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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 wind-speed measurements in tornadoes: A comparison of real and simulated spectra  

SciTech Connect (OSTI)

Bluestein and Unruh have discussed the advantages of using a portable doppler radar to map the wind field in tornadoes. during the spring of 1991 a storm-intercept team from the University of Oklahoma (OU) collected data near five supercell tornadoes in Oklahoma and Kansas. Details about the 1-W, 3-cm, 5-deg half-power beamwidth, CW/FM-CW Doppler radar we used and the methods of data collection and analysis are found in Bluestein and Unruh and Bluestein et al. Using the portable radar, we approximately doubled in only one year the number of tornado spectra that had been collected over a period of almost 20 years by NSSL`s fixed-site Doppler radar. In this paper we will compare observed tornado wind spectra with simulated wind spectra (Zmic and Doviak 1975) in order to learn more about tornado structure.

Bluestein, H.B.; LaDue, J.G.; Stein, H.; Speheger, D. [Oklahoma Univ., Norman, OK (United States); Unruh, W.P. [Los Alamos National Lab., NM (United States)

1993-03-01T23:59:59.000Z

4

Doppler-radar wind-speed measurements in tornadoes: A comparison of real and simulated spectra  

SciTech Connect (OSTI)

Bluestein and Unruh have discussed the advantages of using a portable doppler radar to map the wind field in tornadoes. during the spring of 1991 a storm-intercept team from the University of Oklahoma (OU) collected data near five supercell tornadoes in Oklahoma and Kansas. Details about the 1-W, 3-cm, 5-deg half-power beamwidth, CW/FM-CW Doppler radar we used and the methods of data collection and analysis are found in Bluestein and Unruh and Bluestein et al. Using the portable radar, we approximately doubled in only one year the number of tornado spectra that had been collected over a period of almost 20 years by NSSL's fixed-site Doppler radar. In this paper we will compare observed tornado wind spectra with simulated wind spectra (Zmic and Doviak 1975) in order to learn more about tornado structure.

Bluestein, H.B.; LaDue, J.G.; Stein, H.; Speheger, D. (Oklahoma Univ., Norman, OK (United States)); Unruh, W.P. (Los Alamos National Lab., NM (United States))

1993-01-01T23:59:59.000Z

5

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

SciTech Connect (OSTI)

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

Luke,E.; Kollias, P.

2007-08-06T23:59:59.000Z

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)

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7

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

E-Print Network [OSTI]

on a statistical comparison of four cases comprising nearly 6 h of data. Turbulent dissipation rate comparisons 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

8

ARM - Measurement - Radar Doppler  

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

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9

Sandia National Laboratories: TTU Advanced Doppler Radar  

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

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

10

Doppler Radar Wind Profiles Iwan Holleman  

E-Print Network [OSTI]

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

Stoffelen, Ad

11

Using doppler radar images to estimate aircraft navigational heading error  

DOE Patents [OSTI]

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

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

2012-07-03T23:59:59.000Z

12

Monostatic Coherent Radar Sea Clutter Doppler Analysis Matthew Ritchie  

E-Print Network [OSTI]

measurements are potentially ambiguous. Both the PRF and radio frequency used by the radar system are agile to define what PFA the radar system will experience for a given threshold level. This defines the radarsMonostatic Coherent Radar Sea Clutter Doppler Analysis Matthew Ritchie University College London

Haddadi, Hamed

13

E-Print Network 3.0 - airborne doppler radar Sample Search Results  

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

during the austral summer. The study uses Doppler radar data... to understand this phenomenol- ogy because the convection was sampled by ship and aircraft Doppler radars over......

14

Doppler Radar Wind Profiles Iwan Holleman (holleman@knmi.nl)  

E-Print Network [OSTI]

is required before it can be presented to users or assimilated into numerical weather prediction (NWP) models Institute (KNMI), The Netherlands ABSTRACT Doppler weather radars can be employed to determine wind profiles profiles has been performed at KNMI. The verification results indicate that weather radars can provide high

Stoffelen, Ad

15

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

E-Print Network [OSTI]

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

Stoffelen, Ad

16

ASSIMILATION OF DOPPLER RADAR DATA INTO NUMERICAL WEATHER MODELS  

SciTech Connect (OSTI)

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.

Chiswell, S.; Buckley, R.

2009-01-15T23:59:59.000Z

17

Noise correction of turbulent spectra obtained from Acoustic Doppler Velocimeters  

SciTech Connect (OSTI)

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.

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

2014-03-02T23:59:59.000Z

18

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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19

Ka-Band ARM Zenith Radar (KAZR) Instrument Handbook  

SciTech Connect (OSTI)

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.

Widener, K; Bharadwaj, N; Johnson, K

2012-03-06T23:59:59.000Z

20

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

SciTech Connect (OSTI)

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.

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

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

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

E-Print Network [OSTI]

. They can be used to determine the physical location of each radar measurement and to properly map by simplifications vary with the distance between the analyzed storm and the radar. For single time level wind of Radial Velocity with Two Doppler Radars GUOQING GE Center for Analysis and Prediction of Storms

Gao, Jidong

22

EnKF assimilation of high-resolution, mobile Doppler radar data of the 4 May 20071 Greensburg, Kansas supercell into a numerical cloud model2  

E-Print Network [OSTI]

, and low-level vortex strength and20 longevity.21 22 #12;2 1. Introduction1 Radar is one of few atmospheric routinely collected9 across most of the contiguous United States. The two measured radar variables mostEnKF assimilation of high-resolution, mobile Doppler radar data of the 4 May 20071 Greensburg

Xue, Ming

23

Doppler Lidar (DL) Handbook  

SciTech Connect (OSTI)

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.

Newsom, RK

2012-02-13T23:59:59.000Z

24

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

E-Print Network [OSTI]

were analyzed . Page 13 16 1-km CAZM, 1740-1743 CDT, WSR-57 data 4-km CAZN, 1740-1743 CDT, WSR-57 data 8-km CAZM, 1740-1743 CDT, WSR-57 data 10-km CAZM, 1740-'1743 CDT, WSR-57 data 1-km CAVM, 174Z-1748 CDT, Doppler data . 1 May 1977 (2-km...-181Z CDT, 1 Nay 1977 (2-km grid), Doppler data . 38 ix Figure 15 4-km CAVN, 1805-1812 CDT, 1 May 1977 (2-km grid), Doppler data . Paae 16 17 18 19 20 21 5-km CAVM, 1805-1812 Doppler data . 3-kDI CAVM, 1724-1730 Doppler data . . 4-km...

Beaver, Thomas Foster

1980-01-01T23:59:59.000Z

25

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

E-Print Network [OSTI]

equations. The citations on the following pages follows the style of the Jo rnei of the ~Atmos heric Sciences. In seeking dynam1c and thermodynamic information from Doppler data, particular attention has been given to the tornadic thunderstorm...

Rosser, George Philip

1986-01-01T23:59:59.000Z

26

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

SciTech Connect (OSTI)

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.

Chiswell, S

2009-01-11T23:59:59.000Z

27

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

E-Print Network [OSTI]

, nowcasting of severe weather events, and assimilation into numerical weather prediction models). Ongoing research focuses intensively on the use of radar data for assimilation in numerical weather prediction and hydrological models to improve quantitative precipitation forecasts. As part of this goal

28

Detection of supercooled liquid in mixedphase clouds using radar Doppler spectra  

E-Print Network [OSTI]

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

Shupe, Matthew

29

W-band ARM Cloud Radar (WACR) Handbook  

SciTech Connect (OSTI)

The W-band Atmospheric Radiation Measurement (ARM) Program Cloud Radar (WACR) systems are zenith pointing Doppler radars that probe the extent and composition of clouds at 95.04 GHz. The main purpose of this radar is to determine cloud boundaries (e.g., cloud bottoms and tops). This radar reports estimates for the first three spectra moments for each range gate up to 15 km. The 0th moment is reflectivity, the 1st moment is radial velocity, and the 2nd moment is spectral width. Also available are the raw spectra files. Unlike the millimeter wavelength cloud radar (MMCR), the WACR does not use pulse coding and operates in only copolarization and cross-polarization modes.

Widener, KB; Johnson, K

2005-01-05T23:59:59.000Z

30

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

E-Print Network [OSTI]

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.

Nathan Smith

2004-12-21T23:59:59.000Z

31

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

SciTech Connect (OSTI)

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

Biedermann, Laura Butler

2009-09-01T23:59:59.000Z

32

Doppler characteristics of sea clutter.  

SciTech Connect (OSTI)

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.

Raynal, Ann Marie; Doerry, Armin Walter

2010-06-01T23:59:59.000Z

33

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]

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.

Sang Boo Nam

2009-11-17T23:59:59.000Z

34

Turbulence Spectra from Doppler-broadened Spectral Lines: Tests of the Velocity Channel Analysis and Velocity Coordinate Spectrum Techniques  

E-Print Network [OSTI]

Turbulent motions induce Doppler shifts of observable emission and absorption lines motivating studies of turbulence using precision spectroscopy. We provide the numerical testing of the two most promising techniques, Velocity Channel Analysis (VCA) and Velocity Coordinate Spectrum (VCS). We obtain an expression for the shot noise that the discretization of the numerical data entails and successfully test it. We show that the numerical resolution required for recovering the underlying turbulent spectrum from observations depend on the spectral index of velocity fluctuations, which makes low resolution testing misleading. We demonstrate numerically that, dealing with absorption lines, sampling of turbulence along just a dozen directions provides a high quality spectrum with the VCS technique.

A. Chrupnov; A. Lazarian

2008-11-07T23:59:59.000Z

35

Millimeter Wave Cloud Radar (MMCR) Handbook  

SciTech Connect (OSTI)

The millimeter cloud radar (MMCR) systems probe the extent and composition of clouds at millimeter wavelengths. The MMCR is a zenith-pointing radar that operates at a frequency of 35 GHz. The main purpose of this radar is to determine cloud boundaries (e.g., cloud bottoms and tops). This radar will also report radar reflectivity (dBZ) of the atmosphere up to 20 km. The radar possesses a doppler capability that will allow the measurement of cloud constituent vertical velocities.

KB Widener; K Johnson

2005-01-30T23:59:59.000Z

36

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]

Studies . a. Ground Flash Density b. First Stroke Peak Current . . c. Diurnal Cycle 2. Thunderstorm Characteristics a. Thunderstorm Electrification . . . . . . . b. Thunderstorm Activity . 3. Radar Studies . a. Radar Analysis b. Vertical Profiles... Mexico. Taylor (1978) also found the center of activity to be associated with the supercooled cloud layer between the regions of ? 5'C and ? 20'C. One theory of thunderstorm electrification supports the idea of an ice-related precipitation...

Gremillion, Michael Shane

1998-01-01T23:59:59.000Z

37

Spatial-temporal mesoscale modelling of rainfall intensity using gage and radar data  

E-Print Network [OSTI]

Spatial-temporal mesoscale modelling of rainfall intensity using gage and radar data Montserrat fields. Doppler radar data offer better spatial and temporal coverage, but Doppler radar measures values. We use spatial logistic regression to model the probability of rain for both sources of data

Reich, Brian J.

38

Doppler Tomography  

E-Print Network [OSTI]

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.

T. R. Marsh

2000-11-01T23:59:59.000Z

39

Sandia National Laboratories: 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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -theErikGroundbreakingStandardsTCES Sandia Researchers Win

40

Doppler segmentation  

E-Print Network [OSTI]

is then 2 x 10 Hz/sec. With this frequency modulation rate, the 5 usec pulse would obta1n a 100 MHz bandwidth and, from Equation (3. 2), the system would be able to provide a 1. 5 meter range resolut1on. 5. Transmiss1on Power In the previous s1gnal... 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...

Yeh, Chih-Ping

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Doppler flowmeter  

DOE Patents [OSTI]

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.

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

1981-11-13T23:59:59.000Z

42

Prospects of the WSR-88D Radar for Cloud Studies  

E-Print Network [OSTI]

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 allow observations of a...

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

2011-04-01T23:59:59.000Z

43

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

E-Print Network [OSTI]

of the radar beam for the NCAR CP-3 and CP-4 Doppler radars and the NOAA/TOGA Doppler radar as a function of beamwidth 3 Maximum ref lectivity at selected heights and the range to the closest radar, at 4. 4 km, for the convective cells from the 10-11 June... Maximum ref lectivity at selected heights and the range to the NOAA/TOGA Doppler radar, at 3. 9 km, for the convective cells from the 2 December 1988 monsoon case 21 21 51 56 63 70 76 Table 8 As in Table 7, except for the convective cells from...

Lutz, Kurt Reed

1992-01-01T23:59:59.000Z

44

Imaging synthetic aperture radar  

DOE Patents [OSTI]

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.

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

1997-01-01T23:59:59.000Z

45

A radar study of the interaction between lightning and precipitation  

SciTech Connect (OSTI)

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

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

1988-01-01T23:59:59.000Z

46

Scanning ARM Cloud Radar Handbook  

SciTech Connect (OSTI)

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.

Widener, K; Bharadwaj, N; Johnson, K

2012-06-18T23:59:59.000Z

47

Merged and corrected 915 MHz Radar Wind Profiler moments  

SciTech Connect (OSTI)

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.

Jonathan Helmus,Virendra Ghate, Frederic Tridon

2014-06-25T23:59:59.000Z

48

Merged and corrected 915 MHz Radar Wind Profiler moments  

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

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.

Jonathan Helmus,Virendra Ghate, Frederic Tridon

49

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

SciTech Connect (OSTI)

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

Becherer, R.J.

1991-01-01T23:59:59.000Z

50

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

E-Print Network [OSTI]

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

Swindlehurst, A. Lee

51

QUANTITATIVE ECOLOGY Airborne Radar Observations of the Flight Behavior of Small Insects in  

E-Print Network [OSTI]

, with the vertical air velocity measured at Ã?ight level. We hypothesize that the gregarious behavior of small insectsQUANTITATIVE ECOLOGY Airborne Radar Observations of the Flight Behavior of Small Insects of insects in the convective boundary layer (CBL) is examined by means of proÃ?ling airborne Doppler radar

Geerts, Bart

52

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

E-Print Network [OSTI]

-hydrostatic models, the rapid increase of computer power, and the avail- ability of full-precision radar data in real system must assimilate Doppler radar data including radial velocity and reflectivity, and combine that information with data from satellites, surface stations, and other meso- and micro-scale sensor networks

Xue, Ming

53

High Accuracy Three-Dimensional Radar Sensor Design based on Fuzzy Logic Control Approach  

E-Print Network [OSTI]

High Accuracy Three-Dimensional Radar Sensor Design based on Fuzzy Logic Control Approach Lilin Guo in target tracking. Furthermore, a fuzzy logic controller is proposed to minimize the error between Tracking, Doppler Effect, Fuzzy Logic Controller I. INTRODUCTION Typically, radar sensors are comprised

Fan, Jeffrey

54

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

E-Print Network [OSTI]

products such as bulk hydrometeor identification and Doppler-derived winds to be viewed in real time-depth analysis using radar products, such as Doppler-derived wind vectors and hydrometeor identification, has identification, and rainfall rate. The software was successfully tested during the summers of 2004 and 2005

Rutledge, Steven

55

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

SciTech Connect (OSTI)

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.

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

2012-03-05T23:59:59.000Z

56

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

E-Print Network [OSTI]

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

Moncla, Kerry Louis

2001-01-01T23:59:59.000Z

57

Science Goals for the ARM Recovery Act Radars  

SciTech Connect (OSTI)

Science Goals for the ARM Recovery Act Radars. In October 2008, an ARM workshop brought together approximately 30 climate research scientists to discuss the Atmospheric Radiation Measurement (ARM) Climate Research Facility's role in solving outstanding climate science issues. Through this discussion it was noted that one of ARM's primary contributions is to provide detailed information about cloud profiles and their impact on radiative fluxes. This work supports cloud parameterization development and improved understanding of cloud processes necessary for that development. A critical part of this work is measuring microphysical properties (cloud ice and liquid water content, cloud particle sizes, shapes, and distribution). ARM measurements and research have long included an emphasis on obtaining the best possible microphysical parameters with the available instrumentation. At the time of the workshop, this research was reaching the point where additional reduction in uncertainties in these critical parameters required new instrumentation for applications such as specifying radiative heating profiles, measuring vertical velocities, and studying the convective triggering and evolution of three-dimensional (3D) cloud fields. ARM was already operating a subset of the necessary instrumentation to make some progress on these problems; each of the ARM sites included (and still includes) a cloud radar (operating at 35 or 94 GHz), a cloud lidar, and balloon-borne temperature and humidity sensors. However, these measurements were inadequate for determining detailed microphysical properties in most cases. Additional instrumentation needed to improve retrievals of microphysical processes includes radars at two additional frequencies for a total of three at a single site (35 GHz, 94 GHz, and a precipitation radar) and a Doppler lidar. Evolving to a multi-frequency scanning radar is a medium-term goal to bridge our understanding of two-dimensional (2D) retrievals to the 3D cloud field. These additional microphysical measurements would allow detailed cloud properties to be derived even in the presence of light precipitation. It is important to couple these detailed measurements of cloud microphysics to vertical motion on the cloud scale to couple microphysics with meteorological processes. Vertically pointing Doppler radars provide the vertical motion of cloud particles but, to separate particle motion from air motion, a wind profiler is required. The American Recovery and Reinvestment Act provided the means to address these needs and implement a multi-frequency suite of radars, including scanning radars, at each of the ARM sites. In addition, Doppler lidars have been deployed at several sites. With these new measurement capabilities, ARM has the measurement capabilities to tackle the problems of improving microphysical profile descriptions and evaluating the relationship between our current narrow-field-of view, zenith perspective on clouds to a description of the full 3D cloud field and its temporal evolution.

JH Mather

2012-05-29T23:59:59.000Z

58

Wideband Waveform Design principles for Solid-state Weather Radars  

SciTech Connect (OSTI)

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.

Bharadwaj, Nitin; Chandrasekar, V.

2012-01-01T23:59:59.000Z

59

Submesoscale Coastal Ocean Flows Detected By Very High Frequency Radar and Autonomous Underwater Vehicles  

E-Print Network [OSTI]

Submesoscale Coastal Ocean Flows Detected By Very High Frequency Radar and Autonomous Underwater, autonomous underwater vehicles (AUV), equipped with upward and downward- looking 1.2 MHz Acoustic Doppler and seven snapshots were subsequently time-averaged to form a mean profile from each experiment. In the down-wind

Shay, Lynn K. "Nick"

60

Sandia National Laboratories: Radar Friendly Blades  

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

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

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Downhole pulse radar  

DOE Patents [OSTI]

A borehole logging tool generates a fast rise-time, short duration, high peak-power radar pulse having broad energy distribution between 30 MHz and 300 MHz through a directional transmitting and receiving antennas having barium titanate in the electromagnetically active region to reduce the wavelength to within an order of magnitude of the diameter of the antenna. Radar returns from geological discontinuities are sampled for transmission uphole. 7 figs.

Chang, Hsi-Tien

1987-09-28T23:59:59.000Z

62

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

SciTech Connect (OSTI)

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.

Widener, K; Bharadwaj, N

2012-10-29T23:59:59.000Z

63

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

SciTech Connect (OSTI)

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.

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

2004-09-21T23:59:59.000Z

64

ARM - Measurement - Radar 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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUC : XDCResearch Relatedcontent ARMnumberDoppler ARM Data Discovery Browse

65

ARM - Measurement - Radar reflectivity  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUC : XDCResearch Relatedcontent ARMnumberDoppler ARM Data Discovery

66

Development of the doppler electron velocimeter: theory.  

SciTech Connect (OSTI)

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

Reu, Phillip L.

2007-03-01T23:59:59.000Z

67

Supernova Spectra  

E-Print Network [OSTI]

In this paper are summarized the main advances of the last years in the field of SN spectra . The arguments against a monodimensional sequence for SNIa are discussed as well as the efforts to improve the temporal and spectral coverage of this kind of SNe, with the aim to understand the physics of the explosions for their use as cosmological distance indicators. Although variety is the main character of core-collapse SNe, we have been recently surprised by both exceptionally under- and over-energetic explosions. The main properties of these two extreme subclasses are here reviewed.

M. Turatto

2003-10-29T23:59:59.000Z

68

Overview of Radar Data Compression Valliappa Lakshmanan  

E-Print Network [OSTI]

of radar data is 1km in range and approximately 1 degree in azimuth. 1.1 Size The raw radar data ("Level I are distributed as "moment" data, called Level II. The Level II data comprises a value of radar reflectivity, velocity toward/away from the radar and spectrum width (a measure of the spread of velocity values

Lakshmanan, Valliappa

69

ARM Climate Research Facility Radar Operations Plan  

SciTech Connect (OSTI)

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

Voyles, JW

2012-05-18T23:59:59.000Z

70

Radar polarimetry for geoscience applications  

SciTech Connect (OSTI)

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

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

1990-01-01T23:59:59.000Z

71

High resolution ion Doppler spectroscopy at Prairie View Rotamak  

SciTech Connect (OSTI)

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

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

2012-10-15T23:59:59.000Z

72

Ground Penetrating Radar, Barrow, Alaska  

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

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.

John Peterson

73

915-MHz Radar Wind Profiler (915RWP) Handbook  

SciTech Connect (OSTI)

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.

Coulter, R

2005-01-01T23:59:59.000Z

74

Digital hf radar observations of equatorial spread-F  

SciTech Connect (OSTI)

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

Argo, P.E.

1984-01-01T23:59:59.000Z

75

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

E-Print Network [OSTI]

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

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

2013-01-01T23:59:59.000Z

76

Signal processing for airborne bistatic radar   

E-Print Network [OSTI]

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 ...

Ong, Kian P

77

Antarctic Mapping Project ACTIVE RADAR CALIBRATOR  

E-Print Network [OSTI]

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

Howat, Ian M.

78

ATMOSPHERIC PHYSICS AS OBSERVED BY A VERTICALLY POINTING DOPPLER RADAR Frdric Fabry, and Isztar Zawadzki  

E-Print Network [OSTI]

and precipitation physics and small scale dynamics. We find that many of these images would make wonderful textbook resolution the reflectivity patterns of precipitation (Fabry et al. 1992), the VPR has been upgraded

Fabry, Frederic

79

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

E-Print Network [OSTI]

. Reflectivity examined . B. dBZ gradients examined . C. Radial velocity gradients examined 123 132 139 147 LIST OF FIGURES Figure 1. Map of study area 2. Scan of the April 7 storm at 2200, 2 km in altitude . . 3. April 7/8 reflectivity data / d...BZ: the maximum average dBZ value that was recorded for the scan. Max flash: the maximum average dBZ value that was within two km of any flash. Diff. : the span that separated max dBZ from max flash. This gives an indication of how far from the maximum...

Aclin, Keith Andrew

1995-01-01T23:59:59.000Z

80

Fish embryo multimodal imaging by laser Doppler digital holography  

E-Print Network [OSTI]

A laser Doppler imaging scheme combined to an upright microscope is proposed. Quantitative Doppler imaging in both velocity norm and direction, as well as amplitude contrast of either zebrafish flesh or vasculature is demonstrated.

Verrier, Nicolas; Picart, Pascal; Gross, Michel

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

GMTI radar minimum detectable velocity.  

SciTech Connect (OSTI)

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

Richards, John Alfred

2011-04-01T23:59:59.000Z

82

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

SciTech Connect (OSTI)

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

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

2014-03-01T23:59:59.000Z

83

Raindrop size distributions and associated effective radar reflectivity comparisons /  

E-Print Network [OSTI]

-0. 629869Z6 19. 38 - 8. 59 6. 40 5. o3 0. 0001 0. 0001 0. 0001 0. 0001 F VALUE 184. 66 PR& F 0. 0001 STD DEV 0. 58555116 R-SQUARE 0. 527609 C. V. 41. 2185 LI'ISUBI MEAN 1. 42060192 DF 1 1 1 TYPE IV SS F VALUE 25. 27055111 73... for the detection of severe weather phenomena such as tornadoes, hailstorms, and severe thunderstomns. In addition to storm applications, radar observations, concurrent with di sdrometer determi- nations of raindrop spectra, are important data for cloud physics...

Gosdin, Malcolm Elwood

1982-01-01T23:59:59.000Z

84

Design of a Doppler reflectometer for KSTAR  

SciTech Connect (OSTI)

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.

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

2014-11-15T23:59:59.000Z

85

Equatorial spread {ital F} effects on an HF path: Doppler spread, spatial coherence, and frequency coherence  

SciTech Connect (OSTI)

In August 1990 we participated in the Equatorial Ionospheric Studies sounding rocket campaign near Kwajalein Atoll in the equatorial Pacific region. The campaign included measurements of plasma density using rocket probes and coherent and incoherent scatter radar. During the campaign we fielded high-frequency ionospheric sounders over a bistatic path between Maloelap Atoll and Bikini Atoll in the Marshall Islands. The distance between the transmitters and receivers was 700 km; the ionospheric-reflection region was at 10.18; {degree}N, 168.40;{degree}E, near the magnetic equator. We made three types of measurements: Doppler spread and spatial coherence for a single-frequency CW path; frequency coherence of multiple CW paths; and Doppler spread and time-delay spread for a 60-kHz bandwidth path. We obtained such data over a period of 2 weeks for approximately 2 hours each evening; during this period spread {ital F} was common. Fifty percent of the evenings showed Doppler spread of greater than 6 Hz at the {minus}10 dB level (relative to the peak signal power) and greater than 15 Hz at the {minus}30 dB level. Forty percent of the evenings showed spatial coherence distance of less than 180 m in the direction normal to the bistatic path; 40{percent} of the evenings showed spatial coherence of less than 75 m in the direction parallel to the path. Seventy-five percent of the evenings showed coherence bandwidths of less than 1.5 kHz. {copyright} 1999 American Geophysical Union

Fitzgerald, T.J.; Argo, P.E.; Carlos, R.C. [Los Alamos National Laboratory, Los Alamos, New Mexico (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico (United States)

1999-01-01T23:59:59.000Z

86

Two terminal micropower radar sensor  

DOE Patents [OSTI]

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.

McEwan, T.E.

1995-11-07T23:59:59.000Z

87

Two terminal micropower radar sensor  

DOE Patents [OSTI]

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.

McEwan, Thomas E. (Livermore, CA)

1995-01-01T23:59:59.000Z

88

Radar range measurements in the atmosphere.  

SciTech Connect (OSTI)

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.

Doerry, Armin Walter

2013-02-01T23:59:59.000Z

89

Radar network communication through sensing of frequency hopping  

DOE Patents [OSTI]

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.

Dowla, Farid; Nekoogar, Faranak

2013-05-28T23:59:59.000Z

90

Radar Testbed Characterization for Evaluation of Modulated Scatterer Concepts  

E-Print Network [OSTI]

The following research explores the concepts of communication-embedded radar with an emphasis on radar operation and modulated scatterer concepts. Once firmly established the concept of communication via radar backscatter ...

Casper, Matt

2010-05-27T23:59:59.000Z

91

Radar remote sensing of the lower atmosphere  

E-Print Network [OSTI]

from a numerical weather prediction (NWP) model is examined.numerical weather prediction and empirical site-specific radar clutter models,”

Karimian, Ali

2012-01-01T23:59:59.000Z

92

Ultra-wideband radar motion sensor  

DOE Patents [OSTI]

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.

McEwan, T.E.

1994-11-01T23:59:59.000Z

93

PRECISE DOPPLER MONITORING OF BARNARD'S STAR  

SciTech Connect (OSTI)

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

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

2013-02-20T23:59:59.000Z

94

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

E-Print Network [OSTI]

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...

