Propagation of radar rainfall uncertainty in urban flood simulations

NASA Astrophysics Data System (ADS)

Liguori, Sara; Rico-Ramirez, Miguel

2013-04-01

, 2010. Review of the different sources of uncertainty in single polarization radar-based estimates of rainfall. Surveys in Geophysics 31: 107-129. [4] Rossa A, Liechti K, Zappa M, Bruen M, Germann U, Haase G, Keil C, Krahe P, 2011. The COST 731 Action: A review on uncertainty propagation in advanced hydrometeorological forecast systems. Atmospheric Research 100, 150-167. [5] Rossa A, Bruen M, Germann U, Haase G, Keil C, Krahe P, Zappa M, 2010. Overview and Main Results on the interdisciplinary effort in flood forecasting COST 731-Propagation of Uncertainty in Advanced Meteo-Hydrological Forecast Systems. Proceedings of Sixth European Conference on Radar in Meteorology and Hydrology ERAD 2010. [6] Germann U, Berenguer M, Sempere-Torres D, Zappa M, 2009. REAL - ensemble radar precipitation estimation for hydrology in a mountainous region. Quarterly Journal of the Royal Meteorological Society 135: 445-456. [8] Bowler NEH, Pierce CE, Seed AW, 2006. STEPS: a probabilistic precipitation forecasting scheme which merges and extrapolation nowcast with downscaled NWP. Quarterly Journal of the Royal Meteorological Society 132: 2127-2155. [9] Zappa M, Rotach MW, Arpagaus M, Dorninger M, Hegg C, Montani A, Ranzi R, Ament F, Germann U, Grossi G et al., 2008. MAP D-PHASE: real-time demonstration of hydrological ensemble prediction systems. Atmospheric Science Letters 9, 80-87. [10] Liguori S, Rico-Ramirez MA. Quantitative assessment of short-term rainfall forecasts from radar nowcasts and MM5 forecasts. Hydrological Processes, accepted article. DOI: 10.1002/hyp.8415 [11] Liguori S, Rico-Ramirez MA, Schellart ANA, Saul AJ, 2012. Using probabilistic radar rainfall nowcasts and NWP forecasts for flow prediction in urban catchments. Atmospheric Research 103: 80-95. [12] Harrison DL, Driscoll SJ, Kitchen M, 2000. Improving precipitation estimates from weather radar using quality control and correction techniques. Meteorological Applications 7: 135-144. [13] Harrison DL, Scovell RW, Kitchen

Tracking radar studies of bird migration

NASA Technical Reports Server (NTRS)

Williams, T. C.; Williams, J. M.; Teal, J. M.; Kanwisher, J. W.

1972-01-01

The application of tracking radar for determining the flight paths of migratory birds is discussed. The effects produced by various meteorological parameters are described. Samples of radar scope presentations obtained during tracking studies are presented. The characteristics of the radars and their limitations are examined.

Space Debris Measurements using the Advanced Modular Incoherent Scatter Radar

NASA Astrophysics Data System (ADS)

Nicolls, M.

The Advanced Modular Incoherent Scatter Radar (AMISR) is a modular, mobile UHF phased-array radar facility developed and used for scientific studies of the ionosphere. The radars are completely remotely operated and allow for pulse-to-pulse beam steering over the field-of-view. A satellite and debris tracking capability fully interleaved with scientific operations has been developed, and the AMISR systems are now used to routinely observe LEO space debris, with the ability to simultaneously track and detect multiple objects. The system makes use of wide-bandwidth radar pulses and coherent processing to detect objects as small as 5-10 cm in size through LEO, achieving a range resolution better than 20 meters for LEO targets. The interleaved operations allow for ionospheric effects on UHF space debris measurements, such as dispersion, to be assessed. The radar architecture, interleaved operations, and impact of space weather on the measurements will be discussed.

A Methodology for Phased Array Radar Threshold Modeling Using the Advanced Propagation Model (APM)

DTIC Science & Technology

2017-10-01

TECHNICAL REPORT 3079 October 2017 A Methodology for Phased Array Radar Threshold Modeling Using the Advanced Propagation Model (APM...Head 55190 Networks Division iii EXECUTIVE SUMMARY This report summarizes the methodology developed to improve the radar threshold modeling...PHASED ARRAY RADAR CONFIGURATION ..................................................................... 1 3. METHODOLOGY

System Concepts for the Advanced Post-TRMM Rainfall Profiling Radars

NASA Technical Reports Server (NTRS)

Im, Eastwood; Smith, Eric A.

2000-01-01

Global rainfall is the primary distributor of latent heat through atmospheric circulation. The recently launched Tropical Rainfall Measuring Mission satellite is dedicated to advance our understanding of tropical precipitation patterns and their implications on global climate and its change. The Precipitation Radar (PR) aboard the satellite is the first radar ever flown in space and has provided. exciting, new data on the 3-D rain structures for a variety of scientific uses. However, due to the limited mission lifetime and the dynamical nature of precipitation, the TRMM PR data acquired cannot address all the issues associated with precipitation, its related processes, and the long-term climate variability. In fact, a number of new post-TRMM mission concepts have emerged in response to the recent NASA's request for new ideas on Earth science missions at the post 2002 era. This paper will discuss the system concepts for two advanced, spaceborne rainfall profiling radars. In the first portion of this paper, we will present a system concept for a second-generation spaceborne precipitation radar for operations at the Low Earth Orbit (LEO). The key PR-2 electronics system will possess the following capabilities: (1) A 13.6/35 GHz dual frequency radar electronics that has Doppler and dual-polarization capabilities. (2) A large but light weight, dual-frequency, wide-swath scanning, deployable antenna. (3) Digital chirp generation and the corresponding on-board pulse compression scheme. This will allow a significant improvement on rain signal detection without using the traditional, high-peak-power transmitters and without sacrificing the range resolution. (4) Radar electronics and algorithm to adaptively scan the antenna so that more time can be spent to observe rain rather than clear air. and (5) Built-in flexibility on the radar parameters and timing control such that the same radar can be used by different future rain missions. This will help to reduce the overall

Research relative to weather radar measurement techniques

NASA Technical Reports Server (NTRS)

Smith, Paul L.

1992-01-01

This grant provides for some investigations related to weather radar measurement techniques applicable to meteorological radar systems in Thailand. Quality data are needed from those systems to support TRMM and other scientific investigations. Activities carried out during a trip to the radar facilities at Phuket are described.

Efficient Ways to Learn Weather Radar Polarimetry

ERIC Educational Resources Information Center

Cao, Qing; Yeary, M. B.; Zhang, Guifu

2012-01-01

The U.S. weather radar network is currently being upgraded with dual-polarization capability. Weather radar polarimetry is an interdisciplinary area of engineering and meteorology. This paper presents efficient ways to learn weather radar polarimetry through several basic and practical topics. These topics include: 1) hydrometeor scattering model…

Weather Radars and Lidar for Observing the Atmosphere

NASA Astrophysics Data System (ADS)

(Vivek) Vivekanandan, J.

2010-05-01

The Earth Observing Laboratory (EOL) at the National Center for Atmospheric Research (NCAR) in Boulder, Colorado develops and deploys state-of-the-art ground-based radar, airborne radar and lidar instruments to advance scientific understanding of the earth system. The ground-based radar (S-Pol) is equipped with dual-wavelength capability (S-band and Ka-band). S-Pol is the only transportable radar in the world. In order to capture faster moving weather events such as tornadoes and record observations of clouds over rugged mountainous terrain and ocean, an airborne radar (ELDORA) is used. It is the only airborne Doppler meteorological radar that is able to detect motions in the clear air. The EOL is in the process of building the first phase of a three phase dual wavelength W/Ka-band airborne cloud radar to be called the HIAPER Cloud Radar (HCR). This phase is a pod based W-band radar system with scanning capability. The second phase will add pulse compression and polarimetric capability to the W-band system, while the third phase will add complementary Ka-band radar. The pod-based radar is primarily designed to fly on the Gulfstream V (GV) and C-130 aircraft. The envisioned capability of a millimeter wave radar system on GV is enhanced by coordination with microwave radiometer, in situ probes, and especially by the NCAR GV High-Spectral Resolution Lidar (HSRL) which is also under construction. The presentation will describe the capabilities of current instruments and also planned instrumentation development.

Military Hydrology. Report 8. Feasibility of Utilizing Satellite and Radar Data in Hydrologic Forecasting.

DTIC Science & Technology

1985-09-01

Extratropical Storm ," Draft Report. Atlas, David. 1964. "Advances in Radar Meteorology," Advances in Geophysics, Vol 10, Academic Press, N.Y., pp 318-478. Barnes...forecasting purposes, data on storm morphology, direction of movement, and rate of movement are re- quired in addition to the data cited above. 7...or storm duration. He also showed that, for a given sampling error, the gage density needed for warm season storms was two to three times greater than

Characteristics of C-band meteorological radar echoes at Petrolina, Northeast Brazil

NASA Astrophysics Data System (ADS)

da Silva Aragão, Maria Regina; Correia, Magaly De Fatima; Alves de Araújo, Heráclio

2000-03-01

A unique set of C-band meteorological radar echoes is analyzed. The data were obtained in Petrolina (9°24S, 40°30W), located in the semi-arid region of Northeast Brazil, from January to June 1985. The characteristics analyzed are echo areas, types and patterns.As in other tropical areas of the world, echoes with an area100 km2 dominated, making up 53% of the total number of echoes while echoes with 100 km2radar coverage. A relatively high frequency of stratiform echoes

Applied Meteorology Unit (AMU)

NASA Technical Reports Server (NTRS)

Bauman, William H., Jr.; Crawford, Winifred; Short, David; Barrett, Joe; Watson, Leela

2008-01-01

This report summarizes the Applied Meteorology Unit (AMU) activities for the second quarter of Fiscal Year 2008 (January - March 2008). Projects described are: (1) Peak Wind Tool for User Launch Commit Criteria (LCC), (2) Peak Wind Tool for General Forecasting, (3) Situational Lightning Climatologies for Central Florida. Phase III, (4) Volume Averaged Height Integrated Radar Reflectivity (VAHIRR), (5) Impact of Local Sensors, (6) Radar Scan Strategies for the PAFB WSR-74C Replacement and (7) WRF Wind Sensitivity Study at Edwards Air Force Base.

Advanced Borehole Radar for Hydrogeology

NASA Astrophysics Data System (ADS)

Sato, M.

2014-12-01

Ground Penetrating Radar is a useful tool for monitoring the hydrogeological environment. We have developed GPR systems which can be applied to these purposes, and we will demonstrate examples borehole radar measurements. In order to have longer radar detection range, frequency lower than100MHz has been normally adopted in borehole radar. Typical subsurface fractures of our interests have a few mm aperture and radar resolution is much poorer than a few cm in this frequency range. We are proposing and demonstrating to use radar polarimetry to solve this problem. We have demonstrated that a full-polarimetry borehole radar can be used for characterization of subsurface fractures. Together with signal processing for antenna characteristic compensation to equalize the signal by a dipole antenna and slot antennas, we could demonstrate that polarimetric borehole radar can estimate the surface roughness of subsurface fractures, We believe the surface roughness is closely related to water permeability through the fractures. We then developed a directional borehole radar, which uses optical field sensor. A dipole antenna in a borehole has omni-directional radiation pattern, and we cannot get azimuthal information about the scatterers. We use multiple dipole antennas set around the borehole axis, and from the phase differences, we can estimate the 3-diemnational orientation of subsurface structures. We are using optical electric field sensor for receiver of borehole radar. This is a passive sensor and connected only with optical fibers and does not require any electric power supply to operate the receiver. It has two major advantages; the first one is that the receiver can be electrically isolated from other parts, and wave coupling to a logging cable is avoided. Then, secondary, it can operate for a long time, because it does not require battery installed inside the system. It makes it possible to set sensors in fixed positions to monitor the change of environmental

Classification and correction of the radar bright band with polarimetric radar

NASA Astrophysics Data System (ADS)

Hall, Will; Rico-Ramirez, Miguel; Kramer, Stefan

2015-04-01

The annular region of enhanced radar reflectivity, known as the Bright Band (BB), occurs when the radar beam intersects a layer of melting hydrometeors. Radar reflectivity is related to rainfall through a power law equation and so this enhanced region can lead to overestimations of rainfall by a factor of up to 5, so it is important to correct for this. The BB region can be identified by using several techniques including hydrometeor classification and freezing level forecasts from mesoscale meteorological models. Advances in dual-polarisation radar measurements and continued research in the field has led to increased accuracy in the ability to identify the melting snow region. A method proposed by Kitchen et al (1994), a form of which is currently used operationally in the UK, utilises idealised Vertical Profiles of Reflectivity (VPR) to correct for the BB enhancement. A simpler and more computationally efficient method involves the formation of an average VPR from multiple elevations for correction that can still cause a significant decrease in error (Vignal 2000). The purpose of this research is to evaluate a method that relies only on analysis of measurements from an operational C-band polarimetric radar without the need for computationally expensive models. Initial results show that LDR is a strong classifier of melting snow with a high Critical Success Index of 97% when compared to the other variables. An algorithm based on idealised VPRs resulted in the largest decrease in error when BB corrected scans are compared to rain gauges and to lower level scans with a reduction in RMSE of 61% for rain-rate measurements. References Kitchen, M., R. Brown, and A. G. Davies, 1994: Real-time correction of weather radar data for the effects of bright band, range and orographic growth in widespread precipitation. Q.J.R. Meteorol. Soc., 120, 1231-1254. Vignal, B. et al, 2000: Three methods to determine profiles of reflectivity from volumetric radar data to correct

The Use of Radar to Improve Rainfall Estimation over the Tennessee and San Joaquin River Valleys

NASA Technical Reports Server (NTRS)

Petersen, Walter A.; Gatlin, Patrick N.; Felix, Mariana; Carey, Lawrence D.

2010-01-01

This slide presentation provides an overview of the collaborative radar rainfall project between the Tennessee Valley Authority (TVA), the Von Braun Center for Science & Innovation (VCSI), NASA MSFC and UAHuntsville. Two systems were used in this project, Advanced Radar for Meteorological & Operational Research (ARMOR) Rainfall Estimation Processing System (AREPS), a demonstration project of real-time radar rainfall using a research radar and NEXRAD Rainfall Estimation Processing System (NREPS). The objectives, methodology, some results and validation, operational experience and lessons learned are reviewed. The presentation. Another project that is using radar to improve rainfall estimations is in California, specifically the San Joaquin River Valley. This is part of a overall project to develop a integrated tool to assist water management within the San Joaquin River Valley. This involves integrating several components: (1) Radar precipitation estimates, (2) Distributed hydro model, (3) Snowfall measurements and Surface temperature / moisture measurements. NREPS was selected to provide precipitation component.

Comments on Doppler radar applications

NASA Technical Reports Server (NTRS)

Kessler, E.

1969-01-01

The application of Doppler methods to theoretical or meteorological problems is discussed. Research for using radar to study and monitor severe thunderstorms, turbulence, and tornadoes is recommended.

Analysis of mesoscale convective systems in Catalonia using meteorological radar for the period 1996 2000

NASA Astrophysics Data System (ADS)

Rigo, Tomeu; Llasat, Maria-Carmen

2007-02-01

The aim of this paper is to show a climatology of Mesoscale Convective Systems (MCS) in the NE of the Iberian Peninsula, on the basis of meteorological radar observations. Special attention was paid to those cases that have produced heavy rainfalls during the period 1996-2000. Identification of the MCS was undertaken using two procedures. Firstly, the precipitation structures at the lowest level were recognised by means of a 2D algorithm that distinguishes between convective and non-convective contribution. Secondly, the convective cells were identified using a 3D procedure quite similar to the SCIT (Storm Cell Identification and Tracking) algorithm that looks for the reflectivity cores in each radar volume. Finally, the convective cells (3D) were associated with the 2D structures (convective rainfall areas), in order to characterize the complete MCS. Once this methodology was presented the paper offers a proposal for classifying the precipitation systems, and particularly the MCS. 57 MCS structures were classified: 49% of them were identified as linearly well-organised systems, called TS (39%), LS (18%) and NS (43%). In addition to the classification, the following items were analysed for each MCS found: duration, season, time of day, area affected and direction of movement, and main radar parameters related with convection. The average features of those MCS show an area of about 25000 km 2, Zmax values of 47 dBz, an echotop of 12 km, the maximum frequency at 12 UTC and early afternoon and a displacement towards E-NE. The study was completed by analysing the field at surface, the presence of a mesoscale low near the system and the quasi-stationary features of three cases related with heavy rainfalls. Maximum rainfall (more then 200 mm in 6 h) was related with the presence of a cyclone in combination with the production of a convective train effect.

ARMOR Dual-Polarimetric Radar Observations of Tornadic Debris Signatures

NASA Technical Reports Server (NTRS)

Petersen, W. A,; Carey, L. D.; Knupp, K. R.; Schultz, C.; Johnson, E.

2008-01-01

During the Super-Tuesday tornado outbreak of 5-6 February 2008, two EF-4 tornadoes occurred in Northern Alabama within 75 km range of the University of Alabama in Huntsville (UAH) Advanced Radar for Meteorological and Operational Research (ARMOR, C-band dual-polarimetric). This study will present an analysis of ARMOR radar-indicated dual-polarimetric tornadic debris signatures. The debris signatures were associated with spatially-confined large decreases in the copolar correlation coefficient (rho(hv)hv) that were embedded within broader mesocyclone "hook" signatures. These debris signatures were most obviously manifest during the F-3 to F-4 intensity stages of the tornado(s) and extended to altitudes of approximately 3 km. The rho(hv) signatures of the tornadic debris were the most easily distinguished relative to other polarimetric and radial velocity parameters (e.g., associated with large hail and/or the incipient mesocyclone). Based on our analysis, and consistent with the small number of studies found in the literature, we conclude that dual-polarimetric radar data offer at least the possibility for enhancing specificity and confidence in the process of issuing tornado warnings based only on radar detection of threatening circulation features.

Middle Atmosphere Program. Handbook for MAP. Volume 30: International School on Atmospheric Radar

NASA Technical Reports Server (NTRS)

Fukao, Shoichiro (Editor)

1989-01-01

Broad, tutorial coverage is given to the technical and scientific aspects of mesosphere stratosphere troposphere (MST) meteorological radar systems. Control issues, signal processing, atmospheric waves, the historical aspects of radar atmospheric dynamics, incoherent scatter radars, radar echoes, radar targets, and gravity waves are among the topics covered.

Snow precipitation in Adelie Land, Antarctica. MAR validation using data from a meteorological radar

NASA Astrophysics Data System (ADS)

Gallée, Hubert; Grazioli, Jacopo; Berne, Alexis; Christophe, Genthon

2017-04-01

The regional climate model MAR (Modèle Atmosphérique Régional) has been run over Adélie Land in the frame of the APRES3 project, in order to understand the different physical mechanisms affecting precipitation in this region. An horizontal resolution of 5 km is used. Several case studies have been considered during the period between december 2015 and may 2016. MAR snow precipitation flux is compared to observations made with a meteorological radar operating at Dumont d'Urville during this period. It is found that MAR sometimes simulates a maximum in the precipitation flux which is situated well above the ground, as in the observations. Possible causes may the found in the influence of the dry katabatic airflow often observed in Adélie Land. Our work indicates that the retreive of a precipitation climatology from satellite observations must be done with caution, when these observations are possible only for a significant height above the ground.

Compressive Sensing for Radar and Radar Sensor Networks

DTIC Science & Technology

2013-12-02

Zero Correlation Zone Sequence Pair Sets for MIMO Radar Inspired by recent advances in MIMO radar, we apply orthogonal phase coded waveforms to MIMO ...radar system in order to gain better range resolution and target direction finding performance [2]. We provide and investigate a generalized MIMO radar...ZCZ) sequence-Pair Set (ZCZPS). We also study the MIMO radar ambiguity function of the system using phase coded waveforms, based on which we analyze

Coordinated Radar and Aircraft Observations of Turbulence.

DTIC Science & Technology

1981-05-26

VELOCITY (il/) Jig. 10. Spectrum at two points having excessive radar c / 23 ACKNOWLEDGMENr The direction and support of Mr. 1. Goldman of the FAA...of Doppler Weather Radar to Turbulence Measure- ments Which Affect Aircraft," FAA Report RD-77-145 (March 1977). 2. R. T. Strauch, "Applications of...Meteorological Doppler Radar for Weather- Surveillance Near Air Terminals", IEEE Trans. Geosci. Electron., G15-17, 4 (1979). 3. P. B. MacCready

Radar derived spatial statistics of summer rain. Volume 3: Appendices

NASA Technical Reports Server (NTRS)

Ronnenburg, C.; Bassnett, A.; Knapp, H.; Vann, W. A.

1975-01-01

A collection of selected important memoranda written during the course of the experiment. It contains detailed information on: (1) frequency diversity, (2) radar controller and radar video processor, (3) SPANDAR calibration, and (4) meteorological summaries.

Tracking radar advanced signal processing and computing for Kwajalein Atoll (KA) application

NASA Astrophysics Data System (ADS)

Cottrill, Stanley D.

1992-11-01

Two means are examined whereby the operations of KMR during mission execution may be improved through the introduction of advanced signal processing techniques. In the first approach, the addition of real time coherent signal processing technology to the FPQ-19 radar is considered. In the second approach, the incorporation of the MMW radar, with its very fine range precision, to the MMS system is considered. The former appears very attractive and a Phase 2 SBIR has been proposed. The latter does not appear promising enough to warrant further development.

A parametric study of rate of advance and area coverage rate performance of synthetic aperture radar.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raynal, Ann Marie; William H. Hensley, Jr.; Burns, Bryan L.

2014-11-01

The linear ground distance per unit time and ground area covered per unit time of producing synthetic aperture radar (SAR) imagery, termed rate of advance (ROA) and area coverage rate (ACR), are important metrics for platform and radar performance in surveillance applications. These metrics depend on many parameters of a SAR system such as wavelength, aircraft velocity, resolution, antenna beamwidth, imaging mode, and geometry. Often the effects of these parameters on rate of advance and area coverage rate are non-linear. This report addresses the impact of different parameter spaces as they relate to rate of advance and area coverage ratemore » performance.« less

Lightning Initiation Forecasting: An Operational Dual-Polarimetric Radar Technique

NASA Technical Reports Server (NTRS)

Woodard, Crystal J.; Carey, L. D.; Petersen, W. A.; Roeder, W. P.

2011-01-01

The objective of this NASA MSFC and NOAA CSTAR funded study is to develop and test operational forecast algorithms for the prediction of lightning initiation utilizing the C-band dual-polarimetric radar, UAHuntsville's Advanced Radar for Meteorological and Operational Research (ARMOR). Although there is a rich research history of radar signatures associated with lightning initiation, few studies have utilized dual-polarimetric radar signatures (e.g., Z(sub dr) columns) and capabilities (e.g., fuzzy-logic particle identification [PID] of precipitation ice) in an operational algorithm for first flash forecasting. The specific goal of this study is to develop and test polarimetric techniques that enhance the performance of current operational radar reflectivity based first flash algorithms. Improving lightning watch and warning performance will positively impact personnel safety in both work and leisure environments. Advanced warnings can provide space shuttle launch managers time to respond appropriately to secure equipment and personnel, while they can also provide appropriate warnings for spectators and players of leisure sporting events to seek safe shelter. Through the analysis of eight case dates, consisting of 35 pulse-type thunderstorms and 20 non-thunderstorm case studies, lightning initiation forecast techniques were developed and tested. The hypothesis is that the additional dual-polarimetric information could potentially reduce false alarms while maintaining high probability of detection and increasing lead-time for the prediction of the first lightning flash relative to reflectivity-only based techniques. To test the hypothesis, various physically-based techniques using polarimetric variables and/or PID categories, which are strongly correlated to initial storm electrification (e.g., large precipitation ice production via drop freezing), were benchmarked against the operational reflectivity-only based approaches to find the best compromise between

Total Lightning Observations within Electrified Snowfall using Polarimetric Radar, LMA, and NLDN Measurements

NASA Technical Reports Server (NTRS)

Schultz, Christopher J.; Carey, Lawerence D.; Brunning, Eric C.; Blakeslee, Richard

2013-01-01

Four electrified snowfall cases are examined using total lightning measurements from lightning mapping arrays (LMAs), and the National Lightning Detection Network (NLDN) from Huntsville, AL and Washington D.C. In each of these events, electrical activity was in conjunction with heavy snowfall rates, sometimes exceeding 5-8 cm hr-1. A combination of LMA, and NLDN data also indicate that many of these flashes initiated from tall communications towers and traveled over large horizontal distances. During events near Huntsville, AL, the Advanced Radar for Meteorological and Operational Research (ARMOR) C-band polarimetric radar was collecting range height indicators (RHIs) through regions of heavy snowfall. The combination of ARMOR polarimetric radar and VHF LMA observations suggested contiguous layer changes in height between sloping aggregate-dominated layers and horizontally-oriented crystals. These layers may have provided ideal conditions for the development of extensive regions of charge and resultant horizontal propagation of the lightning flashes over large distances.

