttle Radar Topography Mission (SRTM

  19. Nuclear Spectra from Skyrmions

    SciTech Connect (OSTI)

    Manton, N. S.

    2009-08-26

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

  20. 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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II)Geothermal Energy &WaterNewPhotoionizationPowerRadar Friendly Blades

  1. Ultra-wideband radar sensors and networks

    DOE Patents [OSTI]

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

    2013-08-06

    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.

  2. Magneto-Radar Hidden Metal Detector

    DOE Patents [OSTI]

    McEwan, Thomas E. (Las Vegas, NV)

    2005-07-05

    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.

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

    SciTech Connect (OSTI)

    Chiswell, S.

    2010-01-15

    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.

  4. Doppler Signatures of the Atmospheric Circulation on Hot Jupiters

    E-Print Network [OSTI]

    Showman, Adam P; Lewis, Nikole K; Shabram, Megan

    2013-01-01

    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 blue- 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...

  5. DOPPLER SIGNATURES OF THE ATMOSPHERIC CIRCULATION ON HOT JUPITERS

    E-Print Network [OSTI]

    Showman, Adam P.

    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 ...

  6. Development and characterization analysis of a radar polarimeter 

    E-Print Network [OSTI]

    Bong, Soei Siang

    1984-01-01

    . ACKNOWLEDGEMENTS. TABLE OF CONTENTS LIST OF TABLES. LIST OF FIGURES . CHAPTER I. INTRODUCTION. Problem Statement . Approach. Scope of Thesis CHAPTER II. OPERATION OF RADAR SYSTEMS Background. Frequency Modulated Continuous Wave Radar System. Pulse Radar... System. Overview of the Radar Polarimeter System. Configuration of the RPS. The Truck System Specification. The Radar Head Assembly . The IF Section. Pulse Shaper (Pulse Expander} Section. The IF Receiver Section. The Digital Controller Circuit...

  7. 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.

    2015-04-08

    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. As a result, quasi-classical trajectory studies confirm that the differing rotational state dependence is primarily a kinematic effect.« less

  8. 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)

    2015-04-08

    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.

  9. Radar deception through phantom track generation 

    E-Print Network [OSTI]

    Maithripala, Diyogu Hennadige Asanka

    2006-04-12

    This thesis presents a control algorithm to be used by a team of ECAVs (Electronic Combat Air Vehicle) to deceive a network of radars through the generation of a phantom track. Each ECAV has the electronic capability of ...

  10. 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)

    1994-01-01

    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.

  11. Comparison of optically measured and radar-derived horizontal neutral winds. Master's thesis

    SciTech Connect (OSTI)

    Christie, M.S.

    1990-01-01

    Nighttime thermospheric winds for Sondrestrom, Greenland from 11 nights between 1983 and 1988, have been compared to learn about the O(+)-O collision cross section and the high-latitude atomic oxygen density. The horizontal winds in the magnetic meridian were derived indirectly from incoherent-scatter radar (ISR) measurements on ion velocities antiparallel to the magnetic field and directly from Fabry-Perot interferometer (FPI) measurements of Doppler shifts of the (6300-A) emission of atomic oxygen. In deriving the radar winds, the O(+)-O collision cross section, was scaled by a factor of f what was varied from 0.5 to 5.1. On the basis of several arguments the altitude of the 6300-A emission was assumed to be 230 km. The best agreement between the ISR and FPI winds was obtained when f was increased substantially, to between 1.7 and 3.4. If the average peak emission altitude were higher, these factors would be larger; if it were lower, they would be somewhat smaller. However, if the average altitude were substantially lower it would have been more difficult to have obtained agreement between the two techniques.

  12. A NOVEL X-RAY IMAGING CRYSTAL SPECTROMETER FOR DOPPLER MEASUREMENTS OF ION TEMPERATURE AND PLASMA ROTATION VELOCITY PROFILES

    SciTech Connect (OSTI)

    Bitter, M; Hill, K W; Scott, S; Ince-Cushman, A; Reinke, M; Rice, J E; Beiersdorfer, P; Gu, M F; Lee, S G; Broennimann, C; Eikenberry, E F

    2008-06-06

    A new type of X-ray imaging crystal spectrometer has been implemented on Alcator CMod for Doppler measurements of ion temperature and plasma rotation velocity profiles. The instrument consists of two spherically bent (102)-quartz crystals with radii of curvature of 1444 and 1385 mm and four 'PILATUS II' detector modules. It records spectra of He-like argon from the entire, 72 cm high, elongated plasma cross-section and spectra of H-like argon from a 20 cm high, central region of the plasma, with a spatial resolution of 1.3 cm and a time resolution of less than 20 ms. The new spectrometer concept is also of interest for the diagnosis of burning plasmas on future machines. This paper presents recent experimental results from Aclator C-Mod and discusses challenges in X-ray spectroscopy for the diagnosis of fusion plasmas on future machines.

  13. Radar Testbed Characterization for Evaluation of Modulated Scatterer Concepts

    E-Print Network [OSTI]

    Casper, Matt

    2010-05-27

    of fields including, mass data collection, SAR calibration, and military communication. A radar testbed was developed and charactersized to enable experimental evaluation of communication via modulated scatterer concepts. The radar operates with a 1.84-GHz...

  14. Tracking system for photon-counting laser radar

    E-Print Network [OSTI]

    Chang, Joshua TsuKang

    2007-01-01

    The purpose of this thesis is to build the tracking system for a photon-counting laser radar specifically a laser radar that has the ability to perform direct and coherent detection measurement at low signal levels with ...

  15. 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 ...

  16. Variational Pseudo-Multiple-Doppler Wind Retrieval in the Vertical Plane for Ground-Based Mobile Radar Data

    E-Print Network [OSTI]

    Fedorovich, Evgeni

    et al. 1988; Wakimoto et al. 1996; Dowell and Bluestein 1997; Dowell et al. 1997), and tornadoes (e. The traditional methods of analysis (e.g., Ray et al. 1980; Dowell and Bluestein 1997) involve iterations among

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

    E-Print Network [OSTI]

    Reynolds, Amber Elizabeth

    2009-05-15

    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...

  18. 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

  19. Imaging doppler lidar for wind turbine wake profiling

    DOE Patents [OSTI]

    Bossert, David J.

    2015-11-19

    An imaging Doppler lidar (IDL) enables the measurement of the velocity distribution of a large volume, in parallel, and at high spatial resolution in the wake of a wind turbine. Because the IDL is non-scanning, it can be orders of magnitude faster than conventional coherent lidar approaches. Scattering can be obtained from naturally occurring aerosol particles. Furthermore, the wind velocity can be measured directly from Doppler shifts of the laser light, so the measurement can be accomplished at large standoff and at wide fields-of-view.

  20. Leading neutron spectra

    E-Print Network [OSTI]

    A. B. Kaidalov; V. A. Khoze; A. D. Martin; M. G. Ryskin

    2006-05-27

    It is shown that the observation of the spectra of leading neutrons from proton beams can be a good probe of absorptive and migration effects. We quantify how these effects modify the Reggeized pion-exchange description of the measurements of leading neutrons at HERA. We are able to obtain a satisfactory description of all the features of these data. We also briefly discuss the corresponding data for leading baryons produced in hadron-hadron collisions.

  1. Wind turbine impacts on HF radar ocean surface measurements in

    E-Print Network [OSTI]

    Wyatt, Lucy

    Wind turbine impacts on HF radar ocean surface measurements in Liverpool Bay Alice Robinson School. The characterisation of the wind turbine interference is assessed and the radar cross section estimated. The modulation with wind turbine interference in a HF radar footprint are made. #12;Contents Contents iv List of Tables vii

  2. Testing Doppler type shift for an accelerated source and determination of the universal maximal acceleration

    E-Print Network [OSTI]

    Yaakov Friedman

    2010-06-10

    An experiment for testing Doppler type shift for an accelerated source and determination of the universal maximal acceleration is proposed.

  3. 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

  4. 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

  5. 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

  6. Dual beam translator for use in Laser Doppler anemometry

    DOE Patents [OSTI]

    Brudnoy, David M. (Albany, NY)

    1987-01-01

    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.

  7. Dual beam translator for use in Laser Doppler anemometry

    DOE Patents [OSTI]

    Brudnoy, D.M.

    1984-04-12

    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.

  8. An alternative derivation of Einstein's Doppler shift and aberration formulae

    E-Print Network [OSTI]

    Jean Reignier

    2009-02-06

    I propose an alternative, purely kinematical, derivation of Einstein's Doppler formula. It is valid for periodic signals of any shape that propagate with the velocity of light. The formula is asymptotic in a parameter proportional to the relative variation of the distance source-receiver during one period. As a by-product, I also derive an alternative proof of Einstein's aberration formulae.

  9. Signal to Noise Analysis of iRadar sensors

    SciTech Connect (OSTI)

    Fritzke, A; Top, P

    2009-09-10

    This document follows my process of testing; comparing; and contrasting several iRadars signal to noise ratios for both HH and VV polarization. A brief introduction is given explaining the basics of iRadar technology and what data I was collecting. The process section explains the steps I took to collect my data along with any procedures I followed. The analysis section compares and contrasts five different radars and the two different polarizations. The analysis also details the radars viewing limitations and area. Finally, the report delves into the effects of two radars interfering with each other. A conclusion goes over the success and findings of the project.

  10. Observation of Doppler broadening in $?$-delayed proton-$?$ decay

    E-Print Network [OSTI]

    S. B. Schwartz; C. Wrede; M. B. Bennett; S. N. Liddick; D. Perez-Loureiro; A. Bowe; A. A. Chen; K. A. Chipps; N. Cooper; D. Irvine; E. McNeice; F. Montes; F. Naqvi; R. Ortez; S. D. Pain; J. Pereira; C. Prokop; J. Quaglia; S. J. Quinn; J. Sakstrup; M. Santia; S. Shanab; A. Simon; A. Spyrou; E. Thiagalingam

    2015-10-26

    Background: The Doppler broadening of $\\gamma$-ray peaks due to nuclear recoil from $\\beta$-delayed nucleon emission can be used to measure the energies of the nucleons. This method has never been tested using $\\beta$-delayed proton emission or applied to a recoil heavier than $A=10$. Purpose: To test and apply this Doppler broadening method using $\\gamma$-ray peaks from the $^{26}$P($\\beta p\\gamma$)$^{25}$Al decay sequence. Methods: A fast beam of $^{26}$P was implanted into a planar Ge detector, which was used as a $^{26}$P $\\beta$-decay trigger. The SeGA array of high-purity Ge detectors was used to detect $\\gamma$ rays from the $^{26}$P($\\beta p\\gamma$)$^{25}$Al decay sequence. Results: Radiative Doppler broadening in $\\beta$-delayed proton-$\\gamma$ decay was observed for the first time. The Doppler broadening analysis method was verified using the 1613 keV $\\gamma$-ray line for which the proton energies were previously known. The 1776 keV $\\gamma$ ray de-exciting the 2720 keV $^{25}$Al level was observed in $^{26}$P($\\beta p\\gamma$)$^{25}$Al decay for the first time and used to determine that the center-of-mass energy of the proton emission feeding the 2720-keV level is 5.1 $\\pm$ 1.0 (stat.) $\\pm$ 0.6 (syst.) MeV, corresponding to a $^{26}$Si excitation energy of 13.3 $\\pm$ 1.0 (stat.) $\\pm$ 0.6 (syst.) MeV for the proton-emitting level. Conclusions: The Doppler broadening method has been demonstrated to provide practical measurements of the energies for $\\beta$-delayed nucleon emissions populating excited states of nuclear recoils at least as heavy as $A=25$.

  11. Motion Measurement for Synthetic Aperture Radar.

    SciTech Connect (OSTI)

    Doerry, Armin W.

    2015-01-01

    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.

  12. TABU SEARCH FOR TARGET-RADAR

    E-Print Network [OSTI]

    Hindsbergery and Ren e Victor Valqui Vidalz y Planning and Environment Department Elkraft Power Systems section presents our nal conclusions. 2 The DEHAWK system DEHAWK is a modernization program of the Danish DEHAWK system looking only at two types of units: the illumination radars denoted HIPIR's, HIgh-Power

  13. WAVE-DRIVEN SURFACE FROM HF RADAR

    E-Print Network [OSTI]

    Miami, University of

    FEATURE INTERNAL CURRENTS WAVE-DRIVEN SURFACE FROM HF RADAR By Lynn K. Shay Observations from recent experiments · . . have revealed internal wave signatures. SURFACE CURRENTobservations from high oscillations are within the inter- nal wave continuum from the buoyancy to the in- ertial frequencies

  14. Multipoint photonic doppler velocimetry using optical lens elements

    DOE Patents [OSTI]

    Frogget, Brent Copely; Romero, Vincent Todd

    2014-04-29

    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.

  15. Development of a Drillrod/Telemetry Radar

    SciTech Connect (OSTI)

    Raton Technology Research, Inc.

    1999-11-12

    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.

  16. 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...

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

    Open Energy Info (EERE)

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

  18. Sandia Energy - Siting: Wind Turbine/Radar Interference Mitigation...

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

    Mitigation (TSPEAR & IFT&E) Home Stationary Power Energy Conversion Efficiency Wind Energy Siting and Barrier Mitigation Siting: Wind TurbineRadar Interference...

  19. Phonon characteristics of high {Tc} superconductors from neutron Doppler broadening measurements

    SciTech Connect (OSTI)

    Trela, W.J.; Kwei, G.H.; Lynn, J.E. [Los Alamos National Lab., NM (United States); Meggers, K. [Univ. of Kiel (Germany)

    1994-12-01

    Statistical information on the phonon frequency spectrum of materials can be measured by neutron transmission techniques if they contain nuclei with low energy resonances, narrow enough to be Doppler-broadened, in their neutron cross sections. The authors have carried out some measurements using this technique for materials of the lanthanum barium cuprate class, La{sub 2{minus}x}Ba{sub x}CuO{sub 4}. Two samples with slightly different concentrations of oxygen, one being superconductive, the other not, were examined. Pure lanthanum cuprate was also measured. Lanthanum, barium and copper all have relatively low energy narrow resonances. Thus it should be possible to detect differences in the phonons carried by different kinds of atom in the lattice. Neutron cross section measurements have been made with high energy resolution and statistical precision on the 59m flight path of LANSCE, the pulsed spallation neutron source at Los Alamos National Laboratory. Measurements on all three materials were made over a range of temperatures from 15K to 300K, with small steps through the critical temperature region near 27K. No significant changes in the mean phonon energy of the lanthanum atoms were observed near the critical temperature of the super-conducting material. It appears however that the mean phonon energy of lanthanum in the superconductor is considerably higher than that in the non-superconductors. The samples used in this series of experiments were too thin in barium and copper to determine anything significant about their phonon spectra.

  20. Coherent population trapping resonances at lower atomic levels of Doppler broadened optical lines

    SciTech Connect (OSTI)

    ?ahin, E; Hamid, R; Çelik, M; Özen, G; Izmailov, A Ch

    2014-11-30

    We have detected and analysed narrow high-contrast coherent population trapping (CPT) resonances, which are induced in absorption of a weak monochromatic probe light beam by counterpropagating two-frequency pump radiation in a cell with rarefied caesium vapour. The experimental investigations have been performed by the example of nonclosed three level ?-systems formed by spectral components of the D{sub 2} line of caesium atoms. The applied method allows one to analyse features of the CPT phenomenon directly at a given low long-lived level of the selected ?-system even in sufficiently complicated spectra of atomic gases with large Doppler broadening. We have established that CPT resonances in transmission of the probe beam exhibit not only a higher contrast but also a much lesser width in comparison with well- known CPT resonances in transmission of the corresponding two-frequency pump radiation. The results obtained can be used in selective photophysics, photochemistry and ultra-high resolution atomic (molecular) spectroscopy. (laser applications and other topics in quantum electronics)

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

    E-Print Network [OSTI]

    Bhardwaj, Shubhendu

    2012-01-01

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

  2. Coastal Ocean Studies in Southern San Diego Using High-Frequency Radar Derived Surface Currents

    E-Print Network [OSTI]

    Kim, Sung Yong

    2009-01-01

    high-frequency radar derived surface current measured andcoastal region Chapter 5 derived surface current by viib) vector current map derived from HF radars in southern San

  3. Coastal ocean studies in southern San Diego using high- frequency radar derived surface currents

    E-Print Network [OSTI]

    Kim, Sung Yong

    2009-01-01

    high-frequency radar derived surface current measured andcoastal region Chapter 5 derived surface current by viib) vector current map derived from HF radars in southern San

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

    E-Print Network [OSTI]

    R. R. Ross; A. C. Fabian

    1995-11-14

    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.

  5. Doppler-Free Spectroscopy of Weak Transitions: An Analytical Model Applied to Formaldehyde

    E-Print Network [OSTI]

    Zeppenfeld, M; Pinkse, P W H; Rempe, G

    2007-01-01

    Experimental observation of Doppler-free signals for weak transitions can be greatly facilitated by an estimate for the expected amplitude of the signal. We derive an analytical model which allows the Doppler-free signal amplitude to be estimated for small Doppler-free signals. Application of this model to formaldehyde allows the amplitude of experimentally observed Doppler-free signals to be reproduced to within a factor of two and the relative amplitude of different lines to be reproduced to within a few percent.

  6. Theory of Parabolic Arcs in Interstellar Scintillation Spectra

    E-Print Network [OSTI]

    James M. Cordes; Barney J. Rickett; Daniel R. Stinebring; William A. Coles

    2004-07-03

    Our theory relates the secondary spectrum, the 2D power spectrum of the radio dynamic spectrum, to the scattered pulsar image in a thin scattering screen geometry. Recently discovered parabolic arcs in secondary spectra are generic features for media that scatter radiation at angles much larger than the rms scattering angle. Each point in the secondary spectrum maps particular values of differential arrival-time delay and fringe rate (or differential Doppler frequency) between pairs of components in the scattered image. Arcs correspond to a parabolic relation between these quantities through their common dependence on the angle of arrival of scattered components. Arcs appear even without consideration of the dispersive nature of the plasma. Arcs are more prominent in media with negligible inner scale and with shallow wavenumber spectra, such as the Kolmogorov spectrum, and when the scattered image is elongated along the velocity direction. The arc phenomenon can be used, therefore, to constrain the inner scale and the anisotropy of scattering irregularities for directions to nearby pulsars. Arcs are truncated by finite source size and thus provide sub micro arc sec resolution for probing emission regions in pulsars and compact active galactic nuclei. Multiple arcs sometimes seen signify two or more discrete scattering screens along the propagation path, and small arclets oriented oppositely to the main arc persisting for long durations indicate the occurrence of long-term multiple images from the scattering screen.

  7. ARM - Field Campaign - Cloud Radar IOP

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve4AJ01) (See22,Microphysical PropertiesgovCampaignsCloud Radar IOP ARM

  8. Category: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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmentalBowerbank,CammackFLIR Jump to:RAPID Roadmap Contact Properties Jump to:sourceRadar

  9. How Radar Works | 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIXsource History View NewGuam: Energyarea,Magazine Jump to:II WindHoultonHouston,Radar

  10. 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.

    1993-06-01

    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.

  11. Reconfigurable Data Acquisition System for Weather Radar Applications

    E-Print Network [OSTI]

    Tessier, Russell

    Reconfigurable Data Acquisition System for Weather Radar Applications Rishi Khasgiwale, Luko Krnan-speed data acquisition and processing. Weather-processing systems need to be capable of im- plementing and distribution system for weather radar applications that meets these needs is described in this paper. This FPGA-based

  12. Clock SynthesisRadar Timing/Control PRF Generator

    E-Print Network [OSTI]

    Kansas, University of

    Clock SynthesisRadar Timing/Control AWG DAQ PRF Generator Receiver Transmitter Transmission Through waveform generator for pulse generation. The transmission pulse used currently is a modified linear FM, including a description of the bistatic synchronization technique. The link budget and radar performance

  13. Passive Synthetic Aperture Radar Imaging of Ground Moving Targets

    E-Print Network [OSTI]

    Yazici, Birsen

    waves due to illuminating sources of opportunity such as commercial television, radio, and cell phone of opportunity such as radio, cell phone, and television transmission towers. The absence of active signal synthetic aperture radar. A passive radar imaging system uses small, mobile receivers that do not radiate

  14. Target Discrimination in Synthetic Aperture Radar (SAR) using Artificial Neural Networks 1 TargetDiscriminationinSyntheticApertureRadar(SAR)

    E-Print Network [OSTI]

    Slatton, Clint

    Target Discrimination in Synthetic Aperture Radar (SAR) using Artificial Neural Networks 1 Target principe@cnel.ufl.edu Abstract: This paper addresses target discrimination in synthetic aperture radar (SAR classification but here the goal is discrimination. We will show that the two applications require different cost

  15. Observations of 2D Doppler backscattering on MAST

    E-Print Network [OSTI]

    Thomas, D A; Freethy, S J; Huang, B K; Shevchenko, V F; Vann, R G L

    2015-01-01

    The Synthetic Aperture Microwave Imaging (SAMI) diagnostic has conducted proof-of-principle 2D Doppler backscattering (DBS) experiments on MAST. SAMI actively probes the plasma edge using a wide (+-40 degrees vertical and horizontal) and tuneable (10-35.5 GHz) beam. The Doppler backscattered signal is digitised in vector form using an array of eight Vivaldi PCB antennas. This allows the receiving array to be focused in any direction within the field of view simultaneously to an angular range of 6-24 degrees FWHM at 10-34.5 GHz. This capability is unique to SAMI and is an entirely novel way of conducting DBS experiments. In this paper the feasibility of conducting 2D DBS experiments is explored. Initial measurements of phenomena observed on conventional DBS experiments are presented; such as momentum injection from neutral beams and an abrupt change in power and turbulence velocity coinciding with the onset of H-mode. In addition, being able to carry out 2D DBS imaging allows a measurement of magnetic pitch an...

  16. Impulse radar with swept range gate

    DOE Patents [OSTI]

    McEwan, T.E.

    1998-09-08

    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.

  17. 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)

    1996-01-01

    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.

  18. Radar transponder apparatus and signal processing technique

    DOE Patents [OSTI]

    Axline, R.M. Jr.; Sloan, G.R.; Spalding, R.E.

    1996-01-23

    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. 4 figs.

  19. Reprinted from Journal of the Optical Society of America B Limit of Doppler cooling

    E-Print Network [OSTI]

    Dalibard, Jean

    Reprinted from Journal of the Optical Society of America B Limit of Doppler cooling Y. Castin, H Laser cooling of free atoms is a technique that has been widely investigated both theoretically and experimentally during the past severalyears. The simplest cooling mecha- nism is the so-called Doppler cooling

  20. Sub-Doppler optical resolution by confining a vapour in a nanostructure

    E-Print Network [OSTI]

    Boyer, Edmond

    (typically, 10 or 20 layers of ~ 1µm diameter spheres). Sub-Doppler structures appear in the optical spectrum angles (~ 30-50°), are an original feature associated to the 3-D vapor confinement. It remembers a DickeSub-Doppler optical resolution by confining a vapour in a nanostructure Philippe BALLIN, Elias

  1. Efficient Pulse-Doppler Processing and Ambiguity Functions of Nonuniform Coherent Pulse Trains

    E-Print Network [OSTI]

    Nehorai, Arye

    Efficient Pulse-Doppler Processing and Ambiguity Functions of Nonuniform Coherent Pulse Trains Lafayette, Indiana 47907 Email: {srasool, mrb}@purdue.edu Abstract--We propose a DFT based pulse Doppler processing receiver for staggered pulse trains. The proposed receiver is a simple extension of traditional

  2. THE HUYGENS DOPPLER WIND EXPERIMENT Titan Winds Derived from Probe Radio Frequency Measurements

    E-Print Network [OSTI]

    THE HUYGENS DOPPLER WIND EXPERIMENT Titan Winds Derived from Probe Radio Frequency Measurements M 1998; Accepted in final form 20 December 2001 Abstract. A Doppler Wind Experiment (DWE of Titan's zonal winds will be determined with an accuracy better than 1 m s-1 from the start of mission

  3. Characterization of the Impact of Indoor Doppler Errors on Pedestrian Dead Reckoning

    E-Print Network [OSTI]

    Calgary, University of

    Characterization of the Impact of Indoor Doppler Errors on Pedestrian Dead Reckoning Valérie, University of Calgary 2500 University Drive NW Calgary, Alberta, Canada, T2N 1N4 Abstract--Indoor pedestrian on a Pedestrian Dead Reckoning (PDR) navigation filter is investigated. Doppler errors are simulated using

  4. A spectroscopic view of internal conversion in a small polyatomic molecule: Sub-Doppler intracavity dye laser spectroscopy of thioformaldehyde

    SciTech Connect (OSTI)

    Clouthier, D.J. (Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055 (United States)); Huang, G.; Merer, A.J. (Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, B. C. V6T 1Z1 (Canada))

    1992-08-01

    Intracavity dye laser spectroscopy has been used to obtain sub-Doppler spectra of selected rotational lines in the {ital {tilde A}} {sup 1}{ital A}{sub 2}--{ital {tilde X}} {sup 1}{ital A}{sub 1} 4{sup 1}{sub 0} band of thioformaldehyde with very high resolution and sensitivity. Many of the spectra show extra lines due to perturbations involving high vibrational levels of the ground state. Most of the perturbations observed for {ital K}{sup {prime}}{sub {ital a}} = 0 and 4 are found to correlate well with previous observations of anomalously long single rotational level fluorescence lifetimes and reduced quantum yields (J. Dunlop and D. J. Clouthier, J. Chem. Phys. {bold 93}, 6371 (1990)). {ital S}{sub 1}--{ital S}{sub 0} interaction matrix elements of 0.001--0.006 cm{sup {minus}1} are found for levels involved in simple two level perturbations. The large number of small random perturbations by levels of the ground state is indicative of the first stages of the onset of quantum chaos in a small molecule. Some larger perturbations in the rotational structure are also observed; these are caused by additional local interactions with levels of the nearby triplet state.

  5. Radar transponder operation with compensation for distortion due to amplitude modulation

    DOE Patents [OSTI]

    Ormesher, Richard C. (Albuquerque, NM); Tise, Bertice L. (Albuquerque, NM); Axline, Jr., Robert M. (Albuquerque, NM)

    2011-01-04

    In radar transponder operation, a variably delayed gating signal is used to gate a received radar pulse and thereby produce a corresponding gated radar pulse for transmission back to the source of the received radar pulse. This compensates for signal distortion due to amplitude modulation on the retransmitted pulse.