Crua, Cyril

2015-01-01T23:59:59.000Z

95

Technical Note: Improved implementation of doppler broadening in MCNP5  

SciTech Connect (OSTI)

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

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

2012-09-15T23:59:59.000Z

96

Ultra-wideband radar sensors and networks  

DOE Patents [OSTI]

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.

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

2013-08-06T23:59:59.000Z

97

Magneto-Radar Hidden Metal Detector  

DOE Patents [OSTI]

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.

McEwan, Thomas E. (Las Vegas, NV)

2005-07-05T23:59:59.000Z

98

Computing the apparent centroid of radar targets  

SciTech Connect (OSTI)

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

Lee, C.E.

1996-12-31T23:59:59.000Z

99

Characterizing Ocean Turbulence from Argo, Acoustic Doppler, and Simulation Data  

E-Print Network [OSTI]

. TurbSim models statistics at the height of a turbine hub (5m) well, but do not model coherent eventsCharacterizing Ocean Turbulence from Argo, Acoustic Doppler, and Simulation Data Katherine Mc Ocean Turbulence from Argo, Acoustic Doppler, and Simulation Data written by Katherine McCaffrey has

Fox-Kemper, Baylor

100

A laser Doppler method for noninvasive measurement of flow velocity  

SciTech Connect (OSTI)

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

Biggs, G.L.

1986-11-25T23:59:59.000Z

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Imaging doppler velocimeter with downward heterodyning in the optical domain  

DOE Patents [OSTI]

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

Reu, Phillip L; Hansche, Bruce D

2013-05-21T23:59:59.000Z

102

Nuclear Spectra from Skyrmions  

SciTech Connect (OSTI)

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

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

2009-08-26T23:59:59.000Z

103

E-Print Network 3.0 - analyzing nexrad doppler Sample Search...  

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

microphysical processes. Dual-Doppler techniques are used to analyze the 3D wind field... bulk hydrometeor identification and dual-Doppler wind retrievals. Comparisons are made...

104

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

E-Print Network [OSTI]

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

Lummerzheim, Dirk

105

Widefield laser doppler velocimeter: development and theory.  

SciTech Connect (OSTI)

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

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

2007-03-01T23:59:59.000Z

106

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

SciTech Connect (OSTI)

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.

Chiswell, S.

2010-01-15T23:59:59.000Z

107

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

E-Print Network [OSTI]

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

Droegemeier, Kelvin K.

108

E-Print Network 3.0 - airborne radar sounding Sample Search Results  

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

Radar Remote Sensing Summary: -Based Weather Radar Remote Sensing of Explosive Volcanic Ash Eruption Frank Silvio Marzano, Senior Member, IEEE... radars. These systems can provide...

109

E-Print Network 3.0 - atmospheric radar system Sample Search...  

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

atmospheric... the uncertainty in the relationship between the radar reflectivity and the rainwater mixing ratio, or radar system... of in real radar data processing ... Source:...

110

Iterative synthetic aperture radar imaging algorithms   

E-Print Network [OSTI]

Synthetic aperture radar is an important tool in a wide range of civilian and military imaging applications. This is primarily due to its ability to image in all weather conditions, during both the day and the night, ...

Kelly, Shaun Innes

2014-06-30T23:59:59.000Z

111

Radar investigation of the Hockley salt dome  

E-Print Network [OSTI]

: Geophysics RADAR INVESTIGATION OF THE HOCKLEY SALT DOME A Thesis by UAMES ANDREW HLUCHANEK A'pproved as to style and content by: (Head of Departme t ? Member) May 1. 973 ABSTRACT Radar investigation of the Hockley Salt Dome. . (Nay, 1973) James.... THE PROBLEM. Page A. Probing into Unknown Areas in Salt. . B. Equipment Used. II. BACKGROUND MATERIAL. A. Geology of the Hockley Area. . . B. Economic History of the Hockley Dome Area. . 6 1. Oil 2. Gypsum. 3. Salt C. Geophysical Surveys Over...

Hluchanek, James Andrew

1973-01-01T23:59:59.000Z

112

Doppler electron velocimetry : notes on creating a practical tool.  

SciTech Connect (OSTI)

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

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

2008-11-01T23:59:59.000Z

113

artery doppler flow: Topics by E-print Network  

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

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

114

artery doppler velocimetry: Topics by E-print Network  

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

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

115

acoustic doppler velocimeter: Topics by E-print Network  

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

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

116

al ecocardiograma doppler: Topics by E-print Network  

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

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

117

aplicaciones del doppler: Topics by E-print Network  

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

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

118

adaptive spectral doppler: Topics by E-print Network  

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

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

119

Doppler optical coherence microscopy for studies of cochlear mechanics  

E-Print Network [OSTI]

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

Hong, Stanley S.

120

Extracting Fish and Water Velocity from Doppler Profiler Data  

E-Print Network [OSTI]

Extracting Fish and Water Velocity from Doppler Profiler Data �º Ð 1 ¸ � � �¹ � Ý�¹� � 2 1 to measure fish swimming speeds. This is possible when fish form schools that are large enough so that the multiple Doppler sonar beams are sampling the fish speeds at the same time. In situations where fish

deYoung, Brad

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Ground Penetrating Radar in Hydrogeophysics  

SciTech Connect (OSTI)

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

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

2008-01-15T23:59:59.000Z

122

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

SciTech Connect (OSTI)

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.

Christie, M.S.

1990-01-01T23:59:59.000Z

123

DOPPLER SIGNATURES OF THE ATMOSPHERIC CIRCULATION ON HOT JUPITERS  

SciTech Connect (OSTI)

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

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

2013-01-01T23:59:59.000Z

124

The European Weather Radar Network (OPERA): An opportunity for hydrology!  

E-Print Network [OSTI]

at the European level dates back to COST 72 (Measurement of precipitation by radar) which started in 1979The European Weather Radar Network (OPERA): An opportunity for hydrology! Iwan Holleman1 , Laurent (EARS), Ljubljana (Slovenia). 1 Introduction The tradition of weather radar collaboration

Stoffelen, Ad

125

Educational Innovations in Radar Meteorology Prof. S. A. Rutledge  

E-Print Network [OSTI]

of the most memorable aspects of your graduate level education in radar meteorology? 2. Briefly describe and integrating the radar measurements with other observations #12;NCAR CPNCAR CP--3 and CP3 and CP--3 mobile C3Educational Innovations in Radar Meteorology Prof. S. A. Rutledge Department of Atmospheric Science

Rutledge, Steven

126

Tracking butterfly flight paths across the landscape with harmonic radar  

E-Print Network [OSTI]

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

Northampton, University of

127

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

E-Print Network [OSTI]

's curvature, which caused the cell to lie below the radar bean. The decelerating gust line passed the radar station at 2304Z; its position at 2322Z is shown in (Figure ld, 5 mi markers). A wind-direction change of 60 deg and a wind speed in- 35 crease... markers) formed behind the second. The parent cell moved some 10 mi during the hour of its life cycle, and the gust lines dissipated before reaching the radar. At 0240Z the aerovane (not shown) showed a 55 deg shift in wind direction with a speed of 5...

Luckenbach, Guenther Edward

2012-06-07T23:59:59.000Z

128

Soil-penetrating synthetic aperture radar  

SciTech Connect (OSTI)

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

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

1994-12-01T23:59:59.000Z

129

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

E-Print Network [OSTI]

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 ...

Lothon, Marie

130

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

131

Signal to Noise Analysis of iRadar sensors  

SciTech Connect (OSTI)

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.

Fritzke, A; Top, P

2009-09-10T23:59:59.000Z

132

Transmitter passband requirements for imaging radar.  

SciTech Connect (OSTI)

In high-power microwave power amplifiers for radar, distortion in both amplitude and phase should generally be expected. Phase distortions can be readily equalized. Some amplitude distortions are more problematic than others. In general, especially for SAR using LFM chirps, low frequency modulations such as gain slopes can be tolerated much better than multiple cycles of ripple across the passband of the waveform.

Doerry, Armin Walter

2012-12-01T23:59:59.000Z

133

Motion Measurement for Synthetic Aperture Radar.  

SciTech Connect (OSTI)

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.

Doerry, Armin W.

2015-01-01T23:59:59.000Z

134

Micropower impulse radar technology and applications  

SciTech Connect (OSTI)

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

Mast, J., LLNL

1998-04-15T23:59:59.000Z

135

Solar Supergranulation Waves Detected in Surface Doppler Shift  

E-Print Network [OSTI]

Recently Gizon, Duvall and Schou (2002) suggested that supergranulation has a wave-like component. In this paper I show that the same phenomenon can be observed using surface Doppler shift data, thereby confirming their observations. I am also able to measure the dispersion relation to lower wavenumbers and to extend the results for rotation and meridional flows beyond +/-70 degrees latitude.

J. Schou

2002-08-21T23:59:59.000Z

136

Doppler Ultrasound Driven Biomechanical Model of the Brain for  

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

137

Doppler cooling to the Quantum limit M. Chalony,1  

E-Print Network [OSTI]

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

138

An Atlas of Stellar Spectra  

E-Print Network [OSTI]

An Atlas of Stellar Spectra with an Outline of Spectral Classification ? W. W. Morgan Philip C University of California of the University of Chicago #12; An Atlas of Stellar Spectra with an Outline New York The Cambridge University Press London #12; AN ATLAS OF STELLAR SPECTRA With an Outline

Dworetsky, Mike

139

Non-Gaussianity and CMB aberration and Doppler  

SciTech Connect (OSTI)

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

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

2013-09-01T23:59:59.000Z

140

A WhatandWhere Fusion Neural Network for Recognition and Tracking of Multiple Radar Emitters  

E-Print Network [OSTI]

is proposed for classification of radar pulses in autonomous Electronic Support Measure systems. Radar type a high level of performance on complex, incomplete and overlapping radar data. #12; 1 Introduction RadarA What­and­Where Fusion Neural Network for Recognition and Tracking of Multiple Radar Emitters Eric

Grossberg, Stephen

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Development of a Drillrod/Telemetry Radar  

SciTech Connect (OSTI)

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.

Raton Technology Research, Inc.

1999-11-12T23:59:59.000Z

142

Performance limits for Synthetic Aperture Radar.  

SciTech Connect (OSTI)

The performance of a Synthetic Aperture Radar (SAR) 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, no matter how bright the engineer tasked to generate a system design. 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 SAR system. For example, there are definite optimum frequency bands that depend on weather conditions and range, and minimum radar PRF for a fixed real antenna aperture dimension is independent of frequency. 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''.

Doerry, Armin Walter

2006-02-01T23:59:59.000Z

143

The use of composite radar photographs in synoptic weather analysis  

E-Print Network [OSTI]

. 'Weather Su"eau radar ste- tions have been collecting radar observations. These observations were in the form of time lapse motion pictures of their' ppl scopes made during periods when precipitation echoes vere present. The photographic records thus... TEE MATERIALS USED AND TSE STORMS STUDIED The materials used in this study were (I) X6 xxu aud 33 xxx photosraphic records of ppl scopee at several staticuii; (I) a Seiiei of . hourly composite radar photodraphs of storms which occurred on 27 May...

Smith, G. D.

1957-01-01T23:59:59.000Z

144

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

E-Print Network [OSTI]

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

Boyer, Edmond

145

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

SciTech Connect (OSTI)

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

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

2009-08-20T23:59:59.000Z

146

Modeling Of Surface Deformation From Satellite Radar Interferometry...  

Open Energy Info (EERE)

interferometric synthetic aperture radar) analysis of two-year Radarsat satellite data covering the period May 2006 - March 2008. SAR scenes from two orbit geometries are...

147

Sandia National Laboratories: Siting: Wind Turbine/Radar Interference...  

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

and MIT Lincoln Laboratory). The goal is to overcome interference caused by wind turbines on civilian and military radar systems by developing site planning tools,...

148

INTERAGENCY FIELD TEST & EVALUATION OF WIND TURBINE - RADAR INTERFEREN...  

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

the tests and 2) summaries of three field tests designed to measure the impact of wind turbines on current air surveillance radars and the effectiveness of private sector...

149

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...

150

Development and characterization analysis of a radar polarimeter  

E-Print Network [OSTI]

OF FIGURES FIGURE 2a 2b 3a 3b Sa 5b 10 12 13 14 The Typical Radar-to-Target Geometry. Block Diagram of Frequency Modulated Continuous Wave Radar System. Simplified Frequency Modulated-Continuous Wave Radar System. Block Diagram of a Pulse... 8-1 8-2 C-I C-2 C-3 Approximation Nethod for Focusing the Antenna Pair at Some Height h . Linear FM Pulse Compression . . Signal Characteristics of FM Pulse Radar System Frequency and Time Representation of the filter Response. The Block...

Bong, Soei Siang

2012-06-07T23:59:59.000Z

151

Multipoint photonic doppler velocimetry using optical lens elements  

SciTech Connect (OSTI)

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.

Frogget, Brent Copely; Romero, Vincent Todd

2014-04-29T23:59:59.000Z

152

A Fisheye Lens as a Photonic Doppler Velocimetry Probe  

SciTech Connect (OSTI)

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

Frogget, B. C.

2012-08-16T23:59:59.000Z

153

Experimental investigation of velocity biasing in laser Doppler anemometry  

E-Print Network [OSTI]

Tech University; Chair of Advisory Commettee: Dr. Gerald L. Morrison The effects of several velocity bias reduction schemes were invest- igated using a 3-D laser Doppler anemometer and counter type (burst) signal processors. Amongst these schemes... was the McLaughlin Tiederman 3-D weighting factor, time between data weighting factor, equal time interval sampling and analogue instrumentation measurements. The ana- logue instrumentation measurements were obtained from the analogue frequency outputs...

Wiedner, Brian Gregory

1988-01-01T23:59:59.000Z

154

E-Print Network 3.0 - aperture radar capabilities Sample Search...  

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

SURVEILLANCE NEEDS Summary: -area and long- range aircraft surveillance and weather measurement capability is described and a radar network... to acquire replacement radars. The...

155

E-Print Network 3.0 - asteroid radar astronomy Sample Search...  

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

radar astronomy Search Powered by Explorit Topic List Advanced Search Sample search results for: asteroid radar astronomy Page: << < 1 2 3 4 5 > >> 1 The Mechanics of Moving...

156

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

SciTech Connect (OSTI)

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.

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

1994-12-01T23:59:59.000Z

157

Greenland snow accumulation estimates from satellite radar scatterometer data  

E-Print Network [OSTI]

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

Long, David G.

158

INTERDISCIPLINARY SCIENCE AND APPLICATIONS USING SATELLITE RADAR ALTIMETRY  

E-Print Network [OSTI]

latitude coverage Earth Satellite Altimeters Altimeter measures geocentric sea level and ice sheet instrument has been developed at JPL using the principle of radar interferometry · The new measurementINTERDISCIPLINARY SCIENCE AND APPLICATIONS USING SATELLITE RADAR ALTIMETRY C.K. SHUM EE Wave

159

Lake level variations from satellite radar altimetry with  

E-Print Network [OSTI]

Lake level variations from satellite radar altimetry with retracking of multi-leading edge Shirzad level measurements Increase the number of reliable observations particularly in the shoreline cm Descending tracks Time [year] Waterlevel[m]Lake level variations from satellite radar altimetry

Stuttgart, Universität

160

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

E-Print Network [OSTI]

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

Lorenz, Ralph D.

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

An analysis of radar estimated precipitation to rain gauge measurements  

E-Print Network [OSTI]

the surface. These levels included 1.0 1.5@ 2.0 @ 2.5 km, and 3.0 km. Radar precipitation estimates were calculated at each 1.4 2 level using Z = 30ORand Z = 25OR" . The precipitation amounts, as measured by both the gauges and the radar,were used...

Gleason, Byron Edward

1997-01-01T23:59:59.000Z

162

Radar and sonar probing of potash  

E-Print Network [OSTI]

technique to detect reflections at distances greater than 200 m from clay-salt and clay-anhydrite interfaces. In 1972 Holser et al. mapped the flanks of the Pine Prairie salt dome using a radar logging tool with a 1 microsecond pulse at 230 MHz and a... the first four systems Unterberger (1974) mapped the roof of a tunnel in salt and obtained reflections from salt dome flanks, salt pillars and the tops of salt domes. Hluchanek (1973) used the 440 MHz system to map the top of the salt in the United Salt...

Lopez Aguilar, Luis Felipe

1986-01-01T23:59:59.000Z

163

ARM - Field Campaign - NSA Scanning 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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD) by Microtops Atmospheric Optical Depth (AOD) by Microtops ARMgovCampaignsNSA Scanning Radar IOP ARM

164

E-Print Network 3.0 - abnormal doppler enteral Sample Search...  

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

abnormal doppler enteral Page: << < 1 2 3 4 5 > >> 1 1317 September 2009, Hamburg, Germany Poster abstracts The relationship between abdominal circumference and Summary:...

165

E-Print Network 3.0 - abdominal mediante doppler Sample Search...  

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

abdominal mediante doppler Page: << < 1 2 3 4 5 > >> 1 1317 September 2009, Hamburg, Germany Poster abstracts The relationship between abdominal circumference and Summary:...

166

Radar transponder apparatus and signal processing technique  

DOE Patents [OSTI]

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.

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

1996-01-01T23:59:59.000Z

167

Assembly flow simulation of a radar  

SciTech Connect (OSTI)

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

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

1993-10-01T23:59:59.000Z

168

Synthetic aperture radar processing with tiered subapertures  

SciTech Connect (OSTI)

Synthetic Aperture Radar (SAR) is used to form images that are maps of radar reflectivity of some scene of interest, from range soundings taken over some spatial aperture. Additionally, the range soundings are typically synthesized from a sampled frequency aperture. Efficient processing of the collected data necessitates using efficient digital signal processing techniques such as vector multiplies and fast implementations of the Discrete Fourier Transform. Inherent in image formation algorithms that use these is a trade-off between the size of the scene that can be acceptably imaged, and the resolution with which the image can be made. These limits arise from migration errors and spatially variant phase errors, and different algorithms mitigate these to varying degrees. Two fairly successful algorithms for airborne SARs are Polar Format processing, and Overlapped Subaperture (OSA) processing. This report introduces and summarizes the analysis of generalized Tiered Subaperture (TSA) techniques that are a superset of both Polar Format processing and OSA processing. It is shown how tiers of subapertures in both azimuth and range can effectively mitigate both migration errors and spatially variant phase errors to allow virtually arbitrary scene sizes, even in a dynamic motion environment.

Doerry, A.W. [Sandia National Labs., Albuquerque, NM (United States). Synthetic Aperture Radar Dept.

1994-06-01T23:59:59.000Z

169

A novel photonic Doppler velocimetry for transverse velocity measurement  

SciTech Connect (OSTI)

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

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

2013-01-15T23:59:59.000Z

170

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

SciTech Connect (OSTI)

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

Dolan, Daniel H., III; Ao, Tommy

2010-06-01T23:59:59.000Z

171

Holographic laser Doppler imaging of pulsatile blood flow  

E-Print Network [OSTI]

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

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

2015-01-01T23:59:59.000Z

172

UWB RADAR IMAGING SYSTEM WITH TWO-ELEMENT RECEIVING ARRAY ANTENNA  

E-Print Network [OSTI]

-domain focusing and imaging. Simulated and measured radar images demonstrate radar operation to map out a person considerably the level of signals scat- tered by background beyond the radar FOV. Those high-performed antennaUWB RADAR IMAGING SYSTEM WITH TWO-ELEMENT RECEIVING ARRAY ANTENNA Dmitriy L. Sostanovsky1

Southern California, University of

173

Observed radar reflectivity in convectively coupled Kelvin and mixed Rossby-gravity waves  

E-Print Network [OSTI]

be measurable from surface gauges (>0.5 mm/hr). Addition- ally, the area of radar echo at each height of a normalized probability density function (PDF) of radar echo intensity at that level. Our analysis uses radarObserved radar reflectivity in convectively coupled Kelvin and mixed Rossby-gravity waves A. Swann

Yuter, Sandra

174

The inuence of the interplanetary medium on SuperDARN radar scattering occurrence  

E-Print Network [OSTI]

in the frequency range 8±20 MHz (Greenwald et al., 1995). The level of scatter measured by the radars is highlyThe in¯uence of the interplanetary medium on SuperDARN radar scattering occurrence P. Ballatore1- planetary medium on the radar scattering occurrence, related to the whole array of SuperDARN radars

Paris-Sud XI, Université de

175

Geomorphic Evaluation of Radar Imagery of Southeastern Panama and Northwestern Colombia  

E-Print Network [OSTI]

directly from radar imagery . • • • • . • • • . • • . • • Radar chips from the four major landform regions in Darien Province I Panama: plains, low hills I high hills, and mountains. • • • . • . • • . • . . . Comparison of radar imagery and topographic...-Derived Terrain Slope (a) Data for Darien Province I Panama - Plains. • • • • • • • • • • • • • • • • • • 132 Cumulative Frequency Curves of Radar-Derived Terrain Slope (a) Data for Darien Province I Panama - Low Hills. • . . • • • . . • • . . • • • . 133...

Lewis, Anthony J.

1971-02-01T23:59:59.000Z

176

Quality information for radars and radar data I. Holleman, D. Michelson, G. Galli, U. Germann,  

E-Print Network [OSTI]

.7 Beam attenuation 35 5.8 Wet radome attenuation 36 5.9 Wind turbines 37 5.10 Insects and birds 37 5 and anomalous propagation 51 7.1.3 Birds and actively-flying insects 51 7.2 Weather Radar Wind Profiles 51 7 for wind data 49 7.1 Quality factors for wind data 49 7.1.1 Velocity Aliasing 50 7.1.2 Clutter

Stoffelen, Ad

177

Automatic signal processing of front monitor radar for tunneling machines  

SciTech Connect (OSTI)

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

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

1997-03-01T23:59:59.000Z

178

Monitoring internal organ motion with continuous wave radar in CT  

SciTech Connect (OSTI)

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

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

2013-09-15T23:59:59.000Z

179

Wide band stepped frequency ground penetrating radar  

DOE Patents [OSTI]

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).

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

1996-01-01T23:59:59.000Z

180

Electromagnetic Interrogation and the Doppler Shift Using the Method of Mappings  

E-Print Network [OSTI]

Electromagnetic Interrogation and the Doppler Shift Using the Method of Mappings H.T. Banks, Shuhua University Raleigh, NC 27695-8212 December 11, 2009 Abstract We consider the electromagnetic detection of a Doppler shift for an electromagnetic wave reflecting from a moving interface. This entails solving Maxwell

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

182

Earth curvature and atmospheric refraction effects on radar signal propagation.  

SciTech Connect (OSTI)

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.

Doerry, Armin Walter

2013-01-01T23:59:59.000Z

183

Merging Cloud and Precipitation Radar Data Provides a Better  

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

Merging Cloud and Precipitation Radar Data Provides a Better View of Tropical Rain Clouds For original submission and image(s), see ARM Research Highlights http:www.arm.gov...

184

Coherent radar ice thickness measurements over the Greenland ice sheet  

E-Print Network [OSTI]

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

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

2001-12-27T23:59:59.000Z

185

Differences in radar derived rainfall amounts due to sampling intervals  

E-Print Network [OSTI]

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

Zdenek, David James

1986-01-01T23:59:59.000Z

186

3D REGULARIZED VELOCITY FROM 3D DOPPLER RADIAL VELOCITY X. Chen, J.L. Barron, R.E. Mercer  

E-Print Network [OSTI]

3D REGULARIZED VELOCITY FROM 3D DOPPLER RADIAL VELOCITY X. Chen, J.L. Barron, R.E. Mercer Dept, Ontario, M3H 5T4 Paul.Joe@ec.gc.ca ABSTRACT The recent availability of sequences of 3D Doppler radial velocity datasets provides sufficient information to estimate the 3D velocity of Doppler storms. We present

Barron, John

187

Optical Spectra of Dusty Starbursts  

E-Print Network [OSTI]

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

B. M. Poggianti

2000-11-23T23:59:59.000Z

188

Eect of suprathermal electrons on the intensity and Doppler frequency of electron plasma lines  

E-Print Network [OSTI]

scattering radar experiment, the spectral measurement of the so-called up- and downshifted electron plasma correspond, in the backscatter geom- etry, to two Langmuir waves travelling towards and away from the radar, resulting in an enhance- ment of the intensity of the lines above the thermal level. The presence of photo

Paris-Sud XI, Université de

189

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

DOE Patents [OSTI]

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.

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

2000-01-01T23:59:59.000Z

190

Measuring soil moisture with imaging radars  

SciTech Connect (OSTI)

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

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

1995-07-01T23:59:59.000Z

191

Scanning ARM Cloud Radars Part I: Operational Sampling Strategies  

SciTech Connect (OSTI)

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.

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

2014-03-01T23:59:59.000Z

192

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

SciTech Connect (OSTI)

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.

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

2014-11-15T23:59:59.000Z

193

E-Print Network 3.0 - aperture radar intensity Sample Search...  

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

radar must have a large power-aperture product. Second, in order to obtain accurate wind velocities... arrays. The early radars could be pointed in only a few, Fig. 1. RHI...

194

A Radar-like Iron based Nanohybrid as an Efficient and Stable...  

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

Radar-like Iron based Nanohybrid as an Efficient and Stable Electrocatalyst for Oxygen Reduction. A Radar-like Iron based Nanohybrid as an Efficient and Stable Electrocatalyst for...

195

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

E-Print Network [OSTI]

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 ...

Pradipta, Rezy

2006-01-01T23:59:59.000Z

196

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

E-Print Network [OSTI]

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...

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

2001-10-01T23:59:59.000Z

197

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

E-Print Network [OSTI]

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

Sandwell, David T.

198

E-Print Network 3.0 - airborne pulse doppler Sample Search Results  

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

pulse doppler Page: << < 1 2 3 4 5 > >> 1 JOINT DOMAIN LOCALIZEDPROCESSINGUSING MEASURED SPATIAL STEERINGVECTORS* Summary: by f , d sin OIL, f,2vLYdlPRF,where PRF is the pulse...