Applied Meteorology Unit (AMU)

NASA Technical Reports Server (NTRS)

Bauman, William; Lambert, Winifred; Wheeler, Mark; Barrett, Joe; Watson, Leela

2007-01-01

This report summarizes the Applied Meteorology Unit (AMU) activities for the second quarter of Fiscal Year 2007 (January - March 2007). Tasks reported on are: Obiective Lightning Probability Tool, Peak Wind Tool for General Forecasting, Situational Lightning Climatologies for Central Florida, Anvil Threat Corridor Forecast Tool in AWIPS, Volume Averaqed Heiqht lnteq rated Radar Reflectivity (VAHIRR), Tower Data Skew-t Tool, and Weather Research and Forecastini (WRF) Model Sensitivity Study

Temporal Stability of Soil Moisture and Radar Backscatter Observed by the Advanced Synthetic Aperture Radar (ASAR)

PubMed Central

Wagner, Wolfgang; Pathe, Carsten; Doubkova, Marcela; Sabel, Daniel; Bartsch, Annett; Hasenauer, Stefan; Blöschl, Günter; Scipal, Klaus; Martínez-Fernández, José; Löw, Alexander

2008-01-01

The high spatio-temporal variability of soil moisture is the result of atmospheric forcing and redistribution processes related to terrain, soil, and vegetation characteristics. Despite this high variability, many field studies have shown that in the temporal domain soil moisture measured at specific locations is correlated to the mean soil moisture content over an area. Since the measurements taken by Synthetic Aperture Radar (SAR) instruments are very sensitive to soil moisture it is hypothesized that the temporally stable soil moisture patterns are reflected in the radar backscatter measurements. To verify this hypothesis 73 Wide Swath (WS) images have been acquired by the ENVISAT Advanced Synthetic Aperture Radar (ASAR) over the REMEDHUS soil moisture network located in the Duero basin, Spain. It is found that a time-invariant linear relationship is well suited for relating local scale (pixel) and regional scale (50 km) backscatter. The observed linear model coefficients can be estimated by considering the scattering properties of the terrain and vegetation and the soil moisture scaling properties. For both linear model coefficients, the relative error between observed and modelled values is less than 5 % and the coefficient of determination (R2) is 86 %. The results are of relevance for interpreting and downscaling coarse resolution soil moisture data retrieved from active (METOP ASCAT) and passive (SMOS, AMSR-E) instruments. PMID:27879759

Recent advances in radar applications to agriculture

NASA Technical Reports Server (NTRS)

Morain, S. A.

1970-01-01

A series of remote radar sensing studies are summarized. These efforts comprise geoscience interpretations of such complex phenomena as those manifested in agricultural patterns. Considered are basic remote sensing needs in agriculture and the design and implementation of radar keys in the active microwave region as well as fine resolution radar imagery techniques for agriculture determinations and soil mapping.

Furthur remarks on atmospheric probing by ultrasensitive radar

NASA Technical Reports Server (NTRS)

Atlas, D.

1969-01-01

This paper is supplementary to that of Hardy and Katz. It emphasizes the meteorological value of the various capabilities of ultrasensitive radar, highlights the points of agreement and disagreement, and focuses upon the directions of promising research. The theory of backscatter from a refractively turbulent region is said to be confirmed by the radar observations both with respect to magnitude and wavelength dependence. A reason for the apparent discrepancy between the results of some of the forwardscatter experiments and theory is suggested. Disagreement still exists with respect to the origin of clear air sea breeze echoes; the author does not agree with Hardy and Katz that they are due to insects. However, it is agreed that some unusually widespread echo displays on clear days are indeed due to insects. The meteorological value of ultrasensitive radars demonstrated by Hardy and Katz, here, and by others is so profound as to demand their use in remote atmospheric probing.

Use of Advanced Meteorological Model Output for Coastal Ocean Modeling in Puget Sound

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, Zhaoqing; Khangaonkar, Tarang; Wang, Taiping

2011-06-01

It is a great challenge to specify meteorological forcing in estuarine and coastal circulation modeling using observed data because of the lack of complete datasets. As a result of this limitation, water temperature is often not simulated in estuarine and coastal modeling, with the assumption that density-induced currents are generally dominated by salinity gradients. However, in many situations, temperature gradients could be sufficiently large to influence the baroclinic motion. In this paper, we present an approach to simulate water temperature using outputs from advanced meteorological models. This modeling approach was applied to simulate annual variations of water temperatures of Pugetmore » Sound, a fjordal estuary in the Pacific Northwest of USA. Meteorological parameters from North American Region Re-analysis (NARR) model outputs were evaluated with comparisons to observed data at real-time meteorological stations. Model results demonstrated that NARR outputs can be used to drive coastal ocean models for realistic simulations of long-term water-temperature distributions in Puget Sound. Model results indicated that the net flux from NARR can be further improved with the additional information from real-time observations.« less

Economic project perspectives: An overview of the impact resulting from recent advances in satellite meteorology

NASA Technical Reports Server (NTRS)

Smith, K. R.; Boness, F. H.

1972-01-01

The impact of advanced satellite meteorology on long range weather forecasts, agriculture, commerce, and resource utilization are examined. All data are geared to obtaining a picture of various user needs and possible benefits.

MicroRadarNet: A network of weather micro radars for the identification of local high resolution precipitation patterns

NASA Astrophysics Data System (ADS)

Turso, S.; Paolella, S.; Gabella, M.; Perona, G.

2013-01-01

In this paper, MicroRadarNet, a novel micro radar network for continuous, unattended meteorological monitoring is presented. Key aspects and constraints are introduced. Specific design strategies are highlighted, leading to the technological implementations of this wireless, low-cost, low power consumption sensor network. Raw spatial and temporal datasets are processed on-board in real-time, featuring a consistent evaluation of the signals from the sensors and optimizing the data loads to be transmitted. Network servers perform the final post-elaboration steps on the data streams coming from each unit. Final network products are meteorological mappings of weather events, monitored with high spatial and temporal resolution, and lastly served to the end user through any Web browser. This networked approach is shown to imply a sensible reduction of the overall operational costs, including management and maintenance aspects, if compared to the traditional long range monitoring strategy. Adoption of the TITAN storm identification and nowcasting engine is also here evaluated for in-loop integration within the MicroRadarNet data processing chain. A brief description of the engine workflow is provided, to present preliminary feasibility results and performance estimates. The outcomes were not so predictable, taking into account relevant operational differences between a Western Alps micro radar scenario and the long range radar context in the Denver region of Colorado. Finally, positive results from a set of case studies are discussed, motivating further refinements and integration activities.

Accurate Characterization of Winter Precipitation Using In-Situ Instrumentation, CSU-CHILL Radar, and Advanced Scattering Methods

NASA Astrophysics Data System (ADS)

Newman, A. J.; Notaros, B. M.; Bringi, V. N.; Kleinkort, C.; Huang, G. J.; Kennedy, P.; Thurai, M.

2015-12-01

We present a novel approach to remote sensing and characterization of winter precipitation and modeling of radar observables through a synergistic use of advanced in-situ instrumentation for microphysical and geometrical measurements of ice and snow particles, image processing methodology to reconstruct complex particle three-dimensional (3D) shapes, computational electromagnetics to analyze realistic precipitation scattering, and state-of-the-art polarimetric radar. Our in-situ measurement site at the Easton Valley View Airport, La Salle, Colorado, shown in the figure, consists of two advanced optical imaging disdrometers within a 2/3-scaled double fence intercomparison reference wind shield, and also includes PLUVIO snow measuring gauge, VAISALA weather station, and collocated NCAR GPS advanced upper-air system sounding system. Our primary radar is the CSU-CHILL radar, with a dual-offset Gregorian antenna featuring very high polarization purity and excellent side-lobe performance in any plane, and the in-situ instrumentation site being very conveniently located at a range of 12.92 km from the radar. A multi-angle snowflake camera (MASC) is used to capture multiple different high-resolution views of an ice particle in free-fall, along with its fall speed. We apply a visual hull geometrical method for reconstruction of 3D shapes of particles based on the images collected by the MASC, and convert these shapes into models for computational electromagnetic scattering analysis, using a higher order method of moments. A two-dimensional video disdrometer (2DVD), collocated with the MASC, provides 2D contours of a hydrometeor, along with the fall speed and other important parameters. We use the fall speed from the MASC and the 2DVD, along with state parameters measured at the Easton site, to estimate the particle mass (Böhm's method), and then the dielectric constant of particles, based on a Maxwell-Garnet formula. By calculation of the "particle-by-particle" scattering

Partly cloudy with a chance of migration: Weather, radars, and aeroecology

USGS Publications Warehouse

Chilson, Phillip B.; Frick, Winifred F.; Kelly, Jeffrey F.; Howard, Kenneth W.; Larkin, Ronald P.; Diehl, Robert H.; Westbrook, John K.; Kelly, T. Adam; Kunz, Thomas H.

2012-01-01

Aeroecology is an emerging scientific discipline that integrates atmospheric science, Earth science, geography, ecology, computer science, computational biology, and engineering to further the understanding of biological patterns and processes. The unifying concept underlying this new transdisciplinary field of study is a focus on the planetary boundary layer and lower free atmosphere (i.e., the aerosphere), and the diversity of airborne organisms that inhabit and depend on the aerosphere for their existence. Here, we focus on the role of radars and radar networks in aeroecological studies. Radar systems scanning the atmosphere are primarily used to monitor weather conditions and track the location and movements of aircraft. However, radar echoes regularly contain signals from other sources, such as airborne birds, bats, and arthropods. We briefly discuss how radar observations can be and have been used to study a variety of airborne organisms and examine some of the many potential benefits likely to arise from radar aeroecology for meteorological and biological research over a wide range of spatial and temporal scales. Radar systems are becoming increasingly sophisticated with the advent of innovative signal processing and dual-polarimetric capabilities. These capabilities should be better harnessed to promote both meteorological and aeroecological research and to explore the interface between these two broad disciplines. We strongly encourage close collaboration among meteorologists, radar scientists, biologists, and others toward developing radar products that will contribute to a better understanding of airborne fauna.

Meteorology Products - Naval Oceanography Portal

Science.gov Websites

section Advanced Search... Sections Home Time Earth Orientation Astronomy Meteorology Oceanography Ice You Oceanography Products Tropical Applications Climatology and Archived Data Info Meteorology Products Global Tropical Warnings Naval Meteorology and Oceanography Command, 1100 Balch Blvd, Stennis Space Center, MS

The problem of regime summaries of the data from radar observations. [for cloud system identification

NASA Technical Reports Server (NTRS)

Divinskaya, B. S.; Salman, Y. M.

1975-01-01

Peculiarities of the radar information about clouds are examined in comparison with visual data. An objective radar classification is presented and the relation of it to the meteorological classification is shown. The advisability of storage and summarization of the primary radar data for regime purposes is substantiated.

Probabilistic forecasts based on radar rainfall uncertainty

NASA Astrophysics Data System (ADS)

Liguori, S.; Rico-Ramirez, M. A.

2012-04-01

The potential advantages resulting from integrating weather radar rainfall estimates in hydro-meteorological forecasting systems is limited by the inherent uncertainty affecting radar rainfall measurements, which is due to various sources of error [1-3]. The improvement of quality control and correction techniques is recognized to play a role for the future improvement of radar-based flow predictions. However, the knowledge of the uncertainty affecting radar rainfall data can also be effectively used to build a hydro-meteorological forecasting system in a probabilistic framework. This work discusses the results of the implementation of a novel probabilistic forecasting system developed to improve ensemble predictions over a small urban area located in the North of England. An ensemble of radar rainfall fields can be determined as the sum of a deterministic component and a perturbation field, the latter being informed by the knowledge of the spatial-temporal characteristics of the radar error assessed with reference to rain-gauges measurements. This approach is similar to the REAL system [4] developed for use in the Southern-Alps. The radar uncertainty estimate can then be propagated with a nowcasting model, used to extrapolate an ensemble of radar rainfall forecasts, which can ultimately drive hydrological ensemble predictions. A radar ensemble generator has been calibrated using radar rainfall data made available from the UK Met Office after applying post-processing and corrections algorithms [5-6]. One hour rainfall accumulations from 235 rain gauges recorded for the year 2007 have provided the reference to determine the radar error. Statistics describing the spatial characteristics of the error (i.e. mean and covariance) have been computed off-line at gauges location, along with the parameters describing the error temporal correlation. A system has then been set up to impose the space-time error properties to stochastic perturbations, generated in real-time at

Comparison of cloud top heights derived from FY-2 meteorological satellites with heights derived from ground-based millimeter wavelength cloud radar

NASA Astrophysics Data System (ADS)

Wang, Zhe; Wang, Zhenhui; Cao, Xiaozhong; Tao, Fa

2018-01-01

Clouds are currently observed by both ground-based and satellite remote sensing techniques. Each technique has its own strengths and weaknesses depending on the observation method, instrument performance and the methods used for retrieval. It is important to study synergistic cloud measurements to improve the reliability of the observations and to verify the different techniques. The FY-2 geostationary orbiting meteorological satellites continuously observe the sky over China. Their cloud top temperature product can be processed to retrieve the cloud top height (CTH). The ground-based millimeter wavelength cloud radar can acquire information about the vertical structure of clouds-such as the cloud base height (CBH), CTH and the cloud thickness-and can continuously monitor changes in the vertical profiles of clouds. The CTHs were retrieved using both cloud top temperature data from the FY-2 satellites and the cloud radar reflectivity data for the same time period (June 2015 to May 2016) and the resulting datasets were compared in order to evaluate the accuracy of CTH retrievals using FY-2 satellites. The results show that the concordance rate of cloud detection between the two datasets was 78.1%. Higher consistencies were obtained for thicker clouds with larger echo intensity and for more continuous clouds. The average difference in the CTH between the two techniques was 1.46 km. The difference in CTH between low- and mid-level clouds was less than that for high-level clouds. An attenuation threshold of the cloud radar for rainfall was 0.2 mm/min; a rainfall intensity below this threshold had no effect on the CTH. The satellite CTH can be used to compensate for the attenuation error in the cloud radar data.

Developments in radar and remote-sensing methods for measuring and forecasting rainfall.

PubMed

Collier, C G

2002-07-15

Over the last 25 years or so, weather-radar networks have become an integral part of operational meteorological observing systems. While measurements of rainfall made using radar systems have been used qualitatively by weather forecasters, and by some operational hydrologists, acceptance has been limited as a consequence of uncertainties in the quality of the data. Nevertheless, new algorithms for improving the accuracy of radar measurements of rainfall have been developed, including the potential to calibrate radars using the measurements of attenuation on microwave telecommunications links. Likewise, ways of assimilating these data into both meteorological and hydrological models are being developed. In this paper we review the current accuracy of radar estimates of rainfall, pointing out those approaches to the improvement of accuracy which are likely to be most successful operationally. Comment is made on the usefulness of satellite data for estimating rainfall in a flood-forecasting context. Finally, problems in coping with the error characteristics of all these data using both simple schemes and more complex four-dimensional variational analysis are being addressed, and are discussed briefly in this paper.

Software For Clear-Air Doppler-Radar Display

NASA Technical Reports Server (NTRS)

Johnston, Bruce W.

1990-01-01

System of software developed to present plan-position-indicator scans of clear-air Doppler radar station on color graphical cathode-ray-tube display. Designed to incorporate latest accepted standards for equipment, computer programs, and meteorological data bases. Includes use of Ada programming language, of "Graphical-Kernel-System-like" graphics interface, and of Common Doppler Radar Exchange Format. Features include portability and maintainability. Use of Ada software packages produced number of software modules reused on other related projects.

METEOROLOGICAL AND TRANSPORT MODELING

EPA Science Inventory

Advanced air quality simulation models, such as CMAQ, as well as other transport and dispersion models, require accurate and detailed meteorology fields. These meteorology fields include primary 3-dimensional dynamical and thermodynamical variables (e.g., winds, temperature, mo...

Meteorological and Environmental Inputs to Aviation Systems

NASA Technical Reports Server (NTRS)

Camp, Dennis W. (Editor); Frost, Walter (Editor)

1988-01-01

Reports on aviation meteorology, most of them informal, are presented by representatives of the National Weather Service, the Bracknell (England) Meteorological Office, the NOAA Wave Propagation Lab., the Fleet Numerical Oceanography Center, and the Aircraft Owners and Pilots Association. Additional presentations are included on aircraft/lidar turbulence comparison, lightning detection and locating systems, objective detection and forecasting of clear air turbulence, comparative verification between the Generalized Exponential Markov (GEM) Model and official aviation terminal forecasts, the evaluation of the Prototype Regional Observation and Forecast System (PROFS) mesoscale weather products, and the FAA/MIT Lincoln Lab. Doppler Weather Radar Program.

Sensitivity Analysis of Sampling Number on Quality of Polarmetric Measurements from S-band Dual-Polarization Radar

NASA Astrophysics Data System (ADS)

KIM, H.; Suk, M. K.; Jung, S. A.; Park, J. S.; Ko, J. S.

2016-12-01

The data quality of dual-polarimetric weather radar is subject to radar scanning strategies such as pulse length, pulse repetition frequency (PRF), antenna scan speed, and sampling number. In terms of sampling number, the quality of radar moment data increases with the increasing of sampling number at the given PRF and pulse length while the feasible number of elevation angles decreases for the given time or the time required for radar volume scan increases with the relatively high sampling number. For operational weather radar, the sampling number is subjectively determined by the proficient radar operator. The determination of suitable sampling number is still challengeable for operational dual-polarimetric weather radar.In this study, we analyzed the sensitivity of polarimetric measurements to sampling number based on special radar experiment for rainfall and snowfall events using S-band dual-polarimetric radar (YIT) at Yong-In test bed. For this experiment, YIT radar transmitted a simultaneously polarized beam in horizontal and vertical with pulse length of 1.0 μs and single PRF of 600Hz. The beam width and gate size were 1.0° and 250m, respectively. The volume scan was composed of three PPI scans with three sampling numbers (antenna scan speed) of 40 (15°s-1), 60(10°s-1), and 85(7°s-1) at same elevation angle (=0.2°). We first investigated the spatial fluctuation of the polarimetric measurements according to three sampling numbers using radial texture. As the sampling number increases, the radial fluctuations of polarimetric measurements decrease. Second, we also examined the sensitivity to fuzzy logic based quality control algorithm for dual-polarimetric radar (Ye et al. 2015). The probability density functions (PDFs) of fuzzy logic feature parameters between ground clutter and meteorological echo area were compared. For overlapping area in both PDFs between ground clutter and meteorological echo increases with decreasing the sampling number. As the

Distress detection, location, and communications using advanced space technology. [satellite-borne synthetic aperture radar

NASA Technical Reports Server (NTRS)

Sivertson, W. E., Jr.

1977-01-01

This paper briefly introduces a concept for low-cost, global, day-night, all-weather disaster warning and assistance. Evolving, advanced space technology with passive radio frequency reflectors in conjunction with an imaging synthetic aperture radar is employed to detect, identify, locate, and provide passive communication with earth users in distress. This concept evolved from a broad NASA research on new global search and rescue techniques. Appropriate airborne radar test results from this research are reviewed and related to potential disaster applications. The analysis indicates the approach has promise for disaster communications relative to floods, droughts, earthquakes, volcanic eruptions, and severe storms.

Meteorology/Oceanography Help - Naval Oceanography Portal

Science.gov Websites

section Advanced Search... Sections Home Time Earth Orientation Astronomy Meteorology Oceanography Ice You are here: Home › Help › Meteorology/Oceanography Help USNO Logo USNO Info Meteorology/Oceanography Help Send an e-mail regarding meteorology or oceanography products. Privacy Advisory Your E-Mail

Development and Application of integrated monitoring platform for the Doppler Weather SA-BAND Radar

NASA Astrophysics Data System (ADS)

Zhang, Q.; Sun, J.; Zhao, C. C.; Chen, H. Y.

2017-10-01

The doppler weather SA-band radar is an important part of modern meteorological observation methods, monitoring the running status of radar and the data transmission is important.This paper introduced the composition of radar system and classification of radar data,analysed the characteristics and laws of the radar when is normal or abnormal. Using Macromedia Dreamweaver and PHP, developed the integrated monitoring platform for the doppler weather SA-band radar which could monitor the real-time radar system running status and important performance indicators such as radar power,status parameters and others on Web page,and when the status is abnormal it will trigger the audio alarm.

Simulation of a weather radar display for over-water airborne radar approaches

NASA Technical Reports Server (NTRS)

Clary, G. R.

1983-01-01

Airborne radar approach (ARA) concepts are being investigated as a part of NASA's Rotorcraft All-Weather Operations Research Program on advanced guidance and navigation methods. This research is being conducted using both piloted simulations and flight test evaluations. For the piloted simulations, a mathematical model of the airborne radar was developed for over-water ARAs to offshore platforms. This simulated flight scenario requires radar simulation of point targets, such as oil rigs and ships, distributed sea clutter, and transponder beacon replies. Radar theory, weather radar characteristics, and empirical data derived from in-flight radar photographs are combined to model a civil weather/mapping radar typical of those used in offshore rotorcraft operations. The resulting radar simulation is realistic and provides the needed simulation capability for ongoing ARA research.

Ground and Space Radar Volume Matching and Comparison Software

NASA Technical Reports Server (NTRS)

Morris, Kenneth; Schwaller, Mathew

2010-01-01

This software enables easy comparison of ground- and space-based radar observations. The software was initially designed to compare ground radar reflectivity from operational, ground based Sand C-band meteorological radars with comparable measurements from the Tropical Rainfall Measuring Mission (TRMM) satellite s Precipitation Radar (PR) instrument. The software is also applicable to other ground-based and space-based radars. The ground and space radar volume matching and comparison software was developed in response to requirements defined by the Ground Validation System (GVS) of Goddard s Global Precipitation Mission (GPM) project. This software innovation is specifically concerned with simplifying the comparison of ground- and spacebased radar measurements for the purpose of GPM algorithm and data product validation. This software is unique in that it provides an operational environment to routinely create comparison products, and uses a direct geometric approach to derive common volumes of space- and ground-based radar data. In this approach, spatially coincident volumes are defined by the intersection of individual space-based Precipitation Radar rays with the each of the conical elevation sweeps of the ground radar. Thus, the resampled volume elements of the space and ground radar reflectivity can be directly compared to one another.

Non-mechanical beam control for entry, descent and landing laser radar (Conference Presentation)

NASA Astrophysics Data System (ADS)

Stockley, Jay E.; Kluttz, Kelly; Hosting, Lance; Serati, Steve; Bradley, Cullen P.; McManamon, Paul F.; Amzajerdian, Farzin

2017-05-01

Laser radar for entry, descent, and landing (EDL) applications as well as the space docking problem could benefit from a low size, weight, and power (SWaP) beam control system. Moreover, an inertia free approach employing non-mechanical beam control is also attractive for laser radar that is intended to be employed aboard space platforms. We are investigating a non-mechanical beam steering (NMBS) sub-system based on liquid crystal polarization grating (LCPG) technology with emphasis placed on improved throughput and significant weight reduction by combining components and drastically reducing substrate thicknesses. In addition to the advantages of non-mechanical, gimbal free beam control, and greatly improved SWaP, our approach also enables wide area scanning using a scalable architecture. An extraterrestrial application entails additional environmental constraints, consequently an environmental test plan tailored to an EDL mission will also be discussed. In addition, we will present advances in continuous fine steering technology which would complement the coarse steering LCPG technology. A low-SWaP, non-mechanical beam control system could be used in many laser radar remote sensing applications including meteorological studies and agricultural or environmental surveys in addition to the entry, descent, and landing application.

Influence of Meteorological Regimes on Cloud Microphysics Over Ross Island, Antarctica

NASA Astrophysics Data System (ADS)

Glennon, C.; Wang, S. H.; Scott, R. C.; Bromwich, D. H.; Lubin, D.