  6. ARRA-funded Cloud Radar Development for the Department of Energy's ARM Climate Research Facility

    E-Print Network [OSTI]

    ARRA-funded Cloud Radar Development for the Department of Energy's ARM Climate Research Facility six dual frequency cloud radar systems. These radars will be used by the Atmospheric Radiation on the effects of clouds and precipitation on the climate. Four cloud radar systems will be permanently installed

  7. 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.

    1996-03-12

    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.

  8. 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)

    1996-01-01

    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).

  9. 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)

    2012-09-10

    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.

  10. 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

    2015-01-01

    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.

  11. 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)

    2000-01-01

    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.

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

    SciTech Connect (OSTI)

    Doerry, Armin Walter

    2013-01-01

    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.

  13. Time-frequency analysis of synthetic aperture radar signals

    SciTech Connect (OSTI)

    Johnston, B.

    1996-08-01

    Synthetic aperture radar (SAR) has become an important tool for remote sensing of the environment. SAR is a set of digital signal processing algorithms that are used to focus the signal returned to the radar because radar systems in themselves cannot produce the high resolution images required in remote sensing applications. To reconstruct an image, several parameters must be estimated and the quality of output image depends on the degree of accuracy of these parameters. In this thesis, we derive the fundamental SAR algorithms and concentrate on the estimation of one of its critical parameters. We show that the common technique for estimating this particular parameter can sometimes lead to erroneous results and reduced quality images. We also employ time-frequency analysis techniques to examine variations in the radar signals caused by platform motion and show how these results can be used to improve output image quality.

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

    E-Print Network [OSTI]

    Quimby, Paul W

    2013-01-01

    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, ...

  15. Laser Radar Point-Target Localization at High Photon Efficiency

    E-Print Network [OSTI]

    Shapiro, Jeffrey H.

    2013-01-01

    Minimum error-probability laser radar point-target localization is analyzed, including the effects of dark counts, background counts, and target speckle. Results from preliminary table-top experiments are reported.

  16. Squeezed States and Helmholtz Spectra

    E-Print Network [OSTI]

    Francisco Delgado C.; Bogdan Mielnik; Marco A. Reyes

    1997-09-12

    The 'classical interpretation' of the wave function psi(x) reveals an interesting operational aspect of the Helmholtz spectra. It is shown that the traditional Sturm-Liouville problem contains the simplest key to predict the squeezing effect for charged particle states.

  17. Investigation of tornado models and structure by use of radar 

    E-Print Network [OSTI]

    Finley, William Andrew

    1957-01-01

    has been nost helpful in giving advice as to interpretation of radar echoes. Dr. gaiter J. Saucier has rendered invaluable assistance by the explanation and analysis of certain physical concepts. The wenbers of tha drafting section and photography... 6. Radar Echo Associated with Worchester, Massachusetts Tornado 21 7, Typical Thunderstorn Reproduced frow The Thunderstorn S. Modified Thundatstorn in Dry Enwiroment 9. Vertical Cross Section of Precipitation Pattern in Sinplified Horisontal...

  18. Hierarchical analysis of molecular spectra

    SciTech Connect (OSTI)

    Davis, M.J.

    1996-03-01

    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``).

  19. Scanning ARM Cloud Radars Part I: Operational Sampling Strategies

    SciTech Connect (OSTI)

    Kollias, Pavlos; Bharadwaj, Nitin; Widener, Kevin B.; Jo, Ieng; Johnson, Karen

    2014-03-01

    Probing clouds in three-dimensions has never been done with scanning millimeter-wavelength (cloud) radars in a continuous operating environment. The acquisition of scanning cloud radars by the Atmospheric Radiation Measurement (ARM) program and research institutions around the world generate the need for developing operational scan strategies for cloud radars. Here, the first generation of sampling strategies for the Scanning ARM Cloud Radars (SACRs) is discussed. These scan strategies are designed to address the scientific objectives of the ARM program, however, they introduce an initial framework for operational scanning cloud radars. While the weather community uses scan strategies that are based on a sequence of scans at constant elevations, the SACRs scan strategies are based on a sequence of scans at constant azimuth. This is attributed to the cloud properties that are vastly different for rain and snow shafts that are the primary target of precipitation radars. A “cloud surveillance” scan strategy is introduced (HS-RHI) based on a sequence of horizon-to-horizon Range Height Indicator (RHI) scans that sample the hemispherical sky (HS). The HS-RHI scan strategy is repeated every 30 min to provide a static view of the cloud conditions around the SACR location. Between HS-RHI scan strategies other scan strategies are introduced depending on the cloud conditions. The SACRs are pointing vertically in the case of measurable precipitation at the ground. The radar reflectivities are corrected for water vapor attenuation and non-meteorological detection are removed. A hydrometeor detection mask is introduced based on the difference of cloud and noise statistics is discussed.

  20. Characteristics of Magnetohydrodynamic Oscillations Observed with Michelson Doppler Imager

    E-Print Network [OSTI]

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

    1999-01-01

    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...

  1. 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

    1999-07-19

    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.

  2. A scanning laser Doppler vibrometer for modal testing

    SciTech Connect (OSTI)

    Sriram, P.; Craig, J.I.; Hanagud, S. (Georgia Institute of Technology, Atlanta (USA))

    1990-07-01

    Accelerometers are widely used to sense structural response in modal testing. The mass loading and local effects due to accelerometers are not always negligible. The laser Doppler velocimeter/vibrometer (LDV) is a noncontact optical sensing tool for accurately measuring point velocities. The noncontact nature of the instrument makes it particularly attractive for use on lightweight structures where measurement interaction must be minimized. Real-time scanning LDV's have recently been introduced to measure fluid flow velocity profiles rapidly. In this paper, the development of a real-time scanning LDV for structural applications is described. The instrument can be used to simultaneously measure the velocity response at a series of locations on a vibrating structure. Standard modal analysis techniques can then be applied to extract the usual modal data, e.g., natural frequencies, damping and mode shapes. The special case of beam vibration is considered in this paper though the technique can be readily extended to generic planar measurements. The measurement technique has been validated through modal testing of a simple beam structure. Comparisons between theoretical and LDV measured mode shapes and natural frequencies are presented. 20 refs.

  3. 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)

    2014-11-15

    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.

  4. Weather Radar and Hydrology (Proceedings of a symposium held in Exeter, UK, April 2011) (IAHS Publ. 351, 2011).

    E-Print Network [OSTI]

    Lovejoy, Shaun

    Weather Radar and Hydrology (Proceedings of a symposium held in Exeter, UK, April 2011) (IAHS Publ hydrology; drop distribution; multifractals INTRODUCTION Weather radars remain the only measuring devices

  5. Images of gravitational and magnetic phenomena derived from two-dimensional back-projection Doppler tomography of interacting binary stars

    SciTech Connect (OSTI)

    Richards, Mercedes T.; Cocking, Alexander S.; Fisher, John G.; Conover, Marshall J., E-mail: mrichards@astro.psu.edu, E-mail: asc5097@psu.edu [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States)

    2014-11-10

    We have used two-dimensional back-projection Doppler tomography as a tool to examine the influence of gravitational and magnetic phenomena in interacting binaries that undergo mass transfer from a magnetically active star onto a non-magnetic main-sequence star. This multitiered study of over 1300 time-resolved spectra of 13 Algol binaries involved calculations of the predicted dynamical behavior of the gravitational flow and the dynamics at the impact site, analysis of the velocity images constructed from tomography, and the influence on the tomograms of orbital inclination, systemic velocity, orbital coverage, and shadowing. The H? tomograms revealed eight sources: chromospheric emission, a gas stream along the gravitational trajectory, a star-stream impact region, a bulge of absorption or emission around the mass-gaining star, a Keplerian accretion disk, an absorption zone associated with hotter gas, a disk-stream impact region, and a hot spot where the stream strikes the edge of a disk. We described several methods used to extract the physical properties of the emission sources directly from the velocity images, including S-wave analysis, the creation of simulated velocity tomograms from hydrodynamic simulations, and the use of synthetic spectra with tomography to sequentially extract the separate sources of emission from the velocity image. In summary, the tomography images have revealed results that cannot be explained solely by gravitational effects: chromospheric emission moving with the mass-losing star, a gas stream deflected from the gravitational trajectory, and alternating behavior between stream state and disk state. Our results demonstrate that magnetic effects cannot be ignored in these interacting binaries.

  6. Potential application of the Motorola MSR-20 Radar to DOE site security

    SciTech Connect (OSTI)

    Arlowe, D.; Rebeil, P.; Vigil, R.

    1993-09-01

    This paper describes the results of testing the MSR-20 radar and provides guidance on how this radar may be used to provide early detection and warning of approaching intruders beyond DOE facility site boundaries.

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

    E-Print Network [OSTI]

    Su, Eric Chen

    2014-08-13

    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...

  8. Assessing and Analyzing Near-Surface Radar Snow Accumulation Layers at Summit, Greenland

    E-Print Network [OSTI]

    Overly, Thomas Buckmaster

    2010-04-28

    High vertical-resolution 0.5&mdash2 GHz frequency-modulated continuous-wave radar data collected near Summit on the Greenland Ice Sheet reveal continuous horizons connecting the GRIP and GISP2 deep ice cores. Traced radar ...

  9. 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.

    2001-10-01

    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...

  10. Integrating radar stratigraphy with high resolution visible stratigraphy of the north polar layered deposits, Mars

    E-Print Network [OSTI]

    Byrne, Shane

    Integrating radar stratigraphy with high resolution visible stratigraphy of the north polar layered that radar reflectors can be used as geometric prox- ies for visible stratigraphy. Furthermore in the stratigraphy of the pola

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

    E-Print Network [OSTI]

    Pradipta, Rezy

    2006-01-01

    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 ...

  12. Analysis of TRMM Precipitation Radar Algorithms and Rain over the Tropics and Southeast Texas 

    E-Print Network [OSTI]

    Funk, Aaron

    2013-12-10

    The Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) 2A23 algorithm classifies rain echo as stratiform or convective while the 2A25 algorithm corrects vertical profiles of radar reflectivity for attenuation ...

  13. Doppler-imaging of the planetary debris disc at the white dwarf SDSS J122859.93+104032.9

    E-Print Network [OSTI]

    Manser, Christopher J; Marsh, Thomas R; Veras, Dimitri; Koester, Detlev; Breedt, Elmé; Pala, Anna F; Parsons, Steven G; Southworth, John

    2015-01-01

    Debris discs which orbit white dwarfs are signatures of remnant planetary systems. We present twelve years of optical spectroscopy of the metal-polluted white dwarf SDSS J1228+1040, which shows a steady variation in the morphology of the 8600 {\\AA} Ca II triplet line profiles from the gaseous component of its debris disc. We identify additional emission lines of O I, Mg I, Mg II, Fe II and Ca II in the deep co-added spectra. These emission features (including Ca H & K) exhibit a wide range in strength and morphology with respect to each other and to the Ca II triplet, indicating different intensity distributions of these ionic species within the disc. Using Doppler tomography we show that the evolution of the Ca II triplet profile can be interpreted as the precession of a fixed emission pattern with a period in the range 24-30 years. The Ca II line profiles vary on time-scales that are broadly consistent with general relativistic precession of the debris disc.

  14. Tracking moving radar targets with parallel, velocity-tuned filters

    DOE Patents [OSTI]

    Bickel, Douglas L.; Harmony, David W.; Bielek, Timothy P.; Hollowell, Jeff A.; Murray, Margaret S.; Martinez, Ana

    2013-04-30

    Radar data associated with radar illumination of a movable target is processed to monitor motion of the target. A plurality of filter operations are performed in parallel on the radar data so that each filter operation produces target image information. The filter operations are defined to have respectively corresponding velocity ranges that differ from one another. The target image information produced by one of the filter operations represents the target more accurately than the target image information produced by the remainder of the filter operations when a current velocity of the target is within the velocity range associated with the one filter operation. In response to the current velocity of the target being within the velocity range associated with the one filter operation, motion of the target is tracked based on the target image information produced by the one filter operation.

  15. Statistical maritime radar duct estimation using hybrid genetic algorithmMarkov

    E-Print Network [OSTI]

    Gerstoft, Peter

    Statistical maritime radar duct estimation using hybrid genetic algorithm­Markov chain Monte Carlo encountered in low- altitude maritime radar applications. This is done by statistically estimating the duct of unknowns. Citation: Yardim, C., P. Gerstoft, and W. S. Hodgkiss (2007), Statistical maritime radar duct

  16. Relationship between ice water content and equivalent radar reflectivity for clouds consisting of nonspherical ice particles

    E-Print Network [OSTI]

    Baum, Bryan A.

    Relationship between ice water content and equivalent radar reflectivity for clouds consisting investigates the relationship between ice water content (IWC) and equivalent radar reflectivity (Ze) at 94 GHz. Baum, and A. J. Heymsfield (2008), Relationship between ice water content and equivalent radar

  17. Receiver Antenna Array for a Multichannel Sense-and-Avoid Radar for Small UAVs

    E-Print Network [OSTI]

    Kansas, University of

    Receiver Antenna Array for a Multichannel Sense-and-Avoid Radar for Small UAVs Jose Francisco for use in a sense-and-avoid radar for use in the Cessna C-172 and small Unmanned Aerial Vehicles (UAVs. . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . ..10 1.1.1 Multichannel Sense-and-Avoid Radar for UAVs. . . . . . . . . . . . . . . . . . . . . . ...10

  18. A Semi-Automatic Approach for Estimating Near Surface Internal Layers From Snow Radar

    E-Print Network [OSTI]

    A Semi-Automatic Approach for Estimating Near Surface Internal Layers From Snow Radar Imagery 300 MHz 40 cm 300 m 10 W 20000 ft Patch Array Vivaldi Array Twin-Otter P-3 Snow Radar Snow Cover snow radar echograms #12;Future Work · Improve near surface layer detection algorithms for more data

  19. A SEMI-AUTOMATIC APPROACH FOR ESTIMATING NEAR SURFACE INTERNAL LAYERS FROM SNOW RADAR IMAGERY

    E-Print Network [OSTI]

    A SEMI-AUTOMATIC APPROACH FOR ESTIMATING NEAR SURFACE INTERNAL LAYERS FROM SNOW RADAR IMAGERY changing polar ice sheets. Identifying and tracing near surface internal layers in snow radar echograms can developed an approach for semi-automatically esti- mating near surface internal layers in snow radar

  20. Experimental Demonstration of Cognitive Radar for Target Localization under Strong Interference

    E-Print Network [OSTI]

    Qiu, Robert Caiming

    suppressed in arbitrary bands and with low correlation sidelobes as well. Target localization is demonstrated in [2]. The knowledge-aided fully adaptive approach is explored in cognitive radar which can possess differentiate cognitive radar from previous radar systems are cognitive engine and knowledge base. Cognitive

  1. Principles and Design Considerations for Short-Range Energy Balanced Radar Networks

    E-Print Network [OSTI]

    Massachusetts at Amherst, University of

    behind "Off- The-Grid" (OTG) weather radar networks. These are envisioned as self-contained networks. Donovan1 , David J. McLaughlin1 , Jim Kurose2 1 Electrical and Computer Engineering, 2 Computer Science of the troposphere that are unobserved by today's long-range weather radars. Future distributed radar networks

  2. A Kernel-Based Spatio-Temporal Dynamical Model for Nowcasting Weather Radar Reflectivities

    E-Print Network [OSTI]

    A Kernel-Based Spatio-Temporal Dynamical Model for Nowcasting Weather Radar Reflectivities Ke Xu of the technique and its potential for nowcasting weather radar reflectivities. Key Words: Bayesian, dilation to nowcasting weather radar reflectivities into two general categories. The first is the use of simple

  3. A network of over 10 relatively closely spaced VHF windprofiler radars is under construction in Ontario

    E-Print Network [OSTI]

    Barron, John

    construction in Ontario and Quebec, Canada. Using frequencies in the range 40 to 55 MHz, this network for this, a new network of radars is being developed on a trial basis in the provinces of Ontario and Quebec. The radar network is called the O-QNet network (Ontario- Quebec Network). The proposed radar

  4. Streamflow Forecasting Based on Statistical Applications and Measurements Made with Rain Gage and Weather Radar 

    E-Print Network [OSTI]

    Hudlow, M.D.

    1967-01-01

    measurements taken with weather radar. In addition, accurate estimates of lag time can be made from radar observations. For a storm which is unevenly distributed over the watershed, it is demonstrated that a better estimation of lag time may be made from radar...

  5. Radar wind profiler signal characteristics during bird migration episodes Volker Lehmann1 and Gerd Teschke2

    E-Print Network [OSTI]

    Teschke, Gerd

    Radar wind profiler signal characteristics during bird migration episodes Volker Lehmann1 and Gerd-stationary wind profiler radar signals, which are frequently occurring during the seasonal bird migration as one of the primary sampling parameters of the wind profiler is discussed. 1. Introduction Radar wind

  6. Wavelet-based Methods for Clutter Removal from Radar Wind Profiler Data

    E-Print Network [OSTI]

    Teschke, Gerd

    Wavelet-based Methods for Clutter Removal from Radar Wind Profiler Data Lutz A. Justena, Gerd ABSTRACT The common way to process radar wind profiler (RWP) data by moments estimation of the Fourier filtering, radar wind profiler, signal processing, time-frequency decomposition 1. INTRODUCTION In recent

  7. 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.

    1997-08-01

    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.

  8. 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

    2013-06-13

    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.

  9. 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

    1998-01-01

    A sum-nary of lightning characteristics was developed for the NASA Kennedy Space Center (KSC). From-n a 1989-1996 data set, the spatial patterns, temporal patterns, and first stroke mean peak current were analyzed. Forty five thunderstorms were...

  10. 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)

    2014-02-20

    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.

  11. Control Based Sensor Management for a Multiple Radar Monitoring Scenario

    E-Print Network [OSTI]

    Baclawski, Kenneth B.

    . The emitters exhibit a quasi-periodic radiation pattern, each in a different frequency band metaphor of software development, we map this problem onto a control architecture with one system that monitor sources of electronic radiation in the environment (such as radars). The sources emit radiation

  12. 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. DrinkwaterWinds on QuikScat (QSCAT) satellite instruments are used to illustrate spatiotemporal variability in snow in backscatter, B, in the range 20 ­60 are compared with historical snow accumulation data and recent

  13. 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

    2014-12-01

    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

  14. Assessment Of The Wind Farm Impact On The Radar

    E-Print Network [OSTI]

    Norman, Evgeny D

    2010-01-01

    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 ...

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

    SciTech Connect (OSTI)

    Borque, Paloma; Giangrande, Scott; Kollias, Pavlos

    2014-12-01

    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.

  16. Generating nonlinear FM chirp radar signals by multiple integrations

    DOE Patents [OSTI]

    Doerry, Armin W. (Albuquerque, NM)

    2011-02-01

    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.

  17. 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

  18. Topography of the Lunar Poles from Radar Interferometry: A

    E-Print Network [OSTI]

    Margot, Jean-Luc

    Topography of the Lunar Poles from Radar Interferometry: A Survey of Cold Trap Locations J. L. Margot,1 * D. B. Campbell,1 R. F. Jurgens,2 M. A. Slade2 Detailed topographic maps of the lunar poles are 1030 and 2550 square kilometers for the north and south poles, respectively. Topographic depressions

  19. IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 43, NO. 8, AUGUST 2005 1707 Validation of the Shuttle Radar Topography

    E-Print Network [OSTI]

    Sarabandi, Kamal

    of the Shuttle Radar Topography Mission Height Data Charles G. Brown, Jr., Member, IEEE, Kamal Sarabandi, Fellow, IEEE, and Leland E. Pierce, Senior Member, IEEE Abstract--The Shuttle Radar Topography Mission (SRTM Radar Topography Mission, validation. I. INTRODUCTION THE Shuttle Radar Topography Mission (SRTM

  20. Optical frequency standards for gravitational wave detection using satellite Doppler velocimetry

    E-Print Network [OSTI]

    Vutha, Amar C

    2015-01-01

    Gravitational waves imprint apparent Doppler shifts on the frequency of photons propagating between an emitter and detector of light. This forms the basis of a method to detect gravitational waves using Doppler velocimetry between pairs of satellites. Such detectors, operating in the milli-hertz gravitational frequency band, could lead to the direct detection of gravitational waves. The crucial component in such a detector is the frequency standard on board the emitting and receiving satellites. We point out that recent developments in atomic frequency standards have led to devices that are approaching the sensitivity required to detect gravitational waves from astrophysically interesting sources. The sensitivity of satellites equipped with optical frequency standards for Doppler velocimetry is examined, and a design for a robust, space-capable optical frequency standard is presented.

  1. Optical frequency standards for gravitational wave detection using satellite Doppler velocimetry

    E-Print Network [OSTI]

    Amar C. Vutha

    2015-06-24

    Gravitational waves imprint apparent Doppler shifts on the frequency of photons propagating between an emitter and detector of light. This forms the basis of a method to detect gravitational waves using Doppler velocimetry between pairs of satellites. Such detectors, operating in the milli-hertz gravitational frequency band, could lead to the direct detection of gravitational waves. The crucial component in such a detector is the frequency standard on board the emitting and receiving satellites. We point out that recent developments in atomic frequency standards have led to devices that are approaching the sensitivity required to detect gravitational waves from astrophysically interesting sources. The sensitivity of satellites equipped with optical frequency standards for Doppler velocimetry is examined, and a design for a robust, space-capable optical frequency standard is presented.

  2. 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

  3. Observations of Solar Flare Doppler Shift Oscillations with the Bragg Crystal Spectrometer on Yohkoh

    E-Print Network [OSTI]

    John T. Mariska

    2005-01-06

    Oscillations in solar coronal loops appear to be a common phenomenon. Transverse and longitudinal oscillations have been observed with both the Transition Region and Coronal Explorer and Extreme Ultraviolet Imaging Telescope imaging experiments. Damped Doppler shift oscillations have been observed in emission lines from ions formed at flare temperatures with the Solar Ultraviolet Measurements of Emitted Radiation Spectrometer. These observations provide valuable diagnostic information on coronal conditions and may help refine our understanding of coronal heating mechanisms. I have initiated a study of the time dependence of Doppler shifts measured during flares with the Bragg Crystal Spectrometer (BCS) on Yohkoh. This Letter reports the detection of oscillatory behavior in Doppler shifts measured as a function of time in the emission lines of S XV and Ca XIX. For some flares, both lines exhibit damped Doppler shift oscillations with amplitudes of a few km/s and periods and decay times of a few minutes. The observations appear to be consistent with transverse oscillations. Because the BCS observed continuously for almost an entire solar cycle, it provides numerous flare data sets, which should permit an excellent characterization of the average properties of the oscillations.

  4. Doppler Shift of the de Broglie Waves- Some New Results from Very Old Concepts

    E-Print Network [OSTI]

    Sanchari De; Somenath Chakrabarty

    2015-02-28

    The Doppler shift of de Broglie wave is obtained for fermions and massive bosons using the conventional form of Lorentz transformations for momentum and energy of the particles. A formalism is developed to obtain the variation of wave length for de Broglie waves with temperature for individual particles using the classic idea of Wien in a many body Fermi gas or massive Bose gas.

  5. Velocity Comparisons from Upward and Downward Acoustic Doppler Current Profilers on the West Florida Shelf

    E-Print Network [OSTI]

    Meyers, Steven D.

    of deploying current meters including bottom-mounted, upward looking and surface buoy-mounted, downward looking Acoustic Doppler Current Profilers (ADCPs). In the case of a surface buoy, an ADCP may be mounted within a cage suspended below the buoy (Irish et al. 1992; Seim and Edwards 2005), within the buoy bridle

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

    SciTech Connect (OSTI)

    Rodney Frehlich

    2012-10-30

    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.

  7. Modeling HSGPS Doppler Errors in Indoor Environments for Pedestrian Dead-Reckoning

    E-Print Network [OSTI]

    Calgary, University of

    Modeling HSGPS Doppler Errors in Indoor Environments for Pedestrian Dead-Reckoning Zhe He, Mark The use of high sensitivity GPS (HSGPS) receivers integrated with dead-reckoning sensors for pedestrian navigation has been broadly investigated and applied in the past decade. Pedestrian dead-reckoning (PDR

  8. 3-D laser doppler velocimeter measurements of eccentric annular and labyrinth seals 

    E-Print Network [OSTI]

    Das, Purandar Gururaj

    1993-01-01

    A 3-D laser doppler velocimeter was used to measure the flow field inside a whirling annular and labyrinth seal. The data was collected and phase averaged with the seals operating at a Reynolds number of 24,000 and a ...

  9. Forensic Application of FM-CW and Pulse Radar

    SciTech Connect (OSTI)

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

    2003-01-01

    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.

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

    SciTech Connect (OSTI)

    Doerry, Armin Walter; Marquette, Brandeis

    2013-01-01

    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.

  11. Radar Nowcasting of Total Lightning over the Kennedy Space Center 

    E-Print Network [OSTI]

    Seroka, Gregory Nicholas

    2011-08-08

    intracloud (IC) and/or total (IC + CG) lightning. In addition to CG lightning, IC flashes are of great concern to KSC launch operations. Four years (2006-2009) of summer (June, July, August) daytime (about 14-00 Z) Weather Surveillance Radar ? 1988... Page 1 Florida flash density from 1986-95. ......................................................... 3 2 LDAR-I and LDAR-II site locations ........................................................ 13 3 Various estimates of LDAR-I flash...

  12. 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

    2008-02-14

    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.

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

    SciTech Connect (OSTI)

    Doerry, Armin W.

    2014-08-01

    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.

  14. Statistical maritime radar duct estimation using hybrid genetic algorithm-Markov chain Monte Carlo method

    E-Print Network [OSTI]

    Yardim, Caglar; Gerstoft, Peter; Hodgkiss, William S.

    2007-01-01

    Estimating evaporation duct heights from radar sea echo,”Estimation of surface-based duct parameters from surfaceapplication of an evaporation duct model,” Radio Science,

  15. Technology demonstration of Ka-band digitally-beamformed radar for ice topography mapping

    E-Print Network [OSTI]

    Sadowy, G; Heavey, B; Moller, D; Rignot, E; Zawadzki, M; Rengarajan, S

    2007-01-01

    Beamformed Radar for Ice Topography Mapping Gregory Sadowy,Glacier and Land Ice Surface Topography Interferometer) is aGLISTIN will collect ice topography measurements over a wide

  16. Theoretical spectra of terrestrial exoplanet surfaces

    E-Print Network [OSTI]

    Hu, Renyu

    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 ...