199

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

E-Print Network [OSTI]

), using the Exoplanet Tracker (ET), a new generation Doppler instrument. The planet orbits HD 102195, a young star with solar metallicity that may be part of the local association. The planet imparts radial

Complutense de Madrid, Universidad

200

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

E-Print Network [OSTI]

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

Williams, Logan P

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

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

E-Print Network [OSTI]

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

Marshall, Hans-Peter

202

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

E-Print Network [OSTI]

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

Kansas, University of

203

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 assembler jobs were saved because of this large order. ProSensing is also planning to engage a local defense for similar cloud radar contracts for customers in India, China and Korea. By developing these complex radar

204

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

E-Print Network [OSTI]

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

Kansas, University of

205

A Low Noise Active Integrated Antenna Receiver for Monopulse Radar Applications  

E-Print Network [OSTI]

radiation pattern suitable for monopulse radar applications. Simulation and measurement methodology- polarization levels has been demonstrated. An FMCW radar transceiver using a quasi-Yagi antenna array has beenA Low Noise Active Integrated Antenna Receiver for Monopulse Radar Applications Sylvia Lin, Yongxi

Itoh, Tatsuo

206

ERADERAD 20062006Proceedings ofProceedings of Detecting weather radar clutter  

E-Print Network [OSTI]

of precipitation for every pixel in a Meteosat-8 scene. Via pixel-level image fusion of the radar data weather radar clutter 2.2 Nowcasting SAF products Measuring and mapping of precipitation from spaceERADERAD 20062006Proceedings ofProceedings of Detecting weather radar clutter using satellite

207

BOREHOLE RADAR ATTENUATION-DIFFERENCE TOMOGRAPHY DURING THE TRACER/TIME-LAPSE TEST AT THE BOISE  

E-Print Network [OSTI]

to those suggested by radar level run attenuation differences, shot-receiver attenuation difference be explained by the difference in support volumes for the radar and chemistry measurements, and alsoBOREHOLE RADAR ATTENUATION-DIFFERENCE TOMOGRAPHY DURING THE TRACER/TIME-LAPSE TEST AT THE BOISE

Barrash, Warren

208

Update on the European Weather Radar Network Iwan Holleman, Laurent Delobbe, and Anton Zgonc  

E-Print Network [OSTI]

(EARS) I. INTRODUCTION The tradition of weather radar collaboration at the European level dates back to COST 72 (Measurement of precipitation by radar) which started in 1979 and which presented its final reUpdate on the European Weather Radar Network (OPERA) Iwan Holleman, Laurent Delobbe, and Anton

Stoffelen, Ad

209

P2.2 Segmenting Radar Reflectivity Data using Texture V. Lakshmanan1,2  

E-Print Network [OSTI]

with a different level of detail. Radar data algorithms (e.g: Wolf- son et al. (1999); Johnson et al. (1998)) have to partition the image values into the K bins. The measurement space (the radar reflectivity valuesP2.2 Segmenting Radar Reflectivity Data using Texture V. Lakshmanan1,2 , R. Rabin1,3 , V. De

Lakshmanan, Valliappa

210

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

E-Print Network [OSTI]

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

Stoffelen, Ad

211

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

E-Print Network [OSTI]

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

Houze Jr., Robert A.

212

Tornado identification from analyses of digital radar data  

E-Print Network [OSTI]

of Yukon, 40 km north- west of NSSL. Later, a cell to the northwest of Oklahoma City developed to str'ong intensity and a funnel cloud was reported over Tinker AFB at 1930 CST. Hist~or of the Yukon Storm During the afternoon, the squall line moved... signature 1n analyses of digital radar data from ceni;ra 1 Oklahoma during the Spring. The data were collected by the l0-cm WSR-57 radar at the National Severe S torms Laboratory at Ilorman, Oklahoma. Three types of numerical analyses were used in th1s...

Pittman, Donald Wayne

2012-06-07T23:59:59.000Z

213

Climatological study of radar echo pictures from Albrook Air Force Base, Panama  

E-Print Network [OSTI]

of the radar beam above the surface of the earth for a two degree antenna tilt (From AWS, 1955). . 9 Echo occurrence chart of radar data observed at Albrook AFB, Panama, for the month of January, 1962 Echo occurrence chart of radar date observed... at Albrook AFB, Panama, for the month of April, 1961 Echo occurrence chart of radar data observed at Albrook AFB, Panama, for the month of July, 1961 16 17 18 Topography and radar echo occurrence profiles for a circle of 75-statute-mile radius from...

Bowen, Christopher

2012-06-07T23:59:59.000Z

214

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

SciTech Connect (OSTI)

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

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

1994-11-18T23:59:59.000Z

215

Assessment Of The Wind Farm Impact On The Radar  

E-Print Network [OSTI]

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 ...

Norman, Evgeny D

2010-01-01T23:59:59.000Z

216

Development and Improvement of Airborne Remote Sensing Radar Platforms  

E-Print Network [OSTI]

, and several structures are also developed to enable a NASA P-3 to support a 15-element MCoRDS array, as well as three other radar antenna-arrays used for cryospheric surveying. Together, these aircraft have flown almost 200 missions and collected 550 TB...

Arnold, Emily J.

2013-08-31T23:59:59.000Z

217

Synthetic Aperture Radar Imaging with Motion Estimation and Liliana Borcea  

E-Print Network [OSTI]

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

Papanicolaou, George C.

218

Synthetic aperture radar and interferometry development at Sandia National Laboratories  

SciTech Connect (OSTI)

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

NONE

1993-04-01T23:59:59.000Z

219

2003 Mercury Computer Systems, Inc. Beamforming for Radar  

E-Print Network [OSTI]

© 2003 Mercury Computer Systems, Inc. Beamforming for Radar Systems on COTS Heterogeneous ComputingHeterogeneous Computing PlatformsPlatforms Jeffrey A. Rudin Mercury Computer Systems, Inc. High Performance Embedded Computing (HPEC) Conference September 23, 2003 #12;2© 2003 Mercury Computer Systems, Inc. Outline

Kepner, Jeremy

220

Automatic Radar Antenna Scan Type Recognition in Electronic  

E-Print Network [OSTI]

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

Barshan, Billur

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Tracking Severe Weather Storms in Doppler Radar Images D. Cheng 1 , R. E. Mercer 1 , J. L. Barron 1 and P. Joe 2  

E-Print Network [OSTI]

meteorologist's perception. 1 Introduction Because of the devastation caused by severe storms, the forecasting we have developed an automatic storm tracking system. Tracking past storm movement is a prerequisite to forecasting future storm movement and minimizing property damage. Physically, a storm is an area of updraft

Barron, John

222

EnKF Assimilation of High-Resolution, Mobile Doppler Radar Data of the 4 May 2007 Greensburg, Kansas, Supercell into a Numerical Cloud Model  

E-Print Network [OSTI]

Kalman filter (EnKF) technique into a non- hydrostatic, compressible numerical weather prediction model weather prediction (NWP) models to improve under- standing of convective storm dynamics is now a fairly, Kansas, Supercell into a Numerical Cloud Model ROBIN L. TANAMACHI,*,1,# LOUIS J. WICKER,@ DAVID C. DOWELL

Xue, Ming

223

TIDAL TURBULENCE SPECTRA FROM A COMPLIANT MOORING  

SciTech Connect (OSTI)

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.

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

2013-06-13T23:59:59.000Z

224

atomic recoil spectra: Topics by E-print Network  

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

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

225

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

SciTech Connect (OSTI)

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

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

1990-05-01T23:59:59.000Z

226

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

E-Print Network [OSTI]

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

Rhodes, T. L.

227

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

E-Print Network [OSTI]

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

Zhang, Bo

2013-01-01T23:59:59.000Z

228

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

SciTech Connect (OSTI)

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

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

2010-10-15T23:59:59.000Z

229

Optical frequency standards for gravitational wave detection using satellite Doppler velocimetry  

E-Print Network [OSTI]

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.

Vutha, Amar C

2015-01-01T23:59:59.000Z

230

Congrs SHF : Hydromtrie 2013, Paris, 15-16 mai 2013 Dramais et al. Jaugeage par radar mobile JAUGEAGE PAR RADAR MOBILE,  

E-Print Network [OSTI]

measurement using SVR (Surface Velocity Radar) can be used to measure river discharge during floods surface velocities, additional measurements (bathymetry, velocity profiles, water level) are needed the radar method and other conventional discharge measurements. The quality of the results is very

Boyer, Edmond

231

Forensic Application of FM-CW and Pulse Radar  

SciTech Connect (OSTI)

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.

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

2003-01-01T23:59:59.000Z

232

Radar antenna pointing for optimized signal to noise ratio.  

SciTech Connect (OSTI)

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.

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

2013-01-01T23:59:59.000Z

233

Applicability of radar observations to the prediction of storm runoff  

E-Print Network [OSTI]

of Depaverne. (Yiembe~ 1967 (Yonwh) (Yea ) ABSTRACT Rainfall-runoff relaL'ronships fox 18 storms over the Little Nashita River basin in Oklahoma are studied in order to develop a method for predicting storm losses based on weather-radar observational..., for the use of their computer facilities. Credit is due Mr. M. A. Hartman, Chief Research Engineer, Agricultural Research Service, Chickasha, Oklahoma, for his assistance in obtaining treamflow and rainfall data from records maintained by the Agricultural...

Johnson, Odell Monroe

2012-06-07T23:59:59.000Z

234

Radar echo processing with partitioned de-ramp  

DOE Patents [OSTI]

The spurious-free dynamic range of a wideband radar system is increased by apportioning de-ramp processing across analog and digital processing domains. A chirp rate offset is applied between the received waveform and the reference waveform that is used for downconversion to the intermediate frequency (IF) range. The chirp rate offset results in a residual chirp in the IF signal prior to digitization. After digitization, the residual IF chirp is removed with digital signal processing.

Dubbert, Dale F.; Tise, Bertice L.

2013-03-19T23:59:59.000Z

235

CHAPTER 2: Analysis of cloud radar data 21 1000 1030 1100 1130 1200 1230 1300 1330  

E-Print Network [OSTI]

, and the corresponding noise­ equivalent reflectivity at 1 km measured by the 94 GHz radar (using the cloud­free gates the sensitivity of the radar is to subtract an estimate of the noise â?? N from the measured average power â?¢ P of magnitude below the noise level. Of­ ten rain radars simply reject the data that fall below a particular

Hogan, Robin

236

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

E-Print Network [OSTI]

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

Henderson, Rodney Stuart

1979-01-01T23:59:59.000Z

237

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

E-Print Network [OSTI]

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

Cai, Long

238

Progress towards an accurate determination of the Boltzmann constant by Doppler spectroscopy  

E-Print Network [OSTI]

, 27] consists in recording the Doppler profile of a well- isolated absorption line of an atomic absorption profile of a line in a gas of ammonia at thermal equilibrium. This optical method based) ppm broadening of the absorption linewidth. We also show that, in our well chosen experimental

239

Improved forecasts of extreme weather events by future space borne Doppler wind lidar  

E-Print Network [OSTI]

sensitive areas. To answer these questions simulation experiments with state-of-the-art numerical weather prediction (NWP) models have proved great value to test future meteorological observing systems a prioriImproved forecasts of extreme weather events by future space borne Doppler wind lidar Gert

Marseille, Gert-Jan

240

The Impact of Doppler Spreading on Delay Performance over Multi-hop Wireless Communications  

E-Print Network [OSTI]

promising technologies to provide high data rate transmission through wireless link in multi-hop networks-to-end delay performance over multi-hop wireless transmission. In this paper, we study the impact of Doppler communications are very promising technologies for next generation network to provide high data rate transmission

Haddadi, Hamed

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

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

E-Print Network [OSTI]

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

Stoffelen, Ad

242

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

SciTech Connect (OSTI)

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.

Rodney Frehlich

2012-10-30T23:59:59.000Z

243

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

E-Print Network [OSTI]

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

Buckingham, Michael

244

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

E-Print Network [OSTI]

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

Maryland at College Park, University of

245

Analog FIR Filter Used for Range-Optimal Pulsed Radar Applications  

E-Print Network [OSTI]

.......................................................................................................... 1 1.1. Radar system ...................................................................................................... 2 1.2 Matched filter ...................................................................................................... 4... 1.3 Analog FIR matched filters ................................................................................. 4 1.4 Thesis organization ............................................................................................. 6 2...

Su, Eric Chen

2014-08-13T23:59:59.000Z

246

Probability distribution of low-altitude propagation loss from radar sea clutter data  

E-Print Network [OSTI]

: propagation loss estimation, radar clutter, probabilistic inversion Citation: Gerstoft, P., W. S. Hodgkiss, L within the marine atmospheric surface layer [Liu et al., 1979]. The refractivity profile above

Buckingham, Michael

247

E-Print Network 3.0 - advanced precipitation radar Sample Search...  

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

clutter Summary: of precipitation for every pixel in a Meteosat-8 scene. Via pixel-level image fusion of the radar data... and the Precipitating Clouds product, supervised...

248

E-Print Network 3.0 - airborne l-band radar Sample Search Results  

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

concept will utilize L-band radar and radiometer instruments sharing a rotating... measurement approach with the conically scanning ... Source: Montana, University of - School of...

249

E-Print Network 3.0 - aperture radar insar Sample Search Results  

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

. A further study demonstrated that the phase component of INSAR is only weakly affected by the real aperture... radar (RAR) modulation 12. On the other hand, under ......

250

E-Print Network 3.0 - aperture radar image Sample Search Results  

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

flight trajecto- In synthetic aperture radar (SAR) imaging a scene... -y(s). The projection data and reconstructed ... Source: Yazici, Birsen - Department of Electrical,...

251

E-Print Network 3.0 - avoid radar installations Sample Search...  

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

to 9o differences in flow directions. 1. INTRODUCTION We installed the first HF radar at Coal Oil... Evaluating radial component current measurements from CODAR high frequency...

252

Toward a Diurnal Climatology of Cold-Season Turbulence Statistics in Continental Stratocumulus as Observed by the Atmospheric Radiation Millimeter- Wavelength Cloud Radars  

SciTech Connect (OSTI)

Numerous observational studies of marine stratocumulus have demonstrated a pronounced diurnal cycle. At night, longwave flux divergence at the top of the cloud drives negatively buoyant eddies that tend to keep the boundary layer well mixed. During the day, solar absorption by the cloud tends to reduce the turbulent intensity and often decouples the planetary boundary layer (PBL) into cloud- and sub-cloud circulations. The delicate balance between turbulent intensity, entrainment, and fluxes dictates cloud geometry and persistence, which can significantly impact the shortwave radiation budget. Millimeter-wavelength cloud radars (MMCRs) have been used to study the turbulent structure of boundary layer stratocumulus (e.g. Frisch et al. 1995; Kollias and Albrecht 2000). Analysis is confined to nondrizzling or lightly drizzling cloud systems for which precipitation contamination is negligible. Under such assumptions the Doppler velocity field becomes a proxy for vertical velocity. Prior research has mainly consisted of a few case studies of specific cloud systems using radar scan strategies optimized for this particular cloud type. The MMCR operating at the Southern Great Plains Atmospheric Radiation Measurement Climate Research Facility is broadly configured to be able to detect many different cloud types over a broad range of reflectivities and altitudes, so it is not specifically optimized for PBL clouds. Being in more-or-less continuous operation since the end of 1996, it does, however, have the advantage of long data coverage, which suggests that statistically significant measures of the diurnal cycle of turbulence should be attainable. This abstract summarizes the first few steps toward this goal, using 7 months of cold season MMCR data.

Mechem, D.B.; Kogan, Y.L.; Childers, M.E.; Donner, K.M.

2005-03-18T23:59:59.000Z

253

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

SciTech Connect (OSTI)

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.

Doerry, Armin W.

2014-08-01T23:59:59.000Z

254

Master Thesis: Dual-Doppler technique applied to scanning lidars for the characterization of  

E-Print Network [OSTI]

of single wind turbines for the validation or tuning of wake models [1]. Recent full-field campaigns showed the opportunity to apply ground based scanning lidar or radar measurements to evaluate the wind field in the wake the correlated wind field. The scope of this master thesis is to study the interaction of wakes on the basis

Peinke, Joachim

255

UNLOCKING THE TREASURE CHEST OF LEVEL-II RADAR DATA: LESSONS IN TECHNOLOGY TRANSFER POLICY FOR THE ATMOSPHERIC SCIENCES  

E-Print Network [OSTI]

P 1.6 UNLOCKING THE TREASURE CHEST OF LEVEL-II RADAR DATA: LESSONS IN TECHNOLOGY TRANSFER POLICY This analysis of Level-II radar data presents a great success story about partnerships in technology transfer

256

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

257

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

E-Print Network [OSTI]

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

Marsden, Jerrold

258

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

E-Print Network [OSTI]

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

Marsden, Jerrold

259

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

E-Print Network [OSTI]

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

Kansas, University of

260

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

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

A comparison of velocity measurements from the CUTLASS Finland radar and the EISCAT UHF system  

E-Print Network [OSTI]

A comparison of velocity measurements from the CUTLASS Finland radar and the EISCAT UHF system J. A January 1999 Abstract. The CUTLASS Finland radar, which com- prises an integral part of the Super irregularities within a ®eld-of- view which extends over some four million square kilometres. Within the Finland

Paris-Sud XI, Université de

262

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

E-Print Network [OSTI]

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

Kirkwood, Sheila

263

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

E-Print Network [OSTI]

and VIMS observations S. Rodriguez a, , A. Garcia a , A. Lucas a , T. Appéré a , A. Le Gall b , E. Reffet the Cassini RADAR and VIMS (Visual and Infrared Mapping Spectrometer) images ­ the latter being empirically. Furthermore, the strong correlation between RADAR-mapped dunes and the VIMS ``dark brown'' unit (72%) allows

Narteau, Clément

264

Development of a statistical procedure for detecting the number of signals in a radar measurement  

E-Print Network [OSTI]

Development of a statistical procedure for detecting the number of signals in a radar measurement P multichannel multipulse radar data. A unique aspect of the propo is that it predicts a confidence level number. Of concern is the development of a procedure for computing the number of signals in a measurement data vector

Adve, Raviraj

265

Large density fluctuations in the martian ionosphere as observed by the Mars Express radar sounder  

E-Print Network [OSTI]

in the martian ionosphere. The density measurements show a persistent level of large fluctuations, sometimesLarge density fluctuations in the martian ionosphere as observed by the Mars Express radar sounder Advanced Radar for Subsurface and Ionosphere Sounding) instrument on the Mars Express spacecraft provides

Gurnett, Donald A.

266

A Wideband Radar for Mapping Internal Layers in the Polar Icesheets for Estimating Accumulation Rate  

E-Print Network [OSTI]

at the IGARSS meeting [1]. We have developed an operational radar system for routine measurement. This system of the simulation results and laboratory measurements of the radar system. Also we will present analysis measurements in May 2002. I. INTRODUCTION Over the last century sea level rose by about 15 cm. The sea level

Kansas, University of

267

A DDS and PLL-based X-band FMCW Radar System  

E-Print Network [OSTI]

such as level meter of liquid tanks, collision avoidance, and other short range measurement applications [1A DDS and PLL-based X-band FMCW Radar System Yun-Taek Im, Jee-Hoon Lee, and Seong-Ook Park source, and the PLL is controlled by it. The bandwidth and the sweep time of the FMCW radar system

Park, Seong-Ook

268

Strengths and limitations of MST radar measurements of middle-atmosphere winds  

E-Print Network [OSTI]

levels of the atmosphere. 1 Introduction Radars used for atmospheric wind measurements cover a broadStrengths and limitations of MST radar measurements of middle-atmosphere winds W. K. Hocking for many years to measure atmospheric motions over a wide range of altitudes, from ground level up

Paris-Sud XI, Université de

269

Validation and determination of ice water content-radar reflectivity relationships during CRYSTAL-  

E-Print Network [OSTI]

an empirical IWC-radar relflectivity Ze relationship. The comparisons show that for measurements of in situ IWC and remotely measured radar reflectivity, collocated within 2 km of each other, a single IWC-Ze relationship this level of uncertainty to be consistent with sampling errors associated with comparing two measurements

270

Upper Air Wind Measurements by Weather Radar Iwan Holleman, Henk Benschop, and Jitze van der Meulen  

E-Print Network [OSTI]

or assimilated into numerical weather prediction (NWP) models. Un- der the assumption of a linear wind field background statistics of the weather radar wind profiles against the Hirlam NWP model are at least as good of the VVP wind profiles against the Hirlam NWP model demonstrate the high quality of weather radar wind

Stoffelen, Ad

271

VALIDATION OF RAIN RATE RETRIEVALS FROM SEVIRI USING WEATHER RADAR OBSERVATIONS  

E-Print Network [OSTI]

and for improving parameterization cloud processes in numerical weather prediction (NWP) models or assimilation in these models. Although operational networks of Weather Radars are expanding over Europe and the United StatesVALIDATION OF RAIN RATE RETRIEVALS FROM SEVIRI USING WEATHER RADAR OBSERVATIONS R. A. Roebeling

Stoffelen, Ad

272

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

E-Print Network [OSTI]

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

Houze Jr., Robert A.

273

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

E-Print Network [OSTI]

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

Houze Jr., Robert A.

274

Using Satellite Radar Data to Map and Monitor Variations in Great Lakes Ice Cover  

E-Print Network [OSTI]

Using Satellite Radar Data to Map and Monitor Variations in Great Lakes Ice Cover G.A. Leshkevich synthetic aperture radar (SAR) and scatterometer data, are used to classify and map Great Lakes ice cover and to derive freeze-up date, break- up date, and ice cover duration. These are important indicators of regional

275

Small scale turbulence and instabilities observed simultaneously by radiosondes and the MU radar.  

E-Print Network [OSTI]

Small scale turbulence and instabilities observed simultaneously by radiosondes and the MU radar. R-French field campaign devoted to study small-scale turbulence and instabilities in the lower atmosphere for retrieving small-scale turbulence parameters from ST radars. However, the dominant sources

276

Polarimetric Radar Observation Operator for a Cloud Model with Spectral Microphysics  

E-Print Network [OSTI]

-proven advantages such as hydro- meteor classification and improvement in radar data quality and rainfall modeling via improvement of micro- physical parameterization and direct assimilation of polarimetric radar the output of numerical cloud models was pioneered using the models with bulk parameterization of cloud micro

Mark, Pinsky

277

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

E-Print Network [OSTI]

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

Stoffelen, Ad

278

Radar precipitation echo patterns associated with midwestern severe storms  

E-Print Network [OSTI]

to their appeaxattce en time-lapse Plan Position huttcator oscQloecope (Ppl scope) photogtaphs into several types including isolated and scattered echoes, widespread sheet achene, and several categories of Uae echoes. Cbkracterlstic feacures QF each of these types..., static stahfllty, aad mofsture COLLSCTlON OF DATh Radar doss used la the study coaslsssd of ppl scope Nims exposed at hMwestarn U. S. hlr Fates htr ~ Command (hDC) stathms during ths years 1955, 1956, and 1957. Proctpttatlon atteauathm could he...

Inman, Rex Lee

1959-01-01T23:59:59.000Z

279

Radar investigation of the Cote Blanche salt dome  

E-Print Network [OSTI]

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

Stewart, Robert Donald

1974-01-01T23:59:59.000Z

280

On the effects of atmospheric refraction on radar ground patterns  

E-Print Network [OSTI]

of superrefraction. A radial pattern of AP echoes occurred in a number of cases when there was a strong gradient of N in an elevated refractive layer, but this pattern was not nearly as common as others. Investigations [10, 13, 14, 15, 16] of the atmosphere... when the antenna elevation angle is less than 2 deg and when there is an elevated refracting layer between 1500 ft and 3000 ft above the radar in which the gradient of refractivity is greater than 48N/1000 ft. ACKNONLEDGMENT The author wishes...

Cobb, Lalovee Glendale

1963-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Sandia National Laboratories: evaluating wind-turbine/radar impacts  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1development Sandia,evaluating wind-turbine/radar impacts Sandia Develops Tool to

282

Sandia National Laboratories: Oliktok Point Long Range Radar Station  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -theErik Spoerke SSLSMolten-Salt StorageNoLong Range Radar Station Sierra Unmanned

283

Digitized dual wavelength radar data from a Texas thunderstorm  

E-Print Network [OSTI]

for 1600 CST (Figure 12, p 34; Figure 14, p 37) between cells 8 and Di The maximum Z value in cell D is at least greater than 35 dBZ~ but the e 4 km gradient between the BWER and cell D is only 11 dBZ. The ti. lt of the core appears to he to the left... usually are separated by at least 150 km~ while severe thunderstorms frequently are distributed on a much smaller scale Thus~ weather radars, which can scan radial distances greater than 150 km~ serve as the most useful tool to facilitate severe storm...

Radlein, Robin Ann

1977-01-01T23:59:59.000Z

284

Statistical observations of the MLT, latitude and size of pulsed ionospheric ows with the CUTLASS Finland radar  

E-Print Network [OSTI]

Finland radar G. Provan, T. K. Yeoman Department of Physics and Astronomy, University of Leicester as detected by the CUTLASS Finland HF radar. These ¯ows have been suggested as being created scan data from the CUT- LASS Finland radar have been analysed in order to perform a statistical study

Paris-Sud XI, Université de

285

Assessment of the Performance of the Chilbolton 3-GHz Advanced Meteorological Radar for Cloud-Top-Height Retrieval  

E-Print Network [OSTI]

. The potential for this radar to make useful measurements of low-altitude liquid water cloud structure is investigated. To assess the cloud-height assignment capabilities of the 3-GHz radar, low-level cloudAssessment of the Performance of the Chilbolton 3-GHz Advanced Meteorological Radar for Cloud

286

Regional and Diurnal Variability of the Vertical Structure of Precipitation Systems in Africa Based on Spaceborne Radar Data  

E-Print Network [OSTI]

Rainfall Measuring Mission (TRMM) 2A25 radar reflectivity profiles and derived surface rain rates are used- cation of a radar brightband maximum at the freezing level, and evidence for low-level evaporation on Spaceborne Radar Data BART GEERTS AND TEFERI DEJENE Department of Atmospheric Science, University of Wyoming

Geerts, Bart

287

Vertical Velocity and Buoyancy Characteristics of Coherent Echo Plumes in the Convective Boundary Layer, Detected by a Profiling Airborne Radar  

E-Print Network [OSTI]

scatterers (mostly insects). In this study, airborne radar measurements of the CBL are combined with flight-level Layer, Detected by a Profiling Airborne Radar QUN MIAO AND BART GEERTS University of Wyoming, Laramie 20 June 2005, in final form 8 November 2005) ABSTRACT Aircraft and airborne millimeter-wave radar

Geerts, Bart

288

Comparison of Airborne and Spaceborne 95-GHz Radar Reflectivities and Evaluation of Multiple Scattering Effects in Spaceborne Measurements  

E-Print Network [OSTI]

of coincident measurements collected by an airborne 95-GHz radar during the African Monsoon Multidisci- plinary radar calibration is assessed. Collocated measurements of the spaceborne and airborne radars within the CloudSat measurements have to be corrected for this effect, if one wants to derive accurate level 2

Protat, Alain

289

Uncertainties in radar echo top heights used for hail detection L. Delobbe (1) and I. Holleman (2)  

E-Print Network [OSTI]

of hail is derived from the height of the freezing level and the 45-dBZ radar echo top height (maximum is based on the comparison between reflectivity measurements from two radars on the vertical cross section hail using reflectivity measurements from this type of radar. Most hail detection methods based

Stoffelen, Ad

290

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

SciTech Connect (OSTI)

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

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

1990-01-01T23:59:59.000Z

291

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

SciTech Connect (OSTI)

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

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

2007-07-01T23:59:59.000Z

292

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

DOE Patents [OSTI]

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.

Rhodes, Mark

2013-12-17T23:59:59.000Z

293

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

SciTech Connect (OSTI)

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

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

2012-09-15T23:59:59.000Z

294

Excitation-emission spectra and fluorescence quantum yields for...  

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

Excitation-emission spectra and fluorescence quantum yields for fresh and aged biogenic secondary organic aerosols. Excitation-emission spectra and fluorescence quantum yields for...

295

3-D laser Doppler velocimetry study of incompressible flow through an orifice plate  

E-Print Network [OSTI]

of Advisory Committee: Dr. Gerald Morrison Orifice meters are used extensively in the U. S. for the measurement of natural gas. Uncertainty of metering accuracy has resulted in an estimated 250 million dollars annually in mis-charges. This has led... to the need for basic research on orifice meters in an attempt to improve the accuracy of existing metering facilities. The objective of this present study was to use a 3-D LDV (laser Doppler velocimeter) to obtain detailed velocity and turbulence...