2017-12-01

The Antarctic provides a sharp contrast in cloud microphysics from the high Arctic, due to orographic lifting and resulting strong vertical motions induced by mountain ranges and other varying terrain on several spatial scales. The Atmospheric Radiation Measurement (ARM) West Antarctic Radiation Experiment (AWARE) deployed advanced cloud remote sensing equipment to Ross Island, Antarctica, from December 2015 until January 2016. This equipment included scanning and zenith radars operating in the Ka and X bands, a high spectral resolution lidar (HSRL), and a polarized micropulse lidar (MPL). A major AWARE objective is to provide state-of-the-art data for improving cloud microphysical parameterizations in climate models. To further this objective we have organized and classified the local Ross Island meteorology into distinct regimes using k-means clustering on ERA-Interim reanalysis data. We identify synoptic categories producing unique regimes of cloud cover and cloud microphysical properties over Ross Island. Each day of observations can then be associated with a specific meteorological regime, thus assisting modelers with identifying case studies. High-resolution (1 km) weather forecasts from the Antarctic Mesoscale Prediction System (AMPS) are sorted into these categories. AMPS-simulated anomalies of cloud fraction, near-surface air temperature, and vertical velocity at 500-mb are composited and compared with ground-based radar and lidar-derived cloud properties to identify mesoscale meteorological processes driving Antarctic cloud formation. Synoptic lows over the Ross and Amundsen Seas drive anomalously warm conditions at Ross Island by injecting marine air masses inland over the West Antarctic Ice Sheet (WAIS). This results in ice and mixed-phase orographic cloud systems arriving at Ross Island from the south to southeast along the Transantarctic Mountains. In contrast, blocking over the Amundsen Sea region brings classical liquid-dominated mixed-phase and

Applied Meteorology Unit (AMU) Quarterly Report Third Quarter FY-08

NASA Technical Reports Server (NTRS)

Bauman, William; Crawford, Winifred; Barrett, Joe; Watson, Leela; Dreher, Joseph

2008-01-01

This report summarizes the Applied Meteorology Unit (AMU) activities for the third quarter of Fiscal Year 2008 (April - June 2008). Tasks reported on are: Peak Wind Tool for User Launch Commit Criteria (LCC), Anvil Forecast Tool in AWIPS Phase II, Completion of the Edward Air Force Base (EAFB) Statistical Guidance Wind Tool, Volume Averaged Height Integ rated Radar Reflectivity (VAHIRR), Impact of Local Sensors, Radar Scan Strategies for the PAFB WSR-74C Replacement, VAHIRR Cost Benefit Analysis, and WRF Wind Sensitivity Study at Edwards Air Force Base

Determining Snow Depth Using Airborne Multi-Pass Interferometric Synthetic Aperture Radar

DTIC Science & Technology

2013-09-01

relatively low resolution 10m DEM of the survey area was obtained from the USDA NAIP and then geocorrected to match the SAR image area. Centered on...Propulsion Laboratory LiDAR Light Detection and Ranging METAR Meteorological reporting observations medivac Medical Evacuation NASA National...Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X- SAR) mission was a joint National Aeronautical and Space Administration ( NASA

A new regional RADAR network for nowcasting applications: the RESMAR achievements

NASA Astrophysics Data System (ADS)

Antonini, Andrea; Melani, Samantha; Mazza, Alessandro; Ortolani, Alberto; Gozzini, Bernardo; Corongiu, Manuela; Cristofori, Simone

2013-04-01

Monitoring weather phenomena from radar has an essential role in nowcasting applications. As one of the most useful sources of quantitative precipitation estimation, rainfall radar analysis can be a very useful research tool in supporting methods for rainfall forecasting. Its short-term prediction is often needed in various meteorological and hydrological applications where accurate prediction of rainfall is essential from national service and civil protection forecasting up to agriculture and urban issues. Very recently, Tuscany region (central Italy) is equipped with two X-band radars with a maximum range of 108 km, a beam width of 3° and a high spatial resolution (i.e., radial resolution up to 90m), located in Livorno and Cima del Monte (Elba island) sites. The first system is property of Livorno's port Authority, the second one of Consorzio LaMMA (Laboratory of Monitoring and Environmental Modelling for the sustainable development) who has installed it in the framework of "RESMAR - Environmental Resources in the MARitime Space" activities, a strategic project, financed in the framework of the European Cross-Border Cooperation Programme Italy-France "Maritime", coordinated by the Liguria Region Administration. Both systems are managed by LaMMA. The cross-border sharing of such relevant meteorological observation instruments and the integration of these data with existing tools and methodologies is intended to improve operational regional weather services in nowcasting activities and their impacts on the territory, as those related to LaMMA daily issues. This sharing is widely promoted within RESMAR project between the different partner regions (ARPA-Sardinia, Meteo-France and Liguria). The integration of these data with other complementary and ancillary measurements is also needed to increase the reliability and accuracy of radar measurements in view of both a better meteorological phenomena understanding and quantitative precipitation estimation. The use of

Applied Meteorology Unit (AMU) Quarterly Report First Quarter FY-04

NASA Technical Reports Server (NTRS)

Bauman, William; Wheeler, Mark; Labert, Winifred; Jonathan Case; Short, David

2004-01-01

This report summarizes the Applied Meteorology Unit (AMU) activities for the First Quarter of Fiscal Year 2004 (October - December 2003). Tasks reviewed are: (1) Objective Lightning Probability Forecast, (2) Mesonet Temperature and Wind Climatology, (3) Severe Weather Forecast Decision Aid and (4) Anvil Transparency Relationship to Radar Reflectivity

A study of simultaneous scintillation observations by Chinese FY-2 geostationary meteorological satellite and VHF coherent radar measurements over South China

NASA Astrophysics Data System (ADS)

Zuo, X.; Yu, T.; Xia, C.

2016-12-01

It's a good place for South China to monitor ionospheric scintillation, which are situated near the northern crest of the equatorial ionosphere anomaly. The temporal variation characteristics of Amplitude scintillations of Chinese FY-2 geostationary meteorological satellite (86.5°E) observed at Guangzhou (23.2°N, 113.3°E, dip 18°N) during the period from July 2011 to June 2013 are present. The scintillation occurrence and intensity increase dramatically at September and October in FY-2 satellite link. The scintillation observations of FY-2 geostationary satellite observed at Guangzhou and simultaneous VHF (47.5MHz) coherent radar measurements from Sanya (18.3°N, 109.6°E, dip 13°N) during equinoctial months of 2011 and 2012 are used for a coordinated study for the relationship between the L-band scintillation patches on the propagation path of FY-2 satellite and the extended 3-m irregularity structures known as plumes over South China. The results showed good coincidence of the plumes with scintillation patches in most events. In case study, the zonal drift velocity of the irregularities was estimated by comparison of the onset times of the scintillation and plume and the irregularities were found to drift eastwards at a speed ranging about tens of meters to one hundred meters per second. From the derived value of drift speed and duration of scintillation events, the irregularity patches were found to have east-west extent about a few hundred kilometers. On the other hand, if the plumes on the radar maps occurred at lower altitudes, the associated irregularities would not be able to reach the IPP of the satellite and generate L-band scintillations there. Weak scintillations were observed on FY-2 link without any plume structure on radar backscatter maps occasionally.

Scientific reasons for a network of ST radars and cooperative campaigns

NASA Technical Reports Server (NTRS)

Petitdidier, M.; Crochet, M.

1986-01-01

Due to their capabilities of measuring wind profiles in the troposphere and stratosphere with good time and height resolution, whatever the weather conditions, stratosphere-troposphere (ST) radars are well adapted to carry out atmospheric research in many fields as well as to fulfill the meteorological forecasting needs. Examples are presented from previous and future national or international campaigns planned in France. The ST radars were used first by themselves with the adjunction of radiosonde data. Then networks were built and used to get horizontal parameters. It appears that ST radar networks should naturally be included in cooperative campaigns.

Ka-Band ARM Zenith Radar Corrections Value-Added Product

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Karen; Toto, Tami; Giangrande, Scott

The KAZRCOR Value -added Product (VAP) performs several corrections to the ingested KAZR moments and also creates a significant detection mask for each radar mode. The VAP computes gaseous attenuation as a function of time and radial distance from the radar antenna, based on ambient meteorological observations, and corrects observed reflectivities for that effect. KAZRCOR also dealiases mean Doppler velocities to correct velocities whose magnitudes exceed the radar’s Nyquist velocity. Input KAZR data fields are passed through into the KAZRCOR output files, in their native time and range coordinates. Complementary corrected reflectivity and velocity fields are provided, along with amore » mask of significant detections and a number of data quality flags. This report covers the KAZRCOR VAP as applied to the original KAZR radars and the upgraded KAZR2 radars. Currently there are two separate code bases for the different radar versions, but once KAZR and KAZR2 data formats are harmonized, only a single code base will be required.« less

A depolarization and attenuation experiment using the CTS satellite. [meteorological radar

NASA Technical Reports Server (NTRS)

Bostian, C. W.; Holt, S. B., Jr.; Kauffman, S. R.; Manus, E. A.; Marshall, R. E.; Stutzman, W. L.; Wiley, P. H.

1977-01-01

Rain attenuation and depolarization data collected on the communications technology satellite 11.7 GHz downlink, and changes made in equipment following rain leak damage to the parametric amplifier are discussed. A 15 GHz radar system is described.

Modern Radar Techniques for Geophysical Applications: Two Examples

NASA Technical Reports Server (NTRS)

Arokiasamy, B. J.; Bianchi, C.; Sciacca, U.; Tutone, G.; Zirizzotti, A.; Zuccheretti, E.

2005-01-01

The last decade of the evolution of radar was heavily influenced by the rapid increase in the information processing capabilities. Advances in solid state radio HF devices, digital technology, computing architectures and software offered the designers to develop very efficient radars. In designing modern radars the emphasis goes towards the simplification of the system hardware, reduction of overall power, which is compensated by coding and real time signal processing techniques. Radars are commonly employed in geophysical radio soundings like probing the ionosphere; stratosphere-mesosphere measurement, weather forecast, GPR and radio-glaciology etc. In the laboratorio di Geofisica Ambientale of the Istituto Nazionale di Geofisica e Vulcanologia (INGV), Rome, Italy, we developed two pulse compression radars. The first is a HF radar called AIS-INGV; Advanced Ionospheric Sounder designed both for the purpose of research and for routine service of the HF radio wave propagation forecast. The second is a VHF radar called GLACIORADAR, which will be substituting the high power envelope radar used by the Italian Glaciological group. This will be employed in studying the sub glacial structures of Antarctica, giving information about layering, the bed rock and sub glacial lakes if present. These are low power radars, which heavily rely on advanced hardware and powerful real time signal processing. Additional information is included in the original extended abstract.

Advanced Interferometric Synthetic Aperture Imaging Radar (InSAR) for Dune Mapping

NASA Astrophysics Data System (ADS)

Havivi, Shiran; Amir, Doron; Schvartzman, Ilan; August, Yitzhak; Mamman, Shimrit; Rotman, Stanely R.; Blumberg, Dan G.

2016-04-01

Aeolian morphologies are formed in the presence of sufficient wind energy and available lose particles. These processes occur naturally or are further enhanced or reduced by human intervention. The dimensions of change are dependent primarily on the wind energy and surface properties. Since the 1970s, remote sensing imagery, both optical and radar, have been used for documentation and interpretation of the geomorphologic changes of sand dunes. Remote sensing studies of aeolian morphologies is mostly useful to document major changes, yet, subtle changes, occurring in a period of days or months in scales of centimeters, are very difficult to detect in imagery. Interferometric Synthetic Aperture Radar (InSAR) is an imaging technique for measuring Earth's surface topography and deformation. InSAR images are produced by measuring the radar phase difference between two separated antennas that view the same surface area. Classical InSAR is based on high coherence between two or more images. The output (interferogram) can show subtle changes with an accuracy of several millimeters to centimeters. Very little work has been done on measuring or identifying the changes in dunes using InSAR methods. The reason is that dunes tend to be less coherent than firm, stable, surfaces. This work aims to demonstrate how interferometric decorrelation can be used for identifying dune instability. We hypothesize and demonstrate that the loss of radar coherence over time on dunes can be used as an indication of the dune's instability. When SAR images are acquired at sufficiently close intervals one can measure the time it takes to lose coherence and associate this time with geomorphic stability. To achieve our goals, the coherence change detection method was used, in order to identify dune stability or instability and the dune activity level. The Nitzanim-Ashdod coastal dunes along the Mediterranean, 40 km south of Tel-Aviv, Israel, were chosen as a case study. The dunes in this area are of

Improving Radar Quantitative Precipitation Estimation over Complex Terrain in the San Francisco Bay Area

NASA Astrophysics Data System (ADS)

Cifelli, R.; Chen, H.; Chandrasekar, V.

2017-12-01

A recent study by the State of California's Department of Water Resources has emphasized that the San Francisco Bay Area is at risk of catastrophic flooding. Therefore, accurate quantitative precipitation estimation (QPE) and forecast (QPF) are critical for protecting life and property in this region. Compared to rain gauge and meteorological satellite, ground based radar has shown great advantages for high-resolution precipitation observations in both space and time domain. In addition, the polarization diversity shows great potential to characterize precipitation microphysics through identification of different hydrometeor types and their size and shape information. Currently, all the radars comprising the U.S. National Weather Service (NWS) Weather Surveillance Radar-1988 Doppler (WSR-88D) network are operating in dual-polarization mode. Enhancement of QPE is one of the main considerations of the dual-polarization upgrade. The San Francisco Bay Area is covered by two S-band WSR-88D radars, namely, KMUX and KDAX. However, in complex terrain like the Bay Area, it is still challenging to obtain an optimal rainfall algorithm for a given set of dual-polarization measurements. In addition, the accuracy of rain rate estimates is contingent on additional factors such as bright band contamination, vertical profile of reflectivity (VPR) correction, and partial beam blockages. This presentation aims to improve radar QPE for the Bay area using advanced dual-polarization rainfall methodologies. The benefit brought by the dual-polarization upgrade of operational radar network is assessed. In addition, a pilot study of gap fill X-band radar performance is conducted in support of regional QPE system development. This paper also presents a detailed comparison between the dual-polarization radar-derived rainfall products with various operational products including the NSSL's Multi-Radar/Multi-Sensor (MRMS) system. Quantitative evaluation of various rainfall products is achieved

Probabilistic discrimination between liquid rainfall events, hailstorms, biomass burning and industrial fires from C-Band Radar Polarimetric Variables

NASA Astrophysics Data System (ADS)

Valencia, J. M.; Sepúlveda, J.; Hoyos, C.; Herrera, L.

2017-12-01

Characterization and identification of fire and hailstorm events using weather radar data in a tropical complex topography region is an important task in risk management and agriculture. Polarimetric variables from a C-Band Dual polarization weather radar have potential uses in particle classification, due to the relationship their sensitivity to shape, spatial orientation, size and fall behavior of particles. In this sense, three forest fires and two chemical fires were identified for the Áburra Valley regions. Measurements were compared between each fire event type and with typical data radar retrievals for liquid precipitation events. Results of this analysis show different probability density functions for each type of event according to the particles present in them. This is very important and useful result for early warning systems to avoid precipitation false alarms during fire events within the study region, as well as for the early detection of fires using radar retrievals in remote cases. The comparative methodology is extended to hailstorm cases. Complementary sensors like laser precipitation sensors (LPM) disdrometers and meteorological stations were used to select dates of solid precipitation occurrence. Then, in this dates weather radar data variables were taken in pixels surrounding the stations and solid precipitation polar values were statistically compared with liquid precipitation values. Spectrum precipitation measured by LPM disdrometer helps to define typical features like particles number, fall velocities and diameters for both precipitation types. In addition, to achieve a complete hailstorm characterization, other meteorological variables were analyzed: wind field from meteorological stations and radar wind profiler, profiling data from Micro Rain Radar (MRR), and thermodynamic data from a microwave radiometer.

Comparison of Mesospheric Winds From a High-Altitude Meteorological Analysis System and Meteor Radar Observations During the Boreal Winters of 2009-2010 and 2012-2013

NASA Technical Reports Server (NTRS)

McCormack, J.; Hoppel, K.; Kuhl, D.; de Wit, R.; Stober, G.; Espy, P.; Baker, N.; Brown, P.; Fritts, D.; Jacobi, C.;

Meteorological Satellites (METSAT) and Earth Observing System (EOS) Advanced Microwave Sounding Unit-A (AMSU-A) Stress Analysis Report

NASA Technical Reports Server (NTRS)

Heffner, Robert

1996-01-01

Stress analysis of the primary structure of the Meteorological Satellites Project (METSAT) Advanced Microwave Sounding Units-A, A1 Module using static loads is presented. The structural margins of safety and natural frequency predictions for the METSAT design are reported.

Meteorological Data Visualization in Multi-User Virtual Reality

NASA Astrophysics Data System (ADS)

Appleton, R.; van Maanen, P. P.; Fisher, W. I.; Krijnen, R.

2017-12-01

Due to their complexity and size, visualization of meteorological data is important. It enables the precise examining and reviewing of meteorological details and is used as a communication tool for reporting, education and to demonstrate the importance of the data to policy makers. Specifically for the UCAR community it is important to explore all of such possibilities.Virtual Reality (VR) technology enhances the visualization of volumetric and dynamical data in a more natural way as compared to a standard desktop, keyboard mouse setup. The use of VR for data visualization is not new but recent developments has made expensive hardware and complex setups unnecessary. The availability of consumer of the shelf VR hardware enabled us to create a very intuitive and low cost way to visualize meteorological data. A VR viewer has been implemented using multiple HTC Vive head sets and allows visualization and analysis of meteorological data in NetCDF format (e.g. of NCEP North America Model (NAM), see figure). Sources of atmospheric/meteorological data include radar and satellite as well as traditional weather stations. The data includes typical meteorological information such as temperature, humidity, air pressure, as well as those data described by the climate forecast (CF) model conventions (http://cfconventions.org). Other data such as lightning-strike data and ultra-high-resolution satellite data are also becoming available. The users can navigate freely around the data which is presented in a virtual room at a scale of up to 3.5 X 3.5 meters. The multiple users can manipulate the model simultaneously. Possible mutations include scaling/translating, filtering by value and using a slicing tool to cut-off specific sections of the data to get a closer look. The slicing can be done in any direction using the concept of a `virtual knife' in real-time. The users can also scoop out parts of the data and walk though successive states of the model. Future plans are (a.o.) to

A System Concept for the Advanced Post-TRMM Rainfall Profiling Radars

NASA Technical Reports Server (NTRS)

Im, Eastwood; Smith, Eric A.

1998-01-01

ultimate goal. The Precipitation Radar (PR) aboard the TRMM satellite is the first ever spaceborne radar dedicated to three-dimensional, global precipitation measurements over the tropics and the subtropics, as well as the detailed synopsis of a wide range of tropical rain storm systems. In only twelve months since launch, the PR, together with other science instruments abroad the satellite have already provided unprecedented insights into the rainfall systems. It is anticipated the a lot more exciting and important rain observations would be made by TRMM throughout its mission duration. While TRMM has provided invaluable data to the user community, it is only the first step towards advancing our knowledge on rain processes and its contributions to climate variability. It is envisioned that a TRMM follow-on mission is needed in such a way to capitalize on the pioneering information provided by TRMM, and its instrument capability must be extended beyond TRMM in such a way to fully address the key science questions from microphysical to climatic time scale. In fact, a number of new and innovative mission concepts have recently put forth for this purpose. Almost all of these new concepts have suggested the utility of a more advanced, high-resolution, Doppler-enabled, vertical profiling radar that can provide multi-parameter observations of precipitation. In this paper, a system concept for a second- gene ration precipitation radar (PR-2) which addresses the above requirements will be described.

Advanced multi-frequency radar: Design, preliminary measurements and particle size distribution retrieval

NASA Astrophysics Data System (ADS)

Majurec, Ninoslav

In the spring of 2001 the Microwave Remote Sensing Laboratory (MIRSL) at the University of Massachusetts began the development of an advanced Multi-Frequency Radar (AMFR) system for studying clouds and precipitation. This mobile radar was designed to consist of three polarimetric Doppler subsystems operating at Ku-band (13.4 GHz), Ka-band (35.6 GHz) and W-band (94.92 GHz). This combination of frequency bands allows a measurement of a wide range of atmospheric targets ranging from weakly reflecting clouds to strong precipitation. The antenna beamwidths at each frequency were intentionally matched, ensuring consistent sampling volume. Multi-frequency radar remote sensing techniques are not widely used because few multi-frequency radars are available to the science community. One exception is the 33 GHz/95 GHz UMass Cloud Profiling Radar System (CPRS), which AMFR is intended to replace. AMFR's multi-parameter capabilities are designed for characterizing the complex microphysics of layer clouds and precipitation processes in winter storms. AMFR will also play an important role in developing algorithms and validating measurements for an upcoming generation of space-borne radars. The frequency bands selected for AMFR match those of several sensors that have been deployed or are under development. These include the Japanese Aerospace Exploration Agencies (JAXA's) Tropical Rainfall Measuring Mission (TRMM) satellite Ku-band (13 GHz) radar, the CloudSat W-band (95 GHz) radar, and the Global Precipitation Mission (GPM) satellite radars at Ku-band and Ka-band. This dissertation describes the AMFR hardware design and development. Compared to CPRS, the addition of one extra frequency band (Ku) will extend AMFR's measurement capabilities towards the larger particle sizes (precipitation). AMFR's design is based around high-power klystron amplifiers. This ensures complete coherency (CPRS uses magnetrons and coherent-on-receive technique). The partial loss in sensitivity due to

Development of Radar-Satellite Blended QPF (Quantitative Precipitation Forecast) Technique for heavy rainfall

NASA Astrophysics Data System (ADS)

Jang, Sangmin; Yoon, Sunkwon; Rhee, Jinyoung; Park, Kyungwon

2016-04-01

Due to the recent extreme weather and climate change, a frequency and size of localized heavy rainfall increases and it may bring various hazards including sediment-related disasters, flooding and inundation. To prevent and mitigate damage from such disasters, very short range forecasting and nowcasting of precipitation amounts are very important. Weather radar data very useful in monitoring and forecasting because weather radar has high resolution in spatial and temporal. Generally, extrapolation based on the motion vector is the best method of precipitation forecasting using radar rainfall data for a time frame within a few hours from the present. However, there is a need for improvement due to the radar rainfall being less accurate than rain-gauge on surface. To improve the radar rainfall and to take advantage of the COMS (Communication, Ocean and Meteorological Satellite) data, a technique to blend the different data types for very short range forecasting purposes was developed in the present study. The motion vector of precipitation systems are estimated using 1.5km CAPPI (Constant Altitude Plan Position Indicator) reflectivity by pattern matching method, which indicates the systems' direction and speed of movement and blended radar-COMS rain field is used for initial data. Since the original horizontal resolution of COMS is 4 km while that of radar is about 1 km, spatial downscaling technique is used to downscale the COMS data from 4 to 1 km pixels in order to match with the radar data. The accuracies of rainfall forecasting data were verified utilizing AWS (Automatic Weather System) observed data for an extreme rainfall occurred in the southern part of Korean Peninsula on 25 August 2014. The results of this study will be used as input data for an urban stream real-time flood early warning system and a prediction model of landslide. Acknowledgement This research was supported by a grant (13SCIPS04) from Smart Civil Infrastructure Research Program funded by

Computer-generated imagery for 4-D meteorological data

NASA Technical Reports Server (NTRS)

Hibbard, William L.

1986-01-01

The University of Wisconsin-Madison Space Science and Engineering Center is developing animated stereo display terminals for use with McIDAS (Man-computer Interactive Data Access System). This paper describes image-generation techniques which have been developed to take maximum advantage of these terminals, integrating large quantities of four-dimensional meteorological data from balloon and satellite soundings, satellite images, Doppler and volumetric radar, and conventional surface observations. The images have been designed to use perspective, shading, hidden-surface removal, and transparency to augment the animation and stereo-display geometry. They create an illusion of a moving three-dimensional model of the atmosphere. This paper describes the design of these images and a number of rules of thumb for generating four-dimensional meteorological displays.

Digital Beamforming Synthetic Aperture Radar Developments at NASA Goddard Space Flight Center

NASA Technical Reports Server (NTRS)

Rincon, Rafael; Fatoyinbo, Temilola; Osmanoglu, Batuhan; Lee, Seung Kuk; Du Toit, Cornelis F.; Perrine, Martin; Ranson, K. Jon; Sun, Guoqing; Deshpande, Manohar; Beck, Jaclyn;

Software for storage and processing coded messages for the international exchange of meteorological information

NASA Astrophysics Data System (ADS)

Popov, V. N.; Botygin, I. A.; Kolochev, A. S.

2017-01-01

The approach allows representing data of international codes for exchange of meteorological information using metadescription as the formalism associated with certain categories of resources. Development of metadata components was based on an analysis of the data of surface meteorological observations, atmosphere vertical sounding, atmosphere wind sounding, weather radar observing, observations from satellites and others. A common set of metadata components was formed including classes, divisions and groups for a generalized description of the meteorological data. The structure and content of the main components of a generalized metadescription are presented in detail by the example of representation of meteorological observations from land and sea stations. The functional structure of a distributed computing system is described. It allows organizing the storage of large volumes of meteorological data for their further processing in the solution of problems of the analysis and forecasting of climatic processes.

[Radar as imaging tool in ecology and conservation biology].

PubMed

Matyjasiak, Piotr

2017-01-01

Migrations and dispersal are among the most important ecological processes that shape ecosystems and influence our economy, health and safety. Movements of birds, bats and insects occur in a large spatial scale - regional, continental, or intercontinental. However, studies of these phenomena using classic methods are usually local. Breakthrough came with the development of radar technology, which enabled researchers to study animal movements in the atmosphere in a large spatial and temporal scale. The aim of this article was to present the radar imaging methods used in the research of aerial movements of birds, bats and insects. The types of radars used in research are described, and examples of the use of radar in basic research and in conservation biology are discussed. Radar visualizations are used in studies on the effect of meteorological conditions on bird migration, on spatial and temporal dynamics of movements of birds, bats and insects, and on the mechanism of orientation of migrating birds and insects. In conservation biology research radars are used in the monitoring of endangered species of birds and bats, to monitor bird activity at airports, as well as in assessing the impact of high constructions on flying birds and bats.

Investigation of Advanced Radar Techniques for Atmospheric Hazard Detection with Airborne Weather Radar

NASA Technical Reports Server (NTRS)

Pazmany, Andrew L.

2014-01-01

In 2013 ProSensing Inc. conducted a study to investigate the hazard detection potential of aircraft weather radars with new measurement capabilities, such as multi-frequency, polarimetric and radiometric modes. Various radar designs and features were evaluated for sensitivity, measurement range and for detecting and quantifying atmospheric hazards in wide range of weather conditions. Projected size, weight, power consumption and cost of the various designs were also considered. Various cloud and precipitation conditions were modeled and used to conduct an analytic evaluation of the design options. This report provides an overview of the study and summarizes the conclusions and recommendations.

Reconfigurable signal processor designs for advanced digital array radar systems

NASA Astrophysics Data System (ADS)

Suarez, Hernan; Zhang, Yan (Rockee); Yu, Xining

2017-05-01

The new challenges originated from Digital Array Radar (DAR) demands a new generation of reconfigurable backend processor in the system. The new FPGA devices can support much higher speed, more bandwidth and processing capabilities for the need of digital Line Replaceable Unit (LRU). This study focuses on using the latest Altera and Xilinx devices in an adaptive beamforming processor. The field reprogrammable RF devices from Analog Devices are used as analog front end transceivers. Different from other existing Software-Defined Radio transceivers on the market, this processor is designed for distributed adaptive beamforming in a networked environment. The following aspects of the novel radar processor will be presented: (1) A new system-on-chip architecture based on Altera's devices and adaptive processing module, especially for the adaptive beamforming and pulse compression, will be introduced, (2) Successful implementation of generation 2 serial RapidIO data links on FPGA, which supports VITA-49 radio packet format for large distributed DAR processing. (3) Demonstration of the feasibility and capabilities of the processor in a Micro-TCA based, SRIO switching backplane to support multichannel beamforming in real-time. (4) Application of this processor in ongoing radar system development projects, including OU's dual-polarized digital array radar, the planned new cylindrical array radars, and future airborne radars.

Optimum radars and filters for the passive sphere system

NASA Technical Reports Server (NTRS)

Luers, J. K.; Soltes, A.