  17. A Tool for the Spectral Analysis of the Laser Doppler Anemometer Data of the Cambridge Stratified Swirl Burner

    E-Print Network [OSTI]

    Zhou, Ruigang; Balusamy, Saravanan; Hochgreb, Simone

    2012-06-08

    A series of flow fields generated by a turbulent methane/air stratified swirl burner are investigated using laser Doppler anemometer (LDA). The LDA provides flow field measurements with comparatively high temporal resolutions. However, processing...

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

    DOE Patents [OSTI]

    Rhodes, Mark

    2013-12-17

    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.

  19. 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)

    2010-06-15

    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.

  20. Weather Radar and Hydrology (Proceedings of a symposium held in Exeter, UK, April 2011) (IAHS Publ. 3XX, 2011).

    E-Print Network [OSTI]

    Reading, University of

    for radars with klystron transmitters, for which the frequency of the transmitted signal is essentially with klystron transmitters. Klystron transmitters are very stable in terms of frequency. Weather radars

  1. Modeling Correlations In Prompt Neutron Fission Spectra Uncertainties...

    Office of Scientific and Technical Information (OSTI)

    Modeling Correlations In Prompt Neutron Fission Spectra Uncertainties Citation Details In-Document Search Title: Modeling Correlations In Prompt Neutron Fission Spectra...

  2. 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.; Shumlak, U.

    2011-10-13

    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 functionmore »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. As a result, these measurements are used to gain a better understanding of Z-pinch equilibria.« less

  3. X-ray Doppler Imaging of 44i Boo with Chandra

    E-Print Network [OSTI]

    N. S. Brickhouse; A. K. Dupree; P. R. Young

    2001-10-25

    Chandra High-Energy Transmission Grating observations of the bright eclipsing contact binary 44i Boo show X-ray line profiles which are Doppler-shifted by orbital motions. The X-ray emission spectrum contains a multitude of lines superimposed on a weak continuum, with strong lines of O VIII, Ne X, Fe XVII, and Mg XII. The profiles of these lines from the total observed spectrum show Doppler-broadened widths of ~ 550 km s^{-1}. Line centroids vary with orbital phase, indicating velocity changes of > 180 km s^{-1}. The first-order light curve shows significant variability, but no clear evidence for either primary or secondary eclipses. Flares are observed for all spectral ranges; additionally, the light curve constructed near the peak of the emission measure distribution (T_e = 5 to 8 X 10^6 K) shows quiescent variability as well as flares. The phase-dependences of line profiles and light curves together imply that at least half of the emission is localized at high latitude. A simple model with two regions on the primary star at relatively high latitude reproduces the observed line profile shifts and quiescent light curve. These first clear X-ray Doppler shifts of stellar coronal material illustrate the power of Chandra.

  4. 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)

    1999-01-01

    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.

  5. Apodized RFI filtering of synthetic aperture radar images.

    SciTech Connect (OSTI)

    Doerry, Armin Walter

    2014-02-01

    Fine resolution Synthetic Aperture Radar (SAR) systems necessarily require wide bandwidths that often overlap spectrum utilized by other wireless services. These other emitters pose a source of Radio Frequency Interference (RFI) to the SAR echo signals that degrades SAR image quality. Filtering, or excising, the offending spectral contaminants will mitigate the interference, but at a cost of often degrading the SAR image in other ways, notably by raising offensive sidelobe levels. This report proposes borrowing an idea from nonlinear sidelobe apodization techniques to suppress interference without the attendant increase in sidelobe levels. The simple post-processing technique is termed Apodized RFI Filtering (ARF).

  6. Compressive Radar with Off-Grid and Extended Targets

    E-Print Network [OSTI]

    Fannjiang, Albert

    2012-01-01

    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.

  7. Instructions to: TOM: Teaching flow over Mountains -Worksheet at the radar site

    E-Print Network [OSTI]

    : Is it snowing/raining? What is the intensity (light, heavy)? What do you think the temperature is? How much snow driving to the radar site it was cold and snowing lightly. The snowflakes were small. There was no wind by HighresLOW 8:42 am / 0142 UTC Radar truck leveled #12; 6 EXERCISE 5 Once you are done with Exercises

  8. Stratocumulus Liquid Water Content from Dual-Wavelength Radar ROBIN J. HOGAN

    E-Print Network [OSTI]

    Reading, University of

    Stratocumulus Liquid Water Content from Dual-Wavelength Radar ROBIN J. HOGAN , NICOLAS GAUSSIAT ABSTRACT A technique is described to retrieve stratocumulus liquid water content (LWC) using the integrated water content of the column, which is then partitioned with height according to the radar

  9. Field-scale estimation of volumetric water content using ground-penetrating radar ground wave techniques

    E-Print Network [OSTI]

    Hubbard, Susan

    Field-scale estimation of volumetric water content using ground- penetrating radar ground wave] Ground-penetrating radar (GPR) ground wave techniques were applied to estimate soil water content travel time measurements using 900 and 450 MHz antennas and analyzed these data to estimate water content

  10. CHARACTERIZATION OF BASIC SCATTERING MECHANISMS USING LABORATORY BASED POLARIMETRIC SYNTHETIC APERTURE RADAR IMAGING

    E-Print Network [OSTI]

    Kerekes, John

    with an adjacent vertical surface. In this case, major portion of the transmitted energy is back scattered towards the radar. Theses appear as bright regions in the radar image and occur typically in the urban areas, is related to the wavelength in free space through the diameter of the can [6]. The wavelength in free space

  11. 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

  12. Chapter C-XV-1 Complementary Waveforms for Sidelobe Suppression and Radar Polarimetry

    E-Print Network [OSTI]

    Pezeshki, Ali

    by the ability to control new degrees of freedom and each new generation of radar platforms requires fundamental are increasingly being equipped with arbitrary wave- form generators which enable transmission of different that effectively utilize the degrees of freedom available to current and future generation of radar systems

  13. ERADERAD 20062006Proceedings ofProceedings of The Danish weather radar network

    E-Print Network [OSTI]

    ERADERAD 20062006Proceedings ofProceedings of The Danish weather radar network Rashpal S. Gill, Søren Overgaard and Thomas Bøvith Danish Meteorological Institute, Copenhagen, Denmark. 1 Introduction The Danish Meteorological Institute (DMI) operates four c- band radars for weather monitoring. Three

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

    E-Print Network [OSTI]

    Marshall, Hans-Peter

    FMCW radars for snow research Hans-Peter Marshall a,b,, Gary Koh a a Cold Regions Research; accepted 16 April 2007 Abstract Frequency Modulated Continuous Wave (FMCW) radars have been used by snow measurements, as properties such as snow depth can be measured quickly and non- destructively. Recent advances

  15. Satellite and radar analysis of the volcanic-cumulonimbi at Mount Pinatubo, Philippines, 1991

    E-Print Network [OSTI]

    Daniel, Rosenfeld

    Satellite and radar analysis of the volcanic-cumulonimbi at Mount Pinatubo, Philippines, 1991, Philippines. The observed phenomena included deep convection resulting from (1) lower level eruptions, (2 and radar analysis of the volcanic-cumulonimbi at Mount Pinatubo, Philippines, 1991, J. Geophys. Res., 110

  16. Phase Correction for Coherent Noise Reduction in Short-Range Radar Measurements

    E-Print Network [OSTI]

    Kansas, University of

    electromagnetic energy and geophysical media in a number of remote sensing applications. Unlike long-range and intermediate-range radar systems, the sensitivity of short-range radars is not limited by thermal noise method to account for variations in the phase of the systematic noise sources. This extends the noise

  17. Finland HF and Esrange MST radar observations of polar mesosphere summer echoes

    E-Print Network [OSTI]

    Kirkwood, Sheila

    Finland HF and Esrange MST radar observations of polar mesosphere summer echoes Tadahiko Ogawa1 (200x) xx:1­8 Finland HF and Esrange MST radar observations of polar mesosphere summer echoes Tadahiko in Finland are presented. The echoes were detected at four frequencies of 9, 11, 13 and 15 MHz at slant

  18. 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

  19. OEP Terminal and CONUS Weather Radar Coverage Gap Identification Analysis for NextGen

    E-Print Network [OSTI]

    Cho, John Y. N.

    coverage. The assimilation of data from ground-based profiling instruments and airborne sensors, and is computationally intensive. Such height corrections to weather radar data are not currently conducted operationally to be even slower. Weather observation data from the aircraft surveillance radars are updated quickly enough

  20. A new framebased statistical strategy for bird migration clutter removal in wind profiler radar data

    E-Print Network [OSTI]

    Teschke, Gerd

    A new frame­based statistical strategy for bird migration clutter removal in wind profiler radar clutter removal routine for wind profiler radar data. The basic idea is to put together already existing of the expansion. A Relaxation of the clas- sical constraint T = 2 generates a crucial degree of freedom

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

    E-Print Network [OSTI]

    Gilbes, Fernando

    Off-The-Grid X-band Weather Radar Network for the West Coast of Puerto Rico José A. Ortiz CASA UPRM infrastructure, Low Cost · Off-the-Grid Radars · Mesh Network on West Coast Puerto Rico · Weather Reflectivity infrastructure ­ Low maintenance cost · Off the Grid · Better for uneven terrains · Improved resolution #12

  2. 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

  3. Snow stratigraphy measurements with high-frequency FMCW radar: Comparison with snow micro-penetrometer

    E-Print Network [OSTI]

    Marshall, Hans-Peter

    Snow stratigraphy measurements with high-frequency FMCW radar: Comparison with snow micro The stratigraphy of an alpine snowpack is very important for avalanche danger assessment, as well as interpretation. Tools which can quickly characterize snowpack stratigraphy, such as high frequency radar and mechanical

  4. Surface M2 tidal currents along the North Carolina shelf observed with a high-frequency radar

    E-Print Network [OSTI]

    Miami, University of

    Surface M2 tidal currents along the North Carolina shelf observed with a high-frequency radar measured by a high-frequency (HF) radar. The Ocean Surface Current Radar (OSCR) was deployed at the U. M., and L. K. Shay, Surface M2 tidal currents along the North Carolina shelf observed with a high-frequency

  5. Mid-Infrared Spectra of Be Stars

    E-Print Network [OSTI]

    S. A. Rinehart; J. R. Houck; J. D. Smith

    1999-10-11

    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.

  6. Raman and IR spectra of butane: Anharmonic calculations and interpretation of room temperature spectra

    E-Print Network [OSTI]

    Potma, Eric Olaf

    Raman and IR spectra of butane: Anharmonic calculations and interpretation of room temperature-principles anharmonic calculations are carried out for the IR and Raman spectra of the CAH stretch- ing bands in butane.V. All rights reserved. 1. Introduction n-Butane is of great importance in several disciplines

  7. Hydrogen geocorona: simultaneous optical and radar observations at Arecibo

    SciTech Connect (OSTI)

    Kerr, R.B.

    1986-01-01

    Observations of the geocoronal H/sub ..cap alpha../ emission with a high resolution Fabry-Perot interferometer were made simultaneously with observations of the topside F region using the incoherent scatter radar at Arecibo, for the purpose of monitoring the exobase temperature and the hydrogen velocity distribution over half of a solar cycle. The variation of H density with solar activity agrees with that of previous observations. These observations have shown that the charge exchange reaction of H with H/sup +/ perturbs the ballistic hydrogen velocity distribution above the exobase in the fall and winter months at Arecibo. The exobase temperature is hotter than would be expected for winter solar minimum conditions due to a drop of the protonosphere base during these periods. A multi-constituent analysis of the radar data places the base of the protonosphere near 550 km in the early morning hours of the late fall and early winter. A maximum in downward ion velocities is also observed during these times. For observations near the neutral equinox, the charge exchange reaction does not significantly perturb the neutral hydrogen velocity distribution.

  8. Estimating the instantaneous velocity of randomly moving target swarms in a stratified ocean waveguide by Doppler analysis

    E-Print Network [OSTI]

    Bertsatos, Ioannis

    2011-01-01

    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, ...

  9. The SPECTRa Project: A Wider Chemistry View

    E-Print Network [OSTI]

    Downing, Jim; Tonge, Alan

    2006-10-20

    services computational chemistry determined by interview and survey The Problem Science depends upon data Experimental chemistry data is a resource / asset … Proprietary spectra formats (NMR, IR, UV) : 5-year shelf life PDF image files (supplementary... ="-1.547700"/>

  10. Determinations of photon spectra. Master's thesis

    SciTech Connect (OSTI)

    Wannigman, D.L.

    1989-01-01

    A method is developed to unfold photon spectra from measurements obtained with a sodium iodide counting system. A response matrix is computed by combining photon cross sections with probability distributions of path lengths for incident and internally generated photons in the energy range 0-2.8 MeV. This matrix is inverted and multiplied by a measured pulse height spectrum to obtain the photon energy distribution incident upon the detector. This deconvolution procedure provides improved information about the energy continuum of incident photons and can enhanced the identification of discrete gamma energies. Experiments were performed to verify the unfolding methodology and to evaluate the feasibility and accuracy of this technique. Measured spectra were acquired from indoor and outdoor environments and unfolded. The results show that measured spectra overestimate the number of photons below 240 keV by up to 30 %. When the total exposure was calculated directly from the measured spectra, the low energy contribution was overestimated by a factor of two. This may have implications on the interpretation and calibration of energy dependent dosimeters used for occupational and environmental monitoring.

  11. 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)

    2012-07-01

    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.

  12. Portable Doppler interferometer system for shock diagnostics and high speed motion

    SciTech Connect (OSTI)

    Fleming, K.J.; Crump, O.B. Jr.

    1994-05-01

    VISAR (Velocity Interferometer System for Any Reflector) is a system that uses the Doppler effect and is widely used for measuring the velocity of projectiles, detonations, flying plates, shock pressures (particle velocity) and other high speed/high acceleration motion. Other methods of measurement such as accelerometers and pressure gauges have disadvantages in that they are sensitive to radiation, electromagnetic pulses, and their mass can drastically alter the velocity of the projectile. VISAR uses single frequency-single mode laser fight focused onto a target of interest. Reflected fight from the target is collected and sent through a modified, unequal leg Michelson interferometer. In the interferometer the light is split into two components which travel through the legs of the interferometer cavity and are then recombined. When the light recombines, an interference pattern is created which can range from dark (destructive interference) to bright (constructive interference). When the target moves, the reflected laser light experiences a frequency shift (increase) with respect to the frequency from the target in a static condition. Since the Doppler shifted light is split and routed through an unequal leg interferometer cavity, there is a time lag of the light containing the Doppler information at the recombination point in the interferometer. The effect of the time lag is to create a sinusoidally changing interference pattern (commonly called fringes). Since the interferometer time delay, laser wavelength, and the speed of light are known, an accurate measurement of target velocity/acceleration may be measured by analyzing both the number of tinges and the speed of tinge generation (system accuracy is 3--4%).

  13. Theory of Thermal Motion in Electromagnetically Induced Transparency: Diffusion, Doppler, Dicke and Ramsey

    E-Print Network [OSTI]

    O. Firstenberg; M. Shuker; R. Pugatch; D. R. Fredkin; N. Davidson; A. Ron

    2008-01-30

    We present a theoretical model for electromagnetically induced transparency (EIT) in vapor, that incorporates atomic motion and velocity-changing collisions into the dynamics of the density-matrix distribution. Within a unified formalism we demonstrate various motional effects, known for EIT in vapor: Doppler-broadening of the absorption spectrum; Dicke-narrowing and time-of-flight broadening of the transmission window for a finite-sized probe; Diffusion of atomic coherence during storage of light and diffusion of the light-matter excitation during slow-light propagation; and Ramsey-narrowing of the spectrum for a probe and pump beams of finite-size.

  14. Convergence of Legendre Expansion of Doppler-Broadened Double Differential Elastic Scattering Cross Section

    SciTech Connect (OSTI)

    Arbanas, Goran; Dunn, Michael E; Larson, Nancy M; Leal, Luiz C; Williams, Mark L

    2012-01-01

    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.

  15. Use of a laser doppler vibrometer for high frequency accelerometer characterizations

    SciTech Connect (OSTI)

    Bateman, V.I.; Hansche, B.D.; Solomon, O.M.

    1995-12-31

    A laser doppler vibrometer (LDV) is being used for high frequency characterizations of accelerometers at Sandia National Laboratories (SNL). A LDV with high frequency (up to 1.5 MHz) and high velocity (10 M/s) capability was purchased from a commercial source and has been certified by the Primary Electrical Standards Department at SNL. The method used for this certification and the certification results are presented. Use of the LDV for characterization of accelerometers at high frequencies and of accelerometer sensitivity to cross-axis shocks on a Hopkinson bar apparatus is discussed.

  16. Ultra-wideband short-pulse radar with range accuracy for short range detection

    SciTech Connect (OSTI)

    Rodenbeck, Christopher T; Pankonin, Jeffrey; Heintzleman, Richard E; Kinzie, Nicola Jean; Popovic, Zorana P

    2014-10-07

    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.

  17. Geomorphic Evaluation of Radar Imagery of Southeastern Panama and Northwestern Colombia

    E-Print Network [OSTI]

    Lewis, Anthony J.

    1971-02-01

    Layover. • • • • • • • • • • • • 35 2.4 2.5 Radar Power Return. . • • • • • • • • • • • • • • · . . 2.4. 1 Slope Determination from Radar Power Return. • Radar Shadow . • • ... . • . • • . . .* ~ • • • • • • • 2.5. 1 Types of Elevated Terrain... Features within the Study Area • • 79 3.3. 1.1 Shoreline Coastal Configuration. 79 3.3.1.2 Tidal Flats. . . . • • • . . • . • .• 79 3.3.1.3 Mangrove Coasts • . 0 • • • • 0 82 3.3.1.4 Beach Ridges and Wave Refraction.. 82 3.3. 1.5 Barrier Reefs and Surf...

  18. Two antenna, two pass interferometric synthetic aperture radar

    DOE Patents [OSTI]

    Martinez, Ana; Doerry, Armin W.; Bickel, Douglas L.

    2005-06-28

    A multi-antenna, multi-pass IFSAR mode utilizing data driven alignment of multiple independent passes can combine the scaling accuracy of a two-antenna, one-pass IFSAR mode with the height-noise performance of a one-antenna, two-pass IFSAR mode. A two-antenna, two-pass IFSAR mode can accurately estimate the larger antenna baseline from the data itself and reduce height-noise, allowing for more accurate information about target ground position locations and heights. The two-antenna, two-pass IFSAR mode can use coarser IFSAR data to estimate the larger antenna baseline. Multi-pass IFSAR can be extended to more than two (2) passes, thereby allowing true three-dimensional radar imaging from stand-off aircraft and satellite platforms.

  19. Iterative Self-Dual Reconstruction on Radar Image Recovery

    SciTech Connect (OSTI)

    Martins, Charles; Medeiros, Fatima; Ushizima, Daniela; Bezerra, Francisco; Marques, Regis; Mascarenhas, Nelson

    2010-05-21

    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.

  20. Phase coded, micro-power impulse radar motion sensor

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1996-01-01

    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.

  1. Phase coded, micro-power impulse radar motion sensor

    DOE Patents [OSTI]

    McEwan, T.E.

    1996-05-21

    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.

  2. Inflation and Alternatives with Blue Tensor Spectra

    E-Print Network [OSTI]

    Yi Wang; Wei Xue

    2014-10-20

    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.

  3. Tomography of lensing cross power spectra

    E-Print Network [OSTI]

    Masahiro Takada; Martin White

    2004-09-14

    By obtaining photometric redshift information, tomography allows us to cross-correlate galaxy ellipticities in different source redshift bins. The cross-correlation is non-vanishing because the different bins share much of the foreground mass distribution from which, over Gpc scales, the lensing signal is built. If the redshift bins are thick enough however, the cross-correlations are insensitive to contamination from the intrinsic alignments of galaxies since these fall off rapidly on scales larger than a few tens of Mpc. We forecast how lensing tomography using only the cross-power spectra can constrain cosmological parameters compared to tomography including the auto-spectra. It is shown that the parameter errors are degraded by only O(10%) for 5 or more source redshift bins. Thus, the cross-power spectrum tomography can be a simple, model-independent means of reducing the intrinsic alignment contamination while retaining most of the constraints on cosmology.

  4. Computation of the spectra of the quasars

    E-Print Network [OSTI]

    Jacques Moret-Bailly

    2003-08-28

    The repartition of redshifts of the lines observed in the spectra of the quasars is generally considered as stochastic, but several authors showed that the difference of two redshifts is the product of an integer by a basic redshift zf = 0.062. This property results from a coherent Raman effect during the propagation of the incoherent light in a halo of atomic hydrogen, without any jet of gas, or dark matter. The coherence forbids a blur of the images or of the spectra. The computation of zf does not require any new spectroscopic parameter. The non-linearity of the combination of Lyman absorptions and coherent Raman effect explains both the observed positions of the spectral lines and their high contrast.

  5. Inflation and alternatives with blue tensor spectra

    SciTech Connect (OSTI)

    Wang, Yi; Xue, Wei E-mail: wei.xue@sissa.it

    2014-10-01

    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.

  6. Dynamical analysis of highly excited molecular spectra

    SciTech Connect (OSTI)

    Kellman, M.E. [Univ. of Oregon, Eugene (United States)

    1993-12-01

    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.

  7. Random Matrix Spectra as a Time Series

    E-Print Network [OSTI]

    Ruben Fossion; Gamaliel Torres Vargas; Juan Carlos López Vieyra

    2013-11-23

    Spectra of ordered eigenvalues of finite Random Matrices are interpreted as a time series. Dataadaptive techniques from signal analysis are applied to decompose the spectrum in clearly differentiated trend and fluctuation modes, avoiding possible artifacts introduced by standard unfolding techniques. The fluctuation modes are scale invariant and follow different power laws for Poisson and Gaussian ensembles, which already during the unfolding allows to distinguish the two cases.

  8. Infrared Transmission Spectra for Extrasolar Giant Planets

    E-Print Network [OSTI]

    G. Tinetti; M. C. Liang; A. Vidal-Madjar; D. Ehrenreich; A. Lecavelier des Etangs; Y. Yung

    2006-11-06

    Among the hot Jupiters that transit their parent stars known to date, the two best candidates to be observed with transmission spectroscopy in the mid-infrared (MIR) are HD189733b and HD209458b, due to their combined characteristics of planetary density, orbital parameters and parent star distance and brightness. Here we simulate transmission spectra of these two planets during their primary eclipse in the MIR, and we present sensitivity studies of the spectra to the changes of atmospheric thermal properties, molecular abundances and C/O ratios. Our model predicts that the dominant species absorbing in the MIR on hot Jupiters are water vapor and carbon monoxide, and their relative abundances are determined by the C/O ratio. Since the temperature profile plays a secondary role in the transmission spectra of hot Jupiters compared to molecular abundances, future primary eclipse observations in the MIR of those objects might give an insight on EGP atmospheric chemistry. We find here that the absorption features caused by water vapor and carbon monoxide in a cloud-free atmosphere, are deep enough to be observable by the present and future generation of space-based observatories, such as Spitzer Space Telescope and James Webb Space Telescope. We discuss our results in light of the capabilities of these telescopes.

  9. Computing High Accuracy Power Spectra with Pico

    E-Print Network [OSTI]

    William A. Fendt; Benjamin D. Wandelt

    2007-12-02

    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.

  10. 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

    2004-08-31

    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.

  11. Theory of sub-Doppler cooling of three-level {Lambda} atoms in standing light waves

    SciTech Connect (OSTI)

    Kosachev, D.V.; Rozhdestvenskii, Yu.V. [St. Petersburg State Technical Univ. (Russian Federation)

    1994-12-01

    A general theory of cooling of three-level {Lambda} atoms in two standing light waves between which there is a relative spatial phase shift is presented for arbitrary ratios of the intensity and detuning. It is shown that in the case of equal detuning of the light waves, deep (sub-Doppler) cooling of three-level atoms occurs for any values of the spatial phase shift. For zero spatial phase shift, the atoms are strongly cooled due to coherent population trapping in the given atom-field interaction scheme. On the other hand, for the case of different frequency detunings, sub-Doppler cooling of {Lambda} atoms is possible only with a nonzero relative phase shift; it is shown that this is associated with the so-called {open_quotes}Sisyphus{close_quotes} cooling mechanism. The authors underscore that in their scheme neither a polarization gradient of the exciting waves nor a magnetic field is required to achieve this type of cooling pattern; two standing waves acting on different transitions of a {Lambda} atom are sufficient. 13 refs., 10 figs.

  12. PROBLEM DEPENDENT DOPPLER BROADENING OF CONTINUOUS ENERGY CROSS SECTIONS IN THE KENO MONTE CARLO COMPUTER CODE

    SciTech Connect (OSTI)

    Hart, S. W. D.; Maldonado, G. Ivan; Celik, Cihangir; Leal, Luiz C

    2014-01-01

    For many Monte Carlo codes cross sections are generally only created at a set of predetermined temperatures. This causes an increase in error as one moves further and further away from these temperatures in the Monte Carlo model. This paper discusses recent progress in the Scale Monte Carlo module KENO to create problem dependent, Doppler broadened, cross sections. Currently only broadening the 1D cross sections and probability tables is addressed. The approach uses a finite difference method to calculate the temperature dependent cross-sections for the 1D data, and a simple linear-logarithmic interpolation in the square root of temperature for the probability tables. Work is also ongoing to address broadening theS (alpha , beta) tables. With the current approach the temperature dependent cross sections are Doppler broadened before transport starts, and, for all but a few isotopes, the impact on cross section loading is negligible. Results can be compared with those obtained by using multigroup libraries, as KENO currently does interpolation on the multigroup cross sections to determine temperature dependent cross-sections. Current results compare favorably with these expected results.

  13. Ground penetrating radar characterization of wood piles and the water table in Back Bay, Boston

    E-Print Network [OSTI]

    LeFrançois, Suzanne O'Neil, 1980-

    2003-01-01

    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 ...