Panak, David Leo

2012-06-07T23:59:59.000Z

296

Doppler maps and surface differential rotation of EI Eri from the MUSICOS 1998 observations  

E-Print Network [OSTI]

We present time-series Doppler images of the rapidly-rotating active binary star EI Eri from spectroscopic observations collected during the MUSICOS multi-site campaign in 1998, since the critical rotation period of 1.947 days makes it impossible to obtain time-resolved images from a single site. From the surface reconstructions a weak solar-type differential rotation, as well as a tiny poleward meridional flow are measured.

Zs. K?vári; A. Washuettl; B. H. Foing; K. Vida; J. Bartus; K. Oláh; the MUSICOS 98 team

2008-11-03T23:59:59.000Z

297

A comparison of spotlight synthetic aperture radar image formation techniques  

SciTech Connect (OSTI)

Spotlight synthetic aperture radar images can be formed from the complex phase history data using two main techniques: (1) polar-to-cartesian interpolation followed by two-dimensional inverse Fourier transform (2DFFT), and (2) convolution backprojection (CBP). CBP has been widely used to reconstruct medical images in computer aided tomography, and only recently has been applied to form synthetic aperture radar imagery. It is alleged that CBP yields higher quality images because (1) all the Fourier data are used and (2) the polar formatted data is used directly to form a 2D Cartesian image and therefore 2D interpolation is not required. This report compares the quality of images formed by CBP and several modified versions of the 2DFFT method. We show from an image quality point of view that CBP is equivalent to first windowing the phase history data and then interpolating to an exscribed rectangle. From a mathematical perspective, we should expect this conclusion since the same Fourier data are used to form the SAR image. We next address the issue of parallel implementation of each algorithm. We dispute previous claims that CBP is more readily parallelizable than the 2DFFT method. Our conclusions are supported by comparing execution times between massively parallel implementations of both algorithms, showing that both experience similar decreases in computation time, but that CBP takes significantly longer to form an image.

Knittle, C.D.; Doren, N.E.; Jakowatz, C.V.

1996-10-01T23:59:59.000Z

298

Radar Observations of the 2011 October Draconid Outburst  

E-Print Network [OSTI]

A strong outburst of the October Draconid meteor shower was predicted for October 8, 2011. Here we present the observations obtained by the Canadian Meteor Orbit Radar (CMOR) during the 2011 outburst. CMOR recorded 61 multi-station Draconid echoes and 179 single-station overdense Draconid echoes (covering the magnitude range of +3 <= MV <= +7) between 16-20h UT on October 8, 2011. The mean radiant for the outburst was determined to be a_g = 261.9o +/- 0.3o, d_g = +55.3o +/- 0.3o (J2000) from observations of the underdense multi-station echoes. This radiant location agrees with model predictions to ~1o . The determined geocentric velocity was found to be ~10-15% lower than the model value (17.0 - 19.1 km s^-1 versus 20.4 km s^-1), a discrepancy we attribute to undercorrection for atmospheric deceleration of low density Draconid meteoroids as well as to poor radar radiant geometry during the outburst peak. The mass index at the time of the outburst was determined to be ~ 1.75 using the amplitude distribut...

Ye, Quanzhi; Campbell-Brown, Margaret D; Weryk, Robert J

2013-01-01T23:59:59.000Z

299

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)

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

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

2011-10-13T23:59:59.000Z

300

Method and apparatus for optical Doppler tomographic imaging of fluid flow velocity in highly scattering media  

DOE Patents [OSTI]

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.

Nelson, John Stuart (Laguna Niguel, CA); Milner, Thomas Edward (Irvine, CA); Chen, Zhongping (Irvine, CA)

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

EXPLORING THE MORPHOLOGY OF RAVE STELLAR SPECTRA  

SciTech Connect (OSTI)

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

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

2012-06-01T23:59:59.000Z

302

Improved algorithms for the calculation of resolved resonance cross sections with applications to the structural Doppler effect in fast reactors  

SciTech Connect (OSTI)

Motivated by a need for an economical yet rigorous tool which can address the computation of the structural material Doppler effect, an extremely efficient improved RABANL capability has been developed utilizing the fact that the Doppler broadened line shape functions become essentially identical to the natural line shape functions or Lorentzian limits beyond about 100 Doppler widths from the resonance energy, or when the natural width exceeds about 200 Doppler widths. The computational efficiency has been further enhanced by preprocessing or screening a significant number of selected resonances during library preparation into composition and temperature independent smooth background cross sections. The resonances which are suitable for such pre-processing are those which are either very broad or those which are very weak. The former contribute very little to the Doppler effect and their self-shielding effect can readily be averaged into slowly varying background cross section data, while the latter contribute very little to either the Doppler or to self-shielding effects. To illustrate the accuracy and efficiency of the improved RABANL algorithms and resonance screening techniques, calculations have been performed for two systems, the first with a composition typical of the STF converter region and the second typical of an LMFBR core composition. Excellent agreement has been found for RABANL compared to the reference Monte Carlo solution obtained using the code VIM, and improved results have also been obtained for the narrow resonance approximation in the ultra-fine-group option of MC/sup 2/-2.

Hwang, R.N.; Toppel, B.J.; Henryson, H. II

1980-10-01T23:59:59.000Z

303

Mid-Infrared Spectra of Be Stars  

E-Print Network [OSTI]

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.

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

1999-10-11T23:59:59.000Z

304

Nonlinear cosmological power spectra in Einstein's gravity  

E-Print Network [OSTI]

Is Newton's gravity sufficient to handle the weakly nonlinear evolution stages of the cosmic large-scale structures? Here we resolve the issue by analytically deriving the density and velocity power spectra to the second order in the context of Einstein's gravity. The recently found pure general relativistic corrections appearing in the third-order perturbation contribute to power spectra to the second order. In this work the complete density and velocity power spectra to the second order are derived. The power transfers among different scales in the density power spectrum are estimated in the context of Einstein's gravity. The relativistic corrections in the density power spectrum are estimated to be smaller than the Newtonian one to the second order, but these could be larger than higher-order nonlinear Newtonian terms.

Hyerim Noh; Jai-chan Hwang

2008-05-13T23:59:59.000Z

305

Computing the Primordial Power Spectra Directly  

E-Print Network [OSTI]

The tree order power spectra of primordial inflation depend upon the norm-squared of mode functions which oscillate for early times and then freeze in to constant values. We derive simple differential equations for the power spectra, that avoid the need to numerically simulate the physically irrelevant phases of the mode functions. We also derive asymptotic expansions which should be valid until a few e-foldings before first horizon crossing, thereby avoiding the need to evolve mode functions from the ultraviolet over long periods of inflation.

Maria G. Romania; N. C. Tsamis; R. P. Woodard

2012-07-13T23:59:59.000Z

306

Computing the primordial power spectra directly  

SciTech Connect (OSTI)

The tree order power spectra of primordial inflation depend upon the norm-squared of mode functions which oscillate for early times and then freeze in to constant values. We derive simple differential equations for the power spectra, that avoid the need to numerically simulate the physically irrelevant phases of the mode functions. We also derive asymptotic expansions which should be valid until a few e-foldings before first horizon crossing, thereby avoiding the need to evolve mode functions from the ultraviolet over long periods of inflation.

Romania, Maria G.; Tsamis, N.C. [Institute of Theoretical Physics and Computational Physics, Department of Physics, University of Crete, GR-710 03 Heraklion (Greece); Woodard, R.P., E-mail: romania@physics.uoc.gr, E-mail: tsamis@physics.uoc.gr, E-mail: woodard@phys.ufl.edu [Department of Physics, University of Florida, Gainesville, FL 32611 (United States)

2012-08-01T23:59:59.000Z

307

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

DOE Patents [OSTI]

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.

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

2014-10-07T23:59:59.000Z

308

Determinations of photon spectra. Master's thesis  

SciTech Connect (OSTI)

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.

Wannigman, D.L.

1989-01-01T23:59:59.000Z

309

Iterative Self-Dual Reconstruction on Radar Image Recovery  

SciTech Connect (OSTI)

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.

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

2010-05-21T23:59:59.000Z

310

Lightning and radar observations of hurricane Rita landfall  

SciTech Connect (OSTI)

Los Alamos National Laboratory (LANL) owns and operates an array of Very-Low Frequency (VLF) sensors that measure the Radio-Frequency (RF) waveforms emitted by Cloud-to-Ground (CG) and InCloud (IC) lightning. This array, the Los Alamos Sferic Array (LASA), has approximately 15 sensors concentrated in the Great Plains and Florida, which detect electric field changes in a bandwidth from 200 Hz to 500 kHz (Smith et al., 2002). Recently, LANL has begun development of a new dual-band RF sensor array that includes the Very-High Frequency (VHF) band as well as the VLF. Whereas VLF lightning emissions can be used to deduce physical parameters such as lightning type and peak current, VHF emissions can be used to perform precise 3d mapping of individual radiation sources, which can number in the thousands for a typical CG flash. These new dual-band sensors will be used to monitor lightning activity in hurricanes in an effort to better predict intensification cycles. Although the new LANL dual-band array is not yet operational, we have begun initial work utilizing both VLF and VHF lightning data to monitor hurricane evolution. In this paper, we present the temporal evolution of Rita's landfall using VLF and VHF lightning data, and also WSR-88D radar. At landfall, Rita's northern eyewall experienced strong updrafts and significant lightning activity that appear to mark a transition between oceanic hurricane dynamics and continental thunderstorm dynamics. In section 2, we give a brief overview of Hurricane Rita, including its development as a hurricane and its lightning history. In the following section, we present WSR-88D data of Rita's landfall, including reflectivity images and temporal variation. In section 4, we present both VHF and VLF lightning data, overplotted on radar reflectivity images. Finally, we discuss our observations, including a comparison to previous studies and a brief conclusion.

Henderson, Bradley G [Los Alamos National Laboratory; Suszcynsky, David M [Los Alamos National Laboratory; Hamlin, Timothy E [Los Alamos National Laboratory; Jeffery, C A [Los Alamos National Laboratory; Wiens, Kyle C [TEXAS TECH U.; Orville, R E [TEXAS A& M

2009-01-01T23:59:59.000Z

311

Phase coded, micro-power impulse radar motion sensor  

DOE Patents [OSTI]

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.

McEwan, T.E.

1996-05-21T23:59:59.000Z

312

Phase coded, micro-power impulse radar motion sensor  

DOE Patents [OSTI]

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.

McEwan, Thomas E. (Livermore, CA)

1996-01-01T23:59:59.000Z

313

Improved predictions of reactor antineutrino spectra  

SciTech Connect (OSTI)

Precise predictions of the antineutrino spectra emitted by nuclear reactors is a key ingredient in measurements of reactor neutrino oscillations as well as in recent applications to the surveillance of power plants in the context of nonproliferation of nuclear weapons. We report new calculations including the latest information from nuclear databases and a detailed error budget. The first part of this work is the so-called ab initio approach where the total antineutrino spectrum is built from the sum of all {beta} branches of all fission products predicted by an evolution code. Systematic effects and missing information in nuclear databases lead to final relative uncertainties in the 10-20% range. A prediction of the antineutrino spectrum associated with the fission of {sup 238}U is given based on this ab initio method. For the dominant isotopes we developed a more accurate approach combining information from nuclear databases and reference electron spectra associated with the fission of {sup 235}U, {sup 239}Pu, and {sup 241}Pu, measured at Institut Laue-Langevin (ILL) in the 1980s. We show how the anchor point of the measured total {beta} spectra can be used to suppress the uncertainty in nuclear databases while taking advantage of all the information they contain. We provide new reference antineutrino spectra for {sup 235}U, {sup 239}Pu, and {sup 241}Pu isotopes in the 2-8 MeV range. While the shapes of the spectra and their uncertainties are comparable to those of the previous analysis of the ILL data, the normalization is shifted by about +3% on average. In the perspective of the reanalysis of past experiments and direct use of these results by upcoming oscillation experiments, we discuss the various sources of errors and their correlations as well as the corrections induced by off-equilibrium effects.

Mueller, Th. A.; Lhuillier, D.; Letourneau, A. [Commissariat a l'Energie Atomique et aux Energies Alternatives, Centre de Saclay, IRFU/SPhN, FR-91191 Gif-sur-Yvette (France); Fallot, M.; Cormon, S.; Giot, L.; Martino, J.; Porta, A.; Yermia, F. [Laboratoire SUBATECH, Ecole des Mines de Nantes, Universite de Nantes, CNRS/IN2P3, 4 rue Alfred Kastler, FR-44307 Nantes Cedex 3 (France); Fechner, M.; Lasserre, T.; Mention, G. [Commissariat a l'Energie Atomique et aux Energies Alternatives, Centre de Saclay, IRFU/SPP, FR-91191 Gif-sur-Yvette (France)

2011-05-15T23:59:59.000Z

314

A model for forming airborne synthetic aperture radar images of underground targets  

SciTech Connect (OSTI)

Synthetic Aperture Radar (SAR) from an airborne platform has been proposed for imaging targets beneath the earth`s surface. The propagation of the radar`s energy within the ground, however, is much different than in the earth`s atmosphere. The result is signal refraction, echo delay, propagation losses, dispersion, and volumetric scattering. These all combine to make SAR image formation from an airborne platform much more challenging than a surface imaging counterpart. This report treats the ground as a lossy dispersive half-space, and presents a model for the radar echo based on measurable parameters. The model is then used to explore various imaging schemes, and image properties. Dynamic range is discussed, as is the impact of loss on dynamic range. Modified window functions are proposed to mitigate effects of sidelobes of shallow targets overwhelming deeper targets.

Doerry, A.W.

1994-01-01T23:59:59.000Z

315

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

E-Print Network [OSTI]

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 ...

LeFrançois, Suzanne O'Neil, 1980-

2003-01-01T23:59:59.000Z

316

12B.4 2010 PHASEDARRAY RADAR INNOVATIVE SENSING EXPERIMENT Pam Heinselman 1  

E-Print Network [OSTI]

Sensing Experiment (PARISE) via two components: radar data collection and National Weather Service (NWS." This sampling approach provides denser sampling at low altitudes, where it is needed most. In PARISE 2010

317

Millimeter-wave radar sensor for automotive intelligent cruise control (ICC)  

SciTech Connect (OSTI)

If automotive intelligent cruise-control (ICC) systems are to be successful in the marketplace, they must provide robust performance in a complex roadway environment. Inconveniences caused by reduced performance during inclement weather, interrupted performance due to dropped tracks, and annoying nuisance alarms will not be tolerated by the consumer, and would likely result in the rejection of this technology in the marketplace. An all-weather automotive millimeter-wave (MMW) radar sensor is described that uses a frequency-modulation coplanar-wave (FMCW) radar design capable of acquiring and tracking all obstacles in its field of view. Design tradeoffs are discussed and radar-sensor test results are presented along with the applicability of the radar to collision-warning systems.

Russell, M.E.; Crain, A.; Curran, A.; Campbell, R.A.; Drubin, C.A.; Miccioli, W.F. [Raytheon, Tewksbury, MA (United States)] [Raytheon, Tewksbury, MA (United States)

1997-12-01T23:59:59.000Z

318

A census of precipitation features in the tropics using TRMM: radar, ice scattering, and lightning observations  

E-Print Network [OSTI]

and two ocean regions during August, September and October 1998, this study used radar retrievals and 85 GHz Polarization Corrected Temperatures (PCTs, which passively measure relative concentrations of precipitation-sized ice particles within a cloud...

Nesbitt, Stephen William

1999-01-01T23:59:59.000Z

319

E-Print Network 3.0 - aperture radar sar Sample Search Results  

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

Clusters Jim Stiles, Nathan Goodman, and SiChung Lin Summary: of the overall SAR image. BACKGROUND A radar illuminating an area A of the Earth's surface will receive a complex......

320

Weather Radar and Hydrology 1 Influence of rainfall spatial variability on hydrological modelling: a  

E-Print Network [OSTI]

Weather Radar and Hydrology 1 Influence of rainfall spatial variability on hydrological modelling variability as well as characteristics and hydrological behavior of catchments, we have proceeded simulator and a distributed hydrological model (with four production functions and a distributed transfer

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

E-Print Network 3.0 - aperture radar 3d Sample Search Results  

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

3d Search Powered by Explorit Topic List Advanced Search Sample search results for: aperture radar 3d Page: << < 1 2 3 4 5 > >> 1 CHAPTER 9CHAPTER 9CHAPTER 9:CHAPTER 9: Active and...

322

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

E-Print Network [OSTI]

The goal of this research project is to identify the efficacy of the ground penetrating radar (GPR) technique in locating underground coal mine related subsidence features at Malakoff and Bastrop, Texas. The work at Malakoff has been done...

Save, Neelambari R

2006-04-12T23:59:59.000Z

323

E-Print Network 3.0 - acquisition regime radar Sample Search...  

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

except the data acquisition system and the controller unit... A New Coherent Radar for Ice Sounding in Greenland A. Moussessian 1 , R.L. Jordan 1 , E. Rodriguez... : (818)...

324

Multiple-scattering in radar systems: A review Alessandro Battaglia a,b,, Simone Tanelli c  

E-Print Network [OSTI]

Review Multiple-scattering in radar systems: A review Alessandro Battaglia a,b,Ã, Simone Tanelli c. Tel.: +44 116 2709859. E-mail address: a.battaglia@le.ac.uk (A. Battaglia). Journal of Quantitative Spectroscopy & Radiative Transfer ] (

Hogan, Robin

325

ACTIVE REGION MOSS: DOPPLER SHIFTS FROM HINODE/EXTREME-ULTRAVIOLET IMAGING SPECTROMETER OBSERVATIONS  

SciTech Connect (OSTI)

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.

Tripathi, Durgesh [Inter-University Centre for Astronomy and Astrophysics, Pune University Campus, Pune 411007 (India); Mason, Helen E. [Department of Applied Mathematics and Theoretical Physics, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom); Klimchuk, James A. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2012-07-01T23:59:59.000Z

326

EIS/Hinode observations of Doppler flow seen through the 40 arcsec wide slit  

E-Print Network [OSTI]

The Extreme ultraviolet Imaging Spectrometer (EIS) on board Hinode is the first solar telescope to obtain wide slit spectral images that can be used for detecting Doppler flows in transition region and coronal lines on the Sun and to relate them to their surrounding small scale dynamics. We select EIS lines covering the temperature range 6x10^4 K to 2x10^6 K that give spectrally pure images of the Sun with the 40 arcsec slit. In these images Doppler shifts are seen as horizontal brightenings. Inside the image it is difficult to distinguish shifts from horizontal structures but emission beyond the image edge can be unambiguously identified as a line shift in several lines separated from others on their blue or red side by more than the width of the spectrometer slit (40 pixels). In the blue wing of He II, we find a large number of events with properties (size and lifetime) similar to the well-studied explosive events seen in the ultraviolet spectral range. Comparison with X-Ray Telescope (XRT) images shows many Doppler shift events at the footpoints of small X-ray loops. The most spectacular event observed showed a strong blue shift in transition region and lower corona lines from a small X-ray spot that lasted less than 7 min. The emission appears to be near a cool coronal loop connecting an X-ray bright point to an adjacent region of quiet Sun. The width of the emission implies a line-of-sight velocity of 220 km/s. In addition, we show an example of an Fe XV shift with a velocity about 120 km/s, coming from what looks like a narrow loop leg connecting a small X-ray brightening to a larger region of X-ray emission.

D. E. Innes; R. Attie; H. Hara; M. S. Madjarska

2008-07-08T23:59:59.000Z

327

O{sub 2} rotational temperature measurements in an atmospheric air microdischarge by radar resonance-enhanced multiphoton ionization  

SciTech Connect (OSTI)

Nonintrusive spatially resolved rotational temperature measurements in an atmospheric air microdischarge are presented. The measurements were based on coherent microwave Rayleigh scattering (Radar) from resonance-enhanced multiphoton ionization of molecular oxygen. The open air DC microdischarge source operated in a stable 'normal-glow' mode and pin-to-pin electrodes spaced 1.3 mm apart. The second harmonic of a tunable dye laser beam was focused between the two electrodes and scanned between 286 and 288 nm. Coherent microwave Rayleigh scattering was used to collect the two-photon rotational spectra of O{sub 2} at C{sup 3}{Pi}(v = 2) Leftwards-Arrow X{sup 3}{Sigma}(v Prime = 0) transitions. The Boltzmann plots from analyses of the O{sub 2} rotational lines determined local rotational temperatures at various axial locations between the electrodes. The molecular oxygen rotational temperature varied from {approx}1150 K to {approx}1350 K within the discharge area. The measurements had an accuracy of {approx}{+-}50 K.

Sawyer, Jordan; Wu, Yue; Zhang, Zhili [Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville Tennessee 37996 (United States)] [Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville Tennessee 37996 (United States); Adams, Steven F. [Air Force Research Laboratory (AFRL/RQQE), Wright-Patterson AFB, Ohio 45433-7919 (United States)] [Air Force Research Laboratory (AFRL/RQQE), Wright-Patterson AFB, Ohio 45433-7919 (United States)

2013-06-21T23:59:59.000Z

328

Adaptive Model-Based Mine Detection/Localization using Noisy Laser Doppler Vibration Measurements  

SciTech Connect (OSTI)

The acoustic detection of buried mines is hampered by the fact that at the frequencies required for obtaining useful penetration, the energy is quickly absorbed by the ground. A recent approach which avoids this problem, is to excite the ground with a high-level low frequency sound, which excites low frequency resonances in the mine. These resonances cause a low-level vibration on the surface which can be detected by a Laser Doppler Vibrometer. This paper presents a method of quickly and efficiently detecting these vibrations by sensing a change in the statistics of the signal when the mine is present. Results based on real data are shown.

Sullivan, E J; Xiang, N; Candy, J V

2009-04-06T23:59:59.000Z

329

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

E-Print Network [OSTI]

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.

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

2008-01-30T23:59:59.000Z

330

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

E-Print Network [OSTI]

We report the detection of the first extrasolar planet, ET-1 (HD 102195b), using the Exoplanet Tracker (ET), a new generation Doppler instrument. The planet orbits HD 102195, a young star with solar metallicity that may be part of the local association. The planet imparts radial velocity variability to the star with a semiamplitude of $63.4\\pm2.0$ m s$^{-1}$ and a period of 4.11 days. The planetary minimum mass ($m \\sin i$) is $0.488\\pm0.015$ $M_J$.

Jian Ge; Julian van Eyken; Suvrath Mahadevan; Curtis DeWitt; Stephen R. Kane; Roger Cohen; Andrew Vanden Heuvel; Scott W. Fleming; Pengcheng Guo; Gregory W. Henry; Donald P. Schneider; Lawrence W. Ramsey; Robert A. Wittenmyer; Michael Endl; William D. Cochran; Eric B. Ford; Eduardo L. Martin; Garik Israelian; Jeff Valenti; David Montes

2006-05-10T23:59:59.000Z

331

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

E-Print Network [OSTI]

­ Industry ­ Government · UPRM, UMASS, OU and CSU #12;10,000 ft tornado wind snow 3.05km 04080120160200240 Radar Radar Specifications: · Furuno Marine Based · Frequency = 9.41 GHz · Peak Power = 4 kW / 25 k #12;Results #12;August 29, 2010 #12;Advantages · Low Cost ­ Almost 10 times cheaper than current · Low

Gilbes, Fernando

332

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

E-Print Network [OSTI]

of different display parameters from GSSI's RADAN software package . . . 21 (a) Unfiltered radar profile over an underground storage tank. (b) Profile (a) has been filtered wdth a horizontal high pass boxcar filter, removing the long horizontal reflector... and processed in the laboratory using RADAN, interpretation software developed by GSSI. The radar profile (or radargram) seen on the computer screen is a composition of paraUel series of amplitude versus time. The darkness or color displayed is proportional...

Servos, Stacia Lynn

1998-01-01T23:59:59.000Z

333

Radar cross section of triangular trihedral reflector with extended bottom plate.  

SciTech Connect (OSTI)

Trihedral corner reflectors are the preferred canonical target for SAR performance evaluation for many radar development programs. The conventional trihedrals have problems with substantially reduced Radar Cross Section (RCS) at low grazing angles, unless they are tilted forward, but in which case other problems arise. Consequently there is a need for better low grazing angle performance for trihedrals. This is facilitated by extending the bottom plate. A relevant analysis of RCS for an infinite ground plate is presented. Practical aspects are also discussed.

Brock, Billy C.; Doerry, Armin Walter

2009-05-01T23:59:59.000Z

334

CLOUD CHARACTERISTICS FROM DUAL WAVELENGTH MILLIMETREWAVE RADAR Robin J. Hogan , Anthony J. Illingworth and Henri Sauvageot +  

E-Print Network [OSTI]

­ veloping radar algorithms for measuring LWC is the ubiq­ uitous presence of occasional drizzle drops, which is clearly measurable even for vertically­pointing radars. The differential attenuation due to atmospheric and mean­sea­level pressure it has a (two­way) value of 1.0 dBkm 1 if the air is saturated. Measurements

Reading, University of

335

IFP V4.0:a polar-reformatting image formation processor for synthetic aperture radar.  

SciTech Connect (OSTI)

IFP V4.0 is the fourth generation of an extraordinarily powerful and flexible image formation processor for spotlight mode synthetic aperture radar. It has been successfully utilized in processing phase histories from numerous radars and has been instrumental in the development of many new capabilities for spotlight mode SAR. This document provides a brief history of the development of IFP, a full exposition of the signal processing steps involved, and a short user's manual for the software implementing this latest iteration.

Eichel, Paul H.

2005-09-01T23:59:59.000Z

336

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

E-Print Network [OSTI]

thunderstorm?s dynamics and electrification processes operate. The advent of the WSR- 88D nationwide (U. S.) radar system, the National Lightning Detection Network (NLDN), and 3-dimensional lightning mapping systems (here the Lightning Detection... that are related to storm intensity and can assist in predicting severe weather. 2. Data and methodology The radar data used in this study were from the Dallas-Fort Worth WSR-88D (KFWS), obtained from the National Climatic Data Center...

Steiger, Scott Michael

2007-04-25T23:59:59.000Z

337

Thickness estimation of subsurface layers in asphalt pavement using monstatic ground penetrating radar  

E-Print Network [OSTI]

for the degree of MASTER OF SCIENCE December 1991 Major Subject: Electrical Engineering THICKNESS ESTIMATION OF SUBSURFACE LAYERS IN ASPHALT PAVEMENT USING MONSTATIC GROUND PENETRATING RADAR A Thesis CHUN LOK LAU Approved as to style and content by... ACKNOWLEDGEMENTS. LIST OF FIGURES. . CHAPTER I INTRODUCTION. 1. 1 Importance of pavement profile data. 1. 2 Principle of Ground Penetrating Radar (GPR) . . . 1. 3 Subsurface layer thickness measurement method. . . . . . II GPR ANTENNA AND SYSTEM CALIBRATION...

Lau, Chun Lok

1991-01-01T23:59:59.000Z

338

Some effects of range upon AN/CPS-9 radar reflectivities in thunderstorms  

E-Print Network [OSTI]

SOMB BFFBCTS OF RANGE UPON AN/CPS-9 RADAR RBFLECTIVITIBS IN THUNDBRSTORMS A Thesis Tommy Eugene Sanford Submitted to the Graduate School of the Agricultural and Mechanical College of Texas in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE January 1961 Major Subject: Meteorology SOME EFFECI'S OF RANGE UPON AN/CPS-9 RADAR REFLECTIVITIES IN THUNDERSTORMS A Thesis Tommy Eugene Sanford Approved as to style and content by: (Chairman of Committe ) 4~4 (Head...