1971-01-01

Studies have been conducted to determine the influence of the tracking radar and data reduction technique on the accuracy of the meteorological measurements made in the 30 to 100 kilometer altitude region by the ROBIN passive falling sphere. A survey of accuracy requirements was made of agencies interested in data from this region of the atmosphere. In light of these requirements, various types of radars were evaluated to determine the tracking system most applicable to the ROBIN, and methods were developed to compute the errors in wind and density that arise from noise errors in the radar supplied data. The effects of launch conditions on the measurements were also examined. Conclusions and recommendations have been made concerning the optimum tracking and data reduction techniques for the ROBIN falling sphere system.

Random Forest Application for NEXRAD Radar Data Quality Control

NASA Astrophysics Data System (ADS)

Keem, M.; Seo, B. C.; Krajewski, W. F.

2017-12-01

Identification and elimination of non-meteorological radar echoes (e.g., returns from ground, wind turbines, and biological targets) are the basic data quality control steps before radar data use in quantitative applications (e.g., precipitation estimation). Although WSR-88Ds' recent upgrade to dual-polarization has enhanced this quality control and echo classification, there are still challenges to detect some non-meteorological echoes that show precipitation-like characteristics (e.g., wind turbine or anomalous propagation clutter embedded in rain). With this in mind, a new quality control method using Random Forest is proposed in this study. This classification algorithm is known to produce reliable results with less uncertainty. The method introduces randomness into sampling and feature selections and integrates consequent multiple decision trees. The multidimensional structure of the trees can characterize the statistical interactions of involved multiple features in complex situations. The authors explore the performance of Random Forest method for NEXRAD radar data quality control. Training datasets are selected using several clear cases of precipitation and non-precipitation (but with some non-meteorological echoes). The model is structured using available candidate features (from the NEXRAD data) such as horizontal reflectivity, differential reflectivity, differential phase shift, copolar correlation coefficient, and their horizontal textures (e.g., local standard deviation). The influence of each feature on classification results are quantified by variable importance measures that are automatically estimated by the Random Forest algorithm. Therefore, the number and types of features in the final forest can be examined based on the classification accuracy. The authors demonstrate the capability of the proposed approach using several cases ranging from distinct to complex rain/no-rain events and compare the performance with the existing algorithms (e

Advanced Research into Moving Target Imaging Using Multistatic Radar

DTIC Science & Technology

2009-12-01

1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188...11 C. TEO BENG KOON WILLIAM’S WORK..................................................12 III. DATA ANALYSIS... principles of electromagnetic and radar theory rely on the Maxwell’s equations. Radar theory is a practical expansion of the fundamental theory of

Middle Atmosphere Program. Handbook for MAP. Volume 14: URSI/SCOSTEP Workshop on Technical Aspects of MST Radar

NASA Technical Reports Server (NTRS)

Bowhill, S. A. (Editor); Edwards, B. (Editor)

1984-01-01

Various topics relative to middle atmosphere research were discussed. meteorological and aeronomical requirements for mesosphere-stratosphere-troposphere (MST) radar networks, general circulation of the middle atmosphere, the interpretation of radar returns from clear air, spaced antenna and Doppler techniques for velocity measurement, and techniques for the study of gravity waves and turbulence are among the topics discussed.

Report on the Radar/PIREP Cloud Top Discrepancy Study

NASA Technical Reports Server (NTRS)

Wheeler, Mark M.

1997-01-01

This report documents the results of the Applied Meteorology Unit's (AMU) investigation of inconsistencies between pilot reported cloud top heights and weather radar indicated echo top heights (assumed to be cloud tops) as identified by the 45 Weather Squadron (45WS). The objective for this study is to document and understand the differences in echo top characteristics as displayed on both the WSR-88D and WSR-74C radars and cloud top heights reported by the contract weather aircraft in support of space launch operations at Cape Canaveral Air Station (CCAS), Florida. These inconsistencies are of operational concern since various Launch Commit Criteria (LCC) and Flight Rules (FR) in part describe safe and unsafe conditions as a function of cloud thickness. Some background radar information was presented. Scan strategies for the WSR-74C and WSR-88D were reviewed along with a description of normal radar beam propagation influenced by the Effective Earth Radius Model. Atmospheric conditions prior to and leading up to both launch operations were detailed. Through the analysis of rawinsonde and radar data, atmospheric refraction or bending of the radar beam was identified as the cause of the discrepancies between reported cloud top heights by the contract weather aircraft and those as identified by both radars. The atmospheric refraction caused the radar beam to be further bent toward the Earth than normal. This radar beam bending causes the radar target to be displayed erroneously, with higher cloud top heights and a very blocky or skewed appearance.

Women in Meteorology.

NASA Astrophysics Data System (ADS)

Lemone, Margaret A.; Waukau, Patricia L.

1982-11-01

The names of 927 women who are or have been active in meteorology or closely related fields have been obtained from various sources. Of these women, at least 500 are presently active. An estimated 4-5% of the total number of Ph.D.s in meteorology are awarded to women. About 10% of those receiving B.S. and M.S. degrees are women.The work patterns, accomplishments, and salaries of employed women meteorologists have been summarized from 330 responses to questionnaires, as functions of age, family status, part- or full-time working status, and employing institutions. It was found that women meteorologists holding Ph.D.s are more likely than their male counterparts to be employed by universities. As increasing number of women were employed in operational meteorology, although few of them were married and fewer still responsible for children. Several women were employed by private industry and some had advanced into managerial positions, although at the present time, such positions remain out of the reach of most women.The subjective and objective effects of several gender-related factors have been summarized from the comments and responses to the questionnaires. The primary obstacles to advancement were found to be part-time work and the responsibility for children. Part-time work was found to have a clearly negative effect on salary increase as a function of age. prejudicated discrimination and rules negatively affecting women remain important, especially to the older women, and affirmative action programs are generally seen as beneficial.Surprisingly, in contrast to the experience of women in other fields of science, women Ph.D.s in meteorology earn salaries comparable of their employment in government or large corporations and universities where there are strong affirmative action programs and above-average salaries. Based on the responses to the questionnaire, the small size of the meteorological community is also a factor, enabling women to become recognized

Mars Radar Opens a Planet's Third Dimension

NASA Technical Reports Server (NTRS)

2008-01-01

Radar sounder instruments orbiting Mars have looked beneath the Martian surface and opened up the third dimension for planetary exploration. The technique's success is prompting scientists to think of all the other places in the Solar System where they would like to use radar sounders.

The first radar sounder at Mars was the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) on the European Space Agency's Mars Express Orbiter. It has been joined by the complementary Shallow Subsurface Radar (SHARAD), operating at a different wavelength aboard NASA's Mars Reconnaissance Orbiter. The data in this animation are from SHARAD.

Derivation of Z-R equation using Mie approach for a 77 GHz radar

NASA Astrophysics Data System (ADS)

Bertoldo, Silvano; Lucianaz, Claudio; Allegretti, Marco; Perona, Giovanni

2017-04-01

The ETSI (European Telecommunications Standards Institute) defines the frequency band around 77 GHz as dedicated to automatic cruise control long-range radars. This work aims to demonstrate that, with specific assumption and the right theoretical background it is also possible to use a 77 GHz as a mini weather radar and/or a microwave rain gauge. To study the behavior of a 77 GHz meteorological radar, since the raindrop size are comparable to the wavelength, it is necessary to use the general Mie scattering theory. According to the Mie formulation, the radar reflectivity factor Z is defined as a function of the wavelength on the opposite of Rayleigh approximation in which is frequency independent. Different operative frequencies commonly used in radar meteorology are considered with both the Rayleigh and Mie scattering theory formulation. Comparing them it is shown that with the increasing of the radar working frequency the use of Rayleigh approximation lead to an always larger underestimation of rain. At 77 GHz such underestimation is up to 20 dB which can be avoided with the full Mie theory. The crucial derivation of the most suited relation between the radar reflectivity factor Z and rainfall rate R (Z-R equation) is necessary to achieve the best Quantitative Precipitation Estimation (QPE) possible. Making the use of Mie scattering formulation from the classical electromagnetic theory and considering different radar working frequencies, the backscattering efficiency and the radar reflectivity factor have been derived from a wide range of rain rate using specific numerical routines. Knowing the rain rate and the corresponding reflectivity factor it was possible to derive the coefficients of the Z-R equation for each frequency with the least square method and to obtain the best coefficients for each frequency. The coefficients are then compared with the ones coming from the scientific literature. The coefficients of a 77 GHz weather radar are then obtained. A

Radar cross section lectures

NASA Astrophysics Data System (ADS)

Fuhs, A. E.

A comprehensive account is given of the principles that can be applied in military aircraft configuration studies to minimize the radar cross section (RCS) that will be presented by the resulting design to advanced radars under various mission circumstances. It is noted that, while certain ECM techniques can be nullified by improved enemy electronics in a very short time, RCS reductions may require as much as a decade of radar development before prior levels of detectability can be reestablished by enemy defenses. Attention is given to RCS magnitude determinants, inverse scattering, the polarization and scattering matrix, the RCSs of flat plates and conducting cylinders, and antenna geometry and beam patterns.

May tropospheric noise in satellite radar data affect decision making results?

NASA Astrophysics Data System (ADS)

Bloutsos, Aristeidis; Bekri, Eleni; Moschas, Fanis; Saltogianni, Vasso; Stiros, Stathis; Yannopoulos, Panayotis

2015-04-01

Meteorological and air pollution conditions affect the satellite positioning signals. To investigate the uncertainty introduced in these signals in various meteorological and air pollution conditions, an array of GPS/GNSS stations and another of meteorological and air pollution stations has been established. The study area is expanded next to Patraikos and Corinth Gulf (NW Peloponnisos, Greece), which is characterized by high variability sequences from hot to cold weather, low to high relative humidity and clear to cloudy or/and Sahara dusty atmosphere, as a result of the particular geographical and topographical features of the study area. The GNSS recordings from several stations with very high vertical separation (with altitude up to 1600m and with a gradient of up to 20%) are analyzed in order to control in some extend both the vertical and the horizontal variability of the atmospheric effects, as well as the noise of geodetic recordings. Then, the GPS results will be combined with meteorological and atmospheric pollution data, as well as satellite radar data, in order to evaluate the enhanced troposphere noise in satellite radar and to estimate the magnitude of uncertainty that may cause alterations to decision making results in the management of water and other natural resources. This project takes advantage of GPS stations established in wider study area in the framework of the Corinth Rift Laboratory (http://crlab.eu/) in conjunction to the air pollution and meteorological monitoring stations of the Environmental Engineering Laboratory of the Department of Civil Engineering of the University of Patras. Regarding GPS stations, the project has been partly funded by the PLATO Project of the Greek Secretariat for Research and Technology.

Recent Advances in Radar Polarimetry and Polarimetric SAR Interferometry

DTIC Science & Technology

2005-02-01

Hensley, H. A. Zebker, F. H. Webb, and E. Fielding, 1996, "Surface deformation and coherence measurements of Kilauea Volcano , Hawaii from SIR-C radar...topography, tectonic surface deformation, bulging and subsidence (earthquakes, volcanoes , geo-thermal fields and artesian irrigation, ice fields), glacial...J.J. and Y-J. Kim, 2000, "The relationship between radar polarimetric and interferometric phase," Presented at IGARSS�, Honolulu, Hawaii , July

Ionospheric-thermospheric UV tomography: 2. Comparison with incoherent scatter radar measurements

NASA Astrophysics Data System (ADS)

Dymond, K. F.; Nicholas, A. C.; Budzien, S. A.; Stephan, A. W.; Coker, C.; Hei, M. A.; Groves, K. M.

2017-03-01

The Special Sensor Ultraviolet Limb Imager (SSULI) instruments are ultraviolet limb scanning sensors that fly on the Defense Meteorological Satellite Program F16-F19 satellites. The SSULIs cover the 80-170 nm wavelength range which contains emissions at 91 and 136 nm, which are produced by radiative recombination of the ionosphere. We invert the 91.1 nm emission tomographically using a newly developed algorithm that includes optical depth effects due to pure absorption and resonant scattering. We present the details of our approach including how the optimal altitude and along-track sampling were determined and the newly developed approach we are using for regularizing the SSULI tomographic inversions. Finally, we conclude with validations of the SSULI inversions against Advanced Research Project Agency Long-range Tracking and Identification Radar (ALTAIR) incoherent scatter radar measurements and demonstrate excellent agreement between the measurements. As part of this study, we include the effects of pure absorption by O2, N2, and O in the inversions and find that best agreement between the ALTAIR and SSULI measurements is obtained when only O2 and O are included, but the agreement degrades when N2 absorption is included. This suggests that the absorption cross section of N2 needs to be reinvestigated near 91.1 nm wavelengths.

Radar Versus Stealth: Passive Radar and the Future of U.S. Military Power

DTIC Science & Technology

2009-01-01

minimizing, if not nul- lifying , the advantages of the defensive.”3 Douhet did not envision the many sur- face-to-air threats that would evolve over the...is emerging, enabled by advances in networked computing and passive radar technology. Because of their potential to counter stealth-based airpower...waveforms include FM and AM radio, television, digital audio/video broadcast, and cellular phone networks .38 Today, passive radar is often configured as a

Ducted electromagnetic waves in the Martian ionosphere detected by the Mars Advanced Radar for Subsurface and Ionosphere Sounding radar

NASA Astrophysics Data System (ADS)

Zhang, Zhenfei; Orosei, Roberto; Huang, Qian; Zhang, Jie

2016-07-01

In the data of the Mars Advanced Radar for Subsurface and Ionosphere Sounding on board the European Space Agency (ESA) mission Mars Express (MEX), a distinctive type of signals (called the "epsilon signature"), which is similar to that previously detected during radio sounding of the terrestrial F region ionosphere, is found. The signature is interpreted to originate from multiple reflections of electromagnetic waves propagating along sounder pulse-created, crustal magnetic field-aligned plasma bubbles (waveguides). The signatures have a low (below 0.5%) occurrence rate and apparent cutoff frequencies 3-5 times higher than the theoretical one for an ordinary mode wave. These properties are explained by the influence of the perpendicular ionospheric plasma density gradient and the sounder pulse frequency on the formation of waveguides.

Shuttle ku-band communications/radar technical concepts

NASA Technical Reports Server (NTRS)

Griffin, J. W.; Kelley, J. S.; Steiner, A. W.; Vang, H. A.; Zrubek, W. E.; Huth, G. K.

1985-01-01

Technical data on the Shuttle Orbiter K sub u-band communications/radar system are presented. The more challenging aspects of the system design and development are emphasized. The technical problems encountered and the advancements made in solving them are discussed. The radar functions are presented first. Requirements and design/implementation approaches are discussed. Advanced features are explained, including Doppler measurement, frequency diversity, multiple pulse repetition frequencies and pulse widths, and multiple modes. The communications functions that are presented include advances made because of the requirements for multiple communications modes. Spread spectrum, quadrature phase shift keying (QPSK), variable bit rates, and other advanced techniques are discussed. Performance results and conclusions reached are outlined.

Space Radar Image of Patagonian Ice Fields

NASA Image and Video Library

1999-04-15

, a direct indication of the steep meteorological gradients known to exist in this region. The bluer color of the outlet glaciers is probably due to a thin snow cover. A portion of the terminus of the outlet glacier at the top left center of the images has advanced approximately 600 meters (1,970 feet) in the five-and-a-half months between the two missions. Because of the persistent cloud cover this observation was only possible by using the orbiting, remote imaging radar system. http://photojournal.jpl.nasa.gov/catalog/PIA01778

Facilities for meteorological research at NASA Goddard/Wallops Flight Facility

NASA Technical Reports Server (NTRS)

Gerlach, J. C.; Carr, R. E.

1984-01-01

The technical characteristics of the Atmospheric Sciences Research Facility, the improvements being made to the instrumentation there which will enhance its usefulness in atmospheric research, and several of the on-going research programs are described. Among the area of atmospheric research discussed are clouds and precipitation, lightning, ozone, wind, and storms. Meteorological instruments including Doppler radar, spectrophotometers, and ozone sensors are mentioned. Atmospheric research relevant to aircraft design and COMSTAR communication satellites is briefly discussed.

Application of Radar-Based Accumulated Rainfall Products for Early Detection of Heavy Rainfall Occurrence

NASA Astrophysics Data System (ADS)

Nishiyama, K.; Wakimizu, K.; Yokota, I.; Tsukahara, K.; Moriyama, T.

2016-12-01

In Japan, river and debris flow disasters have been frequently caused by heavy rainfall occurrence under the influence of the activity of a stationary front and associated inflow of a large amount of moisture into the front. However, it is very difficult to predict numerically-based heavy rainfall and associated landslide accurately. Therefore, the use of meteorological radar information is required for enhancing decision-making ability to urge the evacuation of local residents by local government staffs prior to the occurrence of the heavy rainfall disaster. It is also desirable that the local residents acquire the ability to determine the evacuation immediately after confirming radar information by themselves. Actually, it is difficult for untrained local residents and local government staffs to easily recognize where heavy rainfall occurs locally for a couple of hours. This reason is that the image of radar echoes is equivalent to instant electromagnetic distribution measured per a couple of minutes, and the distribution of the radar echoes moves together with the movement of a synoptic system. Therefore, in this study, considering that the movement of radar echoes also may stop in a specific area if stationary front system becomes dominant, radar-based accumulated rainfall information is defined here. The rainfall product is derived by the integration of radar intensity measured every ten minutes during previous 1 hours. Using this product, it was investigated whether and how the radar-based accumulated rainfall displayed at an interval of ten minutes can be applied for early detection of heavy rainfall occurrence. The results are summarized as follows. 1) Radar-based accumulated rainfall products could confirm that some of stationary heavy rainfall systems had already appeared prior to disaster occurrence, and clearly identify the movement of heavy rainfall area. 2) Moreover, accumulated area of rainfall could be visually and easily identified, compared with

The concurrent multiplicative-additive approach for gauge-radar/satellite multisensor precipitation estimates

NASA Astrophysics Data System (ADS)

Garcia-Pintado, J.; Barberá, G. G.; Erena Arrabal, M.; Castillo, V. M.

2010-12-01

Objective analysis schemes (OAS), also called ``succesive correction methods'' or ``observation nudging'', have been proposed for multisensor precipitation estimation combining remote sensing data (meteorological radar or satellite) with data from ground-based raingauge networks. However, opposite to the more complex geostatistical approaches, the OAS techniques for this use are not optimized. On the other hand, geostatistical techniques ideally require, at the least, modelling the covariance from the rain gauge data at every time step evaluated, which commonly cannot be soundly done. Here, we propose a new procedure (concurrent multiplicative-additive objective analysis scheme [CMA-OAS]) for operational rainfall estimation using rain gauges and meteorological radar, which does not require explicit modelling of spatial covariances. On the basis of a concurrent multiplicative-additive (CMA) decomposition of the spatially nonuniform radar bias, within-storm variability of rainfall and fractional coverage of rainfall are taken into account. Thus both spatially nonuniform radar bias, given that rainfall is detected, and bias in radar detection of rainfall are handled. The interpolation procedure of CMA-OAS is built on the OAS, whose purpose is to estimate a filtered spatial field of the variable of interest through a successive correction of residuals resulting from a Gaussian kernel smoother applied on spatial samples. The CMA-OAS, first, poses an optimization problem at each gauge-radar support point to obtain both a local multiplicative-additive radar bias decomposition and a regionalization parameter. Second, local biases and regionalization parameters are integrated into an OAS to estimate the multisensor rainfall at the ground level. The approach considers radar estimates as background a priori information (first guess), so that nudging to observations (gauges) may be relaxed smoothly to the first guess, and the relaxation shape is obtained from the sequential

Regime-dependence of Impacts of Radar Rainfall Data Assimilation

NASA Astrophysics Data System (ADS)

Craig, G. C.; Keil, C.

2009-04-01

Experience from the first operational trials of assimilation of radar data in kilometre scale numerical weather prediction models (operating without cumulus parameterisation) shows that the positive impact of the radar data on convective precipitation forecasts typically decay within a few hours, although certain cases show much longer impacts. Here the impact time of radar data assimilation is related to characteristics of the meteorological environment. This QPF uncertainty is investigated using an ensemble of 10 forecasts at 2.8 km horizontal resolution based on different initial and boundary conditions from a global forecast ensemble. Control forecasts are compared with forecasts where radar reflectivity data is assimilated using latent heat nudging. Examination of different cases of convection in southern Germany suggests that the forecasts can be separated into two regimes using a convective timescale. Short impact times are associated with short convective timescales that are characteristic of equilibrium convection. In this regime the statistical properties of the convection are constrained by the large-scale forcing, and effects of the radar data are lost within a few hours as the convection rapidly returns to equilibrium. When the convective timescale is large (non-equilibrium conditions), the impact of the radar data is longer since convective systems are triggered by the latent heat nudging and are able to persist for many hours in the very unstable conditions present in these cases.

NASA ER-2 Doppler radar reflectivity calibration for the CAMEX project

NASA Technical Reports Server (NTRS)

Caylor, I. J.; Heymsfield, G. M.; Bidwell, S. W.; Ameen, S.

1994-01-01

The NASA ER-2 Doppler radar (EDOP) was flown aboard the ER-2 high-altitude aircraft in September and October 1993 for the Convection and Moisture Experiment. During these flights, the first reliable reflectivity observations were performed with the EDOP instrument. This report details the procedure used to convert real-time engineering data into calibrated radar reflectivity. Application of the calibration results produces good agreement between the EDOP nadir pointing reflectivity and ground truth provided by a National Weather Service WSR-88D radar. The rms deviation between WSR-88D and EDOP is 6.9 dB, while measurements of the ocean surface backscatter coefficient are less than 3 dB from reported scatterometer coefficients. After an initial 30-minute period required for the instrument to reach thermal equilibrium, the radar is stable to better than 0.25 dB during flight. The range performance of EDOP shows excellent agreement with aircraft altimeter and meteorological sounding data.

Radar research at University of Oklahoma (Conference Presentation)

NASA Astrophysics Data System (ADS)

Zhang, Yan R.; Weber, Mark E.

2017-05-01

This abstract is for the academic institution profiles session This presentation will focus on radar research programs at the University of Oklahoma, the radar research in OU has more than 50 years history of collaboration with NOAA, and has been through tremendous growth since early 2000. Before 2010, the focus was weather radar and weather surveillance, and since the Defense, Security and Intelligence (DSI) initiative in 2011, there have many new efforts on the defense and military radar applications. This presentation will focus on the following information: (1) The history, facilities and instrumentations of Advanced Radar Research Center, (2) Focus area of polarimetric phased array systems, (3) Focus area of airborne and spaceborne radars, (4) Intelligent radar information processing, (5) Innovative antenna and components.

Lightning Jump Algorithm and Relation to Thunderstorm Cell Tracking, GLM Proxy and Other Meteorological Measurements

NASA Technical Reports Server (NTRS)

Schultz, Christopher J.; Carey, Lawrence D.; Cecil, Daniel J.; Bateman, Monte

2012-01-01

The lightning jump algorithm has a robust history in correlating upward trends in lightning to severe and hazardous weather occurrence. The algorithm uses the correlation between the physical principles that govern an updraft's ability to produce microphysical and kinematic conditions conducive for electrification and its role in the development of severe weather conditions. Recent work has demonstrated that the lightning jump algorithm concept holds significant promise in the operational realm, aiding in the identification of thunderstorms that have potential to produce severe or hazardous weather. However, a large amount of work still needs to be completed in spite of these positive results. The total lightning jump algorithm is not a stand-alone concept that can be used independent of other meteorological measurements, parameters, and techniques. For example, the algorithm is highly dependent upon thunderstorm tracking to build lightning histories on convective cells. Current tracking methods show that thunderstorm cell tracking is most reliable and cell histories are most accurate when radar information is incorporated with lightning data. In the absence of radar data, the cell tracking is a bit less reliable but the value added by the lightning information is much greater. For optimal application, the algorithm should be integrated with other measurements that assess storm scale properties (e.g., satellite, radar). Therefore, the recent focus of this research effort has been assessing the lightning jump's relation to thunderstorm tracking, meteorological parameters, and its potential uses in operational meteorology. Furthermore, the algorithm must be tailored for the optically-based GOES-R Geostationary Lightning Mapper (GLM), as what has been observed using Very High Frequency Lightning Mapping Array (VHF LMA) measurements will not exactly translate to what will be observed by GLM due to resolution and other instrument differences. Herein, we present some of

Power centroid radar and its rise from the universal cybernetics duality

NASA Astrophysics Data System (ADS)

Feria, Erlan H.

2014-05-01

Power centroid radar (PC-Radar) is a fast and powerful adaptive radar scheme that naturally surfaced from the recent discovery of the time-dual for information theory which has been named "latency theory." Latency theory itself was born from the universal cybernetics duality (UC-Duality), first identified in the late 1970s, that has also delivered a time dual for thermodynamics that has been named "lingerdynamics" and anchors an emerging lifespan theory for biological systems. In this paper the rise of PC-Radar from the UC-Duality is described. The development of PC-Radar, US patented, started with Defense Advanced Research Projects Agency (DARPA) funded research on knowledge-aided (KA) adaptive radar of the last decade. The outstanding signal to interference plus noise ratio (SINR) performance of PC-Radar under severely taxing environmental disturbances will be established. More specifically, it will be seen that the SINR performance of PC-Radar, either KA or knowledgeunaided (KU), approximates that of an optimum KA radar scheme. The explanation for this remarkable result is that PC-Radar inherently arises from the UC-Duality, which advances a "first principles" duality guidance theory for the derivation of synergistic storage-space/computational-time compression solutions. Real-world synthetic aperture radar (SAR) images will be used as prior-knowledge to illustrate these results.

WSR-88D doppler radar detection of corn earworm moth migration.