  14. A Real-Time, Three Dimensional, Rapidly Updating, Heterogeneous Radar Merger Technique

    E-Print Network [OSTI]

    Lakshmanan, Valliappa

    nearly all the WSR-88D radars are compressed using block encoding (Burrows and Wheeler 1994) and transmit in a earth-relative context is extremely important for down stream applications of the data. A combination

  15. Development of an electronically tunable ultra-wideband radar imaging sensor and its components 

    E-Print Network [OSTI]

    Han, Jeongwoo

    2006-08-16

    and receiver respectively for timing control. A novel integrated CSH (Coupled-Slotline Hybrid)sampling mixer has been developed along with the design of the strobe pulse generator appropriate for the impulse radar system. The integrated sampling mixer has...

  16. Understanding the Signal Structure in DVB-T Signals for Passive Radar Detection

    E-Print Network [OSTI]

    Nehorai, Arye

    Audio Broadcast (DAB), Digital Video Broadcast (DVB), FM radio, cellphone base-stations, and various attractive opportunity for radar. Digital television transmitters offer a powerful, well-defined signal

  17. Establishing the sensitivity of Synthetic Aperture Radar to above-ground biomass in wooded savannas 

    E-Print Network [OSTI]

    Viergever, Karin Marijke

    2008-01-01

    Radar for biomass estimation has been widely investigated for temperate, boreal and tropical forests, yet tropical savanna woodlands, which generally form non-continuous cover canopies or sparse woodlands, have been largely ...

  18. New target detector based on geometrical perturbation filters for polarimetric Synthetic Aperture Radar (POL-SAR) 

    E-Print Network [OSTI]

    Marino, Armando

    2010-01-01

    Synthetic Aperture Radar (SAR) is an active microwave remote sensing system able to acquire high resolution images of the scattering behaviour of an observed scene. The contribution of SAR polarimetry (POLSAR) in detection ...

  19. Radar-Derived Forecasts of Cloud-to-Ground Lightning Over Houston, Texas 

    E-Print Network [OSTI]

    Mosier, Richard Matthew

    2011-02-22

    -derived Products....26 1.6 Thesis Objectives and Hypothesis...........................................................................27 2. DATA AND METHODOLOGY..................................................................................29 2.1 Radar............................................................................................42 2.4.4 Storm Cell Position Forecast............................................................................44 2.5 Lightning Correlation..............................................................................................45 2.6 CG...

  20. Numerical modelling of high-frequency ground-penetrating radar antennas 

    E-Print Network [OSTI]

    Warren, Craig

    2009-01-01

    Ground-Penetrating Radar (GPR) is a non-destructive electromagnetic investigative tool used in many applications across the fields of engineering and geophysics. The propagation of electromagnetic waves in lossy materials ...

  1. Radar signal pre-processing to suppress surface bounce and multipath

    DOE Patents [OSTI]

    Paglieroni, David W; Mast, Jeffrey E; Beer, N. Reginald

    2013-12-31

    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.

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

    E-Print Network [OSTI]

    Steiger, Scott Michael

    2007-04-25

    Total lightning mapping, along with radar and NLDN cloud-to-ground lightning data, can be used to diagnose the severity of a storm. Analysis of the 13 October 2001 supercell event (Dallas-Fort Worth, Texas), some supercells ...

  3. Ground penetrating radar technique to locate coal mining related features: case studies in Texas 

    E-Print Network [OSTI]

    Save, Neelambari R

    2006-04-12

    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 ...

  4. On the Feasibility of Precisely Measuring the Properties of a Precipitating Cloud with a Weather Radar 

    E-Print Network [OSTI]

    Runnels, R.C.

    1967-01-01

    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 ...

  5. Stratocumulus Liquid Water Content from Dual-Wavelength Radar ROBIN J. HOGAN

    E-Print Network [OSTI]

    Hogan, Robin

    global cov- erage. By reflecting most of the incoming solar radiation back to space and yet emitting et al. 1984; Slingo 1990). The potential of cloud radar to measure stratocumu- lus has been

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

    E-Print Network [OSTI]

    Henderson, Rodney Stuart

    1979-01-01

    DIGITAL METEOROLOGICAL RADAR DATA COMPARED WITH DIGITAL INFRARED DATA FROM A GEOSTATIONARY METEOROLOGICAL SATELLITE A Thesis by RODNEY STUART HENDFRSON Submitted to the Graduate College of Texas A&M University in partial fulfillment... of the requirement for the degree of MASTER OF SCIFNCE May I979 Ma jor Subject: Meteorology DIGITAL METEOROLOGICAL RADAR DATA COMPARED WITH DIGITAL INFRARED DATA FROM A GEOSTATIONAFY METEOROLOGICAL SATELLITE A Thesis by RODNEY STUART HENDERSON Approved...

  7. Mesoscale divergence, vorticity, and vertical motion compared to radar and rainfall patterns 

    E-Print Network [OSTI]

    Withers, Donald Mead

    1971-01-01

    !e degree of PIASTER OF SCIENCE August 1971 Major Subject: PJeteorology MESOSCALE DIVERGENCE& VORTICITY& AND VERTICAL MOTION COMPARED TO RADAR AND RAINI'ALL PATTERNS A Thesis by DONALD MEAD NITHERS Approved as to style and content by: 88.... ( (Chairman of Committee) (Member) (Head of Depa ent) (Member) August 1971 ASS TRACT Mesoscale Divergence, Vorticity, and Vertica] Motion Compared to Radar and Rainfall Patterns. (August 1971) Donald Mead Nithers, B. S. , University of Oklahoma...

  8. The Status of the ACRF Millimeter Wave Cloud Radars (MMCRs), the Path Forward for Future MMCR Upgrades, the Concept of 3D Volume Imaging Radar and the UAV Radar

    SciTech Connect (OSTI)

    P Kollias; MA Miller; KB Widener; RT Marchand; TP Ackerman

    2005-12-30

    The United States (U.S.) Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility (ACRF) operates millimeter wavelength cloud radars (MMCRs) in several climatological regimes. The MMCRs, are the primary observing tool for quantifying the properties of nearly all radiatively important clouds over the ACRF sites. The first MMCR was installed at the ACRF Southern Great Plains (SGP) site nine years ago and its original design can be traced to the early 90s. Since then, several MMCRs have been deployed at the ACRF sites, while no significant hardware upgrades have been performed. Recently, a two-stage upgrade (first C-40 Digital Signal Processors [DSP]-based, and later the PC-Integrated Radar AcQuisition System [PIRAQ-III] digital receiver) of the MMCR signal-processing units was completed. Our future MMCR related goals are: 1) to have a cloud radar system that continues to have high reliability and uptime and 2) to suggest potential improvements that will address increased sensitivity needs, superior sampling and low cost maintenance of the MMCRs. The Traveling Wave Tube (TWT) technology, the frequency (35-GHz), the radio frequency (RF) layout, antenna, the calibration and radar control procedure and the environmental enclosure of the MMCR remain assets for our ability to detect the profile of hydrometeors at all heights in the troposphere at the ACRF sites.

  9. Correcting second-order contamination in low-resolution spectra

    E-Print Network [OSTI]

    V. Stanishev

    2007-05-23

    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.

  10. Noise in Disordered Systems: Higher Order Spectra in Avalanche Models

    E-Print Network [OSTI]

    Amit P. Mehta; Karin A. Dahmen; M. W. Weissman; Tim Wotherspoon

    2005-01-26

    We present a novel analytic calculation of the Haar power spectra, and various higher order spectra, of mean field avalanche models. We also compute these spectra from a simulation of the zero-temperature mean field RFIM and infinite range RFIM model for $d = 3$. We compare the results and obtain novel exponents.

  11. Nuclear reactor fissile isotopes antineutrino spectra

    E-Print Network [OSTI]

    V. Sinev

    2012-07-30

    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.

  12. Probing nuclear expansion dynamics with $?^-/?^+$-spectra

    E-Print Network [OSTI]

    S. Teis; W. Cassing; M. Effenberger; A. Hombach; U. Mosel; Gy. Wolf

    1997-01-28

    We study the dynamics of charged pions in the nuclear medium via the ratio of differential $\\pi^-$- and $\\pi^+$-spectra in a coupled-channel BUU (CBUU) approach. The relative energy shift of the charged pions is found to correlate with the pion freeze-out time in nucleus-nucleus collisions as well as with the impact parameter of the heavy-ion reaction. Furthermore, the long-range Coulomb force provides a 'clock' for the expansion of the hot nuclear system. Detailed comparisons with experimental data for $Au + Au$ at 1 GeV/A and $Ni + Ni$ at 2.0 GeV/A are presented.

  13. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page| Open Energy Information Serbia-Enhancing CapacityVectren) Jump to: navigation,SouthwoodJump to:NewSpecialSpectra Nova

  14. 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 on Google Bookmark EERE: Alternative Fuels Data Center Home Page| Open Energy Information Serbia-Enhancing CapacityVectren) Jump to: navigation,SouthwoodJump to:NewSpecialSpectra

  15. E-LETTER Earth Planets Space, 65, e5e8, 2013 Doppler shift and broadening in solar wind turbulence

    E-Print Network [OSTI]

    and broadening using magnetic field data in solar wind turbulence. A model of the energy spectrum is constructedE-LETTER Earth Planets Space, 65, e5­e8, 2013 Doppler shift and broadening in solar wind turbulence extraterrestrische Physik, Technische Universit¨at Braunschweig, Mendelssohnstr. 3, D-38106, Germany 3Max

  16. Nebular spectra of pair-instability supernovae

    E-Print Network [OSTI]

    Jerkstrand, A; Heger, A

    2015-01-01

    If very massive stars (M >~ 100 Msun) can form and avoid too strong mass loss during their evolution, they are predicted to explode as pair-instability supernovae (PISNe). One critical test for candidate events is whether their nucleosynthesis yields and internal ejecta structure, being revealed through nebular-phase spectra at t >~ 1 yr, match those of model predictions. Here we compute theoretical spectra based on model PISN ejecta at 1-3 years post-explosion to allow quantitative comparison with observations. The high column densities of PISNe lead to complete gamma-ray trapping for t >~ 2 years which, combined with fulfilled conditions of steady state, leads to bolometric supernova luminosities matching the 56Co decay. Most of the gamma-rays are absorbed by the deep-lying iron and silicon/sulphur layers. The ionization balance shows a predominantly neutral gas state, which leads to emission lines of Fe I, Si I, and S I. For low-mass PISNe the metal core expands slowly enough to produce a forest of distinc...

  17. Analysis of Doppler Lidar Data Acquired During the Pentagon Shield Field Campaign

    SciTech Connect (OSTI)

    Newsom, Rob K. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2011-04-14

    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.

  18. Accurate determination of the Boltzmann constant by Doppler spectroscopy: Towards a new definition of the kelvin

    E-Print Network [OSTI]

    Darquié, Benoît; Sow, Papa Lat Tabara; Lemarchand, Cyril; Triki, Meriam; Tokunaga, Sean; Bordé, Christian J; Chardonnet, Christian; Daussy, Christophe

    2015-01-01

    Accurate molecular spectroscopy in the mid-infrared region allows precision measurements of fundamental constants. For instance, measuring the linewidth of an isolated Doppler-broadened absorption line of ammonia around 10 $\\mu$m enables a determination of the Boltzmann constant k B. We report on our latest measurements. By fitting this lineshape to several models which include Dicke narrowing or speed-dependent collisional effects, we find that a determination of k B with an uncertainty of a few ppm is reachable. This is comparable to the best current uncertainty obtained using acoustic methods and would make a significant contribution to any new value of k B determined by the CODATA. Furthermore, having multiple independent measurements at these accuracies opens the possibility of defining the kelvin by fixing k B, an exciting prospect considering the upcoming redefinition of the International System of Units.

  19. IN-PLANE MODAL TESTING OF A FREE ISOTROPIC PLATE USING LASER DOPPLER VIBROMETER MEASUREMENTS

    SciTech Connect (OSTI)

    Batista, F. B.; Fabro, A. T.; Coser, L. F.; Arruda, J. R. F. [Faculty of Mechanical Engineering, University of Campinas, Campinas, SP 13083-970 (Brazil); Albuquerque, E. L. [Technological Faculty, University of Brasilia, Brasilia, DF 70910-900 (Brazil)

    2010-05-28

    In this work an experimental procedure is proposed to obtain the lowest free in-plane vibration modes of an aluminum plate. Responses are measured along two longitudinal directions on the plate surface at selected points by an out-of-plane laser Doppler vibrometer set up to measure in-plane vibrations. Excitation is made at one specific point of the plate edge using a light impact hammer. The plate is supported by silicone spheres to simulate the free edge boundary conditions and ensure a stable stationary position in order to keep the laser focus distance. Numerical finite element simulations are carried out to compute the in-plane modes and frequencies in order to compare them with the corresponding experimental results. The identified experimental modes agree very well with the numerical predictions. The smooth in-plane modes can be used to identify the plate material constitutive model parameters using existing methods proposed elsewhere by the authors.

  20. Lynx: A High-Resolution Synthetic Aperture Radar

    SciTech Connect (OSTI)

    Doerry, A.W.; Hensley, W.H.; Pace, F.; Stence, J.; Tsunoda, S.I.; Walker, B.C.; Woodring, M.

    1999-03-08

    Lynx is a high resolution, synthetic aperture radar (SAR) that has been designed and built by Sandia National Laboratories in collaboration with General Atomics (GA). Although Lynx may be operated on a wide variety of manned and unmanned platforms, it is primarily intended to be fielded on unmanned aerial vehicles. In particular, it may be operated on the Predator, I-GNAT, or Prowler II platforms manufactured by GA Aeronautical Systems, Inc. The Lynx production weight is less than 120 lb. and has a slant range of 30 km (in 4 mm/hr rain). It has operator selectable resolution and is capable of 0.1 m resolution in spotlight mode and 0.3 m resolution in stripmap mode. In ground moving target indicator mode, the minimum detectable velocity is 6 knots with a minimum target cross-section of 10 dBsm. In coherent change detection mode, Lynx makes registered, complex image comparisons either of 0.1 m resolution (minimum) spotlight images or of 0.3 m resolution (minimum) strip images. The Lynx user interface features a view manager that allows it to pan and zoom like a video camera. Lynx was developed under corporate finding from GA and will be manufactured by GA for both military and commercial applications. The Lynx system architecture will be presented and some of its unique features will be described. Imagery at the finest resolutions in both spotlight and strip modes have been obtained and will also be presented.

  1. CMB aberration and Doppler effects as a source of hemispherical asymmetries

    SciTech Connect (OSTI)

    Notari, Alessio [Departament de Física Fondamental i Institut de Ciéncies del Cosmos, Universitat de Barcelona, Martí i Franqués 1, Barcelona, E-08028 (Spain); Quartin, Miguel [Instituto de Física, Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos 149, Rio de Janeiro, 21941-972 (Brazil); Catena, Riccardo, E-mail: notari@ffn.ub.es, E-mail: mquartin@if.ufrj.br, E-mail: riccardo.catena@theorie.physik.uni-goettingen.de [Institut für Theoretische Physik, Friedrich-Hund-Platz 1, Göttingen, 37077 (Germany)

    2014-03-01

    Our peculiar motion with respect to the CMB rest frame represents a preferred direction in the observed CMB sky since it induces an apparent deflection of the observed CMB photons (aberration) and a shift in their frequency (Doppler). Both effects distort the multipoles a{sub ?m}'s at all ?'s. Such effects are real as it has been recently measured for the first time by Planck according to what was forecast in some recent papers. However, the common lore when estimating a power spectrum from CMB is to consider that Doppler affects only the ? = 1 multipole, neglecting any other corrections. In this work we use simulations of the CMB sky in a boosted frame with a peculiar velocity ??v/c = 1.23 × 10{sup ?3} in order to assess the impact of such effect on power spectrum estimations in different regions of the sky. We show that the boost induces a north-south asymmetry in the power spectrum which is highly significant and non-negligible, of about (0.58±0.10)% for half-sky cuts when going up to ? ? 2500. We suggest that these effects are relevant and may account for some of the north-south asymmetries seen in the Planck data, being especially important at small scales. Finally we analyze the particular case of the ACT experiment, which observed only a small fraction of the sky and show that it suffers a bias of about 1% on the power spectrum and of similar size on some cosmological parameters: for example the position of the peaks shifts by 0.5% and the overall amplitude of the spectrum is about 0.4% lower than a full-sky case.

  2. UV spectra, bombs, and the solar atmosphere

    E-Print Network [OSTI]

    Judge, Philip G

    2015-01-01

    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.

  3. Chemical and isotopic determination from complex spectra

    SciTech Connect (OSTI)

    Zardecki, A.; Strittmatter, R.B.

    1995-07-01

    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.

  4. Automatic position calculating imaging radar with low-cost synthetic aperture sensor for imaging layered media

    DOE Patents [OSTI]

    Mast, Jeffrey E. (Livermore, CA)

    1998-01-01

    An imaging system for analyzing structures comprises a radar transmitter and receiver connected to a timing mechanism that allows a radar echo sample to be taken at a variety of delay times for each radar pulse transmission. The radar transmitter and receiver are coupled to a position determining system that provides the x,y position on a surface for each group of samples measured for a volume from the surface. The radar transmitter and receiver are moved about the surface to collect such groups of measurements from a variety of x,y positions. Return signal amplitudes represent the relative reflectivity of objects within the volume and the delay in receiving each signal echo represents the depth at which the object lays in the volume and the propagation speeds of the intervening material layers. Successively deeper z-planes are backward propagated from one layer to the next with an adjustment for variations in the expected propagation velocities of the material layers that lie between adjacent z-planes.

  5. Automatic position calculating imaging radar with low-cost synthetic aperture sensor for imaging layered media

    DOE Patents [OSTI]

    Mast, J.E.

    1998-08-18

    An imaging system for analyzing structures comprises a radar transmitter and receiver connected to a timing mechanism that allows a radar echo sample to be taken at a variety of delay times for each radar pulse transmission. The radar transmitter and receiver are coupled to a position determining system that provides the x,y position on a surface for each group of samples measured for a volume from the surface. The radar transmitter and receiver are moved about the surface to collect such groups of measurements from a variety of x,y positions. Return signal amplitudes represent the relative reflectivity of objects within the volume and the delay in receiving each signal echo represents the depth at which the object lays in the volume and the propagation speeds of the intervening material layers. Successively deeper z-planes are backward propagated from one layer to the next with an adjustment for variations in the expected propagation velocities of the material layers that lie between adjacent z-planes. 10 figs.

  6. 6 Radar wind profiler and radiosonde wind vectors during MILAGRO This supplemental section shows vertical profiles of horizontal wind vectors from the radar wind profilers at T0, T1

    E-Print Network [OSTI]

    Meskhidze, Nicholas

    6 Radar wind profiler and radiosonde wind vectors during MILAGRO This supplemental section shows vertical profiles of horizontal wind vectors from the radar wind profilers at T0, T1 and T2 along with radiosonde wind vectors at MEX and T1 (labelled as T1R). An arrow pointing up shows winds blowing towards

  7. Performance analysis and algorithm enhancement of feature-aided-tracker (FAT) simulation software using 1-D high-range-resolution (HRR) radar signature profiles

    E-Print Network [OSTI]

    O'Brien, Michael J. (Michael James), 1981-

    2005-01-01

    The current Lincoln Laboratory (LL) MATLAB Feature-Aided-Tracker (FAT) software was adjusted and appended to provide a robust ground-target radar tracking simulation tool. It utilizes algorithms from the LL UAV Radar Moving ...

  8. Active control of passive acoustic fields: Passive synthetic apertureDoppler beamforming with data from an autonomous

    E-Print Network [OSTI]

    Smith, Jerome A.

    Active control of passive acoustic fields: Passive synthetic apertureÕDoppler beamforming with data without the use of an active source under control by the receiver. In this passive case, the properties interest. Passive synthetic aperture sonar has no ana- log in the radar community. In contrast

  9. Real time assimilation of HF radar currents into a coastal ocean model

    E-Print Network [OSTI]

    Breivik, Øyvind; 10.1016/S0924-7963(01)00002-1

    2012-01-01

    A real time assimilation and forecasting system for coastal currents is presented. The purpose of the system is to deliver current analyses and forecasts based on assimilation of high frequency radar surface current measurements. The local Vessel Traffic Service monitoring the ship traffic to two oil terminals on the coast of Norway received the analyses and forecasts in real time. A new assimilation method based on optimal interpolation is presented where spatial covariances derived from an ocean model are used instead of simplified mathematical formulations. An array of high frequency radar antennae provide the current measurements. A suite of nested ocean models comprise the model system. The observing system is found to yield good analyses and short range forecasts that are significantly improved compared to a model twin without assimilation. The system is fast; analysis and six hour forecasts are ready at the Vessel Traffic Service 45 minutes after acquisition of radar measurements.

  10. Telescope Array Radar (TARA) Observatory for Ultra-High Energy Cosmic Rays

    SciTech Connect (OSTI)

    Abbasi, R.; Takai, H.; Allen, C.; Beard, L.; Belz, J.; Besson, D.; Byrne, M.; Abou Bakr Othman, M.; Farhang-Boroujeny, B.; Gardner, A.; Gillman, W.H.; Hanlon, W.; Hanson, J.; Jayanthmurthy, C.; Kunwar, S.; Larson, S. L.; Myers, I.; Prohira, S.; Ratzlaff, K.; Sokolsky, P.; Thomson, G. B.; Von Maluski, D.

    2014-08-19

    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.

  11. 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

    2014-08-19

    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

  12. Radar imagery interpretation to assess the hydrocarbon potential of four sites in the Philippines

    SciTech Connect (OSTI)

    Not Available

    1988-11-17

    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.

  13. Executive summary: Radar imagery interpretation to assess the hydrocarbon potential of four sites in the Phillipines

    SciTech Connect (OSTI)

    Not Available

    1988-11-17

    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. 9 refs., 9 figs., 3 tabs.

  14. Radar imagery interpretation to provide information about several geothermal sites in the Philippines

    SciTech Connect (OSTI)

    Not Available

    1988-11-17

    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 nation-wide 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 geothermal and petroleum 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. 7 refs., 20 figs., 2 tabs.

  15. Telescope Array Radar (TARA) Observatory for Ultra-High Energy Cosmic Rays

    SciTech Connect (OSTI)

    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)

    2014-12-01

    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.

  16. Short range, ultra-wideband radar with high resolution swept range gate

    DOE Patents [OSTI]

    McEwan, T.E.

    1998-05-26

    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.

  17. Short range, ultra-wideband radar with high resolution swept range gate

    DOE Patents [OSTI]

    McEwan, Thomas E. (Livermore, CA)

    1998-05-26

    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.

  18. 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

  19. 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)]

    Karen Johnson; Nitin Bharadwaj

    1990-01-01

    Millimeter Wave Cloud Radar (MMCR), replaces mmcrcal and mmcrmoments datastreams following C-40 processor upgrade of 2003.09.09

  20. IEEE JOURNAL OF OCEANIC ENGINEERING, VOL. 27, NO. 2, APRIL 2002 155 Very High-Frequency Radar Mapping of

    E-Print Network [OSTI]

    Miami, University of

    Weisberg, P. Edgar An, Alexander Soloviev, and Mark Luther Abstract--An ocean surface current radar (OSCR coastal ocean currents over a 7.5 km 8 km domain with a horizontal resolution of 250 m at 700 grid points at the SFOMC. Index Terms--ADCP, coastal ocean circulation, current profiles, surface currents, VHF radar

  1. Evaluation of Ice Water Content Retrievals from Cloud Radar Reflectivity and Temperature Using a Large Airborne In Situ Microphysical Database

    E-Print Network [OSTI]

    Protat, Alain

    Evaluation of Ice Water Content Retrievals from Cloud Radar Reflectivity and Temperature Using the performances of the proposed ice water content (IWC)­radar reflectivity Z and IWC­Z­temperature T relationships produce a very different ice water path, spanning an order of magnitude (Stephens et al. 2002). Clouds

  2. The Long Wavelength Array (LWA): A Large HF/VHF Array for Solar Physics, Ionospheric Science, and Solar Radar

    E-Print Network [OSTI]

    Ellingson, Steven W.

    be an excellent receiver for solar radar, potentially demonstrating accurate geomagnetic storm prediction fromThe Long Wavelength Array (LWA): A Large HF/VHF Array for Solar Physics, Ionospheric Science, and Solar Radar A Ground-Based Instrument Paper for the 2010 NRC Decadal Survey of Solar and Space

  3. 864 IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING, VOL. 36, NO. 3, MAY 1998 Radar Measurements of Snow

    E-Print Network [OSTI]

    Sarabandi, Kamal

    of Snow: Experiment and Analysis John R. Kendra, Member, IEEE, Kamal Sarabandi, Senior Member, IEEE conducted to improve our understanding of radar backscatter from snow-covered ground surfaces. The first experiment involves radar backscatter measurements at C- and X-band of artificial snow of varying depths

  4. On the vertical profile of stratus liquid water flux using a millimeter cloud radar Shelby Frisch Paquita Zuidema Chris Fairall

    E-Print Network [OSTI]

    Zuidema, Paquita

    that calculations of the implied cloud-top entrainment were sensitive to the liquid water flux term of the radar reflectivity is shown graphically below. We estimate an error in the liquid water fluxOn the vertical profile of stratus liquid water flux using a millimeter cloud radar Shelby Frisch

  5. A SYNERGY OF MICROWAVE CLOUD TOMOGRAPHY AND SCANNING RADAR: MOVING TOWARD A 3D VIEW OF CLOUDS

    E-Print Network [OSTI]

    A SYNERGY OF MICROWAVE CLOUD TOMOGRAPHY AND SCANNING RADAR: MOVING TOWARD A 3D VIEW OF CLOUDS D complementary techniques, i.e., cloud microwave tomography and scanning radar, to retrieve 3D cloud properties the sixth moment of cloud droplets, while cloud tomography, by remotely probing cloud microwave emission

  6. The Shuttle Radar Topography Mission Farr, Tom G., Paul A. Rosen, Edward Caro, Robert Crippen, Riley Duren, Scott Hensley, Michael

    E-Print Network [OSTI]

    1 The Shuttle Radar Topography Mission Farr, Tom G., Paul A. Rosen, Edward Caro, Robert Crippen Barbara, CA Douglas Alsdorf Ohio State University Columbus, OH The Shuttle Radar Topography Mission. The Need for Global Topography At the foundation of modern geosciences, quite literally, is knowledge

  7. Radar/Lidar Sensor Fusion for Car-Following on Highways Daniel Gohring, Miao Wang, Michael Schnurmacher, Tinosch Ganjineh

    E-Print Network [OSTI]

    Rojas, Raúl

    Radar/Lidar Sensor Fusion for Car-Following on Highways Daniel G¨ohring, Miao Wang, Michael Schn-time algorithm which enables an autonomous car to comfortably follow other cars at various speeds while keeping that depends on the position as well as the velocity of the followed car. Radar sensors provide reliable

  8. Cross polar cap potentials measured with Super Dual Auroral Radar Network during quasi-steady solar wind and interplanetary magnetic

    E-Print Network [OSTI]

    Shepherd, Simon

    Cross polar cap potentials measured with Super Dual Auroral Radar Network during quasi-steady solar, or cross polar cap potential, ÈPC. Periods are chosen to satisfy the criteria that (1) the solar wind-based radars to functional forms of the electrostatic potential [Ruohoniemi and Baker, 1998]; and global mag

  9. Observation of fast-ion Doppler-shifted cyclotron resonance with shear Alfvn waves

    E-Print Network [OSTI]

    Heidbrink, William W.

    are also found when a hot plasma merges with a colder background plasma, as when the solar wind collides the dominant components of the electromagnetic wave spectra in the solar- terrestrial plasma environments and, consequently, can play crucial roles in mechanisms from solar corona heating to acceleration of charged

  10. 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; Keck, Chris; Sullivan, Jonathan; Brigada, David; Parker, Lorri; Younger, Richard; Biddle, Jason

    2014-10-01

    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.