Sanford, Tom E

1961-01-01T23:59:59.000Z

339

INTERMITTENCY AND MULTIFRACTALITY SPECTRA OF THE MAGNETIC FIELD IN SOLAR ACTIVE REGIONS  

SciTech Connect (OSTI)

We present the results of a study of intermittency and multifractality of magnetic structures in solar active regions (ARs). Line-of-sight magnetograms for 214 ARs of different flare productivity observed at the center of the solar disk from 1997 January until 2006 December are utilized. Data from the Michelson Doppler Imager (MDI) instrument on board the Solar and Heliospheric Observatory operating in the high resolution mode, the Big Bear Solar Observatory digital magnetograph, and the Hinode SOT/SP instrument were used. Intermittency spectra were derived from high-order structure functions and flatness functions. The flatness function exponent is a measure of the degree of intermittency. We found that the flatness function exponent at scales below approximately 10 Mm is correlated with flare productivity (the correlation coefficient is -0.63). The Hinode data show that the intermittency regime is extended toward small scales (below 2 Mm) as compared to the MDI data. The spectra of multifractality, derived from the structure functions and flatness functions, are found to be broader for ARs of higher flare productivity as compared to those of low flare productivity. The magnetic structure of high-flaring ARs consists of a voluminous set of monofractals, and this set is much richer than that for low-flaring ARs. The results indicate the relevance of the multifractal organization of the photospheric magnetic fields to the flaring activity. The strong intermittency observed in complex and high-flaring ARs is a hint that we observe a photospheric imprint of enhanced sub-photospheric dynamics.

Abramenko, Valentyna; Yurchyshyn, Vasyl [Big Bear Solar Observatory, 40386 North Shore Lane, Big Bear City, CA 92314 (United States)

2010-10-10T23:59:59.000Z

340

Inflation and Alternatives with Blue Tensor Spectra  

E-Print Network [OSTI]

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.

Yi Wang; Wei Xue

2014-10-20T23:59:59.000Z

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Dynamical analysis of highly excited molecular spectra  

SciTech Connect (OSTI)

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.

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

1993-12-01T23:59:59.000Z

342

Supernovae Spectra (La Jolla Institute, 1980)  

SciTech Connect (OSTI)

The workshop includes talks by invited speakers on observed supernova spectra, plasma conditions in supernova envelopes, on the present status and future requirements of atomic physics and spectroscopy that contribute to the solutions of the supernova problems. Of the 14 papers presented at the workshop, abstracts of two appeared previously in Energy Research Abstracts and abstracts of the remaining 12 were prepared separately for the data base. (GHT)

Meyerott, R.; Gillespie, G.H. (eds.)

1980-01-01T23:59:59.000Z

343

Statistical Properties of Quantum Graph Spectra  

E-Print Network [OSTI]

A general analytical approach to the statistical description of quantum graph spectra based on the exact periodic orbit expansions of quantum levels is discussed. The exact and approximate expressions obtained in \\cite{Anima} for the probability distribution functions using the spectral hierarchy method are analyzed. In addition, the mechanism of appearance of the universal statistical properties of spectral fluctuations of quantum-chaotic systems is considered in terms of the semiclassical theory of periodic orbits.

Yu. Dabaghian

2006-08-09T23:59:59.000Z

344

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)

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.

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

2005-12-30T23:59:59.000Z

345

The chromospherically active binary star EI Eridani II. Long-term Doppler imaging  

E-Print Network [OSTI]

Data from 11 years of continuous spectroscopic observations of the active RS CVn-type binary star EI Eridani - gained at NSO/McMath-Pierce, KPNO/Coude Feed and during the MUSICOS 98 campaign - were used to obtain 34 Doppler maps in three spectroscopic lines for 32 epochs, 28 of which are independent of each other. Various parameters are extracted from our Doppler maps: average temperature, fractional spottedness, and longitudinal and latitudinal spot-occurrence functions. We find that none of these parameters show a distinct variation nor a correlation with the proposed activity cycle as seen from photometric long-term observations. This suggests that the photometric brightness cycle may not necessarily be due to just a cool spot cycle. The general morphology of the spot pattern remains persistent over the whole period of 11 years. A large cap-like polar spot was recovered from all our images. A high degree of variable activity was noticed near latitudes of approx. 60-70 degrees where the appendages of the polar spot emerged and dissolved.

A. Washuettl; K. G. Strassmeier; M. Weber

2008-11-19T23:59:59.000Z

346

Characteristics of profiles of gamma-ray burst pulses associated with the Doppler effect of fireballs  

E-Print Network [OSTI]

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.

Yi-Ping Qin; Zhi-Bin Zhang; Fu-Wen Zhang; Xiao-Hong Cui

2004-08-31T23:59:59.000Z

347

Resonant Absorption between Moving Atoms due to Doppler Frequency Shift and Quantum Energy Variation  

E-Print Network [OSTI]

By taking both the Doppler frequency shift for electromagnetic wave and the quantum energy variation of matter wave into consideration, a resonant-absorption condition based on the local-ether wave equation is presented to account for a variety of phenomena consistently, including the Ives-Stilwell experiment, the output frequency from ammonia masers, and the M\\"{o}ssbauer rotor experiment. It is found that in the resonant-absorption condition, the major term associated with the laboratory velocity is a dot-product term between this velocity and that of the emitting or absorbing atom. This term appears both in the Doppler frequency shift and the transition frequency variation and then cancels out. Thereby, the experimental results can be independent of the laboratory velocity and hence comply with Galilean relativity, despite the restriction that the involved velocities are referred specifically to the local-ether frame. However, by examining the resonant-absorption condition in the M\\"{o}ssbauer rotor experiment to a higher order, it is found that Galilean relativity breaks down.

Ching-Chuan Su

2002-08-23T23:59:59.000Z

348

Simple Magnetic Flux Balance as an Indicator of Neon VIII Doppler Velocity Partitioning in an Equatorial Coronal Hole  

E-Print Network [OSTI]

We present a novel investigation into the relationship between simple estimates of magnetic flux balance and the Ne VIII Doppler velocity partitioning of a large equatorial coronal hole observed by the Solar Ultraviolet Measurements of Emitted Radiation spectrometer (SUMER) on the Solar and Heliospheric Observatory (SOHO) in November 1999. We demonstrate that a considerable fraction of the large scale Doppler velocity pattern in the coronal hole can be qualitatively described by simple measures of the local magnetic field conditions, i.e., the relative unbalance of magnetic polarities and the radial distance required to balance local flux concentrations with those of opposite polarity.

Scott W. McIntosh; Alisdair R. Davey; Scott W. McIntosh

2006-05-22T23:59:59.000Z

349

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

E-Print Network [OSTI]

............................................................................................................................. 1 1.1 MOTIVATION ............................................................................................................................................................ 1 1.2 DOCUMENT ORGANIZATION... .................................................................................................................................. 3 CHAPTER 2: BACKGROUND ................................................................................................................................ 3 2.1 PREVIOUS ACCUMULATION RADAR DEVELOPMENT...

Lewis, Cameron Scott

2010-11-01T23:59:59.000Z

350

Infrared absorption spectra, radiative efficiencies, and global warming potentials  

E-Print Network [OSTI]

Infrared absorption spectra, radiative efficiencies, and global warming potentials absorption spectra, radiative efficiencies, and global warming potentials of perfluorocarbons: Comparison. (1995) and combined with atmospheric lifetimes from the literature to determine global warming

Wirosoetisno, Djoko

351

vdial lL t f with the strongest Doppler sounds; (4) measured the ankle blood pressure at t" e selected  

E-Print Network [OSTI]

vdial lL t f with the strongest Doppler sounds; (4) measured the ankle blood pressure at t" e selected artery, using the Doppler probe with an occlusive cuff around the ankle (with the lower edge's resting index for each leg was calculated by using the ankle blood plllssure and the maximal (from either

352

ULF wave occurrence statistics in a high-latitude HF Doppler sounder D. M. Wright, T. K. Yeoman, T. B. Jones  

E-Print Network [OSTI]

ULF wave occurrence statistics in a high-latitude HF Doppler sounder D. M. Wright, T. K. Yeoman, T was to establish the optimum con®guration for a new high-latitude Doppler sounder experiment, called DOPE (Wright, 1996; Wright et al., 1997), and to determine the likelihood of the experiment observing pulsation eects

Paris-Sud XI, Université de

353

A comparison of EISCAT and HF Doppler observations of a ULF wave D. M. Wright, T. K. Yeoman, J. A. Davies  

E-Print Network [OSTI]

A comparison of EISCAT and HF Doppler observations of a ULF wave D. M. Wright, T. K. Yeoman, J. A, Wright et al. (1997) presented a detailed study of ULF wave signatures observed by a new sounder at high observed by HF Doppler Correspondence to: D. M. Wright Presented at the Eighth International EISCAT

Paris-Sud XI, Université de

354

Lynx: A High-Resolution Synthetic Aperture Radar  

SciTech Connect (OSTI)

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.

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

1999-03-08T23:59:59.000Z

355

Spatially Interpolated Nonlinear Anodization in Synthetic Aperture Radar Imagery  

SciTech Connect (OSTI)

Spatially Interpolated Nonlinear Anodization in Synthetic Aperture Original formulation of spatially variant anodization for complex synthetic aperture radar (SAR) imagery oversampled at twice the Nyquist rate (2.OX). Here we report a spatially interpolating, noninteger-oversampled SVA sidelobe. The pixel's apparent IPR location is assessed by comparing its value to the sum of its value plus weighted comparable for exact interpolation. However, exact interpolation implies an ideal sine interpolator3 and large components may not be necessary. Note that P is the summation of IPR diagonal values. The value of a sine IPR on the diagonals is a sine-squared; values much less than cardinal direction (m, n) values. This implies that cardinal direction interpolation requires higher precision than diagonal interpolation. Consequently, we employed a smaller set. The spatially interpolated SVA used an 8-point/4-point sine interpolator described above. Table 1 shows the Table 1 results show a two-times speed-up using the 1.3x oversampled and spatially interpolated SVA over the Figure 1d. Detected results of 1.3x oversampled sine interpolated spatially variant

Eichel, Paul H.; Jakowatz, Jr., Charles V.; Yocky, David A.

1999-06-29T23:59:59.000Z

356

The Use of Radar Methods to Determine Moisture Content in the Vadose Zone  

SciTech Connect (OSTI)

Water content is a critical parameter affecting both liquid-phase and vapor-phase contaminant transport in the vadose zone. This means that accurate estimates of in situ water content must be obtained in order to design for the appropriate handling or remediation of a contaminated region of the vadose zone. Traditional methods of sampling the subsurface by drilling and/or direct sampling are very time consuming, limited in terms of spatial coverage, and have the associated risk of contacting and increasing the size of the contaminated area. One solution is to use geophysical methods which can provide a high-resolution, non-invasive means of sampling or imaging the subsurface. The overall objective of our research, defined at the start of this project, was to advance the usefulness of radar methods (ground-based and borehole) as a means of characterizing water content in the vadose zone. We have met this objective by providing research results that can be used to (1) improve the accuracy of water content estimates from radar measurements; (2) provide estimates of the potential error in water content estimates from radar measurements; (3) improve the clarity of radar images; (4) develop large-scale models of the subsurface ''architecture'' using radar images; (5) develop ways of quantifying the spatial heterogeneity of the subsurface through analysis of radar images. We have also been able to identify the critical areas where more research is needed in order to be able to use radar methods most effectively as an accurate means of subsurface characterization.

Rosemary Knight

2003-12-28T23:59:59.000Z

357

Infrared absorption spectra, radiative efficiencies, and global warming potentials  

E-Print Network [OSTI]

Infrared absorption spectra, radiative efficiencies, and global warming potentials of newly.mdpi.com/journal/atmosphere Article Infrared Absorption Spectra, Radiative Efficiencies, and Global Warming Potentials of Newly of 600­1730 cm-1 . These spectra are then used to calculate the radiative efficiencies and global warming

Wirosoetisno, Djoko

358

Nuclear reactor fissile isotopes antineutrino spectra  

E-Print Network [OSTI]

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.

V. Sinev

2012-07-30T23:59:59.000Z

359

Covariance Analysis of Gamma Ray Spectra  

SciTech Connect (OSTI)

The covariance method exploits fluctuations in signals to recover information encoded in correlations which are usually lost when signal averaging occurs. In nuclear spectroscopy it can be regarded as a generalization of the coincidence technique. The method can be used to extract signal from uncorrelated noise, to separate overlapping spectral peaks, to identify escape peaks, to reconstruct spectra from Compton continua, and to generate secondary spectral fingerprints. We discuss a few statistical considerations of the covariance method and present experimental examples of its use in gamma spectroscopy.

Trainham, R.; Tinsley, J.

2013-01-01T23:59:59.000Z

360

Momentum spectra, anisotropic flow, and ideal fluids  

E-Print Network [OSTI]

If the matter produced in ultrarelativistic heavy-ion collisions reaches thermal equilibrium, its subsequent evolution follows the laws of ideal fluid dynamics. We show that general predictions can be made on this basis alone, irrespective of the details of the hydrodynamical model. We derive several scaling rules for momentum spectra and anisotropic flow (in particular the elliptic flow, v2, and the hexadecupole flow, v4) of identified particles. Comparison with existing data is briefly discussed, and qualitative predictions are made for LHC.

N. Borghini; J. -Y. Ollitrault

2006-07-28T23:59:59.000Z

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

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 CenterFranconia, Virginia:FAQ < RAPID Jump to:Seadov Pty Ltd JumpGTZHolland, Illinois:5717551°FarmsSES Jump to: navigation,Spectra Nova

362

SpectraWatt | Open Energy Information  

Open Energy Info (EERE)

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363

Blind Source Separation For Ion Mobility Spectra  

SciTech Connect (OSTI)

Miniaturization is a powerful trend for smart chemical instrumentation in a diversity of applications. It is know that miniaturization in IMS leads to a degradation of the system characteristics. For the present work, we are interested in signal processing solutions to mitigate limitations introduced by limited drift tube length that basically involve a loss of chemical selectivity. While blind source separation techniques (BSS) are popular in other domains, their application for smart chemical instrumentation is limited. However, in some conditions, basically linearity, BSS may fully recover the concentration time evolution and the pure spectra with few underlying hypothesis. This is extremely helpful in conditions where non-expected chemical interferents may appear, or unwanted perturbations may pollute the spectra. SIMPLISMA has been advocated by Harrington et al. in several papers. However, more modern methods of BSS for bilinear decomposition with the restriction of positiveness have appeared in the last decade. In order to explore and compare the performances of those methods a series of experiments were performed.

Marco, S.; Pomareda, V. [Department of Electronics, University of Barcelona, C/Marti i Franques, no 1, planta 2, 08028, Barcelona (Spain); Artificial Olfaction Lab, Institute of BioEngineering of Catalonia and Institut de Bioenginyeria de Catalunya (IBEC), C/Baldiri Reixac 13, 08028 Barcelona (Spain); Pardo, A. [Department of Electronics, University of Barcelona, C/Marti i Franques, no 1, planta 2, 08028, Barcelona (Spain); Kessler, M.; Goebel, J.; Mueller, G. [Department LG-SI 2, EADS Innovation Works, EADS Deutschland GmbH and EADS Innovation Works, Dept. IW-SI-Sensors, Electronics and Systems Integration, 81663 Muenchen (Germany)

2009-05-23T23:59:59.000Z

364

Power spectra of outflow-driven turbulence  

E-Print Network [OSTI]

We investigate the power spectra of outflow-driven turbulence through high-resolution three-dimensional isothermal numerical simulations where the turbulence is driven locally in real-space by a simple spherical outflow model. The resulting turbulent flow saturates at an average Mach number of ~2.5 and is analysed through density and velocity power spectra, including an investigation of the evolution of the solenoidal and compressional components. We obtain a shallow density power spectrum with a slope of ~-1.2 attributed to the presence of a network of localised dense filamentary structures formed by strong shock interactions. The total velocity power spectrum slope is found to be ~-2.0, representative of Burgers shock dominated turbulence model. The density weighted velocity power spectrum slope is measured as ~-1.6, slightly less than the expected Kolmogorov scaling value (slope of -5/3) found in previous works. The discrepancy may be caused by the nature of our real space driving model and we suggest ther...

Moraghan, Anthony; Yoon, Suk-Jin

2015-01-01T23:59:59.000Z

365

Prediction of buried mine-like target radar signatures using wideband electromagnetic modeling  

SciTech Connect (OSTI)

Current ground penetrating radars (GPR) have been tested for land mine detection, but they have generally been costly and have poor performance. Comprehensive modeling and experimentation must be done to predict the electromagnetic (EM) signatures of mines to access the effect of clutter on the EM signature of the mine, and to understand the merit and limitations of using radar for various mine detection scenarios. This modeling can provide a basis for advanced radar design and detection techniques leading to superior performance. Lawrence Livermore National Laboratory (LLNL) has developed a radar technology that when combined with comprehensive modeling and detection methodologies could be the basis of an advanced mine detection system. Micropower Impulse Radar (MIR) technology exhibits a combination of properties, including wideband operation, extremely low power consumption, extremely small size and low cost, array configurability, and noise encoded pulse generation. LLNL is in the process of developing an optimal processing algorithm to use with the MIR sensor. In this paper, we use classical numerical models to obtain the signature of mine-like targets and examine the effect of surface roughness on the reconstructed signals. These results are then qualitatively compared to experimental data.

Warrick, A.L.; Azevedo, S.G.; Mast, J.E.

1998-04-06T23:59:59.000Z

366

Mooring Motion Bias of Point-Doppler Current Meter Measurements Paul Freitag, Michael McPhaden, Chris Meinig, Patricia Plimpton  

E-Print Network [OSTI]

Mooring Motion Bias of Point-Doppler Current Meter Measurements Paul Freitag, Michael Mc). Until 1998 the moorings were instrumented with mechanical current meters (MCMs, either Vector Averaging Current Meters (VACM) or Vector Measuring Current Meters (VMCM)). Comparison with nearby subsurface 150 k

367

13A.1 ASSIMILATION OF SIMULATED NETWORK RADAR DATA OF VARIED STORM TYPES USING ENSRF FOR CONVECTIVE STORM ANALYSES AND FORECASTS  

E-Print Network [OSTI]

installation costs down, the CASA radars will be placed on cell phone towers or other existing infras- tructure with large data transmission capabilities. Unlike the existing pre-programmed radar network, the collabo

Xue, Ming

368

THE USE OF GROUND-PENETRATING RADAR FOR ARCHAEOLOGY: DETERMINING SITE FORMATION PROCESSES AND SUBSURFACE FEATURES ON TUTUILA ISLAND, AMERICAN SAMOA  

E-Print Network [OSTI]

, ceremonial mound (i.e. star mound) construction details were easily seen in radar profiles. Ground penetrating radar has the potential to yield significant details about such mounds, with no physical impact to the site....

Welch, Daniel

2006-07-11T23:59:59.000Z

369

Multi-channel Doppler backscattering measurements in the C-2 field reversed configuration  

SciTech Connect (OSTI)

A versatile heterodyne Doppler Backscattering (DBS) system is used to measure density fluctuation levels (in the wavenumber range k?{sub s} ? 50), and the toroidal E × B flow velocity in the C-2 Field-Reversed Configuration (FRC). Six tunable frequencies in three waveguide bands (26 GHz ? f ? 90 GHz) are launched using monostatic beam optics, via a quasi-optical beam combiner/polarizer and an adjustable parabolic focusing mirror (inside the vacuum enclosure) achieving Gaussian beam spot sizes of 3–5.5 cm at the X/O-mode cutoff. The DBS system covers plasma densities of 0.8 × 10{sup 13} ? n{sub e} ? 1 × 10{sup 14} cm{sup ?3}, and provides access to the FRC core (up to the field null) and across the FRC separatrix into the scrape-off layer plasma.

Schmitz, L., E-mail: lschmitz@ucla.edu; Peebles, W. A. [Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, California 90095 (United States); Ruskov, E. [Department of Physics and Astronomy, University of California, Irvine, Irvine, California 92697 (United States); Deng, B. H.; Gota, H.; Gupta, D.; Tuszewski, M.; Douglass, J.; Binderbauer, M.; Tajima, T. [Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688 (United States)

2014-11-15T23:59:59.000Z

370

Doppler-shifted fluorescence imaging of velocity fields in supersonic reacting flows  

SciTech Connect (OSTI)

The application of Doppler-shifted fluorescence imaging of velocity fields in supersonic reacting flows is analyzed. Focussing on fluorescence of the OH molecule in typical H2-air Scramjet flows, the effects of uncharacterized variations in temperature, pressure, and collisional partner composition across the measurement plane are examined. Detailed measurements of the (1,0) band OH lineshape variations in H2-air combustions are used, along with single-pulse and time-averaged measurements of an excimer-pumped dye laser, to predict the performance of a model velocimeter with typical Scramjet flow properties. The analysis demonstrates the need for modification and control of the laser bandshape in order to permit accurate velocity measurements in the presence of multivariant flow properties. 13 refs.

Allen, M.G.; Davis, S.J.; Kessler, W.J.; Sonnenfroh, D.M. (Physical Sciences, Inc., Andover, MA (United States))

1992-07-01T23:59:59.000Z

371

Outline Phonon spectra of graphene Raman spectra of graphene Crystal lattice dynamics  

E-Print Network [OSTI]

Seminar Heng Wang University of Konstanz July 11, 2013 Heng Wang University of Konstanz () Crystal lattice Raman spectra of graphene What is Raman scattering Applications of Raman spectroscopy of graphene Heng (2013). Heng Wang University of Konstanz () Crystal lattice dynamics July 11, 2013 3 / 19 #12;Outline

372

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)]

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

Widener, Kevin; Bharadwaj, Nitin; Johnson, Karen

373

Two-dimensional Variational Analysis of Near-Surface Moisture from Simulated Radar Refractivity-Related Phase Change Observations  

E-Print Network [OSTI]

provide high-resolution information about the highly variable low-level moisture field. Simulated radar uncertainty and random radar measurement errors. When a separate pre-processing step is applied to unwrap-slant-path water vapor measurements are most effective at the mid to upper levels where slant paths intersect each

Xue, Ming

374

U.S. Government work not protected by U.S. copyright Autonomous FMCW Radar Survey of Antarctic Shear  

E-Print Network [OSTI]

U.S. Government work not protected by U.S. copyright Autonomous FMCW Radar Survey of Antarctic results demonstrate that autonomous survey using high frequency radar is feasible and safe approach accumulation and high wind, and therefore present no surface expressions. To ensure safe navigation across

Marshall, Hans-Peter

375

IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 47, NO. 12, DECEMBER 1999 1807 Millimeter-Wave Radar Phenomenology of  

E-Print Network [OSTI]

-Wave Radar Phenomenology of Power Lines and a Polarimetric Detection Algorithm Kamal Sarabandi, Fellow, IEEE, and Moonsoo Park Abstract-- In this paper, the radar phenomenology of high- voltage power lines and cables are studied by repeating the polarimetric backscatter measurements. Based on this phenomenological study

Sarabandi, Kamal

376

500 IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, VOL. 3, NO. 4, OCTOBER 2006 ELF Radar System Proposed for Localized  

E-Print Network [OSTI]

500 IEEE GEOSCIENCE AND REMOTE SENSING LETTERS, VOL. 3, NO. 4, OCTOBER 2006 ELF Radar System frequency (ELF), finite difference time domain (FDTD), ionospheric disturbances, radar, remote sensing. I to be of sufficiently low power to have negligible heating or any other effects upon the ionospheric anomaly.) Employing

Simpson, Jamesina J.

377

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

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

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.

Abbasi, R. [Univ. of Utah, Salt Lake City, UT (United States); Takai, H. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Allen, C. [Univ. of Kansas, Lawrence, KS (United States); Beard, L. [Purdue Univ., West Lafayette, IN (United States); Belz, J. [Univ. of Utah, Salt Lake City, UT (United States); Besson, D. [Univ. of Kansas, Lawrence, KS (United States). Moscow Engineering and Physics Inst. (Russian Federation); Byrne, M. [Univ. of Utah, Salt Lake City, UT (United States); Abou Bakr Othman, M. [Univ. of Utah, Salt Lake City, UT (United States); Farhang-Boroujeny, B. [Univ. of Utah, Salt Lake City, UT (United States); Gardner, A. [Univ. of Utah, Salt Lake City, UT (United States); Gillman, W.H. [Gillman and Associates, Salt Lake City, UT (United States); Hanlon, W. [Univ. of Utah, Salt Lake City, UT (United States); Hanson, J. [Univ. of Kansas, Lawrence, KS (United States); Jayanthmurthy, C. [Univ. of Utah, Salt Lake City, UT (United States); Kunwar, S. [Univ. of Kansas, Lawrence, KS (United States); Larson, S. L. [Utah State Univ., Logan, UT (United States); Myers, I. [Univ. of Utah, Salt Lake City, UT (United States); Prohira, S. [Univ. of Kansas, Lawrence, KS (United States); Ratzlaff, K. [Univ. of Kansas, Lawrence, KS (United States); Sokolsky, P. [Univ. of Utah, Salt Lake City, UT (United States); Thomson, G. B. [Univ. of Utah, Salt Lake City, UT (United States); Von Maluski, D. [Univ. of Utah, Salt Lake City, UT (United States)

2014-12-01T23:59:59.000Z

378

A Software Tool for Processing the Displacement Time Series Extracted from Raw Radar Data  

SciTech Connect (OSTI)

The application of high-resolution radar waveform and interferometric principles recently led to the development of a microwave interferometer, suitable to simultaneously measuring the (static or dynamic) deflection of several points on a large structure. From the technical standpoint, the sensor is a Stepped Frequency Continuous Wave (SF-CW), coherent radar, operating in the K{sub u} frequency band.In the paper, the main procedures adopted to extract the deflection time series from raw radar data and to assess the quality of data are addressed, and the MATLAB toolbox developed is described. Subsequently, other functions implemented in the software tool (e.g. evaluation of the spectral matrix of the deflection time-histories, identification of natural frequencies and operational mode shapes evaluation) are described and the application to data recorded on full-scale bridges is exemplified.

Coppi, Francesco; Paolo Ricci, Pier [IDS Ingegneria Dei Sistemi S.p.A., Pisa (Italy); Gentile, Carmelo [Politecnico di Milano, Dept. of Structural Engineering, Milan (Italy)

2010-05-28T23:59:59.000Z

379

The Use of Radar Methods to Determine Moisture Content in the Vadose Zone  

SciTech Connect (OSTI)

Moisture content is a critical parameter affecting both liquid-phase and vapor-phase contaminant transport in the vadose zone. The objective of our three-year research project is to determine the optimal way to use of radar methods--both surface and borehole--as a noninvasive means of determining in situ moisture content. In our research we focus on two specific aspects of the link between radar images and moisture content. The first question we address is: Can we use a measure of the dielectric constant of a volume of the subsurface to determine the moisture content of that volume? The second question we address is: Can we use the radar data to characterize the spatial variability in moisture content?

Knight, Rosemary

2001-06-01T23:59:59.000Z

380

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

DOE Patents [OSTI]

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.

McEwan, Thomas E. (Livermore, CA)

1998-05-26T23:59:59.000Z

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

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

SciTech Connect (OSTI)

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.

Not Available

1988-11-17T23:59:59.000Z

382

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

DOE Patents [OSTI]

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.

McEwan, T.E.

1998-05-26T23:59:59.000Z

383

Progress in computing inclusive B decay spectra.  