PubMed

Westbrook, J K; Eyster, R S; Wolf, W W

2014-07-01

Corn earworm (Lepidoptera: Noctuidae) (CEW) populations infesting one crop production area may rapidly migrate and infest distant crop production areas. Although entomological radars have detected corn earworm moth migrations, the spatial extent of the radar coverage has been limited to a small horizontal view above crop production areas. The Weather Service Radar (version 88D) (WSR-88D) continuously monitors the radar-transmitted energy reflected by, and radial speed of, biota as well as by precipitation over areas that may encompass crop production areas. We analyzed data from the WSR-88D radar (S-band) at Brownsville, Texas, and related these data to aerial concentrations of CEW estimated by a scanning entomological radar (X-band) and wind velocity measurements from rawinsonde and pilot balloon ascents. The WSR-88D radar reflectivity was positively correlated (r2=0.21) with the aerial concentration of corn earworm-size insects measured by a scanning X-band radar. WSR-88D radar constant altitude plan position indicator estimates of wind velocity were positively correlated with wind speed (r2=0.56) and wind direction (r2=0.63) measured by pilot balloons and rawinsondes. The results reveal that WSR-88D radar measurements of insect concentration and displacement speed and direction can be used to estimate the migratory flux of corn earworms and other nocturnal insects, information that could benefit areawide pest management programs. In turn, identification of the effects of spatiotemporal patterns of migratory flights of corn earworm-size insects on WSR-88D radar measurements may lead to the development of algorithms that increase the accuracy of WSR-88D radar measurements of reflectivity and wind velocity for operational meteorology.

WSR-88D doppler radar detection of corn earworm moth migration

NASA Astrophysics Data System (ADS)

Westbrook, J. K.; Eyster, R. S.; Wolf, W. W.

2014-07-01

Corn earworm (Lepidoptera: Noctuidae) (CEW) populations infesting one crop production area may rapidly migrate and infest distant crop production areas. Although entomological radars have detected corn earworm moth migrations, the spatial extent of the radar coverage has been limited to a small horizontal view above crop production areas. The Weather Service Radar (version 88D) (WSR-88D) continuously monitors the radar-transmitted energy reflected by, and radial speed of, biota as well as by precipitation over areas that may encompass crop production areas. We analyzed data from the WSR-88D radar (S-band) at Brownsville, Texas, and related these data to aerial concentrations of CEW estimated by a scanning entomological radar (X-band) and wind velocity measurements from rawinsonde and pilot balloon ascents. The WSR-88D radar reflectivity was positively correlated ( r 2 = 0.21) with the aerial concentration of corn earworm-size insects measured by a scanning X-band radar. WSR-88D radar constant altitude plan position indicator estimates of wind velocity were positively correlated with wind speed ( r 2 = 0.56) and wind direction ( r 2 = 0.63) measured by pilot balloons and rawinsondes. The results reveal that WSR-88D radar measurements of insect concentration and displacement speed and direction can be used to estimate the migratory flux of corn earworms and other nocturnal insects, information that could benefit areawide pest management programs. In turn, identification of the effects of spatiotemporal patterns of migratory flights of corn earworm-size insects on WSR-88D radar measurements may lead to the development of algorithms that increase the accuracy of WSR-88D radar measurements of reflectivity and wind velocity for operational meteorology.

Wind turbine impact on operational weather radar I/Q data: characterisation and filtering

NASA Astrophysics Data System (ADS)

Norin, Lars

2017-05-01

For the past 2 decades wind turbines have been growing in number all over the world as a response to the increasing demand for renewable energy. However, the rapid expansion of wind turbines presents a problem for many radar systems, including weather radars. Wind turbines in the line of sight of a weather radar can have a negative impact on the radar's measurements. As weather radars are important instruments for meteorological offices, finding a way for wind turbines and weather radars to co-exist would be of great societal value.Doppler weather radars base their measurements on in-phase and quadrature phase (I/Q) data. In this work a month's worth of recordings of high-resolution I/Q data from an operational Swedish C-band weather radar are presented. The impact of point targets, such as masts and wind turbines, on the I/Q data is analysed and characterised. It is shown that the impact of point targets on single radar pulses, when normalised by amplitude, is manifested as a distinct and highly repeatable signature. The shape of this signature is found to be independent of the size, shape and yaw angle of the wind turbine. It is further demonstrated how the robustness of the point target signature can be used to identify and filter out the impact of wind turbines in the radar's signal processor.

Precipitation Estimation Using Combined Radar/Radiometer Measurements Within the GPM Framework

NASA Technical Reports Server (NTRS)

Hou, Arthur

2012-01-01

The Global Precipitation Measurement (GPM) Mission is an international satellite mission specifically designed to unify and advance precipitation measurements from a constellation of research and operational microwave sensors. The GPM mission centers upon the deployment of a Core Observatory in a 65o non-Sun-synchronous orbit to serve as a physics observatory and a transfer standard for intersatellite calibration of constellation radiometers. The GPM Core Observatory will carry a Ku/Ka-band Dual-frequency Precipitation Radar (DPR) and a conical-scanning multi-channel (10-183 GHz) GPM Microwave Radiometer (GMI). The DPR will be the first dual-frequency radar in space to provide not only measurements of 3-D precipitation structures but also quantitative information on microphysical properties of precipitating particles needed for improving precipitation retrievals from microwave sensors. The DPR and GMI measurements will together provide a database that relates vertical hydrometeor profiles to multi-frequency microwave radiances over a variety of environmental conditions across the globe. This combined database will be used as a common transfer standard for improving the accuracy and consistency of precipitation retrievals from all constellation radiometers. For global coverage, GPM relies on existing satellite programs and new mission opportunities from a consortium of partners through bilateral agreements with either NASA or JAXA. Each constellation member may have its unique scientific or operational objectives but contributes microwave observations to GPM for the generation and dissemination of unified global precipitation data products. In addition to the DPR and GMI on the Core Observatory, the baseline GPM constellation consists of the following sensors: (1) Special Sensor Microwave Imager/Sounder (SSMIS) instruments on the U.S. Defense Meteorological Satellite Program (DMSP) satellites, (2) the Advanced Microwave Scanning Radiometer-2 (AMSR-2) on the GCOM-W1

Applied Meteorology Unit (AMU)

NASA Technical Reports Server (NTRS)

Bauman, William; Crawford, Winifred; Barrett, Joe; Watson, Leela; Wheeler, Mark

2010-01-01

This report summarizes the Applied Meteorology Unit (AMU) activities for the first quarter of Fiscal Year 2010 (October - December 2009). A detailed project schedule is included in the Appendix. Included tasks are: (1) Peak Wind Tool for User Launch Commit Criteria (LCC), (2) Objective Lightning Probability Tool, Phase III, (3) Peak Wind Tool for General Forecasting, Phase II, (4) Upgrade Summer Severe Weather Tool in Meteorological Interactive Data Display System (MIDDS), (5) Advanced Regional Prediction System (ARPS) Data Analysis System (ADAS) Update and Maintainability, (5) Verify 12-km resolution North American Model (MesoNAM) Performance, and (5) Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) Graphical User Interface.

Next Generation P-Band Planetary Synthetic Aperture Radar

NASA Technical Reports Server (NTRS)

Rincon, Rafael; Carter, Lynn; Lu, Dee Pong Daniel

2016-01-01

The Space Exploration Synthetic Aperture Radar (SESAR) is an advanced P-band beamforming radar instrument concept to enable a new class of observations suitable to meet Decadal Survey science goals for planetary exploration. The radar operates at full polarimetry and fine (meter scale) resolution, and achieves beam agility through programmable waveform generation and digital beamforming. The radar architecture employs a novel low power, lightweight design approach to meet stringent planetary instrument requirements. This instrument concept has the potential to provide unprecedented surface and near- subsurface measurements applicable to multiple DecadalSurvey Science Goals.

Next Generation P-Band Planetary Synthetic Aperture Radar

NASA Technical Reports Server (NTRS)

Rincon, Rafael; Carter, Lynn; Lu, Dee Pong Daniel

2017-01-01

The Space Exploration Synthetic Aperture Radar (SESAR) is an advanced P-band beamforming radar instrument concept to enable a new class of observations suitable to meet Decadal Survey science goals for planetary exploration. The radar operates at full polarimetry and fine (meter scale) resolution, and achieves beam agility through programmable waveform generation and digital beamforming. The radar architecture employs a novel low power, lightweight design approach to meet stringent planetary instrument requirements. This instrument concept has the potential to provide unprecedented surface and near- subsurface measurements applicable to multiple Decadal Survey Science Goals.

Applications of high-frequency radar

NASA Astrophysics Data System (ADS)

Headrick, J. M.; Thomason, J. F.

1998-07-01

Efforts to extend radar range by an order of magnitude with use of the ionosphere as a virtual mirror started after the end of World War II. A number of HF radar programs were pursued, with long-range nuclear burst and missile launch detection demonstrated by 1956. Successful east coast radar aircraft detect and track tests extending across the Atlantic were conducted by 1961. The major obstacles to success, the large target-to-clutter ratio and low signal-to-noise ratio, were overcome with matched filter Doppler processing. To search the areas that a 2000 nautical mile (3700 km) radar can reach, very complex and high dynamic range processing is required. The spectacular advances in digital processing technology have made truly wide-area surveillance possible. Use of the surface attached wave over the oceans can enable HF radar to obtain modest extension of range beyond the horizon. The decameter wavelengths used by both skywave and surface wave radars require large physical antenna apertures, but they have unique capabilities for air and surface targets, many of which are of resonant scattering dimensions. Resonant scattering from the ocean permits sea state and direction estimation. Military and commercial applications of HF radar are in their infancy.

Exploring the Use of Radar for Physically-Based Nowcasting of Lightning Cessation

NASA Technical Reports Server (NTRS)

Schultz, Elise V.; Petersen, Walter A.; Carey, Lawrence D.

2011-01-01

NASA's Marshall Space Flight Center and the University of Alabama in Huntsville (UAHuntsville) are collaborating with the 45th Weather Squadron (45WS) at Cape Canaveral Air Force Station (CCAFS) to enable improved nowcasting of lightning cessation. This project centers on use of dual-polarimetric radar capabilities, and in particular, the new C-band dual polarimetric weather radar acquired by the 45WS. Special emphasis is placed on the development of a physically-based operational algorithm to predict lightning cessation. While previous studies have developed statistically based lightning cessation algorithms driven primarily by trending in the actual total lightning flash rate, we believe that dual polarimetric radar variables offer the possibility to improve existing algorithms through the inclusion of physically meaningful trends reflecting interactions between in-cloud electric fields and ice-microphysics. Specifically, decades of polarimetric radar research using propagation differential phase has demonstrated the presence of distinct phase and ice crystal alignment signatures in the presence of strong electric fields associated with lightning. One question yet to be addressed is: To what extent can propagation phase-based ice-crystal alignment signatures be used to nowcast the cessation of lightning activity in a given storm? Accordingly, data from the UAHuntsville Advanced Radar for Meteorological and Operational Research (ARMOR) along with the NASA-MSFC North Alabama Lightning Mapping Array are used in this study to investigate the radar signatures present before and after lightning cessation. Thus far our case study results suggest that the negative differential phase shift signature weakens and disappears after the analyzed storms ceased lightning production (i.e., after the last lightning flash occurred). This is a key observation because it suggests that while strong electric fields may still have been present, the lightning cessation signature was

Advanced Land Observing Satellite (ALOS) Phased Array Type L-Band Synthetic Aperture Radar (PALSAR) mosaic for the Kahiltna terrane, Alaska, 2007-2010

USGS Publications Warehouse

Cole, Christopher J.; Johnson, Michaela R.; Graham, Garth E.

2015-01-01

The USGS has compiled a continuous, cloud-free 12.5-meter resolution radar mosaic of SAR data of approximately 212,000 square kilometers to examine the suitability of this technology for geologic mapping. This mosaic was created from Advanced Land Observing Satellite (ALOS) Phased Array type L-band Synthetic Aperture Radar (PALSAR) data collected from 2007 to 2010 spanning the Kahiltna terrane and the surrounding area. Interpretation of these data may help geologists understand past geologic processes and identify areas with potential for near-surface mineral resources for further ground-based geological and geochemical investigations.

Analysis of general-aviation accidents using ATC radar records

NASA Technical Reports Server (NTRS)

Wingrove, R. C.; Bach, R. E., Jr.

1982-01-01

It is pointed out that general aviation aircraft usually do not carry flight recorders, and in accident investigations the only available data may come from the Air Traffic Control (ATC) records. A description is presented of a technique for deriving time-histories of aircraft motions from ATC radar records. The employed procedure involves a smoothing of the raw radar data. The smoothed results, in combination with other available information (meteorological data and aircraft aerodynamic data) are used to derive the expanded set of motion time-histories. Applications of the considered analytical methods are related to different types of aircraft, such as light piston-props, executive jets, and commuter turboprops, as well as different accident situations, such as takeoff, climb-out, icing, and deep stall.

Rain radar measurement error estimation using data assimilation in an advection-based nowcasting system

NASA Astrophysics Data System (ADS)

Merker, Claire; Ament, Felix; Clemens, Marco

2017-04-01

The quantification of measurement uncertainty for rain radar data remains challenging. Radar reflectivity measurements are affected, amongst other things, by calibration errors, noise, blocking and clutter, and attenuation. Their combined impact on measurement accuracy is difficult to quantify due to incomplete process understanding and complex interdependencies. An improved quality assessment of rain radar measurements is of interest for applications both in meteorology and hydrology, for example for precipitation ensemble generation, rainfall runoff simulations, or in data assimilation for numerical weather prediction. Especially a detailed description of the spatial and temporal structure of errors is beneficial in order to make best use of the areal precipitation information provided by radars. Radar precipitation ensembles are one promising approach to represent spatially variable radar measurement errors. We present a method combining ensemble radar precipitation nowcasting with data assimilation to estimate radar measurement uncertainty at each pixel. This combination of ensemble forecast and observation yields a consistent spatial and temporal evolution of the radar error field. We use an advection-based nowcasting method to generate an ensemble reflectivity forecast from initial data of a rain radar network. Subsequently, reflectivity data from single radars is assimilated into the forecast using the Local Ensemble Transform Kalman Filter. The spread of the resulting analysis ensemble provides a flow-dependent, spatially and temporally correlated reflectivity error estimate at each pixel. We will present first case studies that illustrate the method using data from a high-resolution X-band radar network.

HUD Guidance for the ASKA Experimental STOL Aircraft using Radar Position Information

NASA Technical Reports Server (NTRS)

Yazawa, Kenji; Terui, Yushi; Hardy, Gordon H.

1992-01-01

The paper describes a high performance HUD guidance system installed on the experimental powered-lift STOL aircraft Aska. Since the maiden flight in October 1985, the HUD system has been used in all the flight tests. The HUD has an accurate flight path symbol generated by inertial velocity from the IRS which is updated by up-linked precision radar position data. The flight path symbol is very useful for precise approach and flare control for Aska which has large ground effects. A synthetic runway is also presented, which is conformal with the real runway, using the position data from the ground tracking radar system. Under instrument meteorological conditions, the pilot can approach and land using the HUD synthetic runway as well as in visual meteorological conditions. The HUD system proved to be a valuable aid to the pilot for all the Aska flight tests. A NASA Ames Research Center test pilot demonstrated touch down accuracy of less than 8 meters (peak to peak) for a series of three landings.

Hydrologic applications of weather radar

NASA Astrophysics Data System (ADS)

Seo, Dong-Jun; Habib, Emad; Andrieu, Hervé; Morin, Efrat

2015-12-01

By providing high-resolution quantitative precipitation information (QPI), weather radars have revolutionized hydrology in the last two decades. With the aid of GIS technology, radar-based quantitative precipitation estimates (QPE) have enabled routine high-resolution hydrologic modeling in many parts of the world. Given the ever-increasing need for higher-resolution hydrologic and water resources information for a wide range of applications, one may expect that the use of weather radar will only grow. Despite the tremendous progress, a number of significant scientific, technological and engineering challenges remain to realize its potential. New challenges are also emerging as new areas of applications are discovered, explored and pursued. The purpose of this special issue is to provide the readership with some of the latest advances, lessons learned, experiences gained, and science issues and challenges related to hydrologic applications of weather radar. The special issue features 20 contributions on various topics which reflect the increasing diversity as well as the areas of focus in radar hydrology today. The contributions may be grouped as follows:

Radar Observation of Large Attenuation in Convective Storms: Implications for the Dropsize Distribution

NASA Technical Reports Server (NTRS)

Tian, Lin; Heymsfield, G. M.; Srivastava, R. C.

2000-01-01

Airborne meteorological radars typically operate at attenuating wavelengths. The path integrated attenuation (PIA) can be estimated using the surface reference technique (SRT). In this method, an initial value is determined for the radar cross section of the earth surface in a rain-free area in relatively close proximity to the rain cloud. During subsequent observations of precipitation any decrease 'in the observed surface cross section from the reference value s assumed to be a result of the two-way attenuation along the propagation path. In this paper we present selected instances of high PIA observed over land by an airborne radar. The observations were taken in Brazil and Florida during TRMM (Tropical Rainfall Measurement Mission) field campaigns. We compared these observations with collocated and nearly simultaneous ground-based radar observations by an S-band radar that is not subject to significant attenuation. In this preliminary evaluation, a systematic difference in the attenuation in the two storms is attributed to a difference in the raindrop size distributions; this is supported by observations of ZDR (differential reflectivity).

Intensive probing of clear air convective fields by radar and instrumented drone aircraft.

NASA Technical Reports Server (NTRS)

Rowland, J. R.

1972-01-01

Clear air convective fields were probed in three summer experiments (1969, 1970, and 1971) on an S-band monopulse tracking radar at Wallops Island, Virginia, and a drone aircraft with a takeoff weight of 5.2 kg, wingspan of 2.5 m, and cruising glide speed of 10.3 m/sec. The drone was flown 23.2 km north of the radar and carried temperature, pressure/altitude, humidity, and vertical and airspeed velocity sensors. Extensive time-space convective field data were obtained by taking a large number of RHI and PPI pictures at short intervals of time. The rapidly changing overall convective field data obtained from the radar could be related to the meteorological information telemetered from the drone at a reasonably low cost by this combined technique.

Exploring the Use of Radar for a Physically Based Lightning Cessation Nowcasting Tool

NASA Technical Reports Server (NTRS)

Schultz, Elise V.; Petersen, Walter A.; Carey, Lawrence D.

2011-01-01

NASA s Marshall Space Flight Center (MSFC) and the University of Alabama in Huntsville (UAHuntsville) are collaborating with the 45th Weather Squadron (45WS) at Cape Canaveral Air Force Station (CCAFS) to enable improved nowcasting of lightning cessation. This project centers on use of dual-polarimetric radar capabilities, and in particular, the new C-band dual-polarimetric weather radar acquired by the 45WS. Special emphasis is placed on the development of a physically based operational algorithm to predict lightning cessation. While previous studies have developed statistically based lightning cessation algorithms, we believe that dual-polarimetric radar variables offer the possibility to improve existing algorithms through the inclusion of physically meaningful trends reflecting interactions between in-cloud electric fields and hydrometeors. Specifically, decades of polarimetric radar research using propagation differential phase has demonstrated the presence of distinct phase and ice crystal alignment signatures in the presence of strong electric fields associated with lightning. One question yet to be addressed is: To what extent can these ice-crystal alignment signatures be used to nowcast the cessation of lightning activity in a given storm? Accordingly, data from the UAHuntsville Advanced Radar for Meteorological and Operational Research (ARMOR) along with the NASA-MSFC North Alabama Lightning Mapping Array are used in this study to investigate the radar signatures present before and after lightning cessation. Thus far, our case study results suggest that the negative differential phase shift signature weakens and disappears after the analyzed storms ceased lightning production (i.e., after the last lightning flash occurred). This is a key observation because it suggests that while strong electric fields may still have been present, the lightning cessation signature encompassed the period of the polarimetric negative phase shift signature. To the extent

Development of observed precipitation and meteorological database to understand the wet deposition and dispersion processes in March 2011

NASA Astrophysics Data System (ADS)

Yatagai, Akiyo; Watanabe, Akira; Ishihara, Masahito; Ishihara, Hirohiko; Takara, Kaoru

2014-05-01

The transport and diffusion of the radioactive pollutants from the Fukushima-Daiichi NPP inthe atmosphere caused a disaster for residents in and around Fukushima. Studies have sought to understand the transport, diffusion, and deposition process, and to understand the movement of radioactive pollutants through the soil, vegetation, rivers, and groundwater. However, a detailed simulation and understanding of the distribution of radioactive compounds depend on a simulation of precipitation and on the information on the timing of the emission of these radioactive pollutants from the NPP. Further, precipitation type and its amount affect the various transport process of the radioactive nuclides. Hence, this study first examine the qualitative precipitation pattern and timing in March 2011 using X-band radar data from Fukushima University and three dimensional C-band radar data network of Japan Meteorological Agency. Second, by collecting rain-gauge network and other surface meteorological data, we estimate quantitative precipitation and its type (rain/snow) according to the same method used to create APHRODITE daily grid precipitation (Yatagai et al., 2012) and judge of rain/snow (Yasutomi et al., 2011). For example, the data clarified that snowfall was observed on the night of Mar 15 into the morning of Mar 16 throughout Fukushima prefecture. This had an important effect on the radioactive contamination pattern in Fukushima prefecture. The precipitation pattern itself does not show one-on-one correspondence with the contamination pattern. While the pollutants transported northeast of the NPP and through north Kanto (about 200 km southwest of Fukushima and, 100 km north of Tokyo) went to the northeast, the timing of the precipitation causing the fallout, i.e., wet-deposition, is important. Although the hourly Radar-AMeDAS 1-km-mesh precipitation data of JMA are available publically, it does not represent the precipitation pattern in Nakadori, in central Fukushima

Processing of High Resolution, Multiparametric Radar Data for the Airborne Dual-Frequency Precipitation Radar APR-2

NASA Technical Reports Server (NTRS)

Tanelli, Simone; Meagher, Jonathan P.; Durden, Stephen L.; Im, Eastwood

2004-01-01

Following the successful Precipitation Radar (PR) of the Tropical Rainfall Measuring Mission, a new airborne, 14/35 GHz rain profiling radar, known as Airborne Precipitation Radar - 2 (APR-2), has been developed as a prototype for an advanced, dual-frequency spaceborne radar for a future spaceborne precipitation measurement mission. . This airborne instrument is capable of making simultaneous measurements of rainfall parameters, including co-pol and cross-pol rain reflectivities and vertical Doppler velocities, at 14 and 35 GHz. furthermore, it also features several advanced technologies for performance improvement, including real-time data processing, low-sidelobe dual-frequency pulse compression, and dual-frequency scanning antenna. Since August 2001, APR-2 has been deployed on the NASA P3 and DC8 aircrafts in four experiments including CAMEX-4 and the Wakasa Bay Experiment. Raw radar data are first processed to obtain reflectivity, LDR (linear depolarization ratio), and Doppler velocity measurements. The dataset is then processed iteratively to accurately estimate the true aircraft navigation parameters and to classify the surface return. These intermediate products are then used to refine reflectivity and LDR calibrations (by analyzing clear air ocean surface returns), and to correct Doppler measurements for the aircraft motion. Finally, the the melting layer of precipitation is detected and its boundaries and characteristics are identifIed at the APR-2 range resolution of 30m. The resulting 3D dataset will be used for validation of other airborne and spaceborne instruments, development of multiparametric rain/snow retrieval algorithms and melting layer characterization and statistics.

INSAT-3D: an advanced meteorological mission over Indian Ocean

NASA Astrophysics Data System (ADS)

Katti, V. R.; Pratap, V. R.; Dave, R. K.; Mankad, K. N.

2006-12-01

This paper presents the salient features of INSAT 3D mission and its Met Payloads. INSAT-3D, the next ISRO meteorological satellite aims for a significant technological improvement in sensor capabilities as compared to earlier INSAT missions. It is an exclusive mission designed for enhanced meteorological observations and monitoring of land and ocean surfaces for weather forecasting and disaster warning. The three-axis stabilized geostationary satellite is to carry two meteorological instruments: a six channel Imager and an IR Sounder. Along with the channels in Visible, Middle Infrared, Water Vapor and Thermal Infrared bands, the Imager includes a SWIR channel for wider applications. The Sounder will have eighteen narrow spectral channels in three IR bands in addition to a channel in visible band. INSAT-3D is configured around standard 2000 kg I2K spacecraft bus with 7-year life. Several innovative technologies like on-the-fly correction of scan mirror pointing errors, biannual yaw rotation of the spacecraft, micro-stepping SADA, star sensors and integrated bus management unit have been incorporated to meet the stringent payload requirements like pointing accuracies, thermal management of IR detectors and concurrent operation of both instruments.

Future directions of meteorology related to air-quality research.

PubMed

Seaman, Nelson L

2003-06-01

Meteorology is one of the major factors contributing to air-pollution episodes. More accurate representation of meteorological fields has been possible in recent years through the use of remote sensing systems, high-speed computers and fine-mesh meteorological models. Over the next 5-20 years, better meteorological inputs for air quality studies will depend on making better use of a wealth of new remotely sensed observations in more advanced data assimilation systems. However, for fine mesh models to be successful, parameterizations used to represent physical processes must be redesigned to be more precise and better adapted for the scales at which they will be applied. Candidates for significant overhaul include schemes to represent turbulence, deep convection, shallow clouds, and land-surface processes. Improvements in the meteorological observing systems, data assimilation and modeling, coupled with advancements in air-chemistry modeling, will soon lead to operational forecasting of air quality in the US. Predictive capabilities can be expected to grow rapidly over the next decade. This will open the way for a number of valuable new services and strategies, including better warnings of unhealthy atmospheric conditions, event-dependent emissions restrictions, and now casting support for homeland security in the event of toxic releases into the atmosphere.