  11. Measuring fast electron spectra and laser absorption in relativistic...

    Office of Scientific and Technical Information (OSTI)

    Measuring fast electron spectra and laser absorption in relativistic laser-solid interactions using differential bremsstrahlung photon detectors Citation Details In-Document Search...

  12. Approaches for Developing Uniform Hazard Spectra at Critical...

    Office of Environmental Management (EM)

    Hazard Spectra at Critical Facilities Preliminary Assessment of the Impact of 2014 Seismic Study on WTP Design Evaluation of the SRS Seismic Hazard Considering the EPRI 2013...

  13. A multi-sensor physically based weather/non-weather radar echo classifier using polarimetric and environmental data in a real-time

    E-Print Network [OSTI]

    Lakshmanan, Valliappa

    A multi-sensor physically based weather/non-weather radar echo classifier using polarimetric-hydrometeors. In this work, a multi-sensor physically based algorithm is designed to classify weather/non-weather radar, 2004). Manual quality control (QC) of radar reflectivity data has been practiced at commercial weather

  14. MeteoSvizzera, 6605 Locarno, Switzerland email: Katja.Friedrich@meteoswiss.ch http://www.meteoswiss.ch P11B8: Effects of Radar Beam Shielding on Rainfall

    E-Print Network [OSTI]

    ://www.meteoswiss.ch P11B8: Effects of Radar Beam Shielding on Rainfall Estimation for Polarimetric C-band Radar Katja In the case of radar beam shielding, a weaker transmitted signal reaches precipitation at further ranges 1998 with: Complete shielding in Partial shielding in No shielding to the South 1 2 3 2 4 Height

  15. The use of ground-penetrating radar with a cooperative target

    E-Print Network [OSTI]

    Allen, Christopher Thomas; Shi, K.; Plumb, R. G.

    1998-09-01

    trenchless technology involving the installation of pipes having an internal diameter too small for man entry with steering via remote control. In this operation, the detection and avoidance of existing underground structures (pipelines and cables... into the indoor ground-penetrating radar test tank (the sand pit) at the Radar Systems and Remote Sensing Labo- ratory, The University of Kansas, Lawrence [6]. This test tank is a reinforced concrete enclosure measuring approximately 3.6 5.2 m and is 1.8 m deep...

  16. Comparative analyses for the prediction of streamflow from small watershed by use of digitized radar data 

    E-Print Network [OSTI]

    Braatz, Dean Thomas

    1973-01-01

    , 1972. 6. CONCLUSIONS AND RECOMMENDATIONS. 57 61 81 92 95 a. Conclusions. 95 b. Recommendations 97 APPENDIX A. . . 99 LIST OF REFERENCES. 101 VITA. 106 LIST OF TABLES Table Page Streamflow statistics for the Delaware Creek and Little... relationship of Miller (1972) for the sub-basins of the Delaware Creek and the Little Washita River. 52 Basin average of actual rainfall compared to 0-deg and tilt, digital-radar, estimated rainfall for May 31, 1971, for the periods when radar data were...

  17. R&D Argon Detector at Ash River (RADAR) - Letter of Intent

    E-Print Network [OSTI]

    Adamson, P; Guzowski, P; Habig, A; Holin, A; Huang, J; Kordosky, M; Kreymer, A E; Lang, K; Marshak, M; Mehdiyev, R; Miller, W H; Naples, D; Nichol, R J; Patterson, R B; Sousa, A; Thomas, J; Whitehead, L H

    2013-01-01

    The RADAR project proposes to deploy a 6 kton liquid argon TPC at the NOvA Far Detector building in Ash River, Minnesota, and expose it to the NuMI beam during NOvA running. It will significantly add to the physics capabilities of the NOvA program while providing LBNE with an R&D program based on full-scale TPC module assemblies. RADAR offers an excellent opportunity to improve the full Homestake LBNE project in physics reach, timeline, costs, and fostering international partnership. The anticipated duration of the project's construction is 5 years, with running happening between 2018 and 2023.

  18. Performance limits for exo-clutter Ground Moving Target Indicator (GMTI) radar.

    SciTech Connect (OSTI)

    Doerry, Armin Walter

    2010-09-01

    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'.

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

    E-Print Network [OSTI]

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

    2002-02-01

    . Previously, ground-based and spaceborne radar backscatter have been reconciled by defining an effective range 82 10111 17 82 115 431482, where 82 115 is the antenna range to the snow surface, as illustrated in Fig. 1 [1], [2]. The additional term 1482... is an added range accounting for radar penetration into the scattering medium, which can be significant. The relative size of 1482 is directly related to firn physical properties and is determined experimentally such that 27 48 does not vary with antenna...

  20. On the radar cross section (RCS) prediction of vehicles moving on the ground

    SciTech Connect (OSTI)

    Sabihi, Ahmad

    2014-12-10

    As readers should be aware, Radar Cross Section depends on the factors such as: Wave frequency and polarization, Target dimension, angle of ray incidence, Target’s material and covering, Type of radar system as monostatic or bistatic, space in which contains target and propagating waves, and etc. Having moved or stationed in vehicles can be effective in RCS values. Here, we investigate effective factors in RCS of moving targets on the ground or sea. Image theory in electromagnetic applies to be taken into account RCS of a target over the ground or sea.

  1. Universality of Vibrational Spectra of Globular Proteins

    E-Print Network [OSTI]

    Na, Hyuntae; ben-Avraham, Daniel

    2015-01-01

    It is shown that the density of modes of the vibrational spectrum of globular proteins is universal, i.e., regardless of the protein in question it closely follows one universal curve. The present study, including 135 proteins analyzed with a full atomic empirical potential (CHARMM22) and using the full complement of all atoms Cartesian degrees of freedom, goes far beyond confirming previous claims of universality, finding that universality holds even in the high-frequency range (300- 4000 1/cm), where peaks and turns in the density of states are faithfully reproduced from one protein to the next. We also characterize fluctuations of the spectral density from the average, paving the way to a meaningful discussion of rare, unusual spectra and the structural reasons for the deviations in such "outlier" proteins. Since the method used for the derivation of the vibrational modes (potential energy formulation, set of degrees of freedom employed, etc.) has a dramatic effect on the spectral density, another signific...

  2. Hybrid Estimation of CMB Polarization Power Spectra

    E-Print Network [OSTI]

    G. Efstathiou

    2006-01-05

    This paper generalises the hybrid power spectrum estimator developed in Efstathiou (2004a) to the estimation of polarization power spectra of the cosmic microwave background radiation. The hybrid power spectrum estimator is unbiased and we show that it is close to optimal at all multipoles, provided the pixel noise satisfies certain reasonable constraints. Furthermore, the hybrid estimator is computationally fast and can easily be incorporated in a Monte-Carlo chain for Planck-sized data sets. Simple formulae are given for the covariance matrices, including instrumental noise, and these are tested extensively against numerical simulations. We compare the behaviour of simple pseudo-Cell estimates with maximum likelihood estimates at low multipoles. For realistic sky cuts, maximum likelihood estimates reduce very significantly the mixing of E and B modes. To achieve limits on the scalar-tensor ratio of r<<0.1 from sky maps with realistic sky cuts, maximum likelihood methods, or pseudo-Cell estimators based on unambiguous E and B modes, will be essential.

  3. Inflationary power spectra with quantum holonomy corrections

    SciTech Connect (OSTI)

    Mielczarek, Jakub, E-mail: jakub.mielczarek@uj.edu.pl [Institute of Physics, Jagiellonian University, Reymonta 4, Cracow, 30-059 Poland (Poland)

    2014-03-01

    In this paper we study slow-roll inflation with holonomy corrections from loop quantum cosmology. It was previously shown that, in the Planck epoch, these corrections lead to such effects as singularity avoidance, metric signature change and a state of silence. Here, we consider holonomy corrections affecting the phase of cosmic inflation, which takes place away from the Planck epoch. Both tensor and scalar power spectra of primordial inflationary perturbations are computed up to the first order in slow-roll parameters and V/?{sub c}, where V is a potential of the scalar field and ?{sub c} is a critical energy density (expected to be of the order of the Planck energy density). Possible normalizations of modes at short scales are discussed. In case the normalization is performed with use of the Wronskian condition applied to adiabatic vacuum, the tensor and scalar spectral indices are not quantum corrected in the leading order. However, by choosing an alternative method of normalization one can obtain quantum corrections in the leading order. Furthermore, we show that the holonomy-corrected equations of motion for tensor and scalar modes can be derived based on effective background metrics. This allows us to show that the classical Wronskian normalization condition is well defined for the cosmological perturbations with holonomy corrections.

  4. Laser-Doppler acoustic probing of granular media with in-depth property gradient and varying pore pressures

    SciTech Connect (OSTI)

    Bodet, L.; Dhemaied, A.; Mourgues, R.; Tournat, V.; Rejiba, F.

    2012-05-24

    Non-contacting ultrasonic techniques recently proved to be efficient in the physical modeling of seismic-wave propagation at various application scales, as for instance in the context of geological analogue and seismic modeling. An innovative experimental set-up is proposed here to perform laser-Doppler acoustic probing of unconsolidated granular media with varying pore pressures. The preliminary experiments presented here provide reproducible results and exploitable data, thus validating both the proposed medium preparation and pressure gradient generation procedure.

  5. Dynamic Rotor Deformation and Vibration Monitoring Using a Non-Incremental Laser Doppler Distance Sensor

    SciTech Connect (OSTI)

    Pfister, Thorsten; Guenther, Philipp; Dreier, Florian; Czarske, Juergen

    2010-05-28

    Monitoring rotor deformations and vibrations dynamically is an important task for improving the safety and the lifetime as well as the energy efficiency of motors and turbo machines. However, due to the high rotor speed encountered in particular at turbo machines, this requires concurrently a high measurement rate and high accuracy, which can not be fulfilled by most commercially available sensors. To solve this problem, we developed a non-incremental laser Doppler distance sensor (LDDS), which is able to measure simultaneously the in-plane velocity and the out-of-plane position of moving rough solid objects with micrometer precision. In addition, this sensor concurrently offers a high temporal resolution in the microsecond range, because its position uncertainty is in principle independent of the object velocity in contrast to conventional distance sensors, which is a unique feature of the LDDS. Consequently, this novel sensor enables precise and dynamic in-process deformation and vibration measurements on rotating objects, such as turbo machine rotors, even at very high speed. In order to evidence the capability of the LDDS, measurements of rotor deformations (radial expansion), vibrations and wobbling motions are presented at up to 50,000 rpm rotor speed.

  6. Laser Doppler field sensor for high resolution flow velocity imaging without camera

    SciTech Connect (OSTI)

    Voigt, Andreas; Bayer, Christian; Shirai, Katsuaki; Buettner, Lars; Czarske, Juergen

    2008-09-20

    In this paper we present a laser sensor for highly spatially resolved flow imaging without using a camera. The sensor is an extension of the principle of laser Doppler anemometry (LDA). Instead of a parallel fringe system, diverging and converging fringes are employed. This method facilitates the determination of the tracer particle position within the measurement volume and leads to an increased spatial and velocity resolution compared to conventional LDA. Using a total number of four fringe systems the flow is resolved in two spatial dimensions and the orthogonal velocity component. Since no camera is used, the resolution of the sensor is not influenced by pixel size effects. A spatial resolution of 4 {mu}m in the x direction and 16 {mu}m in the y direction and a relative velocity resolution of 1x10{sup -3} have been demonstrated up to now. As a first application we present the velocity measurement of an injection nozzle flow. The sensor is also highly suitable for applications in nano- and microfluidics, e.g., for the measurement of flow rates.

  7. Range, Doppler and astrometric observables computed from Time Transfer Functions: a survey

    E-Print Network [OSTI]

    A. Hees; S. Bertone; C. Le Poncin-Lafitte; P. Teyssandier

    2014-12-10

    Determining range, Doppler and astrometric observables is of crucial interest for modelling and analyzing space observations. We recall how these observables can be computed when the travel time of a light ray is known as a function of the positions of the emitter and the receiver for a given instant of reception (or emission). For a long time, such a function--called a reception (or emission) time transfer function--has been almost exclusively calculated by integrating the null geodesic equations describing the light rays. However, other methods avoiding such an integration have been considerably developped in the last twelve years. We give a survey of the analytical results obtained with these new methods up to the third order in the gravitational constant $G$ for a mass monopole. We briefly discuss the case of quasi-conjunctions, where higher-order enhanced terms must be taken into account for correctly calculating the effects. We summarize the results obtained at the first order in $G$ when the multipole structure and the motion of an axisymmetric body is taken into account. We present some applications to on-going or future missions like Gaia and Juno. We give a short review of the recent works devoted to the numerical estimates of the time transfer functions and their derivatives.

  8. Pulsed UCN production using a Doppler shifter at J-PARC

    E-Print Network [OSTI]

    Imajo, S; Kitaguchi, M; Iwashia, Y; Yamada, N L; Hino, M; Oda, T; Ino, T; Shimizu, H M; Yamashita, S; Katayama, R

    2015-01-01

    We have constructed a Doppler-shifter-type pulsed ultra-cold neutron (UCN) source at the Materials and Life Science Experiment Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC). Very-cold neutrons (VCNs) with 136-$\\mathrm{m/s}$ velocity in a neutron beam supplied by a pulsed neutron source are decelerated by reflection on a m=10 wide-band multilayer mirror, yielding pulsed UCN. The mirror is fixed to the tip of a 2,000-rpm rotating arm moving with 68-$\\mathrm{m/s}$ velocity in the same direction as the VCN. The repetition frequency of the pulsed UCN is $8.33~\\mathrm{Hz}$ and the time width of the pulse at production is $4.4~\\mathrm{ms}$. In order to increase the UCN flux, a supermirror guide, wide-band monochromatic mirrors, focus guides, and a UCN extraction guide have been newly installed or improved. The count rate of the output neutrons with longitudinal wavelengths longer than $58~\\mathrm{nm}$ is $1.6 \\times 10^{2}~\\mathrm{cps}$, while that of the true UCNs is $80~\\mathrm{cps}$ at ...

  9. Pulsed UCN production using a Doppler shifter at J-PARC

    E-Print Network [OSTI]

    S. Imajo; K. Mishima; M. Kitaguchi; Y. Iwashia; N. L. Yamada; M. Hino; T. Oda; T. Ino; H. M. Shimizu; S. Yamashita; R. Katayama

    2015-07-26

    We have constructed a Doppler-shifter-type pulsed ultra-cold neutron (UCN) source at the Materials and Life Science Experiment Facility (MLF) of the Japan Proton Accelerator Research Complex (J-PARC). Very-cold neutrons (VCNs) with 136-$\\mathrm{m/s}$ velocity in a neutron beam supplied by a pulsed neutron source are decelerated by reflection on a m=10 wide-band multilayer mirror, yielding pulsed UCN. The mirror is fixed to the tip of a 2,000-rpm rotating arm moving with 68-$\\mathrm{m/s}$ velocity in the same direction as the VCN. The repetition frequency of the pulsed UCN is $8.33~\\mathrm{Hz}$ and the time width of the pulse at production is $4.4~\\mathrm{ms}$. In order to increase the UCN flux, a supermirror guide, wide-band monochromatic mirrors, focus guides, and a UCN extraction guide have been newly installed or improved. The count rate of the output neutrons with longitudinal wavelengths longer than $58~\\mathrm{nm}$ is $1.6 \\times 10^{2}~\\mathrm{cps}$, while that of the true UCNs is $80~\\mathrm{cps}$ at an equivalent beampower of $1~\\mathrm{MW}$. The spatial density at production is $1.4~\\mathrm{UCN/cm^{3}}$. This new UCN source enables us to research and develop apparatus necessary for the investigation of the neutron electric dipole moment (nEDM).

  10. In-field use of laser Doppler vibrometer on a wind turbine blade

    SciTech Connect (OSTI)

    Rumsey, M.; Hurtado, J.; Hansche, B.

    1998-12-31

    One of our primary goals was to determine how well a laser Doppler vibrometer (LDV) could measure the structural dynamic response of a wind turbine that was parked in the field. We performed a series of preliminary tests in the lab to determine the basic limitations of the LDV for this application. We then instrumented an installed parked horizontal axis wind turbine with accelerometers to determine the natural frequencies, damping, and mode shapes of the wind turbine and rotor as a baseline for the LDV and our other tests. We also wanted to determine if LDV modal information could be obtained from a naturally (wind) excited wind turbine. We compared concurrently obtained accelerometer and LDV data in an attempt to assess the quality of the LDV data. Our test results indicate the LDV can be successfully used in the field environment of an installed wind turbine, but with a few restrictions. We were successful in obtaining modal information from a naturally (wind) excited wind turbine in the field, but the data analysis requires a large number of averaged data sets to obtain reasonable results. An ultimate goal of this continuing project is to develop a technique that will monitor the health of a structure, detect damage, and hopefully predict an impending component failure.

  11. Detonation wave profiles measured in plastic bonded explosives using 1550 nm photon doppler velocimetry (PDV)

    SciTech Connect (OSTI)

    Gustavsen, Richard L [Los Alamos National Laboratory; Bartram, Brian D [Los Alamos National Laboratory; Sanchez, Nathaniel (nate) J [Los Alamos National Laboratory

    2009-01-01

    We present detonation wave profiles measured in two TATB based explosives and two HMX based explosives. Profiles were measured at the interface of the explosive and a Lithium-Fluoride (LiF) window using 1550 nm Photon Doppler Velocimetry (PDV). Planar detonations were produced by impacting the explosive with a projectile launched in a gas-gun. The impact state was varied to produce varied distance to detonation, and therefore varied support of the Taylor wave following the Chapman-Jouget (CJ) or sonic state. Profiles from experiments with different support should be the same between the Von-Neumann (VN) spike and CJ state and different thereafter. Comparison of profiles with differing support, therefore, allows us to estimate reaction zone lengths. For the TATB based explosive, a reaction zone length of {approx} 3.9 mm, 500 ns was measured in EDC-35, and a reaction zone length of {approx} 6.3 mm, 800 ns was measured in PBX 9502 pre-cooled to -55 C. The respective VN spike state was 2.25 {+-} 0.05 km/s in EDC-35 and 2.4 {+-} 0.1 km/s in the cooled PBX 9502. We do not believe we have resolved either the VN spike state (> 2.6 km/s) nor the reaction zone length (<< 50 ns) in the HMX based explosives.

  12. Broadband proton-decoupled proton spectra Andrew J. Pell

    E-Print Network [OSTI]

    Keeler, James

    Broadband proton-decoupled proton spectra Andrew J. Pell , Richard A. E. Edden§ and James Keeler.ac.uk. #12;Abstract We present a new method for recording broadband proton-decoupled proton spectra with ab reduction in sensitivity when com- pared to a conventional proton spectrum. The method is demonstrated

  13. hal00276997, Raman spectra of misoriented bilayer graphene

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    hal­00276997, version 1 ­ 5 May 2008 Raman spectra of misoriented bilayer graphene P. Poncharal 1 spectra from single layer graphene with a bilayer in which the two layers are arbitrarily misoriented to the similarity of the electronic structures of single layer graphene and misoriented bilayer graphene. Another

  14. Infra-red reflectance and emissivity spectra of nanodiamonds

    E-Print Network [OSTI]

    Maturilli, A; Kulakova, I I; Helbert, J

    2012-01-01

    Reflectance and emissivity spectra of nanodiamonds powder were measured in a dedicated setup at temperatures up to 873 K. The spectra are characterised by presence of sharp bands due to surface-bound functional groups. Thermal desorption of oxygen-containing groups lead to corresponding spectral changes. The maximal emissivity of nanodiamond powder reaches 0.985.

  15. Basics of Polar-Format algorithm for processing Synthetic Aperture Radar images.

    SciTech Connect (OSTI)

    Doerry, Armin Walter

    2012-05-01

    The purpose of this report is to provide a background to Synthetic Aperture Radar (SAR) image formation using the Polar Format (PFA) processing algorithm. This is meant to be an aid to those tasked to implement real-time image formation using the Polar Format processing algorithm.

  16. Tracking Atmospheric Ducts Using Radar Clutter: I. Evaporation Duct Tracking Using Kalman Filters

    E-Print Network [OSTI]

    Gerstoft, Peter

    Tracking Atmospheric Ducts Using Radar Clutter: I. Evaporation Duct Tracking Using Kalman Filters 92093­0238, USA Introduction This paper addresses the problem of tracking evaporation ducts in marine-standard electromagnetic propagation due to formation of lower atmospheric sea ducts is a common occurrence in maritime

  17. Tracking Atmospheric Ducts Using Radar Clutter: II. Surface-based Duct Tracking Using Multiple Model

    E-Print Network [OSTI]

    Gerstoft, Peter

    Tracking Atmospheric Ducts Using Radar Clutter: II. Surface-based Duct Tracking Using Multiple variability in tracking surface-based ducts in marine and coastal environments. The method tracks of the problem and evaporation duct tracking has been introduced in [1]. In previous studies, atmospheric

  18. Automatic Calibrations for Improved Quality Assurance of Coastal HF Radar Currents

    E-Print Network [OSTI]

    California at Santa Barbara, University of

    to the public via the U.S. Integrated Ocean Observing System (USIOOS): http://www.ioos.gov/hfradar/. These real Monitoring, Monitoring Harmful Algal Blooms, Fisheries Management, Modeling, Marine Navigation, Ocean Energy. INTRODUCTION Currently, over 130 HF radar units are providing coastal surface current maps to the public via

  19. Seasonal subsidence and rebound in Las Vegas Valley, Nevada, observed by synthetic aperture radar interferometry

    E-Print Network [OSTI]

    Amelung, Falk

    Seasonal subsidence and rebound in Las Vegas Valley, Nevada, observed by synthetic aperture radar in the subsidence and rebound occurring over stressed aquifer systems, in conjunction with measurements, generally permanent aquifer system compaction and land subsidence at yearly and longer timescales, caused

  20. Radar interferometry for measuring tidal strains across cracks on David Sandwell,1

    E-Print Network [OSTI]

    Sandwell, David T.

    Radar interferometry for measuring tidal strains across cracks on Europa David Sandwell,1 Paul and the plate has been relatively thin ($2 km) [Carr et al., 1998]. However, the present-day average shell relationships and a variety of morphologic characteristics [Carr et al., 1998; Greenberg et al., 1998]. Simple

  1. Radar imagery interpretation to assess the hydrocarbon potential of four sites in the Philippines

    SciTech Connect (OSTI)

    Not Available

    1988-11-17

    The Government of the Republic of the Philippines has invited new bids from international companies to explore for oil and gas in onshore and offshore sedimentary basins. To assist the private oil industry in the evaluation of the petroleum potential of these basins, the Government, with the assistance of a loan from the World Bank has completed a nation-wide basin evaluation program. The primary objective of the project is to further the goals of international energy development by aiding the Republic of the Philippines in the assessment of potential petroleum prospects within the areas imaged by radar. Secondary goals are 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. Geologic maps were prepared for each petroleum prospect region and are included in this report. A discussion on radar principles, lithography, and stratigraphy of the areas is also included. 29 refs., 27 figs., 12 tabs.

  2. Assessing the capabilities of ground penetrating radar for applications in geologic and engineering subsurface studies 

    E-Print Network [OSTI]

    Servos, Stacia Lynn

    1998-01-01

    relative electric permittivity is high (&,=8 1), will cause the relative electric pen-permittivity of soils and rocks to increase. A contrast in electric pen-permittivity between two media gives rise to a reflection in the radar profile. Ground penetrating...

  3. Radar scattering of linear dunes and mega-yardangs: Application to Titan

    E-Print Network [OSTI]

    Paillou, Philippe; Radebaugh, Jani; Wall, Stephen

    2015-01-01

    The Ku-band (13.8 GHz - 2.2 cm) RADAR instrument onboard the Cassini-Huygens spacecraft has revealed the richness of the surface of Titan, as numerous seas, lakes, rivers, cryo-volcanic flows and vast dune fields have been discovered. Linear dunes are a major geomorphological feature present on Titan, covering up to 17% of its surface, mainly in equatorial regions. However, the resolution of the RADAR instrument is not good enough to allow a detailed study of the morphology of these features. In addition, other linear wind-related landforms, such as mega-yardangs (linear wind-abraded ridges formed in cohesive rocks), are likely to present a comparable radar signature that could be confused with the one of dunes. We conducted a comparative study of the radar radiometry of both linear dunes and mega-yardangs, based on representative terrestrial analogues: the linear dunes located in the Great Sand Sea in western Egypt and in the Namib Desert in Namibia, and the mega-yardangs observed in the Lut Desert in easter...