E-Print Network [OSTI]

ar X iv :h ep -p h/ 06 01 18 1v 1 2 1 Ja n 20 06 Progress in computing inclusive B decay spectra Einan Gardi and Jeppe R. Andersen Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge, CB3 0HE, UK We review the progress... V, M0E =1.7GeV x =1GeV, M0E =1.7GeV, fully diff. x =1GeV, M0E =0.66GeV max + =1GeV, P0E =0.66GeV, fully diff. max + =1GeV, P0E Figure 4. The P? spectrum in B¯ ?? Xul?¯ as calculated by DGE [17], after integration over P+ and El in four different...

Gardi, Einan; Andersen, Jeppe R

384

Oxidation of carbynes: Signatures in infrared spectra  

SciTech Connect (OSTI)

We report and solidly interpret the infrared spectrum of both pristine and oxidized carbynes embedded in a pure-carbon matrix. The spectra probe separately the effects of oxidation on sp- and on sp{sup 2}-hybridized carbon, and provide information on the stability of the different structures in an oxidizing atmosphere. The final products are mostly short end-oxidized carbynes anchored with a double bond to sp{sup 2} fragments, plus an oxidized sp{sup 2} amorphous matrix. Our results have important implications for the realization of carbyne-based nano-electronics devices and highlight the active participation of carbynes in astrochemical reactions where they act as carbon source for the promotion of more complex organic species.

Cinquanta, E., E-mail: eugenio.cinquanta@mdm.imm.cnr.it, E-mail: p.rudolf@rug.nl [CIMAINA, University of Milan, Via Celoria 16, 20133 Milano (Italy); Department of Materials Science, University of Milan Bicocca, Via Cozzi 53, 20125 Milano (Italy); Manini, N.; Caramella, L.; Onida, G. [European Theoretical Spectroscopy Facility (ETSF), Via Celoria 16, 20133 Milano (Italy); Physics Department, University of Milan, Via Celoria 16, 20133 Milano (Italy); Ravagnan, L.; Milani, P. [CIMAINA, University of Milan, Via Celoria 16, 20133 Milano (Italy); Physics Department, University of Milan, Via Celoria 16, 20133 Milano (Italy); Rudolf, P., E-mail: eugenio.cinquanta@mdm.imm.cnr.it, E-mail: p.rudolf@rug.nl [Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747AG Groningen (Netherlands)

2014-06-28T23:59:59.000Z

385

Radioactive sample effects on EDXRF spectra  

SciTech Connect (OSTI)

Energy dispersive X-ray fluorescence (EDXRF) is a rapid, straightforward method to determine sample elemental composition. A spectrum can be collected in a few minutes or less, and elemental content can be determined easily if there is adequate energy resolution. Radioactive alpha emitters, however, emit X-rays during the alpha decay process that complicate spectral interpretation. This is particularly noticeable when using a portable instrument where the detector is located in close proximity to the instrument analysis window held against the sample. A portable EDXRF instrument was used to collect spectra from specimens containing plutonium-239 (a moderate alpha emitter) and americium-241 (a heavy alpha emitter). These specimens were then analyzed with a wavelength dispersive XRF (WDXRF) instrument to demonstrate the differences to which sample radiation-induced X-ray emission affects the detectors on these two types of XRF instruments.

Worley, Christopher G [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

386

High-resolution moisture fields retrieved for the first time from both operational and research radars illustrate the low-level moisture variability associated with boundary layer  

E-Print Network [OSTI]

radars illustrate the low-level moisture variability associated with boundary layer processes-Resolution, Low-Level Moisture Fields from Operational NexRad and Research Radars by Rita D. RobeRts, FRéDéRic Fab vapor measurements extracted from radar using an index of refraction (refractivity) technique developed

Reising, Steven C.

387

1498 JOURNAL OF ,\\TMOSPHERIC AND OCEANIC TECHNOLOGY VULIIME 25 A Techniqne for the Automatic Detection of Insect Clutter in Cloud Radar Returns  

E-Print Network [OSTI]

Radiation Measurement (ARM) Program operales 35- GHz millimclcr·w:lvclenglh cloud radars (MMCRs) in several levels in scan- ning weather radar applications (e.g., Vaughn 1985; Achtemeier 199]; Wilson el al. 1994 Detection of Insect Clutter in Cloud Radar Returns EDWARD P. LUKE, PAVLOS KOLLlAS, AND KAREN L. JOHNSON Aml

388

IFT&E Industry Report Wind Turbine-Radar Interference Test Summary.  

SciTech Connect (OSTI)

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.

Karlson, Benjamin; LeBlanc, Bruce Philip; Minster, David G; Estill, Milford; Miller, Bryan Edward; Busse, Franz (MIT LL); Keck, Chris (MIT LL); Sullivan, Jonathan (MIT LL); Brigada, David (MIT LL); Parker, Lorri (MIT LL); Younger, Richard (MIT LL); Biddle, Jason (MIT LL)

2014-10-01T23:59:59.000Z

389

THEORETICAL SPECTRA OF TERRESTRIAL EXOPLANET SURFACES  

SciTech Connect (OSTI)

We investigate spectra of airless rocky exoplanets with a theoretical framework that self-consistently treats reflection and thermal emission. We find that a silicate surface on an exoplanet is spectroscopically detectable via prominent Si-O features in the thermal emission bands of 7-13 {mu}m and 15-25 {mu}m. The variation of brightness temperature due to the silicate features can be up to 20 K for an airless Earth analog, and the silicate features are wide enough to be distinguished from atmospheric features with relatively high resolution spectra. The surface characterization thus provides a method to unambiguously identify a rocky exoplanet. Furthermore, identification of specific rocky surface types is possible with the planet's reflectance spectrum in near-infrared broad bands. A key parameter to observe is the difference between K-band and J-band geometric albedos (A{sub g}(K) - A{sub g}(J)): A{sub g}(K) - A{sub g}(J) > 0.2 indicates that more than half of the planet's surface has abundant mafic minerals, such as olivine and pyroxene, in other words primary crust from a magma ocean or high-temperature lavas; A{sub g}(K) - A{sub g}(J) < -0.09 indicates that more than half of the planet's surface is covered or partially covered by water ice or hydrated silicates, implying extant or past water on its surface. Also, surface water ice can be specifically distinguished by an H-band geometric albedo lower than the J-band geometric albedo. The surface features can be distinguished from possible atmospheric features with molecule identification of atmospheric species by transmission spectroscopy. We therefore propose that mid-infrared spectroscopy of exoplanets may detect rocky surfaces, and near-infrared spectrophotometry may identify ultramafic surfaces, hydrated surfaces, and water ice.

Hu Renyu; Seager, Sara [Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139 (United States); Ehlmann, Bethany L., E-mail: hury@mit.edu [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States)

2012-06-10T23:59:59.000Z

390

Applications of digital radar in the analysis of severe local storms  

E-Print Network [OSTI]

August 1973 Major Subject: Meteorology APPLICATIONS OF DIGITAL RADAR IN THE ANALYSIS OF SEVERE LOCAL STORMS A Thesis JOHN EVERETT VOGEL Approved as to style and content by: (Co-Chairman of Committee) / /. Lier &. i i . 3 I r1 ~ '-d (ri 'i ~ ~ i...(& V (Co-Chairman of Committee) k. )&7 I). *v 'e(C' & ~. (Head of Department) (Member) ( ember) August 1973 ABSTRACT Applications of Digital Radar in the Analysis of Severe Local Storms (August 1973) John E. Vogel, B. S. , Texas A&M University...

Vogel, John Everett

1973-01-01T23:59:59.000Z

391

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

SciTech Connect (OSTI)

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'.

Doerry, Armin Walter

2010-09-01T23:59:59.000Z

392

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

E-Print Network [OSTI]

,399 unique cells, and 1,028,510 to find the best lightning forecast criteria. Results show that using 30 dBZ at the -20 ?C isotherm on cells within 75 km of the radar that have been tracked for at least 2 consecutive scan produces the best forecasts... with a critical success index (CSI) of 0.71. The best VII predictor was 0.734 kg m-2 on cells within 75 km of the radar that have been tracked for at least 2 consecutive scans iv producing a CSI of 0.68. Results of this study further suggest...

Mosier, Richard Matthew

2011-02-22T23:59:59.000Z

393

A Comparison of Simulated Cloud Radar Output from the Multiscale Modeling Framework Global Climate Model with CloudSat Cloud Radar Observations  

SciTech Connect (OSTI)

Over the last few years a new type of global climate model (GCM) has emerged in which a cloud-resolving model is embedded into each grid cell of a GCM. This new approach is frequently called a multiscale modeling framework (MMF) or superparameterization. In this article we present a comparison of MMF output with radar observations from the NASA CloudSat mission, which uses a near-nadir-pointing millimeter-wavelength radar to probe the vertical structure of clouds and precipitation. We account for radar detection limits by simulating the 94 GHz radar reflectivity that CloudSat would observe from the high-resolution cloud-resolving model output produced by the MMF. Overall, the MMF does a good job of reproducing the broad pattern of tropical convergence zones, subtropical belts, and midlatitude storm tracks, as well as their changes in position with the annual solar cycle. Nonetheless, the comparison also reveals a number of model shortfalls including (1) excessive hydrometeor coverage at all altitudes over many convectively active regions, (2) a lack of low-level hydrometeors over all subtropical oceanic basins, (3) excessive low-level hydrometeor coverage (principally precipitating hydrometeors) in the midlatitude storm tracks of both hemispheres during the summer season (in each hemisphere), and (4) a thin band of low-level hydrometeors in the Southern Hemisphere of the central (and at times eastern and western) Pacific in the MMF, which is not observed by CloudSat. This band resembles a second much weaker ITCZ but is restricted to low levels.

Marchand, Roger T.; Haynes, J. M.; Mace, Gerald G.; Ackerman, Thomas P.; Stephens, Graeme L.

2009-01-13T23:59:59.000Z

394

Relativity, Doppler shifts, and retarded times in deriving the correction for the finite speed of light: a comment on 'Second-order Doppler-shift corrections in free-fall absolute gravimeters'  

E-Print Network [OSTI]

In the article (Rothleitner and Francis 2011 Metrologia 48 187-195) the correction due to the finite speed of light in absolute gravimeters is analyzed from the viewpoint of special relativity. The relativistic concepts eventually lead to the two classical approaches to the problem: analysis of the beat frequency, and introduction of the retarded times. In the first approach, an additional time delay has to be assumed, because the frequency of the beam bounced from the accelerated reflector differs at the point of reflection from that at the point of interference. The retarded times formalism is equivalent to a single Doppler shift, but results in the same correction as the beat frequency approach, even though the latter is explicitly combines two Doppler shifts. In our comments we discuss these and other problems we found with the suggested treatment of the correction.

Nagornyi, V D; Zanimonskiy, Y Y

2011-01-01T23:59:59.000Z

395

Kinematical relations among radar-observed water concentrations, vertical motions, and liquid-water drop-size spectra in convective clouds  

E-Print Network [OSTI]

of return settling are often cloudless or consist of cumulus clouds which have had their growth impeded. If conditions in the atmosphere are favorable, convection cells form and the updraft areas associated with these cells develop into cumulonimbus... and time, M & M(x, y, z, t). The x- and y-directions are horizontal and z-direction is positive toward the zenith. If the quantity M is conservative, the local rate of change at a fixed locality (the local change) can be represented by the following...

Runnels, Robert Clayton

1962-01-01T23:59:59.000Z

396

auger decay spectra: Topics by E-print Network  

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

2008-01-01 44 Constraining Mass Spectra with Sterile Neutrinos from Neutrinoless Double Beta Decay, Tritium Beta Decay and Cosmology HEP - Experiment (arXiv) Summary: We...

397

Recovery of constituent spectra using non-negative matrix factorization  

E-Print Network [OSTI]

, mineral exploration, vegetation mapping, hazardous material remediation, and water quality control. #12 to produce spectra across a large number of wavelengths/bands (> 30 bands). Typical wavelength ranges

Parra, Lucas C.

398

annihilation lifetime spectra: Topics by E-print Network  

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

spectra from WIMP annihilation HEP - Theory (arXiv) Summary: If the present dark matter in the Universe annihilates into Standard Model particles, it must contribute to the...

399

Physical Parameterization of Stellar Spectra: The Neural Network Approach  

E-Print Network [OSTI]

We present a technique which employs artificial neural networks to produce physical parameters for stellar spectra. A neural network is trained on a set of synthetic optical stellar spectra to give physical parameters (e.g. T_eff, log g, [M/H]). The network is then used to produce physical parameters for real, observed spectra. Our neural networks are trained on a set of 155 synthetic spectra, generated using the SPECTRUM program written by Gray (Gray & Corbally 1994, Gray & Arlt 1996). Once trained, the neural network is used to yield T_eff for over 5000 B-K spectra extracted from a set of photographic objective prism plates (Bailer-Jones, Irwin & von Hippel 1997a). Using the MK classifications for these spectra assigned by Houk (1975, 1978, 1982, 1988) we have produced a temperature calibration of the MK system based on this set of 5000 spectra. It is demonstrated through the metallicity dependence of the derived temperature calibration that the neural networks are sensitive to the metallicity signature in the real spectra. With further work it is likely that neural networks will be able to yield reliable metallicity measurements for stellar spectra.

Coryn A. L. Bailer-Jones; Mike Irwin; Gerard Gilmore; Ted von Hippel

1997-08-22T23:59:59.000Z

400

Mass generation in coalescence - effects on hadron spectra  

E-Print Network [OSTI]

Different scenarios for the creation of constituent mass in the hadron formation process are discussed. Effects of these may be observable in hadron momentum spectra.

T. Peitzmann

2005-11-07T23:59:59.000Z

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Hybrid Estimation of CMB Polarization Power Spectra  

E-Print Network [OSTI]

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.

G. Efstathiou

2006-01-05T23:59:59.000Z

402

Meridian-scanning photometer, coherent HF radar, and magnetometer observations of the cusp: a case study  

E-Print Network [OSTI]

the transport of mass, energy, and momentum from the solar wind into the near-Earth environment, is facilitated with the CUTLASS Finland coherent HF radar, a meridian-scanning photometer located at Ny AÃ? lesund, Svalbard on the scale of minutes, and which are believed to be related to the dynamic nature of energy and momentum

Paris-Sud XI, Université de

403

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

SciTech Connect (OSTI)

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.

Doerry, Armin Walter

2012-05-01T23:59:59.000Z

404

Ionospheric local model and climatology from long-term databases of multiple incoherent scatter radars  

E-Print Network [OSTI]

Ionospheric local model and climatology from long-term databases of multiple incoherent scatter and climatology from long-term databases of multiple incoherent scatter radars, Geophys. Res. Lett., 32, L20102 to ionospheric and ther- mospheric climatology. The altitude dependence, for in- stance, of various variations

405

Radar Measurements of Ice Sheet Thickness of Outlet Glaciers in Greenland D. Braaten+  

E-Print Network [OSTI]

Radar Measurements of Ice Sheet Thickness of Outlet Glaciers in Greenland D. Braaten+ and S of Kansas Lawrence, KS 66045 U.S.A. Abstract ­ We have conducted airborne measurements over the Greenland the mass balance of the Greenland ice sheet, the University of Kansas has been operating an airborne radio

Kansas, University of

406

A Theory-Based Hydrometeor Identification Algorithm for X-Band Polarimetric Radars  

E-Print Network [OSTI]

A Theory-Based Hydrometeor Identification Algorithm for X-Band Polarimetric Radars BRENDA DOLAN, and comparisons are made with similar S-band hydrometeor identification algorithms applied to data from the S for illustrating bulk hydrometeor types and qualitatively agrees with analysis from KOUN. A simple reflectivity

Rutledge, Steven

407

ALBOTA ET AL. Three-Dimensional Imaging Laser Radars with Geiger-Mode Avalanche Photodiode Arrays  

E-Print Network [OSTI]

· ALBOTA ET AL. Three-Dimensional Imaging Laser Radars with Geiger-Mode Avalanche Photodiode Arrays- lanche photodiodes (APDs) operating in Geiger mode, with integrated timing circuitry for each pixel [2-Mode Avalanche Photodiode Arrays Marius A. Albota, Brian F. Aull, Daniel G. Fouche, Richard M. Heinrichs, David G

408

Downburst-producing thunderstorms in southern Germany: Radar analysis and predictability  

E-Print Network [OSTI]

Downburst-producing thunderstorms in southern Germany: Radar analysis and predictability Nikolai der Atmosphäre, Oberpfaffenhofen, 82234 Wessling, Germany b European Severe Storms Laboratory (ESSL), Münchner Str. 20, 82234 Wessling, Germany a r t i c l e i n f o a b s t r a c t Article history: Received

409

IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING 1 Microphysical Characterization of Microwave Radar  

E-Print Network [OSTI]

.g., Meteosat sensors) are usually exploited for long-range trajectory tracking and for measuring low level measurements may be blocked by water and ice clouds at higher levels and their overall utility is reduced Radar Reflectivity Due to Volcanic Ash Clouds Frank Silvio Marzano, Senior Member, IEEE, Gianfranco

Rose, William I.

410

Improving estimates of African woodland biomass by fusing radar data, models and ground observations  

E-Print Network [OSTI]

Improving estimates of African woodland biomass by fusing radar data, models and ground management of savannahs and woodlands requires accurate estimates of the woody biomass. For these reasons, developing new methods to accurately estimate woody biomass and its changes is high on the political

411

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

E-Print Network [OSTI]

Ice iron/sodium film as cause for high noctilucent cloud radar reflectivity P. M. Bellan1 Received] Noctilucent clouds, tiny cold electrically charged ice grains located at about 85 km altitude, exhibit by assuming the ice grains are coated by a thin metal film; substantial evidence exists indicating

Bellan, Paul M.

412

A Time Series Weather Radar Simulator Based on High-Resolution Atmospheric Models  

E-Print Network [OSTI]

to produce theoretical moment maps, which allow for the study of radar characteristics and limitations given of signal-processing techniques, which help identify and scrutinize factors that may have been overlooked corresponding to that spectral shape. Numerous statistical studies were made possible using this simulation

Xue, Ming

413

An Intercomparison of Radar-Based Liquid Cloud Microphysics Retrievals and Implication for Model Evaluation Studies  

E-Print Network [OSTI]

Research Facility of the US Department of Energy provides long-term continuous cloud and radiation datasets Forks, ND 58202, U.S.A. 4 University of Utah, Salt Lake City, UT 84112, U.S.A. Corresponding Author Dong of single-frequency radar approaches. It is therefore suggested that data users should use the retrievals

Dong, Xiquan

414

Weather Radar Monitoring using the Sun Iwan Holleman and Hans Beekhuis  

E-Print Network [OSTI]

Weather Radar Monitoring using the Sun Iwan Holleman and Hans Beekhuis Technical Report, KNMI TR and azimuthal averaging 13 2.5 Corrected solar power 15 3 Position of the sun 17 3.1 Celestial sphere and equatorial coordinates 17 3.2 Equatorial coordinates of the sun 18 3.3 Conversion to elevation and azimuth 20

Stoffelen, Ad

415

Through-the-wall Imaging Radar Students: Thang Bui and Joseph Rabig  

E-Print Network [OSTI]

radar (SAR) to image objects behind a wall, using a pair of horn antennas and a vector network analyser was used to calibrate out unknown cable and system delays · Objects are resolved at correct locations close to the SAR Focusing delay geometry Theory ­ Image Processing Electromagnetic distance between horn

Ghahramani, Zoubin

416

Synthetic Aperture Radar Imaging with Motion Estimation and , T. Callaghan1  

E-Print Network [OSTI]

principles a synthetic aperture radar (SAR) imaging and target motion estimation method that is combined of the data into properly calibrated small apertures, (b) motion or platform trajectory perturbation estimation process. X-band persistent surveillance SAR is a specific application that is covered by our

Borcea, Liliana

417

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

418

1. Introduction The use of radar rainfall data for hydrological model-  

E-Print Network [OSTI]

feed an interceptor sewer (up to 2.35 m box sec- tion) that conveys flows to a wastewater treatment for the supply of potable water and the treatment of wastewater in the north- west of England. The primary radar rainfall data was as an input to rainfall­runoff models of rural river systems. Building

Fox, Neil I.

419

An annual cycle of Arctic cloud characteristics observed by radar and lidar at SHEBA  

E-Print Network [OSTI]

distribution of cloud boundary heights, and occurrence of liquid phase in clouds are determined from radar-observed clouds containing liquid was 73% for the year. The least amount of liquid water phase was observed during-detected clouds. Liquid was distributed in a combination of all-liquid and mixed phase clouds, and was detected

Shupe, Matthew

420

HF radar in French Mediterranean Sea: an element of MOOSE Mediterranean Ocean Observing System on Environment  

E-Print Network [OSTI]

Sea in the context of climate change and anthropogenic pressure and to supply and maintain longHF radar in French Mediterranean Sea: an element of MOOSE Mediterranean Ocean Observing System , Pascal Guterman2 , Karim Bernardet2 1 Mediterranean Institute of Oceanography (MIO, UM 110, USTV

Boyer, Edmond

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Quality Control and Verification of Weather Radar Wind Profiles IWAN HOLLEMAN  

E-Print Network [OSTI]

- tions of the vertical velocity, which is a sum of the vertical wind velocity and the hydrometeor fall. 1986). Profiles of wind speed and direction, hydrometeor fall speed, and divergence have been obtainedQuality Control and Verification of Weather Radar Wind Profiles IWAN HOLLEMAN Royal Netherlands

Stoffelen, Ad

422

Simultaneous Retreival of Surface Wind Speed and Rain Rate using Radar and Radiometer Measurements  

E-Print Network [OSTI]

to simultaneously retrieve the vertical profile of precipitation and the near-surface wind speed. ResultsSimultaneous Retreival of Surface Wind Speed and Rain Rate using Radar and Radiometer Measurements simultaneously estimates the over ocean near-surface wind speed and rain rate profile using data from a 10.7 GHz

Ruf, Christopher

423

A study of radar reflectivities from hurricane Debra, 24-25 July 1959  

E-Print Network [OSTI]

, Iouis J. , Radar Meteorolo , The University of' Chicago Press, icago, 5. Beoker, G. E. and S. H. Autler, "Water Vapour Absorption of' Electromagnetic Radiation in the Centimetre Wave- length Range, " The Ph sical Review, 70(5, 6):300-307, September...

Durham, Kneeland Secor

1960-01-01T23:59:59.000Z

424

Improvement of radar ice-thickness measurements of Greenland outlet glaciers using SAR processing  

E-Print Network [OSTI]

Extensive aircraft-based radar ice-thickness measurements over the interior and outlet-glacier regions of the Greenland ice sheet have been obtained by the University of Kansas since 1993, with the latest airborne surveys conducted in May 2001...

Braaten, David A.; Gogineni, S. Prasad; Tammana, Dilip; Namburi, Saikiran; Paden, John; Gurumoorthy, Krishna K.

2002-01-01T23:59:59.000Z

425

ESTIMATING BEDROCK AND SURFACE LAYER BOUNDARIES AND CONFIDENCE INTERVALS IN ICE SHEET RADAR IMAGERY USING MCMC  

E-Print Network [OSTI]

ESTIMATING BEDROCK AND SURFACE LAYER BOUNDARIES AND CONFIDENCE INTERVALS IN ICE SHEET RADAR IMAGERY and Computing Indiana University Bloomington, Indiana USA ABSTRACT Climate models that predict polar ice sheet behavior require accurate measurements of the bedrock-ice and ice-air bound- aries in ground

Menczer, Filippo

426

Probabilistic Conic Mixture Model and its Applications to Mining Spatial Ground Penetrating Radar Data  

E-Print Network [OSTI]

to image data is a basic task in pattern recognition and spatial data mining and also is an important a reliable report after the inspection. The patterns appearing in the B-scans [5] of GPR data have shapesProbabilistic Conic Mixture Model and its Applications to Mining Spatial Ground Penetrating Radar

Leeds, University of

427

Range dependent errors in the convective and stratiform partitioning of a radar precipitation estimation algorithm  

E-Print Network [OSTI]

BZ was classified differently by the two radar data sets at the 1.5 km and 3.0 km analysis levels respectively. The percentage of total rainfall from all precipitation classified differently was 26% for the 1.5 km analysis level, and 28% for the 3.0 km level....

Wood, David Richard

1996-01-01T23:59:59.000Z

428

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

SciTech Connect (OSTI)

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.

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)

1994-09-01T23:59:59.000Z

429

CHARACTERIZATION OF AIRFLOWS NEAR THE EXIT OF HVAC REGISTERS USING LASER DOPPLER VELOCIMETRY (LDV).  

SciTech Connect (OSTI)

A facility to characterize the airflow at the exit of HVAC registers was designed and fabricated. The objective of this work is to obtain velocity and turbulence data at the exit of registers, which can then be used as an input boundary condition in a modern Computational Fluid Dynamics (CFD) code to predict the velocity and temperature distribution in an enclosure, and also the register performance parameters such as throw. During the course of this work, two commonly used registers were tested. Both registers were 8 inch x 4 inch sidewall registers. Laser Doppler Velocimetry was used to measure the axial and vertical components of the velocity vector at various locations across the face of the registers. For the two cases of registers studied here, the results suggest that the velocity field at the very exit of each of these registers scales with the flow rate through the registers. This means that, in the mode of operation in which the supply fan (of an HVAC system) has a ''High'' and ''Low'' setting, similar velocity scaling would result for the type of registers tested here.

TUTU,N.K.; KRISHNA,C.R.; ANDREWS,J.W.; BUTCHER,T.A.

2003-03-13T23:59:59.000Z

430

Measurement of fast-changing low velocities by photonic Doppler velocimetry  

SciTech Connect (OSTI)

Despite the increasing popularity of photonic Doppler velocimetry (PDV) in shock wave experiments, its capability of capturing low particle velocities while changing rapidly is still questionable. The paper discusses the performance of short time Fourier transform (STFT) and continuous wavelet transform (CWT) in processing fringe signals of fast-changing low velocities measured by PDV. Two typical experiments are carried out to evaluate the performance. In the laser shock peening test, the CWT gives a better interpretation to the free surface velocity history, where the elastic precursor, main plastic wave, and elastic release wave can be clearly identified. The velocities of stress waves, Hugoniot elastic limit, and the amplitude of shock pressure induced by laser can be obtained from the measurement. In the Kolsky-bar based tests, both methods show validity of processing the longitudinal velocity signal of incident bar, whereas CWT improperly interprets the radial velocity of the shocked sample at the beginning period, indicating the sensitiveness of the CWT to the background noise. STFT is relatively robust in extracting waveforms of low signal-to-noise ratio. Data processing method greatly affects the temporal resolution and velocity resolution of a given fringe signal, usually CWT demonstrates a better local temporal resolution and velocity resolution, due to its adaptability to the local frequency, also due to the finer time-frequency product according to the uncertainty principle.

Song Hongwei; Wu Xianqian; Huang Chenguang; Wei Yangpeng; Wang Xi [Key Laboratory for Hydrodynamics and Ocean Engineering, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China)

2012-07-15T23:59:59.000Z

431

A multi-point laser Doppler vibrometer with fiber-based configuration  

SciTech Connect (OSTI)

Laser Doppler vibrometer (LDV) is a non-contact optical interferometric system to measure vibrations of structures and machines with a high precision. Normal LDV can only offer a single-point measurement. Scanning LDV is usually impractical to do measurement on transient events. In this paper, a fiber-based self-synchronized multi-point LDV is proposed. The multiple laser beams with different frequency shifts are generated from one laser source. The beams are projected onto a vibrating object, reflected and interfered with a common reference beam. The signal including vibration information of multiple spatial points is captured by one single-pixel photodetector. The optical system is mainly integrated by fiber components for flexibility in measurement. Two experiments are conducted to measure a steady-state simple harmonic vibration of a cantilever beam and a transient vibration of a beam clamped at both ends. In the first measurement, a numerical interpolation is applied to reconstruct the mode shape with increased number of data points. The vibration mode obtained is compared with that from FEM simulation. In transient vibration measurement, the first five resonant frequencies are obtained. The results show the new-reported fiber-based multipoint LDV can offer a vibration measurement on various spatial points simultaneously. With the flexibility of fiber configuration, it becomes more practical for dynamic structural evaluation in industrial areas.