Storm Motion Tracking Over The Arno River Basin Through Multiscale Radar Reflectivity Classification and Correlation

NASA Astrophysics Data System (ADS)

Facheris, L.; Tanelli, S.; Giuli, D.

differential reflectivity maps, mean Doppler velocity and Doppler spread maps with a resolution of 125/250 m [3]. [1] Li L. Schmid W. and Joss J., Nowcasting of motion and growth of precipitation with radar over a complex orography Journal of Applied Meteorology, vol. 34, pp. 1286-1300, 1995. [2] L.Facheris, S. Tanelli, F. Argenti, D.Giuli, SWavelet Applica- & cedil;tions to Multiparameter Weather Radar AnalysisT, to be published on SInformation & cedil;Processing for Remote SensingT, Prof. C.H. Chen Ed. for World Scientific Publish- 1 ing Co., pagg. 187-207, 1999 [3] Scarchilli G. Gorgucci E. Giuli D. Facheris L. Freni A. and Vezzani G., Arno Project: Radar System and objectives., Proceedings 25th In- ternational Conference on Radar Meteorology, Paris, France, 24-28 June 1991, pp. 805-808 2

Meteorological Simulations of Ozone Episode Case Days during the 1996 Paso del Norte Ozone Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brown, M.J.; Costigan, K.; Muller, C.

1999-02-01

Meteorological simulations centered around the border cities of El Paso and Ciudad Juarez have been performed during an ozone episode that occurred on Aug. 13,1996 during the 1996 Paso del Norte Ozone Study field campaign. Simulations were petiormed using the HOTMAC mesoscale meteorological model using a 1,2,4, and 8 km horizontal grid size nested mesh system. Investigation of the vertical structure and evolution of the atmospheric boundary layer for the Aug. 11-13 time period is emphasized in this paper. Comparison of model-produced wind speed profiles to rawirisonde and radar profiler measurements shows reasonable agreement. A persistent upper-level jet was capturedmore » in the model simulations through data assimilation. In the evening hours, the model was not able to produce the strong wind direction shear seen in the radar wind profiles. Based on virtual potential temperature profile comparisons, the model appears to correctly simulate the daytime growth of the convective mixed layer. However, the model underestimates the cooling of the surface layer at night. We found that the upper-level jet significantly impacted the turbulence structure of the boundary layer, leading to relatively high turbulent kinetic energy (tke) values aloft at night. The model indicates that these high tke values aloft enhance the mid-morning growth of the boundary layer. No upper-level turbulence measurements were available to verify this finding, however. Radar profiler-derived mixing heights do indicate relatively rapid morning growth of the mixed layer.« less

Dual-Polarimetric Radar-Based Tornado Debris Paths Associated with EF-4 and EF-5 Tornadoes over Northern Alabama During the Historic Outbreak of 27 April 2011

NASA Technical Reports Server (NTRS)

Carey, Lawrence D.; Schultz, Christopher J.; Schultz, Elise V.; Petersen, Walter A.; Gatlin, Patrick N.; Knupp, Kevin R.; Molthan, Andrew L.; Darden, Christopher B.

2011-01-01

An historic tornado and severe weather outbreak devastated much of the southeastern United States between 25 and 28 April 2011. On 27 April 2011, northern Alabama was particularly hard hit by a large number of tornadoes, including several that reached EF-4 and EF-5 on the Enhanced Fujita damage scale. In northern Alabama alone, there were approximately 100 fatalities and hundreds of more people who were injured or lost their homes during the havoc caused by these violent tornadic storms. Two long-track and violent (EF-4 and EF-5) tornadoes occurred within range of the University of Alabama in Huntsville (UAHuntsville) Advanced Radar for Meteorological and Operational Research (ARMOR, C-band dual-polarimetric). A unique capability of dual-polarimetric radar is the near-real time identification of lofted debris associated with ongoing tornadoes on the ground. The focus of this paper is to analyze the dual-polarimetric radar-inferred tornado debris signatures and identify the associated debris paths of the long-track EF-4 and EF-5 tornadoes near ARMOR. The relative locations of the debris and damage paths for each tornado will be ascertained by careful comparison of the ARMOR analysis with NASA MODIS (Moderate Resolution Imaging Spectroradiometer) and ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) satellite imagery of the tornado damage scenes and the National Weather Service tornado damage surveys. With the ongoing upgrade of the WSR-88D (Weather Surveillance Radar - 1988 Doppler) operational network to dual-polarimetry and a similar process having already taken place or ongoing for many private sector radars, dual-polarimetric radar signatures of tornado debris promise the potential to assist in the situational awareness of government and private sector forecasters and emergency managers during tornadic events. As such, a companion abstract (Schultz et al.) also submitted to this conference explores "The use of dual-polarimetric tornadic

Dual-Polarimetric Radar-Based Tornado Debris Paths Associated with EF-4 and EF-5 Tornadoes over Northern Alabama During the Historic Outbreak of 27 April 2011

NASA Technical Reports Server (NTRS)

Carey, Lawrence D.; Schultz, Chrstopher J.; Schultz, Elise V.; Petersen, Walter A.; Gatlin, Patrick N.; Knupp, Kevin R.; Molthan, Andrew L.; Jedlovec, Gary J.; Darden, Christopher B.

2012-01-01

An historic tornado and severe weather outbreak devastated much of the southeastern United States between 25 and 28 April 2011. On 27 April 2011, northern Alabama was particularly hard hit by a large number of tornadoes, including several that reached EF-4 and EF-5 on the Enhanced Fujita damage scale. In northern Alabama alone, there were approximately 100 fatalities and hundreds of more people who were injured or lost their homes during the havoc caused by these violent tornadic storms. Two long-track and violent (EF-4 and EF-5) tornadoes occurred within range of the University of Alabama in Huntsville (UAHuntsville) Advanced Radar for Meteorological and Operational Research (ARMOR, C-band dual-polarimetric). A unique capability of dual-polarimetric radar is the near-real time identification of lofted debris associated with ongoing tornadoes on the ground. The focus of this paper is to analyze the dual-polarimetric radar-inferred tornado debris signatures and identify the associated debris paths of the long-track EF-4 and EF-5 tornadoes near ARMOR. The relative locations of the debris and damage paths for each tornado will be ascertained by careful comparison of the ARMOR analysis with NASA MODIS (Moderate Resolution Imaging Spectroradiometer) and ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) satellite imagery of the tornado damage scenes and the National Weather Service tornado damage surveys. With the ongoing upgrade of the WSR-88D (Weather Surveillance Radar 1988 Doppler) operational network to dual-polarimetry and a similar process having already taken place or ongoing for many private sector radars, dual-polarimetric radar signatures of tornado debris promise the potential to assist in the situational awareness of government and private sector forecasters and emergency managers during tornadic events. As such, a companion abstract (Schultz et al.) also submitted to this conference explores The use of dual-polarimetric tornadic debris

Tenth Biennial Coherent Laser Radar Technology and Applications Conference

NASA Technical Reports Server (NTRS)

Kavaya, Michael J. (Compiler)

1999-01-01

The tenth conference on coherent laser radar technology and applications is the latest in a series beginning in 1980 which provides a forum for exchange of information on recent events current status, and future directions of coherent laser radar (or lidar or lader) technology and applications. This conference emphasizes the latest advancement in the coherent laser radar field, including theory, modeling, components, systems, instrumentation, measurements, calibration, data processing techniques, operational uses, and comparisons with other remote sensing technologies.

Sea-air boundary meteorological sensor

NASA Astrophysics Data System (ADS)

Barbosa, Jose G.

2015-05-01

The atmospheric environment can significantly affect radio frequency and optical propagation. In the RF spectrum refraction and ducting can degrade or enhance communications and radar coverage. Platforms in or beneath refractive boundaries can exploit the benefits or suffer the effects of the atmospheric boundary layers. Evaporative ducts and surface-base ducts are of most concern for ocean surface platforms and evaporative ducts are almost always present along the sea-air interface. The atmospheric environment also degrades electro-optical systems resolution and visibility. The atmospheric environment has been proven not to be uniform and under heterogeneous conditions substantial propagation errors may be present for large distances from homogeneous models. An accurate and portable atmospheric sensor to profile the vertical index of refraction is needed for mission planning, post analysis, and in-situ performance assessment. The meteorological instrument used in conjunction with a radio frequency and electro-optical propagation prediction tactical decision aid tool would give military platforms, in real time, the ability to make assessments on communication systems propagation ranges, radar detection and vulnerability ranges, satellite communications vulnerability, laser range finder performance, and imaging system performance predictions. Raman lidar has been shown to be capable of measuring the required atmospheric parameters needed to profile the atmospheric environment. The atmospheric profile could then be used as input to a tactical decision aid tool to make propagation predictions.

Remote sensing observing systems of the Meteorological Service of Catalonia (SMC): application to thunderstorm surveillance

NASA Astrophysics Data System (ADS)

Argemí, O.; Bech, J.; Pineda, N.; Rigo, T.

2009-09-01

Remote sensing observing systems of the Meteorological Service of Catalonia (SMC) have been upgraded during the last years with newer technologies and enhancements. Recent changes on the weather radar network have been motivated to improve precipitation estimates by radar as well as meteorological surveillance in the area of Catalonia. This region has approximately 32,000 square kilometres and is located in the NE of Spain, limited by the Pyrenees to the North (with mountains exceeding 3000 m) and by the Mediterranean Sea to the East and South. In the case of the total lightning (intra-cloud and cloud-to-ground lightning) detection system, the current upgrades will assure a better lightning detection efficiency and location accuracy. Both upgraded systems help to enhance the tracking and the study of thunderstorm events. Initially, the weather radar network was designed to cover the complex topography of Catalonia and surrounding areas to support the regional administration, which includes civil protection and water authorities. The weather radar network was upgraded in 2008 with the addition of a new C-band Doppler radar system, which is located in the top of La Miranda Mountain (Tivissa) in the southern part of Catalonia enhancing the coverage, particularly to the South and South-West. Technically the new radar is very similar to the last one installed in 2003 (Creu del Vent radar), using a 4 m antenna (i.e., 1 degree beam width), a Vaisala-Sigmet RVP-8 digital receiver and processor and a low power transmitter using a Travelling Wave Tube (TWT) amplifier. This design allows using pulse-compression techniques to enhance radial resolution and sensitivity. Currently, the SMC is upgrading its total lightning detection system, operational since 2003. While a fourth sensor (Amposta) was added last year to enlarge the system coverage, all sensors and central processor will be upgraded this year to the new Vaisala’s total lightning location technology. The new LS8000

Study of meteorological parameters over the central Himalayan region using balloon-borne sensor

NASA Astrophysics Data System (ADS)

Shrivastava, Rahul; Naja, Manish; Gwal, A. K.

2013-06-01

In the present paper we accumulate the recent advances in atmospheric research by analyzing meteorological data. We have calculated meteorological parameters over the central Himalayan region at Nainital (longitude 79.45□ E, latitude 29.35□N). It is a high altitude place (1951 meters) which is very useful for such type of measurement. We have done our work on meteorological parameters in GVAX (Ganges Valley Aerosol Experiment) project. It was an American-Indo project which was use to capture pre-monsoon to post-monsoon conditions to establish a comprehensive baseline for advancements in the study of the effects of Atmospheric conditions of the Ganges Valley. The Balloon Borne Sounding System (BBSS) technique was also used for in-situ measurements of meteorological parameters.

Hands-On Learning Modules for Interdisciplinary Environments: An Example with a Focus on Weather Radar Applications

ERIC Educational Resources Information Center

Chilson, P. B.; Yeary, M. B.

2012-01-01

Learning modules provide an effective means of encouraging cognition and active learning. This paper discusses several such modules that have been developed within a course on weather radar applications intended for students from Electrical Engineering and Meteorology. The modules were designed both to promote interdisciplinary exchange between…

Penn State Radar Systems: Implementation and Observations

NASA Astrophysics Data System (ADS)

Urbina, J. V.; Seal, R.; Sorbello, R.; Kuyeng, K.; Dyrud, L. P.

2014-12-01

Software Defined Radio/Radar (SDR) platforms have become increasingly popular as researchers, hobbyists, and military seek more efficient and cost-effective means for radar construction and operation. SDR platforms, by definition, utilize a software-based interface for configuration in contrast to traditional, hard-wired platforms. In an effort to provide new and improved radar sensing capabilities, Penn State has been developing advanced instruments and technologies for future radars, with primary objectives of making such instruments more capable, portable, and more cost effective. This paper will describe the design and implementation of two low-cost radar systems and their deployment in ionospheric research at both low and mid-latitudes. One radar has been installed near Penn State campus, University Park, Pennsylvania (77.97°W, 40.70°N), to make continuous meteor observations and mid-latitude plasma irregularities. The second radar is being installed in Huancayo (12.05°S, -75.33°E), Peru, which is capable of detecting E and F region plasma irregularities as well as meteor reflections. In this paper, we examine and compare the diurnal and seasonal variability of specular, non- specular, and head-echoes collected with these two new radar systems and discuss sampling biases of each meteor observation technique. We report our current efforts to validate and calibrate these radar systems with other VHF radars such as Jicamarca and SOUSY. We also present the general characteristics of continuous measurements of E-region and F-region coherent echoes using these modern radar systems and compare them with coherent radar events observed at other geographic mid-latitude radar stations.

Advanced Packaging Materials and Techniques for High Power TR Module: Standard Flight vs. Advanced Packaging

NASA Technical Reports Server (NTRS)

Hoffman, James Patrick; Del Castillo, Linda; Miller, Jennifer; Jenabi, Masud; Hunter, Donald; Birur, Gajanana

2011-01-01

The higher output power densities required of modern radar architectures, such as the proposed DESDynI [Deformation, Ecosystem Structure, and Dynamics of Ice] SAR [Synthetic Aperture Radar] Instrument (or DSI) require increasingly dense high power electronics. To enable these higher power densities, while maintaining or even improving hardware reliability, requires advances in integrating advanced thermal packaging technologies into radar transmit/receive (TR) modules. New materials and techniques have been studied and compared to standard technologies.

Investigation of new radar-data-reduction techniques used to determine drag characteristics of a free-flight vehicle

NASA Technical Reports Server (NTRS)

Woodbury, G. E.; Wallace, J. W.

1974-01-01

An investigation was conducted of new techniques used to determine the complete transonic drag characteristics of a series of free-flight drop-test models using principally radar tracking data. The full capabilities of the radar tracking and meteorological measurement systems were utilized. In addition, preflight trajectory design, exact kinematic equations, and visual-analytical filtering procedures were employed. The results of this study were compared with the results obtained from analysis of the onboard, accelerometer and pressure sensor data of the only drop-test model that was instrumented. The accelerometer-pressure drag curve was approximated by the radar-data drag curve. However, a small amplitude oscillation on the latter curve precluded a precise definition of its drag rise.

Reflectivity retrieval in a networked radar environment

NASA Astrophysics Data System (ADS)

Lim, Sanghun

Monitoring of precipitation using a high-frequency radar system such as X-band is becoming increasingly popular due to its lower cost compared to its counterpart at S-band. Networks of meteorological radar systems at higher frequencies are being pursued for targeted applications such as coverage over a city or a small basin. However, at higher frequencies, the impact of attenuation due to precipitation needs to be resolved for successful implementation. In this research, new attenuation correction algorithms are introduced to compensate the attenuation impact due to rain medium. In order to design X-band radar systems as well as evaluate algorithm development, it is useful to have simultaneous X-band observation with and without the impact of path attenuation. One way to obtain that data set is through theoretical models. Methodologies for generating realistic range profiles of radar variables at attenuating frequencies such as X-band for rain medium are presented here. Fundamental microphysical properties of precipitation, namely size and shape distribution information, are used to generate realistic profiles of X-band starting with S-band observations. Conditioning the simulation from S-band radar measurements maintains the natural distribution of microphysical parameters associated with rainfall. In this research, data taken by the CSU-CHILL radar and the National Center for Atmospheric Research S-POL radar are used to simulate X-band radar variables. Three procedures to simulate the radar variables at X-band and sample applications are presented. A new attenuation correction algorithm based on profiles of reflectivity, differential reflectivity, and differential propagation phase shift is presented. A solution for specific attenuation retrieval in rain medium is proposed that solves the integral equations for reflectivity and differential reflectivity with cumulative differential propagation phase shift constraint. The conventional rain profiling algorithms

A Multi-Frequency Wide-Swath Spaceborne Cloud and Precipitation Imaging Radar

NASA Technical Reports Server (NTRS)

Li, Lihua; Racette, Paul; Heymsfield, Gary; McLinden, Matthew; Venkatesh, Vijay; Coon, Michael; Perrine, Martin; Park, Richard; Cooley, Michael; Stenger, Pete;

Compendium of Lecture Notes for Training Class III Meteorological Personnel.

ERIC Educational Resources Information Center

Retallack, B. J.

This compendium of lecture notes provides a course of study for persons who may be involved in a variety of specialized meteorological tasks. The course is considered to be advanced and assumes students have had introductory experiences in meteorology and earth science (covered in a similar compendium). The material is presented in seven units…

TOPEX Project Radar Altimeter Development Requirements and Specifications, Version 6.0

NASA Technical Reports Server (NTRS)

Rossi, Laurence C.

2003-01-01

This document provides the guidelines by which the TOPEX Radar Altimeter hardware development effort for the TOPEX flight project shall be implemented and conducted. The conduct of this activity shall take maximum advantage of the efforts expended during the TOPEX Radar Altimeter Advanced Technology Model development program and other related Radar Altimeter development efforts. This document complies with the TOPEX Project Office document 633-420 (D-2218), entitled, "TOPEX Project Requirements and Constraints for the NASA Radar Altimeter" dated December 1987.

Advanced Differential Radar Interferometry (A-DInSAR) as integrative tool for a structural geological analysis

NASA Astrophysics Data System (ADS)

Crippa, B.; Calcagni, L.; Rossi, G.; Sternai, P.

2009-04-01

Advanced Differential SAR interferometry (A-DInSAR) is a technique monitoring large-coverage surface deformations using a stack of interferograms generated from several complex SLC SAR images, acquired over the same target area at different times. In this work are described the results of a procedure to calculate terrain motion velocity on highly correlated pixels (E. Biescas, M. Crosetto, M. Agudo, O. Monserrat e B. Crippa: Two Radar Interferometric Approaches to Monitor Slow and Fast Land Deformation, 2007) in two area Gemona - Friuli, Northern Italy, Pollino - Calabria, Southern Italy, and, furthermore, are presented some consideration, based on successful examples of the present analysis. The choice of these pixels whose displacement velocity is calculated depends on the dispersion index value (DA) or using coherence values along the stack interferograms. A-DInSAR technique allows to obtain highly reliable velocity values of the vertical displacement. These values concern the movement of minimum surfaces of about 80m2 at the maximum resolution and the minimum velocity that can be recognized is of the order of mm/y. Because of the high versatility of the technology, because of the large dimensions of the area that can be analyzed (of about 10000Km2) and because of the high precision and reliability of the results obtained, we think it is possible to exploit radar interferometry to obtain some important information about the structural context of the studied area, otherwise very difficult to recognize. Therefore we propose radar interferometry as a valid investigation tool whose results must be considered as an important integration of the data collected in fieldworks.

Using phase for radar scatterer classification

NASA Astrophysics Data System (ADS)

Moore, Linda J.; Rigling, Brian D.; Penno, Robert P.; Zelnio, Edmund G.

2017-04-01

Traditional synthetic aperture radar (SAR) systems tend to discard phase information of formed complex radar imagery prior to automatic target recognition (ATR). This practice has historically been driven by available hardware storage, processing capabilities, and data link capacity. Recent advances in high performance computing (HPC) have enabled extremely dense storage and processing solutions. Therefore, previous motives for discarding radar phase information in ATR applications have been mitigated. First, we characterize the value of phase in one-dimensional (1-D) radar range profiles with respect to the ability to correctly estimate target features, which are currently employed in ATR algorithms for target discrimination. These features correspond to physical characteristics of targets through radio frequency (RF) scattering phenomenology. Physics-based electromagnetic scattering models developed from the geometrical theory of diffraction are utilized for the information analysis presented here. Information is quantified by the error of target parameter estimates from noisy radar signals when phase is either retained or discarded. Operating conditions (OCs) of signal-tonoise ratio (SNR) and bandwidth are considered. Second, we investigate the value of phase in 1-D radar returns with respect to the ability to correctly classify canonical targets. Classification performance is evaluated via logistic regression for three targets (sphere, plate, tophat). Phase information is demonstrated to improve radar target classification rates, particularly at low SNRs and low bandwidths.

Thunderstorm monitoring with VLF network and super dense meteorological observation system

NASA Astrophysics Data System (ADS)

Takahashi, Yukihiro; Sato, Mitsuteru

2015-04-01

It's not easy to understand the inside structure and developing process of thunderstorm only with existing meteorological instruments since its horizontal extent of the storm cell is sometimes smaller than an order of 10 km while one of the densest ground network in Japan, AMEDAS, consists of sites located every 17 km in average and the resolution of meteorological radar is 1-2 km in general. Even the X-band radar realizes the resolution of 250 m or larger. Here we suggest a thunderstorm monitoring system consisting of the network of VLF radio wave receivers and the super dense meteorological observation system with simple and low cost plate-type sensors that can be used for measurement both of raindrop and vertical electric field change caused by cloud-to-ground lightning discharge, adding to basic equipments for meteorological measurements. The plate-type sensor consists of two aluminum plates with a diameter of 10-20 cm. We carried out an observation campaign in summer of 2013 in the foothills of Mt. Yastugatake, Yamanashi and Nagano prefectures in Japan, installing 6 plate-type sensors at a distance of about 4 km. Horizontal location, height and charge amount of each lightning discharge are estimated successfully based on the information of electric field changes at several observing sites. Moreover, it was found that the thunderstorm has a very narrow structure smaller than 300 m that cannot be measured by any other ways, counting the positive and negative pulses caused by attachment of raindrop to the sensor plate, respectively. We plan to construct a new super dense observation network in the north Kanto region, Japan, where the lightning activity is most prominent in summer Japan and surrounded by our VLF systems developed for detecting sferics from lightning discharge, distributing more than several tens of sensors at every 4 km or shorter, such as an order of 100 m at minimum. This kind of new type network will reveal the unknown fine structures of

Kinematic and Hydrometer Data Products from Scanning Radars during MC3E

DOE Data Explorer

matthews, Alyssa; Dolan, Brenda; Rutledge, Steven

2016-02-29

Recently the Radar Meteorology Group at Colorado State University has completed major case studies of some top cases from MC3E including 25 April, 20 May and 23 May 2011. A discussion on the analysis methods as well as radar quality control methods is included. For each case, a brief overview is first provided. Then, multiple Doppler (using available X-SAPR and C-SAPR data) analyses are presented including statistics on vertical air motions, sub-divided by convective and stratiform precipitation. Mean profiles and CFAD's of vertical motion are included to facilitate comparison with ASR model simulations. Retrieved vertical motion has also been verified with vertically pointing profiler data. Finally for each case, hydrometeor types are included derived from polarimetric radar observations. The latter can be used to provide comparisons to model-generated hydrometeor fields. Instructions for accessing all the data fields are also included. The web page can be found at: http://radarmet.atmos.colostate.edu/mc3e/research/

Effect of radar rainfall time resolution on the predictive capability of a distributed hydrologic model

NASA Astrophysics Data System (ADS)

Atencia, A.; Llasat, M. C.; Garrote, L.; Mediero, L.

2010-10-01

The performance of distributed hydrological models depends on the resolution, both spatial and temporal, of the rainfall surface data introduced. The estimation of quantitative precipitation from meteorological radar or satellite can improve hydrological model results, thanks to an indirect estimation at higher spatial and temporal resolution. In this work, composed radar data from a network of three C-band radars, with 6-minutal temporal and 2 × 2 km2 spatial resolution, provided by the Catalan Meteorological Service, is used to feed the RIBS distributed hydrological model. A Window Probability Matching Method (gage-adjustment method) is applied to four cases of heavy rainfall to improve the observed rainfall sub-estimation in both convective and stratiform Z/R relations used over Catalonia. Once the rainfall field has been adequately obtained, an advection correction, based on cross-correlation between two consecutive images, was introduced to get several time resolutions from 1 min to 30 min. Each different resolution is treated as an independent event, resulting in a probable range of input rainfall data. This ensemble of rainfall data is used, together with other sources of uncertainty, such as the initial basin state or the accuracy of discharge measurements, to calibrate the RIBS model using probabilistic methodology. A sensitivity analysis of time resolutions was implemented by comparing the various results with real values from stream-flow measurement stations.

Space Radar Laboratory photos taken at Kennedy Space Center

NASA Image and Video Library

1994-03-18

S94-30393 (23 Nov 1993) --- In the south level IV stand of the Operations and Checkout Building low bay, the Space Radar Laboratory -1 (SRL-1) antenna is being placed atop a pallet which holds the antenna electronics. SRL-1 is scheduled to fly on Space Shuttle mission STS-59 next year. It is comprised of two different imaging radars, the Spaceborne Imaging Radar-C (SIR-C) and the X-band Synthetic Aperture Radar (X-SAR). These radars are the most advanced of their kind to fly in space to date, and will allow scientists to make highly detailed studies of the Earth's surface on a global scale. An Interface Verification Test of the antenna and a Mission Sequence Test will be performed on the fully assembled SRL-1 later this month.