  4. Global mapping and characterization of Titan's dune fields with Cassini: Correlation between RADAR and VIMS observations

    E-Print Network [OSTI]

    Narteau, Clément

    Global mapping and characterization of Titan's dune fields with Cassini: Correlation between RADAR dunes have been observed in the equatorial regions of Titan, Saturn's largest moon. As the Cassini-resolution coverage of Titan's surface increases, revealing new dune fields and allowing refinements

  5. Testing the Hill model of transpolar potential with Super Dual Auroral Radar Network observations

    E-Print Network [OSTI]

    Shepherd, Simon

    as a function of solar wind speed and ram pressure, the interplanetary magnetic field, the reconnection electric electric potential and is an important indicator of the amount of energy flowing into and throughTesting the Hill model of transpolar potential with Super Dual Auroral Radar Network observations S

  6. Tidally driven ice speed variation at Helheim Glacier, Greenland, observed with terrestrial radar interferometry

    E-Print Network [OSTI]

    Holland, David

    Tidally driven ice speed variation at Helheim Glacier, Greenland, observed with terrestrial radar Space Flight Center, Greenbelt, MD, USA 4 Earth System Science Interdisciplinary Center, University is usually packed with dense ice melange. Helheim Glacier accelerated and retreated between 2000 and 2005

  7. Ice iron/sodium film as cause for high noctilucent cloud radar reflectivity

    E-Print Network [OSTI]

    Bellan, Paul M.

    Ice iron/sodium film as cause for high noctilucent cloud radar reflectivity P. M. Bellan1 Received by assuming the ice grains are coated by a thin metal film; substantial evidence exists indicating that such a film exists and is caused by the deposition of iron and sodium atoms on the ice grain from iron

  8. A NOVEL APPROACH TO PROFILE CLOUD MICROPHYSICS USING DUAL-FREQUENCY RADARS

    E-Print Network [OSTI]

    .S. Department of Energy Office of Science ABSTRACT Single-frequency radar measurements provide insufficient Contract No. DE-AC02- 98CH10886 with the U.S. Department of Energy. The publisher by accepting-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others

  9. ADDING VALUE TO ARM PRECIPITATION RADAR MEASUREMENTS Scott Collis, Argonne National Laboratory

    E-Print Network [OSTI]

    of Energy Office of Science ABSTRACT The procurement of a network of C- and X-band scanning radars has lead- 98CH10886 with the U.S. Department of Energy. The publisher by accepting the manuscript, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do

  10. Adaptive Beamforming Technique for Accurate Vertical Wind Measurements with Multichannel MST Radar

    E-Print Network [OSTI]

    Sato, Toru

    -constrained minimization of power (NC-DCMP) algo- rithm, which provides not only robustness but also higher accuracy thanAdaptive Beamforming Technique for Accurate Vertical Wind Measurements with Multichannel MST Radar wind estimates due to contamination by horizontal wind components. An adaptive beamforming technique

  11. Radar Observations of MJO and Kelvin Wave Interactions During DYNAMO/AMIE/CINDY2011 

    E-Print Network [OSTI]

    DePasquale, Amanda Michele

    2013-07-05

    on the order of hours or days. These events and the overall MJO convective envelope may interact with convectively coupled waves such as Kelvin waves that propagate more rapidly eastward with time scales of 3-5 days. Radar and sounding data collected during...

  12. Winter Precipitation Microphysics Characterized by Polarimetric Radar and Video Disdrometer Observations in Central Oklahoma

    E-Print Network [OSTI]

    Xue, Ming

    Observations in Central Oklahoma GUIFU ZHANG AND SEAN LUCHS School of Meteorology, and Atmospheric Radar Research Center, University of Oklahoma, Norman, Oklahoma ALEXANDER RYZHKOV Cooperative Institute for Mesoscale Meteorological Studies, Norman, Oklahoma MING XUE School of Meteorology, and Center for Analysis

  13. FRESNEL-ZONE MEASUREMENT AND ANALYSIS OF A DUAL-POLARIZED METEOROLOGICAL RADAR ANTENNA

    E-Print Network [OSTI]

    Collings, Iain B.

    FRESNEL-ZONE MEASUREMENT AND ANALYSIS OF A DUAL- POLARIZED METEOROLOGICAL RADAR ANTENNA D.B. Hayman Fresnel-zone holographic technique was used to obtain the radiation pattern for the upgraded antenna in the measurement of this antenna and the analysis of the results. Keywords: Antenna measurements, Fresnel zone

  14. Development of a 1319-nm Laser Radar Using Fiber Optics and RF Pulse Compression

    E-Print Network [OSTI]

    Kansas, University of

    ;iii Abstract Laser radar systems will play an increasingly important role in global climate change Incubator Program, NRA-98-OES-05 NASA, Langley Research Center Technical Report The University of Kansas #12 (frequency downconversion process) 3.11 Receiver--Data acquisition system 3.12 Receiver

  15. Absorption of MARSIS radar signals: Solar energetic particles and the daytime ionosphere

    E-Print Network [OSTI]

    Carlson, Charles W.

    to investigate the causes of the radar signal ``blackout'' periods when ground reflections from the subsurface magnetic fields, diurnal cycles of ionization, and solar activity. We find that the shorter blackout periods are well correlated with solar activity and that the longest period of blackouts was likely

  16. Effects of magnetite on high-frequency ground-penetrating radar Remke L. Van Dam1

    E-Print Network [OSTI]

    Borchers, Brian

    Effects of magnetite on high-frequency ground-penetrating radar Remke L. Van Dam1 , Jan M. H, paleoclimatology (Maher and Thompson, 1995), soil development (Singer et al., 1996; Van Dam et al., 2008 et al., 2011), the detection of unexploded ordnance (UXO) and land mines (Van Dam et al., 2005

  17. Tsunami signature in the ionosphere: A simulation of OTH radar observations

    E-Print Network [OSTI]

    Occhipinti, Giovanni "Ninto"

    Tsunami signature in the ionosphere: A simulation of OTH radar observations Pierdavide Coïsson,1 ionospheric anomalies following major earthquakes and tsunamis have been detected. Global Positioning System and identification of new techniques to detect ionospheric tsunami signatures. We explore here a new groundbased

  18. Harmonic Path (HAPA) Algorithm for Noncontact Vital Signs Monitoring with IRUWB Radar

    E-Print Network [OSTI]

    Ingram, Mary Ann

    Harmonic Path (HAPA) Algorithm for Non­contact Vital Signs Monitoring with IR­UWB Radar Van Nguyen. INTRODUCTION Vital sign monitoring is fundamental in health care as knowledge of the patient's heart rate (HR consistently and accurately [1]. Currently the most common form of vital sign monitoring in hospitals is pulse

  19. Field-scale estimation of volumetric water content using ground-penetrating radar ground wave techniques

    E-Print Network [OSTI]

    Hubbard, Susan

    Field-scale estimation of volumetric water content using ground- penetrating radar ground wave that the GPR estimates had a root mean square error of volumetric water content of the order of 0 agriculture Citation: Grote, K., S. Hubbard, and Y. Rubin, Field-scale estimation of volumetric water content

  20. STUDY OF CLOUD LIFETIME EFFECTS USING THE SGP HETEROGENEOUS DISTRIBUTED RADAR NETWORK: PRELIMINARY CONSIDERATIONS

    E-Print Network [OSTI]

    STUDY OF CLOUD LIFETIME EFFECTS USING THE SGP HETEROGENEOUS DISTRIBUTED RADAR NETWORK: PRELIMINARY-dimensional morphology and life cycle of clouds. Detailing key cloud processes as they transit from the formation stage to precipitation onset and cloud dissipation is critical towards establishing uncertainties in climate models

  1. Very high resolution precipitation climatologies from the Tropical Rainfall Measuring Mission precipitation radar

    E-Print Network [OSTI]

    Nesbitt, Steve

    Very high resolution precipitation climatologies from the Tropical Rainfall Measuring Mission precipitation radar Stephen W. Nesbitt1 and Alison M. Anders2 Received 4 March 2009; revised 6 July 2009 of topography and precipitation, a tropics-wide (±36° latitude) high resolution (0.1°) ten year (1998

  2. Ground penetrating radar surveys over an alluvial DNAPL site, Paducah Gaseous Diffusion Plant, Kentucky

    SciTech Connect (OSTI)

    Carpenter, P.J. [Northern Illinois Univ., DeKalb, IL (United States). Dept. of Geology]|[Oak Ridge National Lab., TN (United States); Doll, W.E. [Oak Ridge National Lab., TN (United States); Phillips, B.E. [Paducah Gaseous Diffusion Plant, KY (United States)

    1994-09-01

    Ground penetrating radar (GPR) surveys were used to map shallow sands and gravels which are DNAPL migration pathways at the Paducah Gaseous Diffusion Plant in western Kentucky. The sands and gravels occur as paleochannel deposits, at depths of 17-25 ft, embedded in Pleistocene lacustrine clays. More than 30 GPR profiles were completed over the Drop Test Area (DTA) to map the top and base of the paleochannel deposits, and to assess their lateral continuity. A bistatic radar system was used with antenna frequencies of 25 and 50 MHz. An average velocity of 0.25 ft/ns for silty and clayey materials above the paleochannel deposits was established from radar walkaway tests, profiles over culverts of known depth, and comparison of radar sections with borings. In the south portion of the DTA, strong reflections corresponded to the water table at approximately 9-10 ft, the top of the paleochannel deposits at approximately 18 ft, and to gravel horizons within these deposits. The base of these deposits was not visible on the radar sections. Depth estimates for the top of the paleochannel deposits (from 50 records) were accurate to within 2 ft across the southern portion of the DTA. Continuity of these sands and gravels could not be assessed due to interference from air-wave reflections and lateral changes in signal penetration depth. However, the sands and gravels appear to extend across the entire southern portion of the DTA, at depths as shallow as 17 ft. Ringing, air-wave reflections and diffractions from powerlines, vehicles, well casings, and metal equipment severly degraded GPR profiles in the northern portion of the DTA; depths computed from reflection times (where visible) were accurate to within 4 ft in this area. The paleochannel deposits are deeper to the north and northeast where DNAPL has apparently pooled (DNAPL was not directly imaged by the GPR, however). Existing hydrogeological models of the DTA will be revised.

  3. Self-consistent nonlinear kinetic simulations of the anomalous Doppler instability of suprathermal electrons in plasmas

    SciTech Connect (OSTI)

    Lai, W. N. [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom)] [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Chapman, S. C. [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom) [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Department of Mathematics and Statistics, University of Tromsø, Tromsø (Norway); Dendy, R. O. [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom) [Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom); Euratom/CCFE Fusion Association, Culham Science Centre, Abingdon, Oxfordshire OX14 3DB (United Kingdom)

    2013-10-15

    Suprathermal tails in the distributions of electron velocities parallel to the magnetic field are found in many areas of plasma physics, from magnetic confinement fusion to solar system plasmas. Parallel electron kinetic energy can be transferred into plasma waves and perpendicular gyration energy of particles through the anomalous Doppler instability (ADI), provided that energetic electrons with parallel velocities v{sub ||}?(?+?{sub ce})/k{sub ||} are present; here ?{sub ce} denotes electron cyclotron frequency, ? the wave angular frequency, and k{sub ||} the component of wavenumber parallel to the magnetic field. This phenomenon is widely observed in tokamak plasmas. Here, we present the first fully self-consistent relativistic particle-in-cell simulations of the ADI, spanning the linear and nonlinear regimes of the ADI. We test the robustness of the analytical theory in the linear regime and follow the ADI through to the steady state. By directly evaluating the parallel and perpendicular dynamical contributions to j·E in the simulations, we follow the energy transfer between the excited waves and the bulk and tail electron populations for the first time. We find that the ratio ?{sub ce}/(?{sub pe}+?{sub ce}) of energy transfer between parallel and perpendicular, obtained from linear analysis, does not apply when damping is fully included, when we find it to be ?{sub pe}/(?{sub pe}+?{sub ce}); here ?{sub pe} denotes the electron plasma frequency. We also find that the ADI can arise beyond the previously expected range of plasma parameters, in particular when ?{sub ce}>?{sub pe}. The simulations also exhibit a spectral feature which may correspond to the observations of suprathermal narrowband emission at ?{sub pe} detected from low density tokamak plasmas.

  4. Primary Energy Spectra and Elemental Composition. GAMMA Experiment

    E-Print Network [OSTI]

    S. V. Ter-Antonyan; R. M. Martirosov; A. P. Garyaka; V. Eganov; N. Nikolskaya; T. Episkoposyan; J. Procureur; Y. Gallant; L. Jones

    2005-06-24

    On the basis of the Extensive Air Shower data observed by the GAMMA experiment the energy spectra and elemental composition of the primary cosmic rays have been derived in the 1-100 PeV energy range. Reconstruction of the primary energy spectra is carried out in the framework of the SIBYLL and QGSJET interaction models and the hypothesis of the power-law steepening primary energy spectra. All presented results are derived taking into account the detector response, reconstruction uncertainties of EAS parameters and fluctuation of EAS development.

  5. X-ray reflection spectra from ionized slabs

    E-Print Network [OSTI]

    R. R. Ross; A. C. Fabian; A. J. Young

    1999-02-23

    X-ray reflection spectra are an important component in the X-ray spectra of many active galactic nuclei and Galactic black hole candidates. It is likely that reflection takes place from highly ionized surfaces of the accretion disc in some cases. This can lead to strong Comptonization of the emergent iron, and other, absorption and emission features. We present such reflection spectra here, computed in a self-consistent manner with the method described by Ross and Fabian. In particular we emphasise the range where the ionization parameter (the flux to density ratio) \\xi is around and above 10^4. Such spectra may be relevant to the observed spectral features found in black hole candidates such as Cygnus X-1 in the low/hard state.

  6. Supporting Information: Excitation-emission spectra and fluorescence quantum yields

    E-Print Network [OSTI]

    Nizkorodov, Sergey

    @uci.edu #12;2 Figure S1. (a) Absorption spectra of solutions of QS (quinine sulfate or (C20H24N2O2)2 . H2SO4

  7. ARM - Midlatitude Continental Convective Clouds Experiment (MC3E): Multi-Frequency Profilers, S-band Radar (williams-s_band)

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

    Williams, Christopher

    2012-11-06

    This data was collected by the NOAA 449-MHz and 2.8-GHz profilers in support of the Department of Energy (DOE) and NASA sponsored Mid-latitude Continental Convective Cloud Experiment (MC3E). The profiling radars were deployed in Northern Oklahoma at the DOE Atmospheric Radiation Mission (ARM) Southern Great Plans (SGP) Central Facility from 22 April through 6 June 2011. NOAA deployed three instruments: a Parsivel disdrometer, a 2.8-GHz profiler, and a 449-MHz profiler. The parasivel provided surface estimates of the raindrop size distribution and is the reference used to absolutely calibrate the 2.8 GHz profiler. The 2.8-GHz profiler provided unattenuated reflectivity profiles of the precipitation. The 449-MHz profiler provided estimates of the vertical air motion during precipitation from near the surface to just below the freezing level. By using the combination of 2.8-GHz and 449-MHz profiler observations, vertical profiles of raindrop size distributions can be retrieved. The profilers are often reference by their frequency band: the 2.8-GHz profiler operates in the S-band and the 449-MHz profiler operates in the UHF band. The raw observations are available as well as calibrated spectra and moments. This document describes how the instruments were deployed, how the data was collected, and the format of the archived data.

  8. ARM - Midlatitude Continental Convective Clouds Experiment (MC3E): Multi-Frequency Profilers, S-band Radar (williams-s_band)

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

    Williams, Christopher

    This data was collected by the NOAA 449-MHz and 2.8-GHz profilers in support of the Department of Energy (DOE) and NASA sponsored Mid-latitude Continental Convective Cloud Experiment (MC3E). The profiling radars were deployed in Northern Oklahoma at the DOE Atmospheric Radiation Mission (ARM) Southern Great Plans (SGP) Central Facility from 22 April through 6 June 2011. NOAA deployed three instruments: a Parsivel disdrometer, a 2.8-GHz profiler, and a 449-MHz profiler. The parasivel provided surface estimates of the raindrop size distribution and is the reference used to absolutely calibrate the 2.8 GHz profiler. The 2.8-GHz profiler provided unattenuated reflectivity profiles of the precipitation. The 449-MHz profiler provided estimates of the vertical air motion during precipitation from near the surface to just below the freezing level. By using the combination of 2.8-GHz and 449-MHz profiler observations, vertical profiles of raindrop size distributions can be retrieved. The profilers are often reference by their frequency band: the 2.8-GHz profiler operates in the S-band and the 449-MHz profiler operates in the UHF band. The raw observations are available as well as calibrated spectra and moments. This document describes how the instruments were deployed, how the data was collected, and the format of the archived data.

  9. IEEE TRANSACTIONS ON INTELLIGENT TRANSPORTATION SYSTEMS, VOL. 8, NO. 2, JUNE 2007 245 Vehicle Classification Based on the Radar

    E-Print Network [OSTI]

    such as truck volume estimating, traffic planning, roadway tolling, etc.; see e.g., [1]­[4] and references. Another strength is that MW radar sensors are largely immune to adverse weather and light conditions

  10. The Retrieval of Ice Water Content from Radar Reflectivity Factor and Temperature and Its Use in Evaluating a Mesoscale Model

    E-Print Network [OSTI]

    Hogan, Robin

    in Evaluating a Mesoscale Model ROBIN J. HOGAN, MARION P. MITTERMAIER,* AND ANTHONY J. ILLINGWORTH Department-GHz radar with the values held in the Met Office mesoscale forecast model, for eight precipitating

  11. HF Radar Performance in a Low-Energy Environment: CODAR SeaSonde Experience on the West Florida Shelf*

    E-Print Network [OSTI]

    both tidal and subtidal frequency bands. By examining the HF radar radial velocities at low wave energy have evolved along with coastal ocean circulation-observing technologies. Early inferences on surface

  12. Airborne UHF Radar for Fine Resolution Mapping of Near Surface Accumulation Layers in Greenland and West Antarctica

    E-Print Network [OSTI]

    Lewis, Cameron Scott

    2010-11-01

    as understanding sea level rise. Previously developed accumulation layer radars were used as templates for the current single channel system. Improvements were incorporated including increased output power, increased receiver sensitivity, single antenna operation...

  13. Ground-penetrating-radar response to fracture-fluid salinity: Why lower frequencies are favorable for resolving salinity changes

    E-Print Network [OSTI]

    Tsoflias, Georgios P.; Becker, Matthew W.

    2008-08-26

    Time-lapse ground-penetrating-radar (GPR) surveys exploit signal-amplitude changes to monitor saline tracers in fractures and to identify groundwater flow paths. However, the relationships between GPR signal amplitude, phase, and frequency...

  14. Power Spectra to 1% Accuracy between Dynamical Dark Energy Cosmologies

    E-Print Network [OSTI]

    Matthew J. Francis; Geraint F. Lewis; Eric V. Linder

    2007-04-03

    For dynamical dark energy cosmologies we carry out a series of N-body gravitational simulations, achieving percent level accuracy in the relative mass power spectra at any redshift. Such accuracy in the power spectrum is necessary for next generation cosmological mass probes. Our matching procedure reproduces the CMB distance to last scattering and delivers subpercent level power spectra at z=0 and z~3. We discuss the physical implications for probing dark energy with surveys of large scale structure.

  15. Improving the Quality of FORS2 Reduced Spectra

    E-Print Network [OSTI]

    Moehler, Sabine; Boffin, Henri; Rupprecht, Gero; Saviane, Ivo; Freudling, Wolfram

    2015-01-01

    The FORS2 instrument is one of the most widely used and productive instruments on the Very Large Telescope. This article reports on a project to improve the quality of the reduced FORS2 spectra that can be produced with the software provided by ESO. The result of this effort is that spectra of significantly higher quality can now be produced with substantially lower effort by the science user of the data.

  16. Implementation of On-the-Fly Doppler Broadening in MCNP5 for Multiphysics Simulation of Nuclear Reactors

    SciTech Connect (OSTI)

    William Martin

    2012-11-16

    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. Previous work had established the scientific feasibility of obtaining Doppler-broadened cross sections "on-the-fly" (OTF) during the random walk of the neutron. Thus, when a neutron of energy E enters a material region that is at some temperature T, the cross sections for that material at the exact temperature T are immediately obtained 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. A standalone Fortran code has been developed that generates the OTF library for any isotope that can be processed by NJOY. 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., 250K - 3200K. 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 using OTF cross sections greatly reduces the complexity of the input for MCNP, especially for full-core temperature feedback calculations with many temperature regions. This results in an order of magnitude decrease in the number of input lines for full-core configurations, thus simplifying input preparation and reducing the potential for input errors. 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 to use OTF cross sections is negligible. This is a joint project with the University of Michigan, Argonne National Laboratory, and Los Alamos National Laboratory.

  17. A dual polarized x-band pulse radar for ground based electromagnetic scattering experiment / by Allen William White 

    E-Print Network [OSTI]

    White, Allen William

    1978-01-01

    A DUAL POLARIZED X-BAND PULSE RADAR FOR GROUND BASED ELECTROMAGNETIC SCATTERING EXPERIMENT A Thesis by Allen William White Submitted to the Graduate College of Texas A/M University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE May 1978 Major Subject: Electrical Engineering A DUAL POLARIZED X-BAND PULSE RADAR FOR GROUND BASED ELECTROMAGNETIC SCATTERING EXPERIMENTS A Thesis by Allen William White Approved as to style and content by: x m n o ommzttee...

  18. Low-Cost 63% Efficient 2.5-kW UHF Power Amplifier for a Wind Profiler Radar

    E-Print Network [OSTI]

    Popovic, Zoya

    Low-Cost 63% Efficient 2.5-kW UHF Power Amplifier for a Wind Profiler Radar Brad Lindseth1,2 , Tom describes a low-cost 449-MHz 2.5-kW peak pulse amplifier for use in a wind profiling radar. New high- powerW cost upwards of US$30,000 [2,3]. The goal of this work is to develop a low-cost UHF power amplifier

  19. Vertical profiles of radar reflectivity of convective cells in tropical and mid-latitude mesoscale convective systems 

    E-Print Network [OSTI]

    Lutz, Kurt Reed

    1992-01-01

    VERTICAL PROFILES OF RADAR REFLECTIVITY OF CONVECTIVE CELLS IN TROPICAL AND MID-LATITUDE MESOSCALE CONVECTIVE SYSTEMS A Thesis by KURT REED LUTZ 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 December 1992 Major Subject: Meteorology VERTICAL PROFILES OF RADAR REFLECTIVITY OF CONVECTIVE CELLS IN TROPICAL AND MID-LATITUDE MESOSCALE CONVECTIVE SYSTEMS A Thesis by KURT REED LUTZ Approved...

  20. Hard X-ray Spectra and Positions of Solar Flares observed by RHESSI: photospheric albedo, directivity and electron spectra

    E-Print Network [OSTI]

    J. Kasparova; E. P. Kontar; J. C. Brown

    2007-01-30

    We investigate the signature of the photospheric albedo contribution in solar flare hard X-ray spectra, the effect of low energy cutoffs in electron spectra, and the directivity of hard X-ray emission. Using Ramaty High Energy Solar Spectroscopic Imager (RHESSI) flare data we perform a statistical analysis of spatially integrated spectra and positions of solar flares. We demonstrate clear centre-to-limb variation of photon spectral indices in the 15-20 keV energy range and a weaker dependency in the 20-50 keV range which is consistent with photospheric albedo as the cause. The results also suggest that low-energy cutoffs sometimes inferred in mean electron spectra are an artefact of albedo. We also derive the anisotropy (ratio of downward/observer directed photons) of hard X-ray emission in the 15-20 keV range for various heliocentric angles.

  1. Antarctica X-band MiniSAR Crevasse Detection Radar : draft final report.

    SciTech Connect (OSTI)

    Sander, Grant J.; Bickel, Douglas Lloyd

    2010-08-01

    This document is the final report for the 2009 Antarctica Crevasse Detection Radar (CDR) Project. This portion of the project is referred to internally as Phase 2. This is a follow on to the work done in Phase 1 reported on in [1]. Phase 2 involved the modification of a Sandia National Laboratories MiniSAR system used in Phase 1 to work with an LC-130 aircraft that operated in Antarctica in October through November of 2009. Experiments from the 2006 flights were repeated, as well as a couple new flight tests to examine the effect of colder snow and ice on the radar signatures of 'deep field' sites. This document includes discussion of the hardware development, system capabilities, and results from data collections in Antarctica during the fall of 2009.

  2. R&D Argon Detector at Ash River (RADAR) - Letter of Intent

    E-Print Network [OSTI]

    P. Adamson; S. Agarwalla; A. Aurisano; J. J. Evans; P. Guzowski; A. Habig; A. Holin; J. Huang; M. Kordosky; A. E. Kreymer; K. Lang; M. Marshak; R. Mehdiyev; W. H. Miller; D. Naples; R. J. Nichol; V. Paolone; R. B. Patterson; A. Sousa; J. Thomas; L. H. Whitehead

    2013-09-28

    In the RADAR project described in this Letter of Intent, we propose to deploy a 6 kton liquid argon TPC at the NOvA Far Detector building in Ash River, Minnesota, and expose it to the NuMI beam during NOvA running. It will significantly add to the physics capabilities of the NOvA program while providing LBNE with an R&D program based on full-scale TPC module assemblies. RADAR offers an excellent opportunity to improve the full Homestake LBNE project in physics reach, timeline, costs, and fostering international partnership. The anticipated duration of the project's construction is 5 years, with running happening between 2018 and 2023.

  3. Electron-density comparisons between radar observations and 3-D ionospheric model calculations. Master's thesis

    SciTech Connect (OSTI)

    Johnson, M.W.

    1990-01-01

    A comparison of electron densities calculated from the Utah State University First-Principals Ionospheric Model with simultaneous observations taken at Sondrestrom, Millstone, and Arecibo incoherent-scatter radars was undertaken to better understanding the response of the ionosphere at these longitudinally similar yet latitudinally separated locations. The comparison included over 50 days distributed over 3 1/2 years roughly symmetrical about the last solar-minimum in 1986. The overall trend of the comparison was that to first-order the model reproduces electron densities responding to diurnal, seasonal, geomagnetic, and solar-cycle variations for all three radars. However, some model-observation discrepancies were found. These include, failure of the model to correctly produce an evening peak at Millstone, fall-spring equinox differences at Sondrestrom, tidal structure at Arecibo, and daytime NmF2 values at Arecibo.