Yang, C. [Temasek Laboratories and School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Drive, Singapore 637553 (Singapore) [Temasek Laboratories and School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Drive, Singapore 637553 (Singapore); Department of Modern Mechanics, University of Science and Technology of China, Hefei 230027 (China); Institute of Systems Engineering, China Academy of Engineering Physics, Mianyang 621900 (China); Guo, M.; Liu, H.; Yan, K.; Xu, Y. J.; Fu, Y., E-mail: fuyuoptics@gmail.com [Temasek Laboratories and School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Drive, Singapore 637553 (Singapore); Miao, H. [Department of Modern Mechanics, University of Science and Technology of China, Hefei 230027 (China)] [Department of Modern Mechanics, University of Science and Technology of China, Hefei 230027 (China)

2013-12-15T23:59:59.000Z

432

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

SciTech Connect (OSTI)

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.

Pfister, Thorsten; Guenther, Philipp; Dreier, Florian; Czarske, Juergen [Technische Universitaet Dresden, Faculty of Electrical Engineering and Information Technology, Laboratory for Measurement and Testing Techniques, Helmholtzstrasse 18, D-01062 Dresden (Germany)

2010-05-28T23:59:59.000Z

433

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

SciTech Connect (OSTI)

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.

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

2008-09-20T23:59:59.000Z

434

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

E-Print Network [OSTI]

) 218 219 221 Table C-7 XMTR/RCVR (T/R) Enclosure Wire List (50 - pin D connector) ~pa e 223 LIST OF FIGURES ~Fi ure X-Band Radar Scatterometer ~pa e I-2 Basic Block Diagram of the X-Band Radar Scatterometer X-Band Radar Block Diagram...) Produced by the SPST PIN diode Switch Modulator: fo' = 10. 000 GHz 77 ~Fi ure IV-15 ~pa e Graph of the Output Power Deviation of the CW Gunn Oscillator (Model No. MA 86130) as a Function of Temperature ~ ~ ~ ~ ~ 79 IV-16 V-1 V-2 V-3 V-4 V-5 V...

White, Allen William

2012-06-07T23:59:59.000Z

435

hal00276997, Raman spectra of misoriented bilayer graphene  

E-Print Network [OSTI]

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

Paris-Sud XI, Université de

436

Chandra Observations of Associates of $?$ Car: II. Spectra  

E-Print Network [OSTI]

The low resolution X-ray spectra around $\\eta$ Car covering Tr 16 and part of Tr 14 have been extracted from a Chandra CCD ACIS image. Various analysis techniques have been applied to the spectra based on their count rates. The spectra with the greatest number of counts (HD 93162 = WR 25, HD 93129AB, and HD 93250) have been fit with a wind model, which uses several components with different temperatures and depths in the wind. Weaker spectra have been fit with Raymond-Smith models. The weakest spectra are simply inter-compared with strong spectra. In general, fits produce reasonable parameters based on knowledge of the extinction from optical studies and on the range of temperatures for high and low mass stars. Direct comparisons of spectra confirm the consistency of the fitting results and also hardness ratios for cases of unusually large extinction in the clusters. The spectra of the low mass stars are harder than the more massive stars. Stars in the sequence evolving from the main sequence (HD 93250) through the system containing the O supergiant (HD 93129AB) and then through the Wolf-Rayet stage (HD93162), presumably ending in the extreme example of $\\eta$ Car, share the property of being unusually luminous and hard in X-rays. For these X-ray luminous stars, their high mass and evolutionary status (from the very last stages of the main sequence and beyond) is the common feature. Their binary status is mixed, and magnetic status is still uncertain.

Nancy Remage Evans; Eric M. Schlegel; Wayne L. Waldron; Frederick D. Seward; Miriam I. Krauss; Joy Nichols; Scott J. Wolk

2004-05-28T23:59:59.000Z

437

Rendering Optical Effects Based on Spectra Representation in Complex Scenes  

E-Print Network [OSTI]

Rendering Optical Effects Based on Spectra Representation in Complex Scenes Weiming Dong Project ALICE, INRIA Lorraine/Loria, France Weiming.Dong@loria.fr Abstract. Rendering the structural color sensitive phenomena. Achieving the rendering of complex scenes with both the full spectra and RGB light

Paris-Sud XI, Université de

438

Reactivity impact of delayed neutron spectra on MCNP calculations  

SciTech Connect (OSTI)

The new features in MCNP4C, the latest version of the MCNP Monte Carlo code, include the capability to sample from delayed as well as prompt fission emission spectra. Previous versions of MCNP all have sampled exclusively from prompt spectra. Delayed neutrons typically account for <1% of all neutrons emitted from fission, but the emission spectra for delayed neutrons are somewhat softer than those for prompt neutrons. Because of the softer spectrum, delayed neutrons are less likely to leak from the system, and they also are less likely to cause fission in isotopes that have an effective threshold for fission (e.g., {sup 238}U and {sup 240}Pu). Consequently, the inclusion of delayed neutron spectra can have a small but significant effect on reactivity calculations. This study performs MCNP4C calculations for a series of established benchmarks and quantifies the reactivity impact of the delayed neutron spectra.

Mosteller, R.D.; Werner, C.J.

2000-07-01T23:59:59.000Z

439

Spectra of hadrons and muons in the atmosphere: primary spectra, characteristics of hadron-air interactions  

E-Print Network [OSTI]

Self-consistency of interaction models QGSJET 01, SIBYLL 2.1, NEXUS 3.97 and QGSJET II is checked in terms of their ability to reproduce simultaneously experimental data on fluxes of muons and hadrons. From this point of view SIBYLL 2.1 gives the most acceptable, though not quite satisfactory, results. Analysis of the situation for muons supports our previous conclusions, that high-energy muon deficit is due both to underestimation of primary light nuclei fluxes in direct emulsion chamber experiments and to softness of $p+A\\to\\pi^\\pm,K^\\pm+X$ inclusive spectra in fragmentation region, especially prominent in case of QGSJET 01 model.

A. V. Yushkov; A. A. Lagutin

2006-12-01T23:59:59.000Z

440

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

E-Print Network [OSTI]

numbers: 94.20.Bb, 52.25.Sw, 52.35.Mw, 94.20.Tt A powerful O-mode electromagnetic pump wave trans- mitted eight low-power, O-mode MDR waves with different frequen- cies fi, i 1, 2, . . . , 8, around f0 Institute of Space Physics, Uppsala Division, S-755 91 Uppsala, Sweden (Received 25 September 1996

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

About the Reference AM 1.5 Spectra American Society for Testing and Materials (ASTM) Terrestrial Reference Spectra  

E-Print Network [OSTI]

of specified atmospheric conditions. These distributions of power (watts per square meter per nanometer.gsfc.nasa.gov/space/model/atmos/us_standard.html.) The spectra are modeled using the SMARTS2 (version 2.9.2) Simple Model for Atmospheric Transmission used in conjunction with SMARTS to produce the reference spectra is NOT the AM0 spectrum in ASTM E-490

Chen, C. Julian

442

Case studies in magnetics and ground penetrating radar, Shreveport Convention Center, Shreveport, LA and Yankee Boy Rock Glacier, Ouray, CO  

E-Print Network [OSTI]

The use of geophysical tools such as magnetics and ground penetrating radar are becoming more prevalent in site characterization studies and other geologic research. Two case studies which illustrate this are described here. The first case study...

Pierce, Carl J

2002-01-01T23:59:59.000Z

443

Relative Information in Phase of Radar Range Pro les Brian Rigling , Lee C. Potter and Randolph L. Moses  

E-Print Network [OSTI]

. Moses The Ohio State University Department of Electrical and Computer Engineering 2015 Neil Avenue is adopted for the radar backscatter, and information is quanti ed using the variance of parameters estimated

Moses, Randolph L.

444

30 ENGINEERING & SCIENCE WI NTE R 2012 Whether processing radar signals in Norway or assessing rock properties in Nigeria, Calte  

E-Print Network [OSTI]

30 ENGINEERING & SCIENCE WI NTE R 2012 Whether processing radar signals in Norway or assessing rock deeply into basic physics to solve problems. Oslo, Norway, José Navarro, PhD '94, Astronomy José Navarro

445

THE Be STAR SPECTRA (BeSS) DATABASE  

SciTech Connect (OSTI)

Be stars vary on many timescales, from hours to decades. A long time base of observations to analyze certain phenomena in these stars is therefore necessary. Collecting all existing and future Be star spectra into one database has thus emerged as an important tool for the Be star community. Moreover, for statistical studies, it is useful to have centralized information on all known Be stars via an up-to-date catalog. These two goals are what the Be Star Spectra (BeSS, http://basebe.obspm.fr) database proposes to achieve. The database contains an as-complete-as-possible catalog of known Be stars with stellar parameters, as well as spectra of Be stars from all origins (any wavelength, any epoch, any resolution, etc.). It currently contains over 54,000 spectra of more than 600 different Be stars among the {approx}2000 Be stars in the catalog. A user can access and query this database to retrieve information on Be stars or spectra. Registered members can also upload spectra to enrich the database. Spectra obtained by professional as well as amateur astronomers are individually validated in terms of format and science before being included in BeSS. In this paper, we present the database itself as well as examples of the use of BeSS data in terms of statistics and the study of individual stars.

Neiner, C.; De Batz, B. [LESIA, UMR 8109 du CNRS, Observatoire de Paris, UPMC, Univ. Paris Diderot, 92195 Meudon Cedex (France); Cochard, F. [Shelyak Instruments, Les Roussets, 38420 Revel (France); Floquet, M.; Mekkas, A. [GEPI, UMR 8111 du CNRS, Observatoire de Paris, Univ. Paris Diderot, 92195 Meudon Cedex (France); Desnoux, V., E-mail: coralie.neiner@obspm.fr [ARAS, Astronomical Ring for Access to Spectroscopy (Country Unknown)

2011-11-15T23:59:59.000Z

446

Semi-automated Extraction of Digital Objective Prism Spectra  

E-Print Network [OSTI]

We describe a method for the extraction of spectra from high dispersion objective prism plates. Our method is a catalogue driven plate solution approach, making use of the Right Ascension and Declination coordinates for the target objects. In contrast to existing methods of photographic plate reduction, we digitize the entire plate and extract spectra off-line. This approach has the advantages that it can be applied to CCD objective prism images, and spectra can be re-extracted (or additional spectra extracted) without having to re-scan the plate. After a brief initial interactive period, the subsequent reduction procedure is completely automatic, resulting in fully-reduced, wavelength justified spectra. We also discuss a method of removing stellar continua using a combination of non-linear filtering algorithms. The method described is used to extract over 12,000 spectra from a set of 92 objective prism plates. These spectra are used in an associated project to develop automated spectral classifiers based on neural networks.

Coryn A. L. Bailer-Jones; Mike Irwin; Ted von Hippel

1998-04-23T23:59:59.000Z

447

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)]

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.

Williams, Christopher

448

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

SciTech Connect (OSTI)

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.

Williams, Christopher

2012-11-06T23:59:59.000Z

449

Doppler-Shift Asymmetry in High-Velocity Maser Emission from Shocks in Circumnuclear Disks  

E-Print Network [OSTI]

SHORT VERSION: The rapidly rotating, masing circumnuclear disk in the central sub-parsec region of the galaxy NGC 4258 is remarkably circular and Keplerian, yet a striking asymmetry appears in the maser spectrum: the red-shifted, high- velocity sources are much more numerous and significantly more intense than the blue-shifted ones. A similar strong asymmetry appears also in the recently discovered, masing, circumnuclear disks in NGC 1068 and NGC 4945, thus suggesting it may be a general phenomenon. We show that the observed Doppler-shift asymmetry can naturally arise due to spiral shocks in circumnuclear disks, independent of the existence of a warp in the disk or the azimuthal direction to the observer. The high velocities of these features reflect the rotational velocities in the disk, and have nothing to do with the shock speed. In NGC 4258 - the currently most well-defined masing disk - the proposed scenario can also account for the intriguing clustering of the high-velocity maser spots in distinct clumps, the restricted spatial distribution of the low-velocity sources, and the dip in the maser spectrum at the systemic velocity of the disk. In this case we infer a disk mass of ~10E4 M_sun and a mass accretion rate of order ~7E-3 M_sun/year, which may be consistent with an advection-dominated accretion flow. The model is consistent with the observed Keplerian rotation, and introduces only negligible corrections to the previously derived black hole mass and galaxy distance. Predictions include slow systematic drifts in the velocity and position of all the high-velocity features, and the existence of circumnuclear disks which are delineated only by high-velocity maser emission.

Eyal Maoz; Christopher F. McKee

1997-04-04T23:59:59.000Z

450

Jack Rabbit Pretest 2021E PT7 Photonic Doppler Velocimetry Data Volume 7 Section 1  

SciTech Connect (OSTI)

The Jack Rabbit Pretest (PT) 2021E PT7 experiment was fired on April 3, 2008 at the Contained Firing Facility, Site 300, Lawrence Livermore National Laboratory. This experiment is part of an effort to determine the properties of LX-17 in a regime where corner-turning behavior and dead-zone formation are not well understood. Photonic Doppler Velocimetry (PDV) measured diagnostic plate velocities confirming the presence of a persistent LX-17 dead-zone formation and the resultant impulse gradient applied under the diagnostic plate. The Jack Rabbit Pretest 2021E PT7, 160 millimeter diameter experiment returned data on all eight PDV probes. The probes measured on the central axis and at 20, 30, 35, 45, 55, 65, 75 millimeters from the central axis. The experiment was shot at an ambient room temperature of 65 degrees Fahrenheit. The PDV earliest signal extinction was 50.7 microseconds at 45 millimeters. The latest PDV signal extinction time was 65.0 microseconds at 20 millimeters. The measured velocity ranged from meters per second to thousands of meters per second. First detonation wave induced jump-off was measured at 55 millimeters and at 15.2 microseconds. The PDV data provided an unambiguous indication of dead-zone formation and an impulse gradient applied to the diagnostic plate. The central axis had a last measured velocity of 1447 meters per second. At 65 millimeters the last measured velocity was 2360 meters per second. The low-to-high velocity ratio was 0.61. Velocity data was integrated to compute diagnostic plate cross section profiles. Velocity data was differentiated to compute a peak pressure under the diagnostic plate at the central axis of 49 kilobars at 23.3 microseconds. Substantial motion (>1 m/s) of the diagnostic plate over the dead-zone is followed by detonation region motion within approximately 4.6 microseconds.

Hart, M M; Strand, O T; Bosson, S T; Bonner, R A; Hester, D M

2008-06-25T23:59:59.000Z

451

Jack Rabbit Pretest 2021E PT4 Photonic Doppler Velocimetry Data Volume 4 Section 1  

SciTech Connect (OSTI)

The Jack Rabbit Pretest (PT) 2021E PT4 was fired on March 19, 2008 at the Contained Firing Facility, Site 300, Lawrence Livermore National Laboratory. This experiment is part of an effort to determine the properties of LX-17 in a regime where corner-turning behavior and dead-zone formation are not well understood. Photonic Doppler Velocimetry (PDV) measured diagnostic plate velocities confirming the presence of a persistent LX-17 dead-zone formation and the resultant impulse gradient applied under the diagnostic plate. The Jack Rabbit Pretest 2021E PT4, 120 millimeter diameter experiment returned data on all eight PDV probes. The probes measured on the central axis and at 10, 20, 25, 30, 35, 40, 50 millimeters from the central axis. The experiment was shot at an ambient room temperature of 64 degrees Fahrenheit. The earliest PDV signal extinction was 44.9 microseconds at 30 millimeters. The latest PDV signal extinction time was 69.5 microseconds at 10 millimeters. The measured velocity ranged from meters per second to thousands of meters per second. First detonation wave induced jump-off was measured at 50 millimeters at 13.3 microseconds. The PDV data provided an unambiguous indication of dead-zone formation and an impulse gradient applied to the diagnostic plate. The central axis had a last measured velocity of 1558 meters per second. At 40 millimeters the last measured velocity was 2019 meters per second. The low-to-high velocity ratio was 0.77. Velocity data was integrated to compute diagnostic plate cross section profiles. Velocity data was differentiated to compute a peak pressure under the diagnostic plate at the central axis of 98.6 kilobars at 15.0 microseconds. Substantial motion (>1 m/s) of the diagnostic plate over the dead-zone is followed by detonation region motion within approximately 0.7 microseconds.

Hart, M M; Strand, O T; Bosson, S T; Bonner, R A; Hester, D M

2008-06-25T23:59:59.000Z

452

Jack Rabbit Pretest 2021E PT6 Photonic Doppler Velocimetry Data Volume 6 Section 1  

SciTech Connect (OSTI)

The Jack Rabbit Pretest (PT) 2021E PT6 experiment was fired on April 1, 2008 at the Contained Firing Facility, Site 300, Lawrence Livermore National Laboratory. This experiment is part of an effort to determine the properties of LX-17 in a regime where corner-turning behavior and dead-zone formation are not well understood. Photonic Doppler Velocimetry (PDV) measured diagnostic plate velocities confirming the presence of a persistent LX-17 dead-zone formation and the resultant impulse gradient applied under the diagnostic plate. The Jack Rabbit Pretest 2021E PT6, 160 millimeter diameter experiment returned data on all eight PDV probes. The probes measured on the central axis and at 20, 30, 35, 45, 55, 65, 75 millimeters from the central axis. The experiment was shot at an ambient room temperature of 65 degrees Fahrenheit. The earliest PDV signal extinction was 54.2 microseconds at 30 millimeters. The latest PDV signal extinction time was 64.5 microseconds at the central axis. The measured velocity ranged from meters per second to thousands of meters per second. First detonation wave induced jump-off was measured at 55 millimeters at 14.1 microseconds. The PDV data provided an unambiguous indication of dead-zone formation and an impulse gradient applied to the diagnostic plate. The central axis had a last measured velocity of 1860 meters per second. At 55 millimeters the last measured velocity was 2408 meters per second. The low-to-high velocity ratio was 0.77. Velocity data was integrated to compute diagnostic plate cross section profiles. Velocity data was differentiated to compute a peak pressure under the diagnostic plate at the central axis of 227 kilobars at 20.1 microseconds, indicating a late time chemical reaction in the LX-17 dead-zone. Substantial motion (>1 m/s) of the diagnostic plate over the dead-zone is followed by detonation region motion within approximately 1.7 microseconds.

Hart, M M; Strand, O T; Bosson, S T; Bonner, R A; Hester, D M

2008-06-25T23:59:59.000Z

453

Jack Rabbit Pretest 2021E PT5 Photonic Doppler Velocimetry Data Volume 5 Section 1  

SciTech Connect (OSTI)

The Jack Rabbit Pretest (PT) 2021E PT5 was fired on March 17, 2008 at the Contained Firing Facility, Site 300, Lawrence Livermore National Laboratory. This experiment is part of an effort to determine the properties of LX-17 in a regime where corner-turning behavior and dead-zone formation are not well understood. Photonic Doppler Velocimetry (PDV) measured diagnostic plate velocities confirming the presence of a persistent LX-17 dead-zone formation and the resultant impulse gradient applied under the diagnostic plate. The Jack Rabbit Pretest 2021E PT5, 160 millimeter diameter experiment returned data on all eight PDV probes. The probes measured on the central axis and at 20, 30, 35, 45, 55, 65, 75 millimeters from the central axis. The experiment was shot at an ambient room temperature of 65 degrees Fahrenheit. The earliest PDV signal extinction was 40.0 microseconds at 45 millimeters. The latest PDV signal extinction time was 64.9 microseconds at 20 millimeters. The measured velocity ranged from meters per second to thousands of meters per second. First detonation wave induced jump-off was measured at 55 millimeters at 12.8 microseconds. The PDV data provided an unambiguous indication of dead-zone formation and an impulse gradient applied to the diagnostic plate. The central axis had a last measured velocity of 1877 meters per second. At 65 millimeters the last measured velocity was 2277 meters per second. The low-to-high velocity ratio was 0.82. Velocity data was integrated to compute diagnostic plate cross section profiles. Velocity data was differentiated to compute a peak pressure under the diagnostic plate at the central axis of 78 kilobars at 11.9 and 21.2 microseconds. Substantial motion (>1 m/s) of the diagnostic plate over the dead-zone is followed by detonation region motion within approximately 4.1 microseconds.

Hart, M M; Strand, O T; Bosson, S T; Bonner, R A; Hester, D M

2008-06-25T23:59:59.000Z

454

Jack Rabbit Pretest 2021E PT3 Photonic Doppler Velocimetry Data Volume 3 Section 1  

SciTech Connect (OSTI)

The Jack Rabbit Pretest (PT) 2021E PT3 was fired on March 12, 2008 at the Contained Firing Facility, Site 300, Lawrence Livermore National Laboratory. This experiment is part of an effort to determine the properties of LX-17 in a regime where corner-turning behavior and dead-zone formation are not well understood. Photonic Doppler Velocimetry (PDV) measured diagnostic plate velocities confirming the presence of a persistent LX-17 dead-zone formation and the resultant impulse gradient applied under the diagnostic plate. The Jack Rabbit Pretest 2021E PT3, 120 millimeter diameter experiment returned data on all eight PDV probes. The probes measured on the central axis and at 10, 20, 25, 30, 35, 40, 50 millimeters from the central axis. The experiment was shot at an ambient room temperature of 65 degrees Fahrenheit. The earliest PDV signal extinction was 41.7 microseconds at 30 millimeters. The latest PDV signal extinction time was 65.0 microseconds at 10 millimeters. The measured velocity ranged from meters per second to thousands of meters per second. First detonation wave induced jump-off was measured at 40 millimeters at 10.9 microseconds. The PDV data provided an unambiguous indication of dead-zone formation and an impulse gradient applied to the diagnostic plate. The central axis had a last measured velocity of 1636 meters per second. At 40 millimeters the last measured velocity was 2056 meters per second. The low-to-high velocity ratio was 0.80. Velocity data was integrated to compute diagnostic plate cross section profiles. Velocity data was differentiated to compute a peak pressure under the diagnostic plate at the central axis of 64.6 kilobars at 15.7 microseconds. Substantial motion (>1 m/s) of the diagnostic plate over the dead-zone is followed by detonation region motion within approximately 2.2 microseconds.

Hart, M M; Strand, O T; Bosson, S T; Bonner, R A; Hester, D M

2008-06-25T23:59:59.000Z

455

Vibrational Spectra of the Azabenzenes Revisited: Anharmonic Force Fields  

E-Print Network [OSTI]

Anharmonic force fields and vibrational spectra of the azabenzene series (pyridine, pyridazine, pyrimidine, pyrazine, s-triazine, 1,2,3-triazine, 1,2,4-triazine and s-tetrazine) and benzene are obtained using density functional theory (DFT) with the B97-1 exchange-correlation functional and a triple-zeta plus double polarization (TZ2P) basis set. Overall, the fundamental frequencies computed by second-order rovibrational perturbation theory are in excellent agreement with experiment. The resolution of the presently calculated anharmonic spectra is such that they represent an extremely useful tool for the assignment and interpretation of the experimental spectra, especially where resonances are involved.

Boese, A D; Martin, Jan M.L.

2003-01-01T23:59:59.000Z

456

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

SciTech Connect (OSTI)

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.

Johnson, M.W.

1990-01-01T23:59:59.000Z

457

A low-cost, high-resolution, video-rate imaging optical radar  

SciTech Connect (OSTI)

Sandia National Laboratories has developed a unique type of portable low-cost range imaging optical radar (laser radar or LADAR). This innovative sensor is comprised of an active floodlight scene illuminator and an image intensified CCD camera receiver. It is a solid-state device (no moving parts) that offers significant size, performance, reliability, and simplicity advantages over other types of 3-D imaging sensors. This unique flash LADAR is based on low cost, commercially available hardware, and is well suited for many government and commercial uses. This paper presents an update of Sandia`s development of the Scannerless Range Imager technology and applications, and discusses the progress that has been made in evolving the sensor into a compact, low, cost, high-resolution, video rate Laser Dynamic Range Imager.

Sackos, J.T.; Nellums, R.O.; Lebien, S.M.; Diegert, C.F. [Sandia National Labs., Albuquerque, NM (United States); Grantham, J.W.; Monson, T. [Air Force Research Lab., Eglin AFB, FL (United States)

1998-04-01T23:59:59.000Z

458

accuracy power spectra: Topics by E-print Network  

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

A. Fendt; Benjamin D. Wandelt 2007-12-02 2 Power Spectra to 1% Accuracy between Dynamical Dark Energy Cosmologies Astrophysics (arXiv) Summary: For dynamical dark energy...

459

approximation neutron spectra: Topics by E-print Network  

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

of heavy elements. V. Suleimanov; K. Werner 2007-02-15 47 Theoretical description of prompt fission neutron multiplicity and spectra Nuclear Theory (arXiv) Summary: The present...

460

activation neutron spectra: Topics by E-print Network  

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

of heavy elements. V. Suleimanov; K. Werner 2007-02-15 27 Theoretical description of prompt fission neutron multiplicity and spectra Nuclear Theory (arXiv) Summary: The present...

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Direct Analysis of Spectra of Type Ic Supernovae  

E-Print Network [OSTI]

Synthetic spectra generated with the parameterized supernova synthetic-spectrum code SYNOW are compared with observed photospheric-phase optical spectra of the normal Type Ic SN 1994I and the peculiar Type Ic SNe 1997ef and 1998bw. The observed spectra can be matched fairly well with synthetic spectra that are based on spherical symmetry and that include lines of just a few ions that are expected to appear on the basis of LTE calculations. Spectroscopic estimates of the mass and kinetic energy of the line-forming layers of the ejected matter give conventional values for SN 1994I but high kinetic energy ($\\sim 30 \\times 10^{51}$ erg) for SN 1997ef and even higher ($\\sim 60 \\times 10^{51}$ erg) for SN 1998bw. It is likely that even if SNe 1997ef and 1998bw were non-spherical, they also were hyper-energetic.

D. Branch

1999-06-09T23:59:59.000Z

462

Power Spectra to 1% Accuracy between Dynamical Dark Energy Cosmologies  

E-Print Network [OSTI]

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.

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

2007-04-03T23:59:59.000Z

463

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

SciTech Connect (OSTI)

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.

Ji, Zhengping [Los Alamos National Laboratory; Weng, Juyang [Los Alamos National Laboratory; Luciw, Matthew [IEEE; Zeng, Shuqing [IEEE

2010-10-19T23:59:59.000Z

464

Imaging targets embedded in a lossy half space with Synthetic Aperture Radar  

SciTech Connect (OSTI)

This paper addresses theoretical aspects of forming images from an airborne Synthetic Aperture Radar (SAR) of targets buried below the earth`s surface. Soil is generally a lossy, dispersive medium, with wide ranging variability in these attributes depending on soil type, moisture content, and a host of other physical properties. Focussing a SAR subsurface image presents new dimensions of complexity relative to its surface-image counterpart, even when the soil`s properties are known. This paper treats the soil as a lossy, dispersive half space, and presents a practical model for the radar echo-delay time to point scatterers within it. This model is then used to illustrate effects of refraction, dispersion, and attenuation on a SAR`s phase histories, and the resulting image. Various data collection geometries and processing strategies are examined for both 2-Dimensional and 3-Dimensional SAR images. The conclusions from this work are that (1) focussing a SAR image must generally take into account both refraction and dispersion, (2) resolving targets at different depths in lossy soils requires perhaps unprecedented sidelobe attenuation, that for some soils may only be achievable with specialized window functions, (3) the impulse response of the soil itself places a practical limit on the usable bandwidth of the radar, and (4) dynamic ranges and sensitivities will need to be orders of magnitude greater than typical surface-imaging SARs, leading to significant impact on SAR parameters, for example compressing the usable range of pulse repetition frequencies (PRFs).