Shuttle imaging radar-C science plan

NASA Technical Reports Server (NTRS)

1986-01-01

The Shuttle Imaging Radar-C (SIR-C) mission will yield new and advanced scientific studies of the Earth. SIR-C will be the first instrument to simultaneously acquire images at L-band and C-band with HH, VV, HV, or VH polarizations, as well as images of the phase difference between HH and VV polarizations. These data will be digitally encoded and recorded using onboard high-density digital tape recorders and will later be digitally processed into images using the JPL Advanced Digital SAR Processor. SIR-C geologic studies include cold-region geomorphology, fluvial geomorphology, rock weathering and erosional processes, tectonics and geologic boundaries, geobotany, and radar stereogrammetry. Hydrology investigations cover arid, humid, wetland, snow-covered, and high-latitude regions. Additionally, SIR-C will provide the data to identify and map vegetation types, interpret landscape patterns and processes, assess the biophysical properties of plant canopies, and determine the degree of radar penetration of plant canopies. In oceanography, SIR-C will provide the information necessary to: forecast ocean directional wave spectra; better understand internal wave-current interactions; study the relationship of ocean-bottom features to surface expressions and the correlation of wind signatures to radar backscatter; and detect current-system boundaries, oceanic fronts, and mesoscale eddies. And, as the first spaceborne SAR with multi-frequency, multipolarization imaging capabilities, whole new areas of glaciology will be opened for study when SIR-C is flown in a polar orbit.

The study of fresh-water lake ice using multiplexed imaging radar

USGS Publications Warehouse

Leonard, Bryan M.; Larson, R.W.

1975-01-01

The study of ice in the upper Great Lakes, both from the operational and the scientific points of view, is receiving continued attention. Quantitative and qualitative field work is being conducted to provide the needed background for accurate interpretation of remotely sensed data. The data under discussion in this paper were obtained by a side-looking multiplexed airborne radar (SLAR) supplemented with ground-truth data.Because of its ability to penetrate adverse weather, radar is an especially important instrument for monitoring ice in the upper Great Lakes. It has previously been shown that imaging radars can provide maps of ice cover in these areas. However, questions concerning both the nature of the surfaces reflecting radar energy and the interpretation of the radar imagery continually arise.Our analysis of ice in Whitefish Bay (Lake Superior) indicates that the combination of the ice/water interlace and the ice/air interface is the major contributor to the radar backscatter as seen on the imagery At these frequencies the ice has a very low relative dielectric permittivity (< 3.0) and a low loss tangent Thus, this ice is somewhat transparent to the energy used by the imaging SLAR system. The ice types studied include newly formed black ice, pancake ice, and frozen and consolidated pack and brash ice.Although ice thickness cannot be measured directly from the received signals, it is suspected that by combining the information pertaining to radar backscatter with data on the meteorological and sea-state history of the area, together with some basic ground truth, better estimates of the ice thickness may be provided. In addition, certain ice features (e.g. ridges, ice-foot formation, areas of brash ice) may be identified with reasonable confidence. There is a continued need for additional ground work to verify the validity of imaging radars for these types of interpretations.

Multimission airborne radar for the 1990s

NASA Astrophysics Data System (ADS)

Robinson, Thomas H.

1986-07-01

The continuing trend towards the development and production of aircraft capable of multiple missions indicates that future airborne radars must provide a broad spectrum of air-to-air and air-to-ground modes. This paper investigates the modal and functional requirements of a multimode radar projected for the mid-1990s period. The paper is divided into two sections. In the first, the multimission capabilities of current radars are presented to establish trends and capabilities. In the second, the requirements of the next generation system are established. Current multimode radars lay the basis for future systems. The experience gained on the APG-65 and APG-63/70 radars is presented and conclusions are drawn regarding their impact on future system requirements. Not only are modes and performance reviewed for these radars but also their system architecture. The discussion starts with the APG-65 radar which is the first true multimission radar with programmable signal and data processing. Following this, the evolution of the APG-63 radar, culminating with the most recent upgrading resulting in redesignation of APG-70, is presented. The incorporation of air-to-ground capabilities in the APG-70, resulting from the Dual Role Fighter program, is reviewed. Results from the Advanced Fighter Capabilities Demonstration program are presented showing how high resolution SAR was incorporated into a full weapon delivery solution. The specific radar requirements for the next decade radar system are developed. This development is done in two parts. First, mode requirements are synthesized for air superiority, navigation and strike/interdiction operation. This includes low altitude penetration requirements and a review of radar timeline constraints which arise. Second, the fundamental functional requirements needed to implement the mode requirements are explored. Architectural issues and their impact on reliability and sustainability are also considered.

Ionospheric footprint of magnetosheathlike particle precipitation observed by an incoherent scatter radar

NASA Technical Reports Server (NTRS)

Watermann, Jurgen; Lummerzheim, Dirk; De La Beaujardiere, Odile; Newell, Patrick T.; Rich, Frederic J.

1994-01-01

We have examined Sondrestrom incoherent scatter radar observations of ionospheric plasma density and temperature distributions and measurements of F region ion drifts that were made during a prenoon pass of the Defense Meteorological Satellite Program (DMSP)-F7 satellite through the radar field of view. The spacecraft traversed a region of intense electron precipitation with a characteristic energy below approximately 200 eV. Particles with such low characteristic energies are believed to be directly or indirectly of magnetosheath origin. The precipitation region had a width about 2 deg invariant latitude and covered the low-latitude boundary layer (LLBL), the cusp, and the equatorward section of the plasma mantle (PM). The corotating radar observed a patch of enhanced electron density and elevated electron temperature in the F2 region between about 10.5 and 12 magnetic local time in the same invariant latitude range where DMSP-F7 detected the soft-electron flux. The ion drift pattern, also obtained by radar, shows that it is unlikely that the plasma patch was produced by solar radiation and advected into the radar field of view. We suggest that the radar observed modifications of the ionospheric plasma distribution, which resulted from direct entry of magnetosheath electrons into the magnetosphere and down to ionospheric altitudes. Model calculations of the ionospheric response to the observed electron precipitation support our interpretation. The spectral characteristics of the electron flux in the LLBL, cusp, and equatorward section of the PM were in this case too similar to allow to distinguish between them by using incoherent scatter radar measurements only.

COMBINING A MONOSTATIC SODAR WITH A RADAR WIND PROFILER AND RASS IN A POWER PLANT POLLUTION STUDY

EPA Science Inventory

A single-beam monostatic sodar, radar wind profiler, radio acoustic sounding system (RASS), and in situ sensors mounted on a 100-m tower were used to acquire meteorological data in the vicinity of a coal burning power plant in a northern Thailand valley. hese data were used to ex...

Analysis of the Meteorology Associated with the 1997 NASA Glenn Twin Otter Icing Events

NASA Technical Reports Server (NTRS)

Bernstein, Ben C.

2000-01-01

This part of the document contains an analysis of the meteorology associated with the premier icing encounters from the January-March 1997 NASA Twin Otter dataset. The purpose of this analysis is to provide a meteorological context for the aircraft data collected during these flights. For each case, the following data elements are presented: (1) A detailed discussion of the Twin Otter encounter, including locations, liquid water contents, temperatures and microphysical makeup of the clouds and precipitation aloft, (2) Upper-air charts, providing hand-analyzed locations of lows, troughs, ridges, saturated/unsaturated air, temperatures, warm/cold advection, and jet streams, (3) Balloon-borne soundings, providing vertical profiles of temperature, moisture and winds, (4) Infrared satellite data, providing cloud locations and cloud top temperature, (5) 3-hourly surface charts, providing hand-analyzed locations of lows, highs, fronts, precipitation (including type) and cloud cover, (6) Hourly plots of icing pilot reports, providing the icing intensity, icing type, icing altitudes and aircraft type, (7) Hourly, regional radar mosaics, providing fine resolution of the locations of precipitation (including intensity and type), pilot reports of icing (including intensity and type), surface observations of precipitation type and Twin Otter tracks for a one hour window centered on the time of the radar data, and (8) Plots of data from individual NEXRAD radars at times and elevation angles that have been matched to Twin Otter flight locations. Outages occurred in nearly every dataset at some point. All relevant data that was available is presented here. All times are in UTC and all heights are in feet above mean sea level (MSL).

Science Results from the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR): Progress Report

NASA Technical Reports Server (NTRS)

Evans, Diane L. (Editor); Plaut, Jeffrey (Editor)

1996-01-01

The Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) is the most advanced imaging radar system to fly in Earth orbit. Carried in the cargo bay of the Space Shuttle Endeavour in April and October of 1994, SIR-C/X-SAR simultaneously recorded SAR data at three wavelengths (L-, C-, and X-bands; 23.5, 5.8, and 3.1 cm, respectively). The SIR-C/X-SAR Science Team consists of 53 investigator teams from more than a dozen countries. Science investigations were undertaken in the fields of ecology, hydrology, ecology, and oceanography. This report contains 44 investigator team reports and several additional reports from coinvestigators and other researchers.

Support of imaging radar for the shuttle system and subsystem definition study, phase 2

NASA Technical Reports Server (NTRS)

1974-01-01

An orbital microwave imaging radar system suggested for use in conjunction with the space shuttle is presented. Several applications of the system are described, including agriculture, meteorology, terrain analysis, various types of mapping, petroleum and mineral exploration, oil spill detection and sea and lake ice monitoring. The design criteria, which are based on the requirements of the above applications, are discussed.

Remote Sensing Global Surface Air Pressure Using Differential Absorption BArometric Radar (DiBAR)

NASA Technical Reports Server (NTRS)

Lin, Bing; Harrah, Steven; Lawrence, Wes; Hu, Yongxiang; Min, Qilong

2016-01-01

Tropical storms and severe weathers are listed as one of core events that need improved observations and predictions in World Meteorological Organization and NASA Decadal Survey (DS) documents and have major impacts on public safety and national security. This effort tries to observe surface air pressure, especially over open seas, from space using a Differential-absorption BArometric Radar (DiBAR) operating at the 50-55 gigahertz O2 absorption band. Air pressure is among the most important variables that affect atmospheric dynamics, and currently can only be measured by limited in-situ observations over oceans. Analyses show that with the proposed space radar the errors in instantaneous (averaged) pressure estimates can be as low as approximately 4 millibars (approximately 1 millibar under all weather conditions). With these sea level pressure measurements, the forecasts of severe weathers such as hurricanes will be significantly improved. Since the development of the DiBAR concept about a decade ago, NASA Langley DiBAR research team has made substantial progress in advancing the concept. The feasibility assessment clearly shows the potential of sea surface barometry using existing radar technologies. The team has developed a DiBAR system design, fabricated a Prototype-DiBAR (P-DiBAR) for proof-of-concept, conducted lab, ground and airborne P-DiBAR tests. The flight test results are consistent with the instrumentation goals. Observational system simulation experiments for space DiBAR performance based on the existing DiBAR technology and capability show substantial improvements in tropical storm predictions, not only for the hurricane track and position but also for the hurricane intensity. DiBAR measurements will lead us to an unprecedented level of the prediction and knowledge on global extreme weather and climate conditions.

Using Radar, Lidar, and Radiometer measurements to Classify Cloud Type and Study Middle-Level Cloud Properties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Zhien

2010-06-29

The project is mainly focused on the characterization of cloud macrophysical and microphysical properties, especially for mixed-phased clouds and middle level ice clouds by combining radar, lidar, and radiometer measurements available from the ACRF sites. First, an advanced mixed-phase cloud retrieval algorithm will be developed to cover all mixed-phase clouds observed at the ACRF NSA site. The algorithm will be applied to the ACRF NSA observations to generate a long-term arctic mixed-phase cloud product for model validations and arctic mixed-phase cloud processes studies. To improve the representation of arctic mixed-phase clouds in GCMs, an advanced understanding of mixed-phase cloud processesmore » is needed. By combining retrieved mixed-phase cloud microphysical properties with in situ data and large-scale meteorological data, the project aim to better understand the generations of ice crystals in supercooled water clouds, the maintenance mechanisms of the arctic mixed-phase clouds, and their connections with large-scale dynamics. The project will try to develop a new retrieval algorithm to study more complex mixed-phase clouds observed at the ACRF SGP site. Compared with optically thin ice clouds, optically thick middle level ice clouds are less studied because of limited available tools. The project will develop a new two wavelength radar technique for optically thick ice cloud study at SGP site by combining the MMCR with the W-band radar measurements. With this new algorithm, the SGP site will have a better capability to study all ice clouds. Another area of the proposal is to generate long-term cloud type classification product for the multiple ACRF sites. The cloud type classification product will not only facilitates the generation of the integrated cloud product by applying different retrieval algorithms to different types of clouds operationally, but will also support other research to better understand cloud properties and to validate model

Radar Sensing for Intelligent Vehicles in Urban Environments

PubMed Central

Reina, Giulio; Johnson, David; Underwood, James

2015-01-01

Radar overcomes the shortcomings of laser, stereovision, and sonar because it can operate successfully in dusty, foggy, blizzard-blinding, and poorly lit scenarios. This paper presents a novel method for ground and obstacle segmentation based on radar sensing. The algorithm operates directly in the sensor frame, without the need for a separate synchronised navigation source, calibration parameters describing the location of the radar in the vehicle frame, or the geometric restrictions made in the previous main method in the field. Experimental results are presented in various urban scenarios to validate this approach, showing its potential applicability for advanced driving assistance systems and autonomous vehicle operations. PMID:26102493

Radar Sensing for Intelligent Vehicles in Urban Environments.

PubMed

Reina, Giulio; Johnson, David; Underwood, James

2015-06-19

Radar overcomes the shortcomings of laser, stereovision, and sonar because it can operate successfully in dusty, foggy, blizzard-blinding, and poorly lit scenarios. This paper presents a novel method for ground and obstacle segmentation based on radar sensing. The algorithm operates directly in the sensor frame, without the need for a separate synchronised navigation source, calibration parameters describing the location of the radar in the vehicle frame, or the geometric restrictions made in the previous main method in the field. Experimental results are presented in various urban scenarios to validate this approach, showing its potential applicability for advanced driving assistance systems and autonomous vehicle operations.

Navy Needs to Establish Effective Metrics to Achieve Desired Outcomes for SPY1 Radar Sustainment (Redacted)

DTIC Science & Technology

2016-08-01

a series on SPY-1 radar spare parts. The SPY-1 radar is an advanced , automatic detect and track radar system . The SPY-1 radar is one of 13 major...the AEGIS Weapon System could be adversely impacted if parts needed to maintain the SPY-1 radars are not transported to the warfighters when...for SPY-1 Radar Sustainment (Report No. DODIG-2016-116) We are providing this report for review and comment. Naval Supply Systems Command Weapon

Using Remote Sensing and Radar Meteorological Data to Support Watershed Assessments Comprising Integrated Environmental Modeling

EPA Science Inventory

Meteorological (MET) data required by watershed assessments comprising Integrated Environmental Modeling (IEM) traditionally have been provided by land-based weather (gauge) stations, although these data may not be the most appropriate for adequate spatial and temporal resolution...

Radar-derived quantitative precipitation estimation in complex terrain over the eastern Tibetan Plateau

NASA Astrophysics Data System (ADS)

Gou, Yabin; Ma, Yingzhao; Chen, Haonan; Wen, Yixin

2018-05-01

Quantitative precipitation estimation (QPE) is one of the important applications of weather radars. However, in complex terrain such as Tibetan Plateau, it is a challenging task to obtain an optimal Z-R relation due to the complex spatial and temporal variability in precipitation microphysics. This paper develops two radar QPE schemes respectively based on Reflectivity Threshold (RT) and Storm Cell Identification and Tracking (SCIT) algorithms using observations from 11 Doppler weather radars and 3264 rain gauges over the Eastern Tibetan Plateau (ETP). These two QPE methodologies are evaluated extensively using four precipitation events that are characterized by different meteorological features. Precipitation characteristics of independent storm cells associated with these four events, as well as the storm-scale differences, are investigated using short-term vertical profile of reflectivity (VPR) clusters. Evaluation results show that the SCIT-based rainfall approach performs better than the simple RT-based method for all precipitation events in terms of score comparison using validation gauge measurements as references. It is also found that the SCIT-based approach can effectively mitigate the local error of radar QPE and represent the precipitation spatiotemporal variability better than the RT-based scheme.

Quality Control and Calibration of the Dual-Polarization Radar at Kwajalein, RMI

NASA Technical Reports Server (NTRS)

Marks, David A.; Wolff, David B.; Carey, Lawrence D.; Tokay, Ali

2010-01-01

Weather radars, recording information about precipitation around the globe, will soon be significantly upgraded. Most of today s weather radars transmit and receive microwave energy with horizontal orientation only, but upgraded systems have the capability to send and receive both horizontally and vertically oriented waves. These enhanced "dual-polarimetric" (DP) radars peer into precipitation and provide information on the size, shape, phase (liquid / frozen), and concentration of the falling particles (termed hydrometeors). This information is valuable for improved rain rate estimates, and for providing data on the release and absorption of heat in the atmosphere from condensation and evaporation (phase changes). The heating profiles in the atmosphere influence global circulation, and are a vital component in studies of Earth s changing climate. However, to provide the most accurate interpretation of radar data, the radar must be properly calibrated and data must be quality controlled (cleaned) to remove non-precipitation artifacts; both of which are challenging tasks for today s weather radar. The DP capability maximizes performance of these procedures using properties of the observed precipitation. In a notable paper published in 2005, scientists from the Cooperative Institute for Mesoscale Meteorological Studies (CIMMS) at the University of Oklahoma developed a method to calibrate radars using statistically averaged DP measurements within light rain. An additional publication by one of the same scientists at the National Severe Storms Laboratory (NSSL) in Norman, Oklahoma introduced several techniques to perform quality control of radar data using DP measurements. Following their lead, the Topical Rainfall Measuring Mission (TRMM) Satellite Validation Office at NASA s Goddard Space Flight Center has fine-tuned these methods for specific application to the weather radar at Kwajalein Island in the Republic of the Marshall Islands, approximately 2100 miles

Development and Testing of the VAHIRR Radar Product

NASA Technical Reports Server (NTRS)

Barrett, Joe III; Miller, Juli; Charnasky, Debbie; Gillen, Robert; Lafosse, Richard; Hoeth, Brian; Hood, Doris; McNamara, Todd

2008-01-01

Lightning Launch Commit Criteria (LLCC) and Flight Rules (FR) are used for launches and landings at government and commercial spaceports. They are designed to avoid natural and triggered lightning strikes to space vehicles, which can endanger the vehicle, payload, and general public. The previous LLCC and FR were shown to be overly restrictive, potentially leading to costly launch delays and scrubs. A radar algorithm called Volume Averaged Height Integrated Radar Reflectivity (VAHIRR), along with new LLCC and FR for anvil clouds, were developed using data collected by the Airborne Field Mill II research program. VAHIRR is calculated at every horizontal position in the coverage area of the radar and can be displayed similar to a two-dimensional derived reflectivity product, such as composite reflectivity or echo tops. It is the arithmetic product of two quantities not currently generated by the Weather Surveillance Radar 1988 Doppler (WSR-88D): a volume average of the reflectivity measured in dBZ and the average cloud thickness based on the average echo top height and base height. This presentation will describe the VAHIRR algorithm, and then explain how the VAHIRR radar product was implemented and tested on a clone of the National Weather Service's (NWS) Open Radar Product Generator (ORPG-clone). The VAHIRR radar product was then incorporated into the Advanced Weather Interactive Processing System (AWIPS), to make it more convenient for weather forecasters to utilize. Finally, the reliability of the VAHIRR radar product was tested with real-time level II radar data from the WSR-88D NWS Melbourne radar.

Applications of Polarimetric Radar to the Hydrometeorology of Urban Floods in St. Louis

NASA Astrophysics Data System (ADS)

Chaney, M. M.; Smith, J. A.; Baeck, M. L.

2017-12-01

Predicting and responding to flash flooding requires accurate spatial and temporal representation of rainfall rates. The polarimetric upgrade of all US radars has led to optimism about more accurate rainfall rate estimation from the NEXRAD network of WSR-88D radars in the US. Previous work has proposed different algorithms to do so, but significant uncertainties remain, especially for extreme short-term rainfall rates that control flash floods in urban settings. We will examine the relationship between radar rainfall estimates and gage rainfall rates for a catalog of 30 storms in St. Louis during the period of polarimetric radar measurements, 2012-2016. The storms are selected to provide a large sample of extreme rainfall measurements at the 15-minute to 3-hour time scale. A network of 100 rain gages and a lack of orographic or coastal effects make St. Louis an interesting location to study these relationships. A better understanding of the relationships between polarimetric radar measurements and gage rainfall rates will aid in refining polarimetric radar rainfall algorithms, in turn helping hydrometeorologists predict flash floods and other hazards associated with severe rainfall. Given the fact that St. Louis contains some of the flashiest watersheds in the United States (Smith and Smith, 2015), it is an especially important urban area in which to have accurate, real-time rainfall data. Smith, Brianne K, and James A Smith. "The Flashiest Watersheds in the Contiguous United States." American Meteorological Society (2015): 2365-2381. Web.

Three-dimensional mosaicking of the South Korean radar network

NASA Astrophysics Data System (ADS)

Berenguer, Marc; Sempere-Torres, Daniel; Lee, GyuWon

2016-04-01

Dense radar networks offer the possibility of improved Quantitative Precipitation Estimation thanks to the additional information collected in the overlapping areas, which allows mitigating errors associated with the Vertical Profile of Reflectivity or path attenuation by intense rain. With this aim, Roca-Sancho et al. (2014) proposed a technique to generate 3-D reflectivity mosaics from the multiple radars of a network. The technique is based on an inverse method that simulates the radar sampling of the atmosphere considering the characteristics (location, frequency and scanning protocol) of each individual radar. This technique has been applied to mosaic the observations of the radar network of South Korea (composed of 14 S-band radars), and integrate the observations of the small X-band network which to be installed near Seoul in the framework of a project funded by the Korea Agency for Infrastructure Technology Advancement (KAIA). The evaluation of the generated 3-D mosaics has been done by comparison with point measurements (i.e. rain gauges and disdrometers) and with the observations of independent radars. Reference: Roca-Sancho, J., M. Berenguer, and D. Sempere-Torres (2014), An inverse method to retrieve 3D radar reflectivity composites, Journal of Hydrology, 519, 947-965, doi: 10.1016/j.jhydrol.2014.07.039.

Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) after nine years of operation: A summary

NASA Astrophysics Data System (ADS)

Orosei, R.; Jordan, R. L.; Morgan, D. D.; Cartacci, M.; Cicchetti, A.; Duru, F.; Gurnett, D. A.; Heggy, E.; Kirchner, D. L.; Noschese, R.; Kofman, W.; Masdea, A.; Plaut, J. J.; Seu, R.; Watters, T. R.; Picardi, G.

2015-07-01

Mars Express, the first European interplanetary mission, carries the Mars Advanced Radar for Subsurface and Ionosphere Sounding (MARSIS) to search for ice and water in the Martian subsurface. Developed by an Italian-US team, MARSIS transmits low-frequency, wide-band radio pulses penetrating below the surface and reflected by dielectric discontinuities linked to structural or compositional changes. MARSIS is also a topside ionosphere sounder, transmitting a burst of short, narrow-band pulses at different frequencies that are reflected by plasma with varying densities at different altitudes. The radar operates since July 2005, after the successful deployment of its 40 m antenna, acquiring data at altitudes lower than 1200 km. Subsurface sounding (SS) data are processed on board by stacking together a batch of echoes acquired at the same frequency. On ground, SS data are further processed by correlating the received echo with the transmitted waveform and compensating de-focusing caused by the dispersive ionosphere. Ground processing of active ionospheric sounding (AIS) data consists in the reconstruction of the electron density profile as a function of altitude. MARSIS observed the internal structure of Planum Boreum outlining the Basal Unit, an icy deposit lying beneath the North Polar Layered Deposits thought to have formed in an epoch in which climate was markedly different from the current one. The total volume of ice in polar layered deposits could be estimated, and parts of the Southern residual ice cap were revealed to consist of ≈ 10 m of CO2 ice. Radar properties of the Vastitas Borealis Formation point to the presence of large quantities of ice buried beneath the surface. Observations of the ionosphere revealed the complex interplay between plasma, crustal magnetic field and solar wind, contributing to space weather studies at Mars. The presence of three-dimensional plasma structures in the ionosphere was revealed for the first time. MARSIS could

Use of geostationary meteorological satellite images in convective rain estimation for flash-flood forecasting

NASA Astrophysics Data System (ADS)

Wardah, T.; Abu Bakar, S. H.; Bardossy, A.; Maznorizan, M.

2008-07-01

SummaryFrequent flash-floods causing immense devastation in the Klang River Basin of Malaysia necessitate an improvement in the real-time forecasting systems being used. The use of meteorological satellite images in estimating rainfall has become an attractive option for improving the performance of flood forecasting-and-warning systems. In this study, a rainfall estimation algorithm using the infrared (IR) information from the Geostationary Meteorological Satellite-5 (GMS-5) is developed for potential input in a flood forecasting system. Data from the records of GMS-5 IR images have been retrieved for selected convective cells to be trained with the radar rain rate in a back-propagation neural network. The selected data as inputs to the neural network, are five parameters having a significant correlation with the radar rain rate: namely, the cloud-top brightness-temperature of the pixel of interest, the mean and the standard deviation of the temperatures of the surrounding five by five pixels, the rate of temperature change, and the sobel operator that indicates the temperature gradient. In addition, three numerical weather prediction (NWP) products, namely the precipitable water content, relative humidity, and vertical wind, are also included as inputs. The algorithm is applied for the areal rainfall estimation in the upper Klang River Basin and compared with another technique that uses power-law regression between the cloud-top brightness-temperature and radar rain rate. Results from both techniques are validated against previously recorded Thiessen areal-averaged rainfall values with coefficient correlation values of 0.77 and 0.91 for the power-law regression and the artificial neural network (ANN) technique, respectively. An extra lead time of around 2 h is gained when the satellite-based ANN rainfall estimation is coupled with a rainfall-runoff model to forecast a flash-flood event in the upper Klang River Basin.

Real-time simulation of an airborne radar for overwater approaches

NASA Technical Reports Server (NTRS)

Karmarkar, J.; Clark, D.