  4. ON THE WEAK-WIND PROBLEM IN MASSIVE STARS: X-RAY SPECTRA REVEAL A MASSIVE HOT WIND IN {mu} COLUMBAE

    SciTech Connect (OSTI)

    Huenemoerder, David P.; Oskinova, Lidia M.; Todt, Helge; Ignace, Richard; Waldron, Wayne L.; Hamaguchi, Kenji

    2012-09-10

    {mu} Columbae is a prototypical weak-wind O star for which we have obtained a high-resolution X-ray spectrum with the Chandra LETG/ACIS instrument and a low-resolution spectrum with Suzaku. This allows us, for the first time, to investigate the role of X-rays on the wind structure in a bona fide weak-wind system and to determine whether there actually is a massive hot wind. The X-ray emission measure indicates that the outflow is an order of magnitude greater than that derived from UV lines and is commensurate with the nominal wind-luminosity relationship for O stars. Therefore, the {sup w}eak-wind problem{sup -}identified from cool wind UV/optical spectra-is largely resolved by accounting for the hot wind seen in X-rays. From X-ray line profiles, Doppler shifts, and relative strengths, we find that this weak-wind star is typical of other late O dwarfs. The X-ray spectra do not suggest a magnetically confined plasma-the spectrum is soft and lines are broadened; Suzaku spectra confirm the lack of emission above 2 keV. Nor do the relative line shifts and widths suggest any wind decoupling by ions. The He-like triplets indicate that the bulk of the X-ray emission is formed rather close to the star, within five stellar radii. Our results challenge the idea that some OB stars are 'weak-wind' stars that deviate from the standard wind-luminosity relationship. The wind is not weak, but it is hot and its bulk is only detectable in X-rays.

  5. Incremental online object learning in a vehicular radar-vision fusion framework

    SciTech Connect (OSTI)

    Ji, Zhengping; Weng, Juyang; Luciw, Matthew; Zeng, Shuqing

    2010-10-19

    In this paper, we propose an object learning system that incorporates sensory information from an automotive radar system and a video camera. The radar system provides a coarse attention for the focus of visual analysis on relatively small areas within the image plane. The attended visual areas are coded and learned by a 3-layer neural network utilizing what is called in-place learning, where every neuron is responsible for the learning of its own signal processing characteristics within its connected network environment, through inhibitory and excitatory connections with other neurons. The modeled bottom-up, lateral, and top-down connections in the network enable sensory sparse coding, unsupervised learning and supervised learning to occur concurrently. The presented work is applied to learn two types of encountered objects in multiple outdoor driving settings. Cross validation results show the overall recognition accuracy above 95% for the radar-attended window images. In comparison with the uncoded representation and purely unsupervised learning (without top-down connection), the proposed network improves the recognition rate by 15.93% and 6.35% respectively. The proposed system is also compared with other learning algorithms favorably. The result indicates that our learning system is the only one to fit all the challenging criteria for the development of an incremental and online object learning system.

  6. A 77 GHz Transceiver for Automotive Radar System Using a120nm In AlAs/In GaAs Metamorphic HEMTs

    E-Print Network [OSTI]

    Kwon, Youngwoo

    A 77 GHz Transceiver for Automotive Radar System Using a120nm 0.4 0.35 In AlAs/In GaAs Metamorphic-mail:ykwon@snu.ac.kr) Abstract -- In this work, we demonstrate a compact 77GHz single-chip transceiver for an automotive radar at the transmitter and a 5dB conversion gain at the receiver. Index Terms -- Automotive radar, 77GHz, MHEMT, MMIC

  7. ARM: W-Band Scanning ARM Cloud Radar (W-SACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

    SciTech Connect (OSTI)

    Dan Nelson; Joseph Hardin; Iosif Lindenmaier; Bradley Isom; Karen Johnson; Nitin Bharadwaj

    1990-01-01

    W-Band Scanning ARM Cloud Radar (W-SACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

  8. ARM: X-Band Scanning ARM Cloud Radar (XSACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

    SciTech Connect (OSTI)

    Dan Nelson; Joseph Hardin; Iosif Lindenmaier; Bradley Isom; Karen Johnson; Nitin Bharadwaj

    2011-09-14

    X-Band Scanning ARM Cloud Radar (XSACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

  9. ARM: Ka-Band Scanning ARM Cloud Radar (KASACR) Hemispherical Sky RHI Scan (6 horizon-to-horizon scans at 30-degree azimuth intervals)

    SciTech Connect (OSTI)

    Dan Nelson; Joseph Hardin; Iosif Lindenmaier; Bradley Isom; Karen Johnson; Nitin Bharadwaj

    2011-05-24

    Ka-Band Scanning ARM Cloud Radar (KASACR) Hemispherical Sky RHI Scan (6 horizon-to-horizon scans at 30-degree azimuth intervals)

  10. ARM: X-Band Scanning ARM Cloud Radar (XSACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

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

    Dan Nelson; Joseph Hardin; Iosif (Andrei) Lindenmaier; Bradley Isom; Karen Johnson; Nitin Bharadwaj

    X-Band Scanning ARM Cloud Radar (XSACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

  11. ARM: W-Band Scanning ARM Cloud Radar (W-SACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

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

    Dan Nelson; Joseph Hardin; Iosif (Andrei) Lindenmaier; Bradley Isom; Karen Johnson; Nitin Bharadwaj

    W-Band Scanning ARM Cloud Radar (W-SACR) Hemispherical Sky RHI Scans (6 horizon-to-horizon scans at 30-degree azimuth intervals)

  12. ARM: Ka-Band Scanning ARM Cloud Radar (KASACR) Hemispherical Sky RHI Scan (6 horizon-to-horizon scans at 30-degree azimuth intervals)

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

    Dan Nelson; Joseph Hardin; Iosif (Andrei) Lindenmaier; Bradley Isom; Karen Johnson; Nitin Bharadwaj

    Ka-Band Scanning ARM Cloud Radar (KASACR) Hemispherical Sky RHI Scan (6 horizon-to-horizon scans at 30-degree azimuth intervals)

  13. JUNE 2002 835F R I S C H E T A L . The Retrieval of Stratus Cloud Droplet Effective Radius with Cloud Radars

    E-Print Network [OSTI]

    Shupe, Matthew

    . (1999). Another retrieval for stratocumulus cloud properties using solar radiation, microwave ra obtained from a microwave radiometer; the second uses the radar reflectivity and an assumption

  14. Electronic Spectra from TDDFT and Machine Learning in Chemical Space

    E-Print Network [OSTI]

    Ramakrishnan, Raghunathan; Tapavicza, Enrico; von Lilienfeld, O Anatole

    2015-01-01

    Due to its favorable computational efficiency time-dependent (TD) density functional theory (DFT) enables the prediction of electronic spectra in high-throughput fashion across chemical space. Unfortunately, its predictions can be inaccurate. Machine learning models can resolve this issue when trained on deviations of reference coupled-cluster singles and doubles (CC2) spectra from TDDFT excitation energies, or even from DFT gap. Numerical evidence is produced for the low-lying singlet-singlet vertical electronic spectra of over 20 thousand diverse and synthetically feasible organic molecules with up to eight CONF atoms. Out-of-sample prediction errors decay monotonously as a function of training set size. For a training set of 10 thousand molecules, CC2 excitation energies can be reproduced within $\\pm$0.1 eV. Analysis of our spectral database with chromophore counting suggests that even higher accuracies can be achieved. We discuss open challenges associated with data-driven modeling of transition intensiti...

  15. Gamma-ray Output Spectra from 239 Pu Fission

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

    Ullmann, John

    2015-05-25

    Gamma-ray multiplicities, individual gamma-ray energy spectra, and total gamma energy spectra following neutron-induced fission of 239Pu were measured using the DANCE detector at Los Alamos. Corrections for detector response were made using a forward-modeling technique based on propagating sets of gamma rays generated from a paramaterized model through a GEANT model of the DANCE array and adjusting the parameters for best fit to the measured spectra. The results for the gamma-ray spectrum and multiplicity are in general agreement with previous results, but the measured total gamma-ray energy is about 10% higher. A dependence of the gamma-ray spectrum on the gamma-raymore »multplicity was also observed. Global model calculations of the multiplicity and gamma energy distributions are in good agreement with the data, but predict a slightly softer total-energy distribution.« less

  16. Definition of energy-calibrated spectra for national reachback

    SciTech Connect (OSTI)

    Kunz, Christopher L.; Hertz, Kristin L.

    2014-01-01

    Accurate energy calibration is critical for the timeliness and accuracy of analysis results of spectra submitted to National Reachback, particularly for the detection of threat items. Many spectra submitted for analysis include either a calibration spectrum using 137Cs or no calibration spectrum at all. The single line provided by 137Cs is insufficient to adequately calibrate nonlinear spectra. A calibration source that provides several lines that are well-spaced, from the low energy cutoff to the full energy range of the detector, is needed for a satisfactory energy calibration. This paper defines the requirements of an energy calibration for the purposes of National Reachback, outlines a method to validate whether a given spectrum meets that definition, discusses general source considerations, and provides a specific operating procedure for calibrating the GR-135.

  17. The near-infra-red spectra of ferric acetylacetonate 

    E-Print Network [OSTI]

    Owen, James Travis

    1965-01-01

    15 23 Bibliography. Appendix 1. Appendix 2. 26 27 LIST OF FIGURES Figure 6a 6b 10 Oh d Orbital Energies. D d Orbital Energies 3 Energy-Level Matrix Ferric Ion Transitions . Spectrum of Filter DO-2-600 Electric Vector Parallel... the lead washers with plugs of. Apiezon Q. Zn this way, the crystal was in contact with metal so that heat conduction was rapid and the crystal was at the same time effectively' maskede 15 CHAPTER VI SPECTRA Figures 6 and 7 are spectra of ferric...

  18. Exact Mapping between Tensor and Most General Scalar Power Spectra

    E-Print Network [OSTI]

    Jose Beltran Jimenez; Marcello Musso; Christophe Ringeval

    2013-09-03

    We prove an exact relation between the tensor and the scalar primordial power spectra generated during inflation. Such a mapping considerably simplifies the derivation of any power spectra as they can be obtained from the study of the tensor modes only, which are much easier to solve. As an illustration, starting from the second order slow-roll tensor power spectrum, we derive in a few lines the next-to-next-to-leading order power spectrum of the comoving curvature perturbation in generalized single field inflation with a varying speed of sound.

  19. Flow, spectra and HBT radii in heavy-ion collisions

    E-Print Network [OSTI]

    Piotr Bozek; Iwona Wyskiel

    2009-09-12

    The expansion of the fireball created in relativistic heavy ion collisions is described using the 3+1D hydrodynamical model. Experimentally observed transverse momentum spectra at different rapdities, elliptic flow and HBT correlations of produced particles can be reproduced. We give estimates of shear viscosity corrections at freeze-out, which we find important only for the elliptic flow coefficient.

  20. Energy spectra and dissipation Mikel Indurain, Equipe Planto

    E-Print Network [OSTI]

    Madeleine, Jean-Baptiste

    Energy spectra and dissipation Mikel Indurain, Equipe Planéto LMD LMDZ.EARTH LMDZ.GENERIC LMDZ.MARS #12;Dissipation : introduction Energy transfer from large scales to small scales. Problem : energy : introduction Energy transfer from large scales to small scales. Problem : energy accumulation if dissipative

  1. AO14: Detection of Aircraft Emission Signatures in Atmospheric Spectra

    E-Print Network [OSTI]

    Oxford, University of

    damaging levels. NOx (NO2 and NO) are the next most abundant molecules in aircraft emissions. HighAO14: Detection of Aircraft Emission Signatures in Atmospheric Spectra Supervisors: Dr A. Dudhia emissions is both relevant and important. Aircraft emissions are analysed and NO2 is selected as the most

  2. The Effect of Magnetic Turbulence Energy Spectra and

    E-Print Network [OSTI]

    Ng, Chung-Sang

    The Effect of Magnetic Turbulence Energy Spectra and Pickup Ions on the Heating of the Solar Wind ADimensionless parameter: [Iroshnikov 1963, Kraichnan 1965] #12;Solar wind turbulence model The steady state solar wind turbulence model developed by [Matthaeus et al. 1994, 1996] and later developments: Steady

  3. Database on the Net for Particle Correlations and Spectra

    E-Print Network [OSTI]

    J. Schmidt-Sorensen; T. Csorgo

    1996-11-30

    A fully interactive database is presented, which provides user-friendly access to experimental results on single-particle spectra and two-particle correlations (particle interferometry or HBT-effect). The database is available on the World-Wide-Web at: http://www.quark.lu.se/~janus/hbt_home.html .

  4. Calculated Phonon Spectra of Plutonium at High Temperatures

    E-Print Network [OSTI]

    Savrasov, Sergej Y.

    Calculated Phonon Spectra of Plutonium at High Temperatures X. Dai,1 S. Y. Savrasov,2 * G. Kotliar dynamical proper- ties of plutonium using an electronic structure method, which incorporates correlation anharmonic and can be stabilized at high temperatures by its phonon entropy. Plutonium (Pu) is a material

  5. Multivariate classification of infrared spectra of cell and tissue samples

    DOE Patents [OSTI]

    Haaland, David M. (Albuquerque, NM); Jones, Howland D. T. (Albuquerque, NM); Thomas, Edward V. (Albuquerque, NM)

    1997-01-01

    Multivariate classification techniques are applied to spectra from cell and tissue samples irradiated with infrared radiation to determine if the samples are normal or abnormal (cancerous). Mid and near infrared radiation can be used for in vivo and in vitro classifications using at least different wavelengths.

  6. Optical Spectra of the High Voltage Erosive Water Discharge

    E-Print Network [OSTI]

    Pirozerski, A L

    2008-01-01

    In the present paper kinetics of emission spectra of the high voltage erosive water discharge at near ultraviolet and visible spectral ranges has been investigated. Obtained results show a similarity of physical properties of this discharge (and of corresponding plasmoids) to that of some other types of erosional discharges which also result in the formation of dust-gas fireballs.

  7. ROTATIONAL SPECTRA OF SMALL PAHs: ACENAPHTHENE, ACENAPHTHYLENE, AZULENE, AND FLUORENE

    E-Print Network [OSTI]

    Thorwirth, Sven

    hydrocarbons have been observed by Fourier transform microwave spectroscopy of a molecular beam and fluorene have also been measured in the 3 mm region by conventional free-space absorption spectroscopy and their vibrational spectra, polycyclic aromatic hydrocarbons (PAHs) are widely be- lieved to be responsible molecular

  8. The spectra of super line multigraphs Department of Computer Science

    E-Print Network [OSTI]

    Ellis, Robert B.

    The spectra of super line multigraphs Jay Bagga Department of Computer Science Ball State, the super line multigraph of index r of G, denoted Mr(G), has for vertices all the r-subsets of edges. Two all the eigenvalues of Mr(G) and their multiplicities in terms of those of G. Key words. super line

  9. Laser Doppler Velocimetry for Joint Measurements of Acoustic and Mean Flow Velocities : LMS-based Algorithm and CRB Calculation

    E-Print Network [OSTI]

    Simon, Laurent; Degroot, Anne; Lionet, Louis; 10.1109/TIM.2008.917670

    2009-01-01

    This paper presents a least mean square (LMS) algorithm for the joint estimation of acoustic and mean flow velocities from laser doppler velocimetry (LDV) measurements. The usual algorithms used for measuring with LDV purely acoustic velocity or mean flow velocity may not be used when the acoustic field is disturbed by a mean flow component. The LMS-based algorithm allows accurate estimations of both acoustic and mean flow velocities. The Cram\\'er-Rao bound (CRB) of the associated problem is determined. The variance of the estimators of both acoustic and mean flow velocities is also given. Simulation results of this algorithm are compared with the CRB and the comparison leads to validate this estimator.

  10. Innovative Coal Solids-Flow Monitoring and Measurement Using Phase-Doppler and Mie Scattering Techniques

    SciTech Connect (OSTI)

    Stephen Seong Lee

    2010-01-19

    Fuel flow to individual burners is complicated and difficult to determine on coal fired boilers, since coal solids were transported in a gas suspension that is governed by the complex physics of two-phase flow. The objectives of the project were the measurements of suspended coal solids-flows in the simulated test conditions. Various extractive methods were performed manually and can give only a snapshot result of fuel distribution. In order to measure particle diameter & velocity, laser based phase-Doppler particle analyzer (PDPA) and particle image velocimetry (PIV) were carefully applied. Statistical methods were used to analyze particle characteristics to see which factors have significant effect. The transparent duct model was carefully designed and fabricated for the laser-based-instrumentation of solids-flow monitoring (LISM). The experiments were conducted with two different kinds of particles with four different particle diameters. The particle types were organic particles and saw dust particles with the diameter range of 75-150 micron, 150-250 micron, 250-355 micron and 355-425 micron. The densities of the particles were measured to see how the densities affected the test results. Also the experiment was conducted with humid particles and fog particles. To generate humid particles, the humidifier was used. A pipe was connected to the humidifier to lead the particle flow to the intersection of the laser beam. The test results of the particle diameter indicated that, the mean diameter of humid particles was between 6.1703 microns and 6.6947 microns when the humid particle flow was low. When the humid particle flow was high, the mean diameter was between 6.6728 microns and 7.1872 microns. The test results of the particle mean velocity indicated that the mean velocity was between 1.3394 m/sec and 1.4556 m/sec at low humid particle flow. When the humid particle flow was high, the mean velocity was between 1.5694 m/sec and 1.7856 m/sec. The Air Flow Module, TQ AF 17 and shell ondina oil were used to generate fog particles. After the oil was heated inside the fog generator, the blower was used to generate the fog. The fog flew along the pipe to the intersection of the laser beam. The mean diameter of the fog particles was 5.765 microns. Compared with the humid particle diameter, we observed that the mean diameter of the fog particles was smaller than the humid particles. The test results of particle mean velocity was about 3.76 m/sec. Compared with the mean velocity of the humid particles, we can observed the mean velocity of fog particles were greater than humid particles. The experiments were conducted with four different kinds of particles with five different particle diameters. The particle types were organic particles, coal particles, potato particles and wheat particles with the diameter range of 63-75 micron, less than 150 micron, 150-250 micron, 250-355 micron and 355-425 micron. To control the flow rate, the control gate of the particle dispensing hopper was adjusted to 1/16 open rate, 1/8 open rate and 1/4 open rate. The captured image range was 0 cm to 5 cm from the control gate, 5 cm to 10 cm from the control gate and 10 cm to 15 cm from the control gate. Some of these experiments were conducted under both open environment conditions and closed environment conditions. Thus these experiments had a total of five parameters which were type of particles, diameter of particles, flow rate, observation range, and environment conditions. The coal particles (diameter between 63 and 75 microns) tested under the closed environment condition had three factors that were considered as the affecting factors. They were open rate, observation range, and environment conditions. In this experiment, the interaction of open rate and observation range had a significant effect on the lower limit. On the upper limit, the open rate and environment conditions had a significant effect. In addition, the interaction of open rate and environment conditions had a significant effect. The coal particles tested (diameter between 63 and 75

  11. Estimation of stellar atmospheric parameters from SDSS/SEGUE spectra

    E-Print Network [OSTI]

    P. Re Fiorentin; C. A. L. Bailer-Jones; Y. S. Lee; T. C. Beers; T. Sivarani; R. Wilhelm; C. Allende Prieto; J. E. Norris

    2007-03-13

    We present techniques for the estimation of stellar atmospheric parameters (Teff,logg,[Fe/H]) for stars from the SDSS/SEGUE survey. The atmospheric parameters are derived from the observed medium-resolution (R=2000) stellar spectra using non-linear regression models trained either on (1) pre-classified observed data or (2) synthetic stellar spectra. In the first case we use our models to automate and generalize parametrization produced by a preliminary version of the SDSS/SEGUE Spectroscopic Parameter Pipeline (SSPP). In the second case we directly model the mapping between synthetic spectra (derived from Kurucz model atmospheres) and the atmospheric parameters, independently of any intermediate estimates. After training, we apply our models to various samples of SDSS spectra to derive atmospheric parameters, and compare our results with those obtained previously by the SSPP for the same samples. We obtain consistency between the two approaches, with RMS deviations of 150K in Teff, 0.35dex in logg, and 0.22dex in [Fe/H]. The models are applied to pre-processed spectra, either via Principal Components Analysis or a Wavelength Range Selection method, which employs a subset of the full 3850-9000A spectral range. This is both for computational reasons, and because it delivers higher accuracy. From an analysis of cluster candidates with available SDSS spectroscopy (M15, M13, M2, and NGC2420), we find evidence for small systematic offsets in Teff and/or logg for the atmospheric parameter estimates from the model trained on real data with the SSPP. Thus, this model turns out to derive more precise, but less accurate, atmospheric parameters than the model trained on synthetic data.

  12. Development of Radar Navigation and Radio Data Transmission for Microhole Coiled Tubing Bottom Hole Assemblies

    SciTech Connect (OSTI)

    Larry G. Stolarczyk; Gerald L. Stolarczyk; Larry Icerman; John Howard; Hooman Tehrani

    2007-03-25

    This Final Technical Report summarizes the research and development (R&D) work performed by Stolar Research Corporation (Stolar) under U.S. Department of Energy (DOE) Contract Number DE-FC26-04NT15477. This work involved the development of radar navigation and radio data transmission systems for integration with microhole coiled tubing bottom hole assemblies. Under this contract, Stolar designed, fabricated, and laboratory and field tested two advanced technologies of importance to the future growth of the U.S. oil and gas industry: (1) real-time measurement-while-drilling (MWD) for guidance and navigation of coiled tubing drilling in hydrocarbon reservoirs and (2) two-way inductive radio data transmission on coiled tubing for real-time, subsurface-to-surface data transmission. The operating specifications for these technologies are compatible with 3.5-inch boreholes drilled to a true vertical depth (TVD) of 5,000 feet, which is typical of coiled tubing drilling applications. These two technologies (i.e., the Stolar Data Transmission System and Drill String Radar) were developed into pre-commercial prototypes and tested successfully in simulated coiled tubing drilling conditions. Integration of these two technologies provides a real-time geosteering capability with extremely quick response times. Stolar is conducting additional work required to transition the Drill String Radar into a true commercial product. The results of this advanced development work should be an important step in the expanded commercialization of advanced coiled tubing microhole drilling equipment for use in U.S. hydrocarbon reservoirs.

  13. Sandia National Laboratories land use permit for operations at Oliktok Alaska Long Range Radar Station.

    SciTech Connect (OSTI)

    Catechis, Christopher Spyros

    2013-02-01

    The property subject to this Environmental Baseline Survey (EBS) is located at the Oliktok Long Range Radar Station (LRRS). The Oliktok LRRS is located at 70%C2%B0 30' W latitude, 149%C2%B0 53' W longitude. It is situated at Oliktok Point on the shore of the Beaufort Sea, east of the Colville River. The purpose of this EBS is to document the nature, magnitude, and extent of any environmental contamination of the property; identify potential environmental contamination liabilities associated with the property; develop sufficient information to assess the health and safety risks; and ensure adequate protection for human health and the environment related to a specific property.

  14. ARM - PI Product - Merged and corrected 915 MHz Radar Wind Profiler moments

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Comments?govInstrumentsnoaacrnBarrow, Alaska OutreachCalendar NSAProductsMerged and corrected 915 MHz Radar Wind

  15. Moab Site Installs Radar Unit to Monitor for Future Potential Rockfalls |

    Broader source: Energy.gov (indexed) [DOE]

    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 Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustmentsShirleyEnergyTher i nAand DOE SafetyofDepartment.Efficiency RebateDepartment of Energy radar

  16. Forthcoming Upgrades to the ARM MMCRs: Improved Radar Processor and Dual-Polarization

    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: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would likeUniverse (Journal Article)Forthcoming Upgrades to the ARM MMCRs: Improved Radar

  17. To cite this document: Mure-Dubois, James and Vincent, Franois and Bonacci, David Sonar and radar SAR processing for parking lot detection. (2011) In

    E-Print Network [OSTI]

    Mailhes, Corinne

    2011-01-01

    SAR processing for parking lot detection. (2011) In: International Radar Symposium (IRS) 2011, 07-oatao@inp-toulouse.fr #12;Sonar and Radar SAR Processing for Parking Lot Detection James Mure-Dubois , Franc¸ois Vincent non-trivial test scenes. The chosen application is parking lot detection. Laboratory results obtained

  18. 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]

    Xue, Ming

    sensing of the lower atmosphere. The devel- opment of low-cost, high-spatial density (also short range (WSR-88D) radar and a network of four low-cost radars planned for the Oklahoma test bed by the new of the Atmosphere (CASA). Such networks are meant to adaptively probe the lower atmosphere that is often missed

  19. Compressive radar with off-grid targets: a perturbation approach This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Fannjiang, Albert

    Compressive radar with off-grid targets: a perturbation approach This article has been downloaded.1088/0266-5611/29/5/054008 Compressive radar with off-grid targets: a perturbation approach Albert Fannjiang1,3 and Hsiao-Chieh Tseng2 1. In particular, a simple, perturbation method is developed to reduce the gridding error for off-grid targets

  20. Radar Remote Sensing Estimates of Waves and Wave Forcing at a Tidal Inlet GUILLERMO M. DAZ MNDEZ AND MERRICK C. HALLER

    E-Print Network [OSTI]

    Haller, Merrick

    Radar Remote Sensing Estimates of Waves and Wave Forcing at a Tidal Inlet GUILLERMO M. DÍAZ MÉNDEZ transformation through a tidal inlet is investigated with radar remote sensing. The frequency of wave breaking-wave conditions, in good agreement (R 5 0.95) with observations. 1. Introduction Remote sensing technology offers

  1. Updated database plus software for line-mixing in CO2 infrared spectra and their test using laboratory spectra

    E-Print Network [OSTI]

    Gamache, Robert R.

    for the space-borne detection of carbon dioxide sources and sinks. & 2010 Elsevier Ltd. All rights reserved. 1 March 2010 Keywords: CO2 Line mixing Infrared spectra Remote sensing a b s t r a c t In a previous, temperature and pressure pro- files, CO2 atmospheric amount, see Sec. VII.4 of Ref. [1]). For such remote

  2. Wind Speed Dependence of Single-Site Wave-Height Retrievals from High-Frequency Radars

    E-Print Network [OSTI]

    Miami, University of

    -order returns to the ocean surface wave energy spectra. Methods to invert the Barrick (1972) equations, Georgia Institute of Technology, Savannah, Georgia @ Department of Earth and Ocean Sciences, Marine

  3. UWB radar technique for arc detection in coaxial cables and waveguides

    SciTech Connect (OSTI)

    Maggiora, R.; Salvador, S.