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

1994-05-01T23:59:59.000Z

465

Continuous-wave radar to detect defects within heat exchangers and steam generator tubes.  

SciTech Connect (OSTI)

A major cause of failures in heat exchangers and steam generators in nuclear power plants is degradation of the tubes within them. The tube failure is often caused by the development of cracks that begin on the outer surface of the tube and propagate both inwards and laterally. A new technique was researched for detection of defects using a continuous-wave radar method within metal tubing. The experimental program resulted in a completed product development schedule and the design of an experimental apparatus for studying handling of the probe and data acquisition. These tests were completed as far as the prototypical probe performance allowed. The prototype probe design did not have sufficient sensitivity to detect a defect signal using the defined radar technique and did not allow successful completion of all of the project milestones. The best results from the prototype probe could not detect a tube defect using the radar principle. Though a more precision probe may be possible, the cost of design and construction was beyond the scope of the project. This report describes the probe development and the status of the design at the termination of the project.

Nassersharif, Bahram (New Mexico State University, Las Cruces, NM); Caffey, Thurlow Washburn Howell; Jedlicka, Russell P. (New Mexico State University, Las Cruces, NM); Garcia, Gabe V. (New Mexico State University, Las Cruces, NM); Rochau, Gary Eugene

2003-01-01T23:59:59.000Z

466

Relativistic formulation of coordinate light time, Doppler and astrometric observables up to the second post-Minkowskian order  

E-Print Network [OSTI]

Given the extreme accuracy of modern space science, a precise relativistic modeling of observations is required. In particular, it is important to describe properly light propagation through the Solar System. For two decades, several modeling efforts based on the solution of the null geodesic equations have been proposed but they are mainly valid only for the first order Post-Newtonian approximation. However, with the increasing precision of ongoing space missions as Gaia, GAME, BepiColombo, JUNO or JUICE, we know that some corrections up to the second order have to be taken into account for future experiments. We present a procedure to compute the relativistic coordinate time delay, Doppler and astrometric observables avoiding the integration of the null geodesic equation. This is possible using the Time Transfer Function formalism, a powerful tool providing key quantities such as the time of flight of a light signal between two point-events and the tangent vector to its null-geodesic. Indeed we show how to compute the Time Transfer Functions and their derivatives (and thus range, Doppler and astrometric observables) up to the second post-Minkowskian order. We express these quantities as quadratures of some functions that depend only on the metric and its derivatives evaluated along a Minkowskian straight line. This method is particularly well adapted for numerical estimations. As an illustration, we provide explicit expressions in static and spherically symmetric space-time up to second post-Minkowskian order. Then we give the order of magnitude of these corrections for the range/Doppler on the BepiColombo mission and for astrometry in a GAME-like observation.

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

2014-01-29T23:59:59.000Z

467

Test for consistence of a flyby anomaly simulation with the observed Doppler residuals for the Messenger flybys of Mercury  

E-Print Network [OSTI]

In 2007, the observed Earth flyby anomalies have been successfully simulated using an empirical formula (H. J. Busack, 2007). This simulation has led to the prediction of anomaly values, to be expected for the Rosetta flybys of Mars in 2007, and following twice of Earth in 2007 and 2009. While the data for the Mars flyby are yet under evaluation, the predictions of the formula for the last two Earth flybys of Rosetta are fully confirmed now. This is remarkable, since an alternatively proposed formula (Anderson et al., 2007) failed to predict the correct values for the recent flybys. For the Mercury flybys of the Messenger spacecraft, this alternative formula predicts a null result. In the meantime, Doppler residuals of these flybys on 14.01.2008 and 06.10.2008 are availabel. On both flybys, significant residuals were observed, using gravity data derived by Mariner 10 on Mercury (D. E. Smith et al., 2009). According to the authors, these residuals cannot be eliminated totally by adjustment of the second degree gravity coefficients and by assumption of irregular mass concentrations of acceptable value on Mercury. In this investigation, I adapt the output of the simulation program to compare with the measured Doppler residuals of the Mercury flybys without changing the formerly derived parameters for the Earth flybys. The simulation with these parameters leads to Doppler residuals of the Mercury flybys compatible with the measured curves. Additionally, the expected flyby anomalies are calculated. Since the gravity field of Mercury is not explored yet with sufficient accuracy, this result cannot be falsified or confirmed until the evaluation of the coming Mercury orbits of Messenger will be finished. If the proposed empirical formula would be confirmed then again, this would be a strong indication of an underlying physical reality.

Hans-Juergen Busack

2010-03-07T23:59:59.000Z

468

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

E-Print Network [OSTI]

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

Kwon, Youngwoo

469

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)

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

Widener, Kevin; Nelson, Dan; Bharadwaj, Nitin; Lindenmaier, Iosif [Andrei; Johnson, Karen

2011-09-14T23:59:59.000Z

470

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)]

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

Widener, Kevin; Nelson, Dan; Bharadwaj, Nitin; Lindenmaier, Iosif [Andrei; Johnson, Karen

471

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)]

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

Bharadwaj, Nitin; Widener, Kevin

472

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)]

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

Widener, Kevin; Nelson, Dan; Bharadwaj, Nitin; Lindenmaier, Iosif [Andrei; Johnson, Karen

473

Assessment of Solder Interconnect Integrity in Dismantled Electronic Components from N57 and B61 Tube-Type Radars  

SciTech Connect (OSTI)

Aging analyses were performed on solder joints from two radar units: (1) a laboratory, N57 tube-type radar unit and (2) a field-returned, B61-0, tube-type radar unit. The cumulative temperature environments experienced by the units during aging were calculated from the intermetallic compound layer thickness and the mean Pb-rich phase particle size metrics for solder joints in the units, assuming an aging time of 35 years for both radars. Baseline aging metrics were obtained from a laboratory test vehicle assembled at AS/FM and T; the aging kinetics of both metrics were calculated from isothermal aging experiments. The N57 radar unit interconnect board solder joints exhibited very little aging. The eyelet solder joints did show cracking that most likely occurred at the time of assembly. The eyelet, SA1126 connector solder joints, showed some delamination between the Cu pad and underlying laminate. The B61 field-returned radar solder joints showed a nominal degree of aging. Cracking of the eyelet solder joints was observed. The Pb-rich phase particle measurements indicated additional aging of the interconnects as a result of residual stresses. Cracking of the terminal pole connector, pin-to-pin solder joint was observed; but it was not believed to jeopardize the electrical functionality of the interconnect. Extending the stockpile lifetime of the B61 tube-type radar by an additional 20 years would not be impacted by the reliability of the solder joints with respect to further growth of the intermetallic compound layer. Additional coarsening of the Pb-rich phase will increase the joints' sensitivity to thermomechanical fatigue.

Rejent, J.A.; Vianco, P.T.; Woodrum, R.A.

1999-07-01T23:59:59.000Z

474

E-Print Network 3.0 - altered epr spectra Sample Search Results  

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

EPR spectra were acquired using a spectrometer (model E-109; Varian Associates, Palo Alto, CA... ). Acqui- sition ofconventional EPR spectra required scans ... Source: Thomas,...

475

Isotopically selective, Doppler-free, saturation spectroscopy of lutetium isotopes via resonance ionization mass spectrometry  

SciTech Connect (OSTI)

A new technique utilizing RIMS to obtain very high resolution atomic spectra with isotopic selectivity has been demonstrated. This technique allows the precise determination of HF splitting constants, limited only by the transition's natural linewidth. In addition, it is also feasible with this technique to accurately determine atomic isotope shifts. The exact determination of HF component line positions provides data for isotopically selective ionization which, in turn, will increase RIMS' dynamic range. Future work includes the incorporation of a /open quotes/vibrating/close quotes/ mirror and the study of rarer isotopes, i.e., /sup 174/Lu, /sup 173/Lu, /sup 172/Lu, /sup 171/Lu, and possibly, /sup 170/Lu. 13 refs., 3 figs.

Fearey, B.L.; Parent, D.C.; Keller, R.A.; Miller, C.M.

1988-01-01T23:59:59.000Z

476

The width of gamma-ray burst spectra  

E-Print Network [OSTI]

The emission processes active in the highly relativistic jets of gamma-ray bursts (GRBs) remain unknown. In this paper we propose a new measure to describe spectra: the width of the $EF_E$ spectrum, a quantity dependent only on finding a good fit to the data. We apply this to the full sample of GRBs observed by Fermi/GBM and CGRO/BATSE. The results from the two instruments are fully consistent. We find that the median widths of spectra from long and short GRBs are significantly different (chance probability $<10^{-6}$). The width does not correlate with either duration or hardness, and this is thus a new, independent distinction between the two classes. Comparing the measured spectra with widths of spectra from fundamental emission processes -- synchrotron and blackbody radiation -- the results indicate that a large fraction of GRB spectra are too narrow to be explained by synchrotron radiation from a distribution of electron energies: for example, 78% of long GRBs and 85% of short GRBs are incompatible wi...

Axelsson, Magnus

2014-01-01T23:59:59.000Z

477

Lifetime measurements by the Doppler-shift attenuation method in the {sup 115}Sn({alpha},n{gamma}){sup 118}Te reaction  

SciTech Connect (OSTI)

{gamma} rays were measured at several angles in both singles and coincidence modes in the {sup 115}Sn({alpha},n{gamma}){sup 118}Te reaction at 15 MeV on a thick target. Multipolarities and mixing ratios were determined from the {gamma}-ray angular distribution analysis. Lifetimes of 11 low- and medium-spin excited states in {sup 118}Te were determined from a Monte Carlo Doppler-shift attenuation method analysis of the Doppler broadened line shapes of {gamma} rays deexciting the levels. The results are discussed in comparison with the predictions of the interacting boson model.

Mihai, C. [Horia Hulubei National Institute of Physics and Nuclear Engineering, RO-077125 Bucharest (Romania); Faculty of Physics, University of Bucharest, Bucharest (Romania); Pasternak, A. A. [Cyclotron Laboratory, A.F. Ioffe Physical Technical Institute, 194021 St. Petersburg (Russian Federation); Pascu, S.; Filipescu, D.; Ivascu, M.; Bucurescu, D.; Cata-Danil, I.; Deleanu, D.; Ghita, D. G.; Glodariu, T.; Marginean, N.; Marginean, R.; Negret, A.; Sava, T.; Stroe, L.; Suliman, G.; Zamfir, N. V. [Horia Hulubei National Institute of Physics and Nuclear Engineering, RO-077125 Bucharest (Romania); Cata-Danil, G. [Horia Hulubei National Institute of Physics and Nuclear Engineering, RO-077125 Bucharest (Romania); Physics Department, University 'Politehnica' of Bucharest, Bucharest (Romania)

2011-05-15T23:59:59.000Z

478

ASAP progress and expenditure report for the month of December 1--31, 1995. Joint UK/US radar program  

SciTech Connect (OSTI)

The RAR/SAR is a high-priority radar system for the joint US/UK Program. Based on previous experiment results and coordination with the UK, specifications needed for future radar experiments were identified as follows: dual polarimetric (HH and VV) with medium to high resolution in SAR mode. Secondary airborne installation requirements included; high power (circa 10kw) and SLIER capability to emulate Tupelev-134 type system; initially x-band but easily extendible to other frequencies. In FY96 we intended to enhance the radar system`s capabilities by providing a second polarization (VV), spotlight imaging mode, extended frequency of operation to include S- band, increase power, and interface to an existing infrared sensor. Short term objectives are: continue to evaluate and characterize the radar system; upgrade navigation and real-time processing capability to refine motion compensation; upgrade to dual polarimetry (add VV); and develop a ``spotlight`` mode capability. Accomplishments this reporting period: design specifications for the SAR system polarimetric upgrade are complete. The upgrade is ready to begin the procurement cycle when funds become available. System characterization is one of the highest priority tasks for the SAR. Although the radar is dedicated for our use, Hughes is waiting for contract funding before allowing us access to the hardware

Twogood, R.E.; Brase, J.M.; Chambers, D.H.; Mantrom, D.D.; Miller, M.G.; Newman, M.J.; Robey, H.F.; Vigars, M.L.

1996-01-19T23:59:59.000Z

479

Acoustic Doppler Current Profiler Measurements in the Tailrace at John Day Dam  

SciTech Connect (OSTI)

Acoustic Doppler current profilers (ADCPs) were used to measure water velocities in the tailrace at John Day Dam over a two-week period in February 2005. Data were collected by the Pacific Northwest National Laboratory for the Hydraulic Design Section, Portland District, U.S. Army Corps of Engineers (USACE). The objective of this project was therefore to collect field measurements of water velocities in the near-field draft tube exit zone as well as the far-field tailrace to be used for improving these models. Field data were collected during the project using five separate ADCPs. Mobile ADCP data were collected using two ADCPs mounted on two separate boats. Data were collected by either holding the boat on-station at pre-defined locations for approximately 10 minutes or in moving transect mode when the boat would move over large distances during the data collection. Results from the mobile ADCP survey indicated a complex hydrodynamic flow field in the tailrace downstream of John Day Dam. A large gyre was noted between the skeleton section of the powerhouse and non-spilling portion of the spillway. Downstream of the spillway, the spillway flow is constrained against the navigation lock guide wall, and large velocities were noted in this region. Downstream of the guide wall, velocities decreased as the spillway jet dispersed. Near the tailrace island, the flow split was measured to be approximately equal on Day 2 (25.4 kcfs spillway/123 kcfs total). However, approximately 60% of the flow passed along the south shore of the island on Day 1 (15.0 kcfs spillway/150 kcfs total). At a distance of 9000 ft downstream of the dam, flows had equalized laterally and were generally uniform over the cross section. The collection of water velocities near the draft tube exit of an operating turbine unit is not routine, and equipment capable of measuring 3D water velocities in these zones are at the forefront of hydraulic measurement technology. Although the feasibility of measuring 1D water velocity magnitudes has been previously demonstrated by the authors, the feasibility of resolving 3D water velocity vectors given the heterogeneity of the flow field was unknown before this study’s data were collected. Both the 1D and 3D data were collected by deploying three ADCPs on dual-axis rotators directly above the draft tube exit of Turbine Unit 16. These instruments collected 1D data during both the mobile reconnaissance campaign and a later one-week period with zero spillway discharge. During the zero spillway discharge period, Turbine Unit 16 was operated over a range of discharges. Approximately 12 hours of 1D velocity data were collected at low (12 kcfs), middle (16.2 kcfs), and high (19.2 kcfs) turbine discharges. The 1D dataset indicates large differences in flow patterns and RMS velocity fluctuations among the various discharge levels. Results from this project show that it is technically feasible to measure 3D water velocities directly downstream of an operating turbine unit using a narrow beam swath (i.e., 6-degree) ADCP. Data products from these 3D velocity data include a measurement of the draft tube barrel flow distribution (a.k.a., the flow split), directional changes and the general decay of velocity as flow exits the draft tube and enters the tailrace, and a relative measure of the homogeneity of the flow field.

Cook, Chris B.; Dibrani, Berhon; Serkowski, John A.; Richmond, Marshall C.; Titzler, P. Scott; Dennis, Gary W.

2006-01-30T23:59:59.000Z

480

Electronic Spectra from TDDFT and Machine Learning in Chemical Space  

E-Print Network [OSTI]

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...

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

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "radar doppler spectra" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Morphing the CMB: a technique for interpolating power spectra  

E-Print Network [OSTI]

The confrontation of the Cosmic Microwave Background (CMB) theoretical angular power spectrum with available data often requires the calculation of large numbers of power spectra. The standard practice is to use a fast code to compute the CMB power spectra over some large parameter space, in order to estimate likelihoods and constrain these parameters. But as the dimensionality of the space under study increases, then even with relatively fast anisotropy codes, the computation can become prohibitive. This paper describes the employment of a "morphing" strategy to interpolate new power spectra based on previously calculated ones. We simply present the basic idea here, and illustrate with a few examples; optimization of interpolation schemes will depend on the specific application. In addition to facilitating the exploration of large parameter spaces, this morphing technique may be helpful for Fisher matrix calculations involving derivatives.

Kris Sigurdson; Douglas Scott

2000-03-16T23:59:59.000Z

482

Direct Analysis of Spectra of Type Ib Supernovae  

E-Print Network [OSTI]

Synthetic spectra generated with the parameterized supernova synthetic-spectrum code SYNOW are compared to photospheric-phase spectra of Type Ib supernovae (SNe Ib). Although the synthetic spectra are based on many simplifying approximations, including spherical symmetry, they account well for the observed spectra. Our sample of SNe Ib obeys a tight relation between the velocity at the photosphere, as determined from the Fe II features, and the time relative to that of maximum light. From this we infer that the masses and the kinetic energies of the events in this sample were similar. After maximum light the minimum velocity at which the He I features form usually is higher than the velocity at the photosphere, but the minimum velocity of the ejected helium is at least as low as 7000 kms. Previously unpublished spectra of SN 2000H reveal the presence of hydrogen absorption features, and we conclude that hydrogen lines also were present in SNe 1999di and 1954A. Hydrogen appears to be present in SNe Ib in general, although in most events it becomes too weak to identify soon after maximum light. The hydrogen-line optical depths that we use to fit the spectra of SNe 2000H, 1999di, and 1954A are not high, so only a mild reduction in the hydrogen optical depths would be required to make these events look like typical SNe Ib. Similarly, the He I line optical depths are not very high, so a moderate reduction would make SNe Ib look like SNe Ic.

David Branch

2001-06-20T23:59:59.000Z

483

Particle Spectra in Statistical Models with Energy and Momentum Conservation  

E-Print Network [OSTI]

Single particle momentum spectra are calculated within three micro-canonical statistical ensembles, namely, with conserved system energy, system momentum, as well as system energy and momentum. Deviations from the exponential spectrum of the grand canonical ensemble are quantified and discussed. For mean particle multiplicity and temperature, typical for p+p interactions at the LHC energies, the effect of the conservation laws extends to transverse momenta as low as about 3 GeV/c. The results may help to interpret spectra measured in nuclear collisions at high energies, in particular, their system size dependence.

V. V. Begun; M. Gazdzicki; M. I. Gorenstein

2012-01-27T23:59:59.000Z

484

IMPLEMENTING THE STANDARD SPECTRUM METHOD FOR ANALYSIS OF ?-? COINCIDENCE SPECTRA  

SciTech Connect (OSTI)

The standard deconvolution analysis tool (SDAT) algorithms were developed and tested at the University of Texas at Austin. These algorithms utilize the standard spectrum technique for spectral analysis of {beta}-{gamma} coincidence spectra for nuclear explosion monitoring. Work has been conducted under this contract to implement these algorithms into a useable scientific software package with a graphical user interface. Improvements include the ability to read in PHD formatted data, gain matching, and data visualization. New auto-calibration algorithms were developed and implemented based on 137Cs spectra for assessment of the energy vs. channel calibrations. Details on the user tool and testing are included.

Biegalski, S.; Flory, Adam E.; Schrom, Brian T.; Ely, James H.; Haas, Derek A.; Bowyer, Ted W.; Hayes, James C.

2011-09-14T23:59:59.000Z

485

Entropy spectra of single horizon black holes in two dimensions  

E-Print Network [OSTI]

The Hod conjecture proposes that the asymptotic quasinormal frequencies determine the entropy quantum of a black hole. Considering the Maggiore modification of this conjecture we calculate the entropy spectra of general, single horizon, asymptotically flat black holes in two-dimensional dilaton gravity. We also compute the entropy quanta of the two-dimensional Witten and AdS(2) black holes. Using the results for the entropy quanta of these two-dimensional black holes we discuss whether the produced values are generic. Finally we extend the results on the entropy spectra of other black holes.

A. Lopez-Ortega

2011-12-29T23:59:59.000Z

486

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

SciTech Connect (OSTI)

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.

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

2007-03-25T23:59:59.000Z

487

Geomorphological significance of Ontario Lacus on Titan: Integrated interpretation of Cassini VIMS, ISS and RADAR data and comparison with the Etosha Pan (Namibia)  

E-Print Network [OSTI]

Geomorphological significance of Ontario Lacus on Titan: Integrated interpretation of Cassini VIMS (ISS) in 2004 and 2005, Visual and Infrared Mapping Spectrometer (VIMS) in 2007 and 2009 and RADAR of Ontario Lacus, based on a joint analysis of ISS, VIMS and RADAR SAR datasets, along with the T49

Brest, Université de

488

Comparison of melting level altitudes from the NCEP reanalysis with TRMM precipitation radar data  

E-Print Network [OSTI]

two-thirds of the TRMM [TMI] swath. " 1. 3. Previous Studies Radar meteorologists use the term "melting layer" to describe the region (up to several hundred meters thick) just below the O' C isotherm where the bright band appears. Conversely, much... feature of Figure 3 is the large area of 5000 m enclosed in a dual-fingered shape centered on the equator in the central and western Pacific. An intrusion of lower heights centered on the equator from 125'E to 175'W divides the large area into two...

Harris, Gettys Nunn

1999-01-01T23:59:59.000Z

489

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

E-Print Network [OSTI]

analysis, 1800 CST, May 16, 1969 33. 700-mb analysis, 1800 CST, May 16, 1969 34. 500-mb analysis, 1800 CST, May 16, 1969 35. Radar contours, 2033 CST, May 16, 1969 36. Rainfall, 2015-2030 CST, May 16, 1969 37. Surface wind analysis, 2030 CST, May 16..., 1969 49 51 52 53 54 55 56 57 38. 850-mb streamline and equi. valent potential tempera- ture analyses, 2030 CST, May 16, 1969 58 39. 850-mb temperature and dew-point analyses, 2030 CST, May 16, 1969 59 40. 700-mb streamline and equivalent...

Withers, Donald Mead

1971-01-01T23:59:59.000Z

490

Correction of motion measurement errors beyond the range resolution of a synthetic aperture radar  

DOE Patents [OSTI]

Motion measurement errors that extend beyond the range resolution of a synthetic aperture radar (SAR) can be corrected by effectively decreasing the range resolution of the SAR in order to permit measurement of the error. Range profiles can be compared across the slow-time dimension of the input data in order to estimate the error. Once the error has been determined, appropriate frequency and phase correction can be applied to the uncompressed input data, after which range and azimuth compression can be performed to produce a desired SAR image.

Doerry, Armin W. (Albuquerque, NM); Heard, Freddie E. (Albuquerque, NM); Cordaro, J. Thomas (Albuquerque, NM)

2008-06-24T23:59:59.000Z

491

Meteorological significance of frontal thin-line angel echoes observed by CPS-9 radar  

E-Print Network [OSTI]

Effects of Vertical Wind-Shear on Convection Cells in the Atmosphere and Ocean 83 86 C. Radar Observations of Benard Cells and the Effects of Vertical Wind-Shear 89 D. Possible Effects of Wind-Shear Modified Convection Cells Exhibited by the Angel... of the Relationship between Wind-shear and Angel Echo Patterns 102 D. Summary of Conclusions REFERENCES APPENDIX 103 105 110 LIST OF FIGURES Figure 1. Surface Nap, 1500C, 10 December 1957 2. PPI Photographs~ 10 December 1957 3. Cold-frontal and Thin...

Miller, Donald Bradford

2012-06-07T23:59:59.000Z

492

ARM - Publications: Science Team Meeting Documents: W-Band ARM Cloud 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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD) by Microtops AtmosphericApplication andAnthe Infrared LandSystem W-Band ARM Cloud Radar System

493

SciTech Connect: Radar cross section of triangular trihedral reflector with  

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:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administrationcontroller systemsBi (2) Sr (2) Ca (2)Frameworkextended bottom plate. Radar

494

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

SciTech Connect (OSTI)

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.

Catechis, Christopher Spyros

2013-02-01T23:59:59.000Z

495

Neutrino signal of supernova shock wave propagation:MSW distortion of the spectra and neucleosynthesis  

E-Print Network [OSTI]

Neutrino signal of supernova shock wave propagation:MSW distortion of the spectra and neucleosynthesis

Kawagoe, S; Sumiyoshi, K; Yamada, H; Kajino, T

2006-01-01T23:59:59.000Z

496

Modified floor response spectra for the Brookhaven National Laboratory High Flux Beam Reactor (HFBR)  

SciTech Connect (OSTI)

This report documents the modified floor response spectra that will be used for future seismic evaluations of structures, systems, and components (SSC`s) within the HFBR and the technical basis for the modified floor response spectra. When used within this report, the term ``current spectra`` refers to the 1978 spectra developed in BNL Informal Report BNL-26019.

Morante, R.J.; Skonieczny, J.

1994-03-01T23:59:59.000Z

497

ABSORPTION LINES IN THE SPECTRA OF DISTANT OBJECTS 1 John N. Bahcall  

E-Print Network [OSTI]

ABSORPTION LINES IN THE SPECTRA OF DISTANT OBJECTS 1 John N. Bahcall Institute for Advanced Study) of absorption-line systems which may be expected to occur in the spectra of distant objects. Absorption in the spectra of quasars and BL LAC objects. However, the fact that quasars exhibit rich absorption spectra

Bahcall, John

498

Tomographic data developed using the ABEM RAMAC borehole radar system at the Mixed Waste Landfill Integrated Demonstration  

SciTech Connect (OSTI)

The ABEM RAMAC borehole radar system was run as part of the Mixed Waste Landfill Integrated Demonstration for Sandia National Laboratories at Kirtland AFB. Tomograms were created between three test boreholes-UCAP No. 1, UCAP No. 2, and UCAP No. 3. These tomograms clearly delineate areas of amplitude attenuation and residual time of arrival or slowness differences. Plots for slowness were made using both the maximum and minimum of the first arrival pulse. The data demonstrates that the ABEM RAMAC 60-MHz pulse sampling radar system can be used to collect usable data in a highly conductive environment.

MacLeod, G.A.; Barker, D.L.; Molnar, S. [Raytheon Services Nevada, Las Vegas, NV (United States)

1994-02-18T23:59:59.000Z

499

Infrared spectra of carbon monoxide adsorbed on palladium black  

SciTech Connect (OSTI)

The authors investigate the heterogeneous adsorption of carbon monoxide and the concurrent catalytic and sorptive properties of palladium black from the standpoint of a comprehensive analysis of the infrared spectra of the reaction pathways and their various products as well as the pressure dependence of the line behavior at various wavelengths.

Vozdvizhenskii, V.F.; Levintova, T.D.; Sokol'skii, D.V.

1986-06-01T23:59:59.000Z

500

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

E-Print Network [OSTI]

ROTATIONAL SPECTRA OF SMALL PAHs: ACENAPHTHENE, ACENAPHTHYLENE, AZULENE, AND FLUORENE S. Thorwirth in the frequency range from 7 to 37 GHz. Initial searches for acenaphthene (C12H10), acenaphthylene (C12H8 and experimentally derived ground-state rotational constants is achieved. Selected transitions of acenaphthene

Thorwirth, Sven