    2009-11-26

    As spread spectrum technology has revolutionized the communications industry, Ultra Wide Band (UWB) technology is dramatically improving radar performances. These advanced signal processing techniques have been adapted to coaxial cables and waveguides to provide new features and enhanced performance on arc detection. UWB signals constituted by a sequence of chips (properly chosen to reduce side lobes and to improve detection accuracy) are transmitted along the transmission lines at a specified Pulse Repetition Frequency (PRF) and their echoes are received by means of directional couplers. The core of the receiver is an ultra high-speed correlator implemented in a Digital Signal Processor (DSP). When a target (arc) is detected, its position and its 'radar cross section' are calculated to be able to provide the arc position along the transmission line and to be able to classify the type of detected arc. The 'background scattering' is routinely extracted from the received signal at any pulse. This permits to be resilient to the background structure of transmission lines (bends, junctions, windows, etc.). Thanks to the localization feature, segmentation is also possible for creating sensed and non-sensed zones (for example, to be insensitive to antenna load variations)

  4. On the computation of preliminary orbits for space debris with radar observations

    E-Print Network [OSTI]

    Giovanni F. Gronchi; Linda Dimare; Davide Bracali Cioci; Helene Ma

    2015-01-29

    We introduce a new method to perform preliminary orbit determination for space debris on low Earth orbits (LEO). This method works with tracks of radar observations: each track is composed by $n\\ge 4$ topocentric position vectors per pass of the satellite, taken at very short time intervals. We assume very accurate values for the range $\\rho$, while the angular positions (i.e. the line of sight, given by the pointing of the antenna) are less accurate. We wish to correct the errors in the angular positions already in the computation of a preliminary orbit. With the information contained in a pair of radar tracks, using the laws of the two-body dynamics, we can write 8 equations in 8 unknowns. The unknowns are the components of the topocentric velocity orthogonal to the line of sight at the two mean epochs of the tracks, and the corrections $\\Delta$ to be applied to the angular positions. We take advantage of the fact that the components of $\\Delta$ are typically small. We show the results of some tests, performed with simulated observations, and compare this algorithm with Gibbs' method and the Keplerian integrals method.

  5. A High Resolution, Light-Weight, Synthetic Aperture Radar for UAV Application

    SciTech Connect (OSTI)

    Doerry, A.W.; Hensley, W.H.; Stence, J.; Tsunoda, S.I. Pace, F.; Walker, B,C.; Woodring, M.

    1999-05-27

    (U) Sandia National Laboratories in collaboration with General Atomics (GA) has designed and built a high resolution, light-weight, Ku-band Synthetic Aperture Radar (SAR) known as "Lynx". Although Lynx can be operated on a wide variety of manned and unmanned platforms, its design is optimized for use on medium altitude Unmanned Aerial Vehicles (UAVS). In particular, it can be operated on the Predator, I-GNAT, and Prowler II platforms manufactured by GA. (U) The radar production weight is less than 120 lb and operates within a 3 GHz band from 15.2 GHz to 18.2 GHz with a peak output power of 320 W. Operating range is resolution and mode dependent but can exceed 45 km in adverse weather (4 mm/hr rain). Lynx has operator selectable resolution and is capable of 0.1 m resolution in spotlight mode and 0.3 m resolution in stripmap mode, over substantial depression angles (5 to 60 deg) and squint angles (broadside ±45 deg). Real-time Motion Compensation is implemented to allow high-quality image formation even during vehicle turns and other maneuvers.

  6. Signatures of Granulation in the Spectra of K-Dwarfs

    E-Print Network [OSTI]

    I. Ramirez; C. Allende Prieto; D. L. Lambert; M. Asplund

    2007-12-03

    Very high resolution (R>150,000) spectra of a small sample of nearby K-dwarfs have been acquired to measure the line asymmetries and central wavelength shifts caused by convective motions present in stellar photospheres. This phenomenon of granulation is modeled by 3D hydrodynamical simulations but they need to be confronted with accurate observations to test their realism before they are used in stellar abundance studies. We find that the line profiles computed with a 3D model agree reasonably well with the observations. The line bisectors and central wavelength shifts on K-dwarf spectra have a maximum amplitude of only about 200 m/s and we have been able to resolve these granulation effects with a very careful observing strategy. By computing a number of iron lines with 1D and 3D models (assuming local thermodynamic equilibrium), we find that the impact of 3D-LTE effects on classical iron abundance determinations is negligible.

  7. Absorption Features in Spectra of Magnetized Neutron Stars

    SciTech Connect (OSTI)

    Suleimanov, V.; Hambaryan, V.; Neuhaeuser, R.; Potekhin, A. Y.; Pavlov, G. G.; Adelsberg, M. van; Werner, K.

    2011-09-21

    The X-ray spectra of some magnetized isolated neutron stars (NSs) show absorption features with equivalent widths (EWs) of 50-200 eV, whose nature is not yet well known.To explain the prominent absorption features in the soft X-ray spectra of the highly magnetized (B{approx}10{sup 14} G) X-ray dim isolated NSs (XDINSs), we theoretically investigate different NS local surface models, including naked condensed iron surfaces and partially ionized hydrogen model atmospheres, with semi-infinite and thin atmospheres above the condensed surface. We also developed a code for computing light curves and integral emergent spectra of magnetized neutron stars with various temperature and magnetic field distributions over the NS surface. We compare the general properties of the computed and observed light curves and integral spectra for XDINS RBS 1223 and conclude that the observations can be explained by a thin hydrogen atmosphere above the condensed iron surface, while the presence of a strong toroidal magnetic field component on the XDINS surface is unlikely.We suggest that the harmonically spaced absorption features in the soft X-ray spectrum of the central compact object (CCO) 1E 1207.4-5209 (hereafter 1E 1207) correspond to peaks in the energy dependence of the free-free opacity in a quantizing magnetic field, known as quantum oscillations. To explore observable properties of these quantum oscillations, we calculate models of hydrogen NS atmospheres with B{approx}10{sup 10}-10{sup 11} G(i.e., electron cyclotron energy E{sub c,e}{approx}0.1-1 keV) and T{sub eff} = 1-3 MK. Such conditions are thought to be typical for 1E 1207. We show that observable features at the electron cyclotron harmonics with EWs {approx_equal}100-200 eV can arise due to these quantum oscillations.

  8. Spectra of Relic Gravitons and Brans-Dicke Theory

    E-Print Network [OSTI]

    B. K. Sahoo

    2004-06-11

    The spectra of relic gravitational waves produced as a result of cosmological expansion of the inflationary models are derived in Brans-Dicke theory of gravity.The time dependence of the very early Hubble parameter and matter energy density are derived from frequency dependent spectrum of relic gravitational waves.Also it is found that Brans-Dicke scalar field contributes to the energy density of relic gravitons.

  9. Transmission spectra of two-dimensional quantum structures

    E-Print Network [OSTI]

    Kia Manouchehri; J. B. Wang

    2006-09-05

    To study the ballistic transport of charge carriers in nano-structured quantum devices, a highly efficient numerical technique is developed, which provides continuous transmission spectra for arbitrarily complex potential geometries in two dimensions. We apply the proposed method to single and double barrier structures and compare the results with those obtained using standard techniques for computing transmission coefficients. Excellent numerical agreement as well as considerable computational saving is demonstrated.

  10. Software realization of the complex spectra analysis algorithm in R

    E-Print Network [OSTI]

    Bakhrushin, Vladimir

    2015-01-01

    Software realization of the complex spectra decomposition on unknown number of similarcomponents is proposed.The algorithm is based on non-linear minimizing the sum of squared residuals of the spectrum model. For the adequacy checking the complex of criteria is used.It tests the model residuals correspondence with the normal distribution, equality to zero of their mean value and autocorrelation. Also the closeness of residuals and experimental data variances is checked.

  11. Mechanical approach to the neutrons spectra collimation and detection

    SciTech Connect (OSTI)

    Sadeghi, H.; Roshan, M. V.

    2014-11-15

    Neutrons spectra from most of known sources require being collimated for numerous applications; among them one is the Neutron Activation Analysis. High energy neutrons are collimated through a mechanical procedure as one of the most promising methods. The output energy of the neutron beam depends on the velocity of the rotating Polyethylene disks. The collimated neutrons are then measured by an innovative detection technique with high accuracy.

  12. Fluorescent spectra of chromatographic fractions of crude oils 

    E-Print Network [OSTI]

    Dixon, William Samuel

    1952-01-01

    of Results, ~ ~ ~ ~ ~ ~ i ~ ~ ~ ~ 25 XI. Bibliography. ~ . "" o" . . ". .. . . . ~ 26 XII. Appendix PURPOSE This invest1gation ?as undertaken in an effort to develop a means of the chromatographic separation of a crude oil~ and to examine... these fractions by spectro;ra hic means to determines (l) v'hether there are differences in the fluorescent spectra of the various chromatographic fractions oi a given crude oil, and (2) whether there are differ- ences between similar chromatographic fractions...

  13. Intermittency Spectra of the Magnetic Field in Solar Active Valentyna Abramenko and Vasyl Yurchyshyn

    E-Print Network [OSTI]

    - Physical Data and Processes: turbulence 1. Introduction Energy release processes in solar active regions of the solar disk from January 1997 until December 2006 are utilized. Data from the Michelson Doppler Imager is straightforward and reliable. Another type of energy release is an impulsive process known as solar flares

  14. Non-linear power spectra in the synchronous gauge

    E-Print Network [OSTI]

    Jai-chan Hwang; Hyerim Noh; Donghui Jeong; Jinn-Ouk Gong; Sang Gyu Biern

    2014-08-20

    We study the non-linear corrections to the matter and velocity power spectra in the synchronous gauge (SG). We consider the perturbations up to third order in a zero-pressure fluid in flat cosmological background, which is relevant for the non-linear growth of cosmic structure. As a result, we point out that the SG is an inappropriate coordinate choice when handling the non-linear growth of the large-scale structure. Although the equations in the SG happen to coincide with those in the comoving gauge (CG) to linear order, they differ from second order. In particular, the second order hydrodynamic equations in the the SG are apparently in the Lagrangian form, whereas those in the CG are in the Eulerian form. Thus, the non-linear power spectra naively presented in the original SG show strange behavior quite different from the result of the Newtonian theory even on sub-horizon scales. The power spectra in the SG show regularized behaviors only after we introduce convective terms in the second order so that the equations in two gauges coincide to the second order.

  15. cbs4denver.com -CSU Researches Develop Improved Radar For Troops http://cbs4denver.com/local/csu.radar.improvements.2.697978.html 1 of 2 4/11/2008 9:17 PM

    E-Print Network [OSTI]

    Chong, Edwin K. P.

    Lifestyle Beauty & Style Family Apr 11, 2008 5:09 pm US/Mountain Digg | Facebook | E-mail | Print Reporting be to develop the actual radars which Chong says could be small portable units with a battery and some sort

  16. Radar Nowcasting of Total Lightning over the Kennedy Space Center GREGORY N. SEROKA,* RICHARD E. ORVILLE, AND COURTNEY SCHUMACHER

    E-Print Network [OSTI]

    Radar Nowcasting of Total Lightning over the Kennedy Space Center GREGORY N. SEROKA,* RICHARD E-derived predictors of total lightning over the Kennedy Space Center (KSC). Four years (2006­ 09) of summer (June houses the Kennedy Space Center (KSC) and its critical daily operations. While examining storms over

  17. REDUCTION OF VIBRATION-INDUCED ARTIFACTS IN SYNTHETIC-APERTURE-RADAR IMAGERY USING THE FRACTIONAL FOURIER TRANSFORM

    E-Print Network [OSTI]

    Santhanam, Balu

    REDUCTION OF VIBRATION-INDUCED ARTIFACTS IN SYNTHETIC-APERTURE-RADAR IMAGERY USING THE FRACTIONAL of objects exhibit- ing low-level vibrations are accompanied by localized arti- facts, or ghost targets to the non-stationary nature of the returned signals from vibrating objects. Re- cently, a method based

  18. A 1.56 THz Spot Scanning Radar Range for Fully Polarimetric W-Band Scale Model Measurements

    E-Print Network [OSTI]

    Massachusetts at Lowell, University of

    , with a fourth mixer providing a system phase reference. The full 2x2 complex polarization scattering matrix (PSM simple calibration objects and a tank are presented. Keywords: Compact Range, PSM, Radar, RCS, Scale polarization scattering matrix (PSM) for each resolved scattering center. Theoretically, the PSM provides

  19. Modeling of Tsunami Detection by High Frequency Radar Based on Simulated Tsunami Case Studies in the Mediterranean Sea

    E-Print Network [OSTI]

    Grilli, Stéphan T.

    basin) and HF radar remote sensing to develop and validate a new type of tsunami detection algorithm as low as 5 cm/s, i.e., in deeper water, beyond the shelf and further away from the coast, thus providing to the near- est coastal areas, and thus both their energy spreading is low and their propagation time

  20. The Long Wavelength Array (LWA): A Large HF/VHF Array for Solar Physics, Ionospheric Science, and Solar Radar

    E-Print Network [OSTI]

    Ellingson, Steven W.

    construction in New Mexico, and discuss the scientific goals of the project in the areas of solar, ionosphericThe Long Wavelength Array (LWA): A Large HF/VHF Array for Solar Physics, Ionospheric Science, and Solar Radar Namir E. Kassim Naval Research Laboratory, Washington, DC 20375 Stephen M. White AFRL

  1. An estimate of strong local body forcing and gravity wave radiation based on OH airglow and meteor radar observations

    E-Print Network [OSTI]

    Vadas, Sharon

    with an OH airglow imager and the meteor radar at the MU Observatory in Japan. This was a wave breaking event to anticipate the scales of secondary waves generated through local body forcing and their potentialAn estimate of strong local body forcing and gravity wave radiation based on OH airglow and meteor

  2. Dual-Band Multi-Channel Airborne Radar for Mapping the Internal and Basal Layers of Polar Ice Sheets

    E-Print Network [OSTI]

    Marathe, Kiran Chidambara

    2008-03-06

    peak power of 1.6 kW for collecting data to develop effective ice sheet models. The pulse signal has a duration of 3 us or 10 us. The radar has 1 transmitter and 6 receivers inside the aircraft and an 8 element dipole antenna array mounted beneath...

  3. Evaluation of Terrestrial Laser Scanning and Ground Penetrating Radar for Field-Based High-Throughput Phenotyping in Wheat Breeding 

    E-Print Network [OSTI]

    Thompson, Sean M

    2014-08-05

    laser scanning (TLS) and ground penetrating radar (GPR) have the potential to fill this gap by non-invasively estimating biomass and mapping three-dimensional above- and below-ground vegetation. The research objective was to evaluate the use of TLS...

  4. Effects of Signal Processing and Antenna Frequency on the Geostatistical Structure of Ground-Penetrating Radar Data

    E-Print Network [OSTI]

    Barrash, Warren

    Effects of Signal Processing and Antenna Frequency on the Geostatistical Structure of Ground with application of signal processing or by changing the signal frequency. We perform geostatistical analyses of surface radar reflection profiles in order to investigate the effects of data processing and antenna

  5. Impact of CASA Radar and Oklahoma Mesonet Data Assimilation on the Analysis and Prediction of Tornadic Mesovortices in an MCS

    E-Print Network [OSTI]

    Droegemeier, Kelvin K.

    Impact of CASA Radar and Oklahoma Mesonet Data Assimilation on the Analysis and Prediction and Prediction of Storms, and School of Meteorology, University of Oklahoma, Norman, Oklahoma KEITH BREWSTER Center for Analysis and Prediction of Storms, Norman, Oklahoma JIDONG GAO National Severe Storms

  6. ERAD 2012 -THE SEVENTH EUROPEAN CONFERENCE ON RADAR IN METEOROLOGY AND HYDROLOGY Bird migration monitoring across Europe using

    E-Print Network [OSTI]

    Graaf, Martin de

    monitoring across Europe using weather radar M. de Graaf1, H. Leijnse1, A. Dokter2, J. Shamoun-Baranes2, H for monitoring bird migration across Europe. Reflections from birds (around -10 dBZ) are generally much weaker data from the autumn of 2011 from several stations in western Europe. With the resulting data bird

  7. Type IIb supernova SN 2011dh: Spectra and photometry from the...

    Office of Scientific and Technical Information (OSTI)

    IIb supernova SN 2011dh: Spectra and photometry from the ultraviolet to the near-infrared Citation Details In-Document Search Title: Type IIb supernova SN 2011dh: Spectra and...

  8. PAH FEATURES IN THE ISO SWS01 SPECTRA OF [WR] PLANETARY NEBULAE

    E-Print Network [OSTI]

    Gorny, Slawomir K.

    of observations. Our spectra, obtained with speed = 1, have been reduced using the IA sotware in Garching

  9. Self-mixing detection of backscattered radiation in a single-mode erbium fibre laser for Doppler spectroscopy and velocity measurements

    SciTech Connect (OSTI)

    Dmitriev, A K; Konovalov, A N; Ul'yanov, V A [Institute on Laser and Information Technologies, Russian Academy of Sciences, Shatura, Moscow Region (Russian Federation)

    2014-04-28

    We report an experimental study of the self-mixing effect in a single-mode multifrequency erbium fibre laser when radiation backscattered from an external moving object arrives at its cavity. To eliminate resulting chaotic pulsations in the laser, we have proposed a technique for suppressing backscattered radiation through the use of multimode fibre for radiation delivery. The multifrequency operation of the laser has been shown to lead to strong fluctuations of the amplitude of the Doppler signal and a nonmonotonic variation of the amplitude with distance to the scattering object. In spite of these features, the self-mixing signal was detected with a high signal-to-noise ratio (above 10{sup 2}) when the radiation was scattered by a rotating disc, and the Doppler frequency shift, evaluated as the centroid of its spectrum, had high stability (0.15%) and linearity relative to the rotation rate. We conclude that the self-mixing effect in this type of fibre laser can be used for measuring the velocity of scattering objects and in Doppler spectroscopy for monitoring the laser evaporation of materials and biological tissues. (control of laser radiation parameters)

  10. Infiltrating a thin or single layer opal with an atomic vapour: sub-doppler signals and crystal optics

    E-Print Network [OSTI]

    Moufarej, Elias; Zabkov, Ilya; Laliotis, Athanasios; Ballin, Philippe; Klimov, Vasily; Bloch, Daniel

    2014-01-01

    Artificial thin glass opals can be infiltrated with a resonant alkali-metal vapour, providing novel types of hybrid systems. The reflection at the interface between the substrate and the opal yields a resonant signal, which exhibits sub-Doppler structures in linear spectroscopy for a range of oblique incidences. This result is suspected to originate in an effect of the three-dimensional confinement of the vapour in the opal interstices. It is here extended to a situation where the opal is limited to a few or even a single layer opal film, which is a kind of bidimensional grating. We have developed a flexible one-dimensional layered optical model, well suited for a Langmuir-Blodgett opal. Once extended to the case of a resonant infiltration, the model reproduces quick variations of the lineshape with incidence angle or polarization. Alternately, for an opal limited to a single layer of identical spheres, a three-dimensional numerical calculation was developed. It predicts crystalline anisotropy, which is demon...

  11. Mesoscale Spectra of Mars's Atmosphere Derived from MGS TES Infrared Radiances TAKESHI IMAMURA

    E-Print Network [OSTI]

    and potential energy spectra as a function of horizontal wavenumber. Each spectrum has two different wave spectra of the atmospheric potential energy of Mars at mesoscales (wavelengths of 64­957 km) were obtained-scale ends, the spectra sometimes show prominent steepening with slopes from 2 to 3. The power peaks

  12. Theoretical Studiesof Transannular Interactions. 111. The Absorption and Emission Spectra of a

    E-Print Network [OSTI]

    Glass, Leon

    5063 Theoretical Studiesof Transannular Interactions. 111. The Absorption and Emission Spectra June 13, 1966 Abstract: An interpretationof the absorption and emission spectra of a multilayered and emission spectra of the paracyclophanes.2a In these compounds the sepa- ration of the aromatic rings, which

  13. Electron-Electron Bremsstrahlung Emission and the Inference of Electron Flux Spectra in Solar Flares

    E-Print Network [OSTI]

    Piana, Michele

    to the hard X-ray emission from solar flares, the latter is normally ignored. Such an omission in the study of hard X-ray spectra from solar flares. With the high-resolution hard X- ray spectra madeElectron-Electron Bremsstrahlung Emission and the Inference of Electron Flux Spectra in Solar

  14. Derivation of global hyperspectral resolution surface emissivity spectra from advanced infrared sounder radiance measurements

    E-Print Network [OSTI]

    Li, Jun

    Derivation of global hyperspectral resolution surface emissivity spectra from advanced infrared 9 July 2008; published 6 August 2008. [1] The global IR surface emissivity spectra are very. In this study, global IR surface emissivity spectra have been generated by using AIRS radiance measurements from

  15. The troposphere-to-stratosphere transition in kinetic energy spectra and nonlinear

    E-Print Network [OSTI]

    Wirosoetisno, Djoko

    The troposphere-to-stratosphere transition in kinetic energy spectra and nonlinear spectral fluxes) The troposphere-to-stratosphere transition in kinetic energy spectra and nonlinear spectral fluxes as seen-to-Stratosphere Transition in Kinetic Energy Spectra and Nonlinear Spectral Fluxes as Seen in ECMWF Analyses B. H. BURGESS

  16. Difference spectra of late intermediates of the bacteriorhodopsin photocycle

    SciTech Connect (OSTI)

    Govindjee, R.; Dancshazy, Zs.; Ebrey, T.G. (Univ. of Illinois, Urbana (United States))

    1989-01-01

    The flash-induced difference absorbance spectra of bacteriorhodopsin (BR) were measured at various times after an actinic flash using a diode array spectrophotometer (300-700 nm). Difference spectra for three late bacteriorhodopsin photocycle intermediates M[sup fast] (M[sup f]), M[sup slow] (M[sup s]) and R are reported. The main distinguishing features of the 3 difference spectra at pH = 10.5 and 5C are as follows: M[sup f]: [triangle]A[sub max] = 412 nm, a shoulder at 436 nm, no absorbance change at 350 nm, [triangle]A[sub min] = 565 nm, [triangle]A412/[triangle]A565 = 0.8-0.9. M[sup s]: [triangle]A[sub max] = 412 nm, a shoulder at 386 nm, [triangle]A[sub min] = 570-575 nm, [triangle]A412/[triangle]A575 = 0.6. R: [triangle]A[sub max] = 336 and 350 nm (double peak ), minor peaks at 386 and 412 nms, [triangle]A[sub min] = 585-590 nm; [triangle]A350/[triangle]A585 = 0.2. The t[sub 1/2] of M[sup f], M[sup s] and R and the relative weights of BR570 recovered with these rates are: 1 sec (50%), 3-5 sec (25%) and 35 sec (25%) respectively. These spectral features can also be seen at pH = 7, [minus]16C, and at pH = 9-10.5, 20C. Based on some assumptions, the absorption maximum of R was calculated to be at ca. 550 nm. The extinction coefficient of R is approximately 70% that of light-adapted BR.

  17. Single particle spectra based of modern effective interactions

    E-Print Network [OSTI]

    C. Barbieri

    2006-04-03

    The self-consistent Green's function method is applied to 16O using a G-matrix and Vucom as effective interactions, both derived from the Argonne v18 potential. The present calculations are performed in a larger model space than previously possible. The experimental single particle spectra obtained with the G-matrix are essentially independent of the oscillator length of the basis. The results shows that Vucom better reproduces spin-orbit splittings but tends to overestimate the gap at the Fermi energy.

  18. Resonant Inelastic Scattering Spectra of Free Molecules with Vibrational Resolution

    SciTech Connect (OSTI)

    Hennies, Franz; Pietzsch, Annette; Berglund, Martin; Foehlisch, Alexander; Schmitt, Thorsten; Strocov, Vladimir; Karlsson, Hans O.; Andersson, Joakim; Rubensson, Jan-Erik

    2010-05-14

    Inelastic x-ray scattering spectra excited at the 1s{sup -1{pi}}* resonance of gas phase O{sub 2} have been recorded with an overall energy resolution that allows for well-resolved vibrational progressions. The nuclear wave packet dynamics in the intermediate state is reflected in vibrational excitations of the electronic ground state, and by fine-tuning the excitation energy the dissociation dynamics in the predissociative B{sup '} {sup 3{Pi}}{sub g} final state is controlled.

  19. Wideband radar cross section reduction using two-dimensional phase gradient metasurfaces

    SciTech Connect (OSTI)

    Li, Yongfeng; Qu, Shaobo; Wang, Jiafu; Chen, Hongya; Zhang, Jieqiu; Xu, Zhuo; Zhang, Anxue

    2014-06-02

    Phase gradient metasurface (PGMs) are artificial surfaces that can provide pre-defined in-plane wave-vectors to manipulate the directions of refracted/reflected waves. In this Letter, we propose to achieve wideband radar cross section (RCS) reduction using two-dimensional (2D) PGMs. A 2D PGM was designed using a square combination of 49 split-ring sub-unit cells. The PGM can provide additional wave-vectors along the two in-plane directions simultaneously, leading to either surface wave conversion, deflected reflection, or diffuse reflection. Both the simulation and experiment results verified the wide-band, polarization-independent, high-efficiency RCS reduction induced by the 2D PGM.

  20. Estimating Saturated Hydraulic Conductivity from Surface Ground-Penetrating Radar Monitoring of Infiltration

    E-Print Network [OSTI]

    Léger, Emmanuel; Coquet, Yves

    2013-01-01

    In this study we used Hydrus-1D to simulate water infiltration from a ring infiltrometer. We generated water content profiles at each time step of infiltration, based on a particular value of the saturated hydraulic conductivity while knowing the other van Genuchten parameters. Water content profiles were converted to dielectric permittivity profiles using the Complex Refractive Index Method relation. We then used the GprMax suite of programs to generate radargrams and to follow the wetting front using arrival time of electromagnetic waves recorded by a Ground-Penetrating Radar (GPR). Theoretically, the depth of the inflection point of the water content profile simulated at any infiltration time step is related to the peak of the reflected amplitude recorded in the corresponding trace in the radargram. We used this relationship to invert the saturated hydraulic conductivity for constant and falling head infiltrations. We present our method on synthetic examples and on two experiments carried out on sand. We f...