1982-01-01

Software developed to provide a real time simulation of an airborne radar for overwater approaches to oil rig platforms is documented. The simulation is used to study advanced concepts for enhancement of airborne radar approaches (ARA) in order to reduce crew workload, improve approach tracking precision, and reduce weather minimums. ARA's are currently used for offshore helicopter operations to and from oil rigs.

Validation of Mode-S Meteorological Routine Air Report aircraft observations

NASA Astrophysics Data System (ADS)

Strajnar, B.

2012-12-01

The success of mesoscale data assimilation depends on the availability of three-dimensional observations with high spatial and temporal resolution. This paper describes an example of such observations, available through Mode-S air traffic control system composed of ground radar and transponders on board the aircraft. The meteorological information is provided by interrogation of a dedicated meteorological data register, called Meteorological Routine Air Report (MRAR). MRAR provides direct measurements of temperature and wind, but is only returned by a small fraction of aircraft. The quality of Mode-S MRAR data, collected at the Ljubljana Airport, Slovenia, is assessed by its comparison with AMDAR and high-resolution radiosonde data sets, which enable high- and low-level validation, respectively. The need for temporal smoothing of raw Mode-S MRAR data is also studied. The standard deviation of differences between smoothed Mode-S MRAR and AMDAR is 0.35°C for temperature, 0.8 m/s for wind speed and below 10 degrees for wind direction. The differences with respect to radiosondes are larger, with standard deviations of approximately 1.7°C, 3 m/s and 25 degrees for temperature, wind speed and wind direction, respectively. It is concluded that both wind and temperature observations from Mode-S MRAR are accurate and therefore potentially very useful for data assimilation in numerical weather prediction models.

Microbursts in JAWS depicted by Doppler radars, PAM, and aerial photographs

NASA Technical Reports Server (NTRS)

Fujita, T. T.; Wakimoto, R. M.

1983-01-01

Preliminary results obtained from the JAWS (Joint Airport Weather Studies) Project near Denver, Colorado in the spring and summer of 1982 using Doppler radar, PAM, and aerial photography are presented. The definitions of the microburst phenomenon are discussed, and statistics comparing NIMROD (Northern Illinois Meteorological Research On Downbursts) for the Midwest region are compared with JAWS for the High Plains region. Possible parent clouds of the microburst are considered, and an analysis of a macroburst/microburst event on July 14, 1982 is presented.

The Meteorology of Storms that Produce Narrow Bipolar Events

NASA Technical Reports Server (NTRS)

Lang, Timothy J.; McCaul, Eugene W.; Cummer, Steven A.

2013-01-01

Narrow Bipolar Events (NBEs) are compact intracloud discharges that produce the most powerful lightning-related radio frequency signals that have been observed. However, their luminosity is below the threshold for detectability from current and past spaceborne optical sensors. NBEs have been loosely associated with convective intensity, but their occurrence tends to be highly localized in time and space within a thunderstorm, and there remain many questions about whether and to what extent they are significantly related to meteorological processes within thunderstorms. Using the North Alabama Lightning Mapping Array (NALMA), the National Lightning Detection Network, and available Doppler and polarimetric radar data, case studies will be presented for storm events that produced large numbers of NBEs (10s-100s) during their lifetimes. NBEs are documented via a method that identifies high peak power (>40-50 dBW) initial VHF sources within a specific altitude band in the upper levels of thunderstorms. The production of NBEs, including spatial and temporal variability, will be compared to the radar-inferred kinematic and microphysical structure and evolution of thunderstorms, as well as their NALMA- and NLDN-inferred electrical characteristics. The results should provide new insights into the relationships between NBEs and thunderstorm processes.

Automatic identification of bird targets with radar via patterns produced by wing flapping.

PubMed

Zaugg, Serge; Saporta, Gilbert; van Loon, Emiel; Schmaljohann, Heiko; Liechti, Felix

2008-09-06

Bird identification with radar is important for bird migration research, environmental impact assessments (e.g. wind farms), aircraft security and radar meteorology. In a study on bird migration, radar signals from birds, insects and ground clutter were recorded. Signals from birds show a typical pattern due to wing flapping. The data were labelled by experts into the four classes BIRD, INSECT, CLUTTER and UFO (unidentifiable signals). We present a classification algorithm aimed at automatic recognition of bird targets. Variables related to signal intensity and wing flapping pattern were extracted (via continuous wavelet transform). We used support vector classifiers to build predictive models. We estimated classification performance via cross validation on four datasets. When data from the same dataset were used for training and testing the classifier, the classification performance was extremely to moderately high. When data from one dataset were used for training and the three remaining datasets were used as test sets, the performance was lower but still extremely to moderately high. This shows that the method generalizes well across different locations or times. Our method provides a substantial gain of time when birds must be identified in large collections of radar signals and it represents the first substantial step in developing a real time bird identification radar system. We provide some guidelines and ideas for future research.

Remote Sensing of In-Flight Icing Conditions: Operational, Meteorological, and Technological Considerations

NASA Technical Reports Server (NTRS)

Ryerson, Charles C.

2000-01-01

Remote-sensing systems that map aircraft icing conditions in the flight path from airports or aircraft would allow icing to be avoided and exited. Icing remote-sensing system development requires consideration of the operational environment, the meteorological environment, and the technology available. Operationally, pilots need unambiguous cockpit icing displays for risk management decision-making. Human factors, aircraft integration, integration of remotely sensed icing information into the weather system infrastructures, and avoid-and-exit issues need resolution. Cost, maintenance, power, weight, and space concern manufacturers, operators, and regulators. An icing remote-sensing system detects cloud and precipitation liquid water, drop size, and temperature. An algorithm is needed to convert these conditions into icing potential estimates for cockpit display. Specification development requires that magnitudes of cloud microphysical conditions and their spatial and temporal variability be understood at multiple scales. The core of an icing remote-sensing system is the technology that senses icing microphysical conditions. Radar and microwave radiometers penetrate clouds and can estimate liquid water and drop size. Retrieval development is needed; differential attenuation and neural network assessment of multiple-band radar returns are most promising to date. Airport-based radar or radiometers are the most viable near-term technologies. A radiometer that profiles cloud liquid water, and experimental techniques to use radiometers horizontally, are promising. The most critical operational research needs are to assess cockpit and aircraft system integration, develop avoid-and-exit protocols, assess human factors, and integrate remote-sensing information into weather and air traffic control infrastructures. Improved spatial characterization of cloud and precipitation liquid-water content, drop-size spectra, and temperature are needed, as well as an algorithm to

A Meteorological Supersite for Aviation and Cold Weather Applications

NASA Astrophysics Data System (ADS)

Gultepe, Ismail; Agelin-Chaab, M.; Komar, J.; Elfstrom, G.; Boudala, F.; Zhou, B.

2018-05-01

The goal of this study is to better understand atmospheric boundary layer processes and parameters, and to evaluate physical processes for aviation applications using data from a supersite observing site. Various meteorological sensors, including a weather and environmental unmanned aerial vehicle (WE-UAV), and a fog and snow tower (FSOS) observations are part of the project. The PanAm University of Ontario Institute of Technology (UOIT) Meteorological Supersite (PUMS) observations are being collected from April 2015 to date. The FSOS tower gathers observations related to rain, snow, fog, and visibility, aerosols, solar radiation, and wind and turbulence, as well as surface and sky temperature. The FSOSs are located at three locations at about 450-800 m away from the PUMS supersite. The WE-UAV measurements representing aerosol, wind speed and direction, as well as temperature (T) and relative humidity (RH) are provided during clear weather conditions. Other measurements at the PUMS site include cloud backscattering profiles from CL51 ceilometer, MWR observations of liquid water content (LWC), T, and RH, and Microwave Rain Radar (MRR) reflectivity profile, as well as the present weather type, snow water depth, icing rate, 3D-ultrasonic wind and turbulence, and conventional meteorological observations from compact weather stations, e.g., WXTs. The results based on important weather event studies, representing fog, snow, rain, blowing snow, wind gust, planetary boundary layer (PBL) wind research for UAV, and icing conditions are given. The microphysical parameterizations and analysis processes for each event are provided, but the results should not be generalized for all weather events and be used cautiously. Results suggested that integrated observing systems based on data from a supersite as well as satellite sites can provide better information applicable to aviation meteorology, including PBL weather research, validation of numerical weather model predictions, and

Meteorological tools in support to the railway security system on the Calabria region

NASA Astrophysics Data System (ADS)

Laviola, Sante; Gabriele, Salvatore; Iovine, Giulio; Baldini, Luca; Chiravalloti, Francesco; Federico, Stefano; Miglietta, Marcello Mario; Milani, Lisa; Procopio, Antonio; Roberto, Nicoletta; Tiesi, Alessandro; Agostino, Mario; Niccoli, Raffaele; Stassi, Sergio; Rago, Valeria

2017-04-01

RAMSES (RAilway Meteorological SEcurity System) is a pilot project co-funded by the Italian Railway Company - RFI S.p.A. and conceived for the mitigation of the hydrological risk along the Calabria railways. RAMSES aims at improving the forecast of very short life-cycle convection systems, responsible of intense and localized rainfalls affecting small catchment areas, which are often underestimated by the numerical weather models and even non-adequately detected by the network of sparse raingauges. The RAMSES operational design is based on a synergistic and integrated architecture, providing a series of information able to identify the most active convective cells and monitoring their evolution in terms of vertical structure, rain intensity and geo-hydrological effects at ground (debris flow, landslides, collapses of bridges, erosion of the ballast). The RAMSES meteorological component is designed to identify and track the short-term evolution (15-60 min) of convective cells, by means of imaging techniques based on dual-polarization weather radar and Meteosat data. In support of this quasi-real time analysis, the numerical model WRF provides the weather forecast at 3-6 hours range by ingesting, through the assimilation system LAPS, the observational data (rain gauges, ground weather stations, radar, satellites) in order to improve the initial condition. Finally, the hydraulic flow modeling is used to assess the ground effects in terms of landslide susceptibility, rainfall-runoff intensity, debris impact on the drainage network and evaluate of risk along the railway track.

Diagnosing Meteorological Conditions Associated with Sprites and Lightning with Large Charge Moment Changes (CMC) over Oklahoma

NASA Technical Reports Server (NTRS)

Flores-Rivera, Lizxandra; Lang, Timothy J.

2014-01-01

Sprites are a category of Transient Luminous Events (TLEs) that occur in the upper atmosphere above the tops of Mesoscale Convective Systems (MCSs). They are commonly associated with lightning that produce large charge moment changes (CMCs). Synergistic use of satellite and radar-retrieved observations together with sounding data, forecasts, and lightning-detection networks allowed the diagnosis and analysis of the meteorological conditions associated with sprites as well as large-CMC lightning over Oklahoma.

Radar-based rainfall estimation: Improving Z/R relations through comparison of drop size distributions, rainfall rates and radar reflectivity patterns

NASA Astrophysics Data System (ADS)

Neuper, Malte; Ehret, Uwe

2014-05-01

The relation between the measured radar reflectivity factor Z and surface rainfall intensity R - the Z/R relation - is profoundly complex, so that in general one speaks about radar-based quantitative precipitation estimation (QPE) rather than exact measurement. Like in Plato's Allegory of the Cave, what we observe in the end is only the 'shadow' of the true rainfall field through a very small backscatter of an electromagnetic signal emitted by the radar, which we hope has been actually reflected by hydrometeors. The meteorological relevant and valuable Information is gained only indirectly by more or less justified assumptions. One of these assumptions concerns the drop size distribution, through which the rain intensity is finally associated with the measured radar reflectivity factor Z. The real drop size distribution is however subject to large spatial and temporal variability, and consequently so is the true Z/R relation. Better knowledge of the true spatio-temporal Z/R structure therefore has the potential to improve radar-based QPE compared to the common practice of applying a single or a few standard Z/R relations. To this end, we use observations from six laser-optic disdrometers, two vertically pointing micro rain radars, 205 rain gauges, one rawindsonde station and two C-band Doppler radars installed or operated in and near the Attert catchment (Luxembourg). The C-band radars and the rawindsonde station are operated by the Belgian and German Weather Services, the rain gauge data was partly provided by the French, Dutch, Belgian, German Weather Services and the Ministry of Agriculture of Luxembourg and the other equipment was installed as part of the interdisciplinary DFG research project CAOS (Catchment as Organized Systems). With the various data sets correlation analyzes were executed. In order to get a notion on the different appearance of the reflectivity patterns in the radar image, first of all various simple distribution indices (for example the

14 CFR Appendix G to Part 121 - Doppler Radar and Inertial Navigation System (INS): Request for Evaluation; Equipment and...

Code of Federal Regulations, 2010 CFR

2010-01-01

... latitudes, a review of navigation, flight planning, and applicable meteorology. (3) The methods for updating... Radar or Inertial Navigation System must submit a request for evaluation of the system to the Flight... operations 30 days prior to the start of evaluation flights. (b) The application must contain: (1) A summary...

14 CFR Appendix G to Part 121 - Doppler Radar and Inertial Navigation System (INS): Request for Evaluation; Equipment and...

Code of Federal Regulations, 2014 CFR

2014-01-01

... latitudes, a review of navigation, flight planning, and applicable meteorology. (3) The methods for updating... Radar or Inertial Navigation System must submit a request for evaluation of the system to the Flight... operations 30 days prior to the start of evaluation flights. (b) The application must contain: (1) A summary...

14 CFR Appendix G to Part 121 - Doppler Radar and Inertial Navigation System (INS): Request for Evaluation; Equipment and...

Code of Federal Regulations, 2013 CFR

2013-01-01

... latitudes, a review of navigation, flight planning, and applicable meteorology. (3) The methods for updating... Radar or Inertial Navigation System must submit a request for evaluation of the system to the Flight... operations 30 days prior to the start of evaluation flights. (b) The application must contain: (1) A summary...

14 CFR Appendix G to Part 121 - Doppler Radar and Inertial Navigation System (INS): Request for Evaluation; Equipment and...

Code of Federal Regulations, 2011 CFR

2011-01-01

... latitudes, a review of navigation, flight planning, and applicable meteorology. (3) The methods for updating... Radar or Inertial Navigation System must submit a request for evaluation of the system to the Flight... operations 30 days prior to the start of evaluation flights. (b) The application must contain: (1) A summary...

14 CFR Appendix G to Part 121 - Doppler Radar and Inertial Navigation System (INS): Request for Evaluation; Equipment and...

Code of Federal Regulations, 2012 CFR

2012-01-01

... latitudes, a review of navigation, flight planning, and applicable meteorology. (3) The methods for updating... Radar or Inertial Navigation System must submit a request for evaluation of the system to the Flight... operations 30 days prior to the start of evaluation flights. (b) The application must contain: (1) A summary...

Coherent laser radar at 2 microns using solid-state lasers

NASA Technical Reports Server (NTRS)

Henderson, Sammy W.; Suni, Paul J. M.; Hale, Charley P.; Hannon, Stephen M.; Magee, James R.; Bruns, Dale L.; Yuen, Eric H.

1993-01-01

Coherent laser radar systems using 2-micron Tm- and Tm, Ho-doped solid-state lasers are useful for the remote range-resolved measurement of atmospheric winds, aerosol backscatter, and DIAL measurements of atmospheric water vapor and CO2 concentrations. Recent measurements made with a 2-micron coherent laser radar system, advances in the laser technology, and atmospheric propagation effects on 2-micron coherent lidar performance are described.

Coordinated Radar Resource Management for Networked Phased Array Radars

DTIC Science & Technology

2014-12-01

Coordinated radar resource management for networked phased array radars Peter W. Moo and Zhen Ding Radar Sensing & Exploitation Section Defence...15] P.W. Moo . Scheduling for multifunction radar via two-slope benefit functions. Radar, Sonar Navigation, IET, 5(8):884 –894, Oct. 2011. [16] M.I

Development of Radar Control system for Multi-mode Active Phased Array Radar for atmospheric probing

NASA Astrophysics Data System (ADS)

Yasodha, Polisetti; Jayaraman, Achuthan; Thriveni, A.

2016-07-01

active phased array radar and the RC system ensures that the commands/experimental parameter data are properly transferred to all subsystems especially to TR modules. In case of failure of any TR module, it is indicated to the user for further rectification. Realisation of the RC system is at an advanced stage. More details will be presented in the conference.

HF radar signatures of the cusp and low-latitude boundary layer

NASA Technical Reports Server (NTRS)

Baker, K. B.; Dudeney, J. R.; Greenwald, R. A.; Pinnock, M.; Newell, P. T.; Rodger, A. S.; Mattin, N.; Meng, C.-I.

1995-01-01

Continuous ground-based observations of ionospheric and magnetospheric regions are critical to the Geospace Environmental Modeling (GEM) program. It is therefore important to establish clear intercalibrations between different ground-based instruments and satellites in order to clearly place the ground-based observations in context with the corresponding in situ satellite measurements. HF-radars operating at high latitudes are capable of observing very large spatial regions of the ionosphere on a nearly continuous basis. In this paper we report on an intercalibration study made using the Polar Anglo-American Conjugate Radar Experiment radars located at Goose Bay, Labrador, and Halley Station, Antarctica, and the Defense Meteorological Satellite Program (DMSP) satellites. The DMSP satellite data are used to provide clear identifications of the ionospheric cusp and the low-latitude boundary layer (LLBL). The radar data for eight cusp events and eight LLBL events have been examined in order to determine a radar signature of these ionospheric regions. This intercalibraion indicates that the cusp is always characterized by wide, complex Doppler power spectra, whereas the LLBL is usually found to have spectra dominated by a single component. The distribution of spectral widths in the cusp is of a generally Gaussian form with a peak at about 220 m/s. The distribution of spectral widths in the LLBL is more like an exponential distribution, with the peak of the distribution occurring at about 50 m/s. There are a few cases in the LLBL where the Doppler power spectra are strikingly similar to those observed in the cusp.

Operation of a Radar Altimeter over the Greenland Ice Sheet

NASA Technical Reports Server (NTRS)

Grund, Matthew D.

1996-01-01

This thesis presents documentation for the Advanced Application Flight Experiment (AAFE) pulse compression radar altimeter and its role in the NASA Multisensor Airborne Altimetry Experiment over Greenland in 1993. The AAFE Altimeter is a Ku-band microwave radar which has demonstrated 14 centimeter range precision in operation over arctic ice. Recent repairs and improvements were required to make the Greenland missions possible. Transmitter, receiver and software modifications, as well as the integration of a GPS receiver are thoroughly documented. Procedures for installation, and operation of the radar are described. Finally, suggestions are made for further system improvements.

Dual-Polarimetric Radar-Based Tornado Debris Signatures and Paths Associated with Tornadoes Over Northern Alabama During the Historic Outbreak of 27 April 2011

NASA Technical Reports Server (NTRS)

Carey, Lawrence D.; Schultz, Christopher J.; Schultz, Elise V.; Petersen, Walter A.; Gatlin, Patrick N.; Knupp, Kevin R.; Molthan, Andrew L.; Jedloved, Gary J.; Carcione, Brian C.; Darden, Christopher B.;

The Next Generation of Airborne Polarimetric Doppler Weather Radar: NCAR/EOL Airborne Phased Array Radar (APAR) Development

NASA Astrophysics Data System (ADS)

Moore, James; Lee, Wen-Chau; Loew, Eric; Vivekanandan, Jothiram; Grubišić, Vanda; Tsai, Peisang; Dixon, Mike; Emmett, Jonathan; Lord, Mark; Lussier, Louis; Hwang, Kyuil; Ranson, James

2017-04-01

The National Center for Atmospheric Research (NCAR) Earth observing Laboratory (EOL) is entering the third year of preliminary system design studies, engineering prototype testing and project management plan preparation for the development of a novel Airborne Phased Array Radar (APAR). This system being designed by NCAR/EOL will be installed and operated on the NSF/NCAR C-130 aircraft. The APAR system will consist of four removable C-band Active Electronically Scanned Arrays (AESA) strategically placed on the fuselage of the aircraft. Each AESA measures approximately 1.5 x 1.9 m and is composed of 3000 active radiating elements arranged in an array of line replaceable units (LRU) to simplify maintenance. APAR will provide unprecedented observations, and in conjunction with the advanced radar data assimilation schema, will be able to address the key science questions to improve understanding and predictability of significant and high-impact weather APAR, operating at C-band, allows the measurement of 3-D kinematics of the more intense portions of storms (e.g. thunderstorm dynamics and tornadic development, tropical cyclone rainband structure and evolution) with less attenuation compared with current airborne Doppler radar systems. Polarimetric measurements are not available from current airborne tail Doppler radars. However, APAR, with dual-Doppler and dual polarization diversity at a lesser attenuating C-band wavelength, will further advance the understanding of the microphysical processes within a variety of precipitation systems. The radar is sensitive enough to provide high resolution measurements of winter storm dynamics and microphysics. The planned APAR development that would bring the system to operational readiness for research community use aboard the C-130 is expected to take 8 years once major funding support is realized. The authors will review the overall APAR design and provide new details of the system based on our Technical Requirements Document

Radar-derived Quantitative Precipitation Estimation in Complex Terrain over the Eastern Tibetan Plateau

NASA Astrophysics Data System (ADS)

Gou, Y.

2017-12-01

Quantitative Precipitation Estimation (QPE) is one of the important applications of weather radars. However, in complex terrain such as Tibetan Plateau, it is a challenging task to obtain an optimal Z-R relation due to the complex space time variability in precipitation microphysics. This paper develops two radar QPE schemes respectively based on Reflectivity Threshold (RT) and Storm Cell Identification and Tracking (SCIT) algorithms using observations from 11 Doppler weather radars and 3294 rain gauges over the Eastern Tibetan Plateau (ETP). These two QPE methodologies are evaluated extensively using four precipitation events that are characterized by different meteorological features. Precipitation characteristics of independent storm cells associated with these four events, as well as the storm-scale differences, are investigated using short-term vertical profiles of reflectivity clusters. Evaluation results show that the SCIT-based rainfall approach performs better than the simple RT-based method in all precipitation events in terms of score comparison using validation gauge measurements as references, with higher correlation (than 75.74%), lower mean absolute error (than 82.38%) and root-mean-square error (than 89.04%) of all the comparative frames. It is also found that the SCIT-based approach can effectively mitigate the radar QPE local error and represent precipitation spatiotemporal variability better than RT-based scheme.

Scanning Radar Investigations to Characterize Cloud and Precipitation Processes for ASR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Venkatachalam, Chandrasekar

2016-12-17

The project conducted investigations in the following areas related to scanning radar retrievals: a) Development for Cloud drizzle separation studies for the ENA site based on Doppler Spectra b) Advanced radar retrieval for the SGP site c) Characterizing falling snow using multifrequency dual-polarization measurements d) BAECC field experiment. More details about these investigations can be found within each subtopic within the report.

Numeric Computation of the Radar Cross Section of In-flight Projectiles

DTIC Science & Technology

2016-11-01

SUBJECT TERMS computational electromagnetics , radar signature, ballistic trajectory, radar cross section, RCS 16. SECURITY CLASSIFICATION OF: 17...under the generic category of rockets, artillery, and mortar (RAM). The electromagnetic (EM) modeling team at the US Army Research Laboratory (ARL) is...ARL-TR-5145. 5. Balanis C. Advanced engineering electromagnetics . New York (NY): Wiley; 1989. 6. Ruck G, Barrick DE, Stuart WD, Krichbaum CK

Radar soundings of the ionosphere of Mars.

PubMed

Gurnett, D A; Kirchner, D L; Huff, R L; Morgan, D D; Persoon, A M; Averkamp, T F; Duru, F; Nielsen, E; Safaeinili, A; Plaut, J J; Picardi, G

2005-12-23

We report the first radar soundings of the ionosphere of Mars with the MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding) instrument on board the orbiting Mars Express spacecraft. Several types of ionospheric echoes are observed, ranging from vertical echoes caused by specular reflection from the horizontally stratified ionosphere to a wide variety of oblique and diffuse echoes. The oblique echoes are believed to arise mainly from ionospheric structures associated with the complex crustal magnetic fields of Mars. Echoes at the electron plasma frequency and the cyclotron period also provide measurements of the local electron density and magnetic field strength.

AMSNEXRAD-Automated detection of meteorite strewnfields in doppler weather radar

NASA Astrophysics Data System (ADS)

Hankey, Michael; Fries, Marc; Matson, Rob; Fries, Jeff

2017-09-01

For several years meteorite recovery in the United States has been greatly enhanced by using Doppler weather radar images to determine possible fall zones for meteorites produced by witnessed fireballs. While most fireball events leave no record on the Doppler radar, some large fireballs do. Based on the successful recovery of 10 meteorite falls 'under the radar', and the discovery of radar on more than 10 historic falls, it is believed that meteoritic dust and or actual meteorites falling to the ground have been recorded on Doppler weather radar (Fries et al., 2014). Up until this point, the process of detecting the radar signatures associated with meteorite falls has been a manual one and dependent on prior accurate knowledge of the fall time and estimated ground track. This manual detection process is labor intensive and can take several hours per event. Recent technological developments by NOAA now help enable the automation of these tasks. This in combination with advancements by the American Meteor Society (Hankey et al., 2014) in the tracking and plotting of witnessed fireballs has opened the possibility for automatic detection of meteorites in NEXRAD Radar Archives. Here in the processes for fireball triangulation, search area determination, radar interfacing, data extraction, storage, search, detection and plotting are explained.

Assessing the competing roles of model resolution and meteorological forcing fidelity in hyperresolution simulations of snowpack and streamflow in the southern Rocky Mountains

NASA Astrophysics Data System (ADS)

Gochis, D. J.; Dugger, A. L.; Karsten, L. R.; Barlage, M. J.; Sampson, K. M.; Yu, W.; Pan, L.; McCreight, J. L.; Howard, K.; Busto, J.; Deems, J. S.

2017-12-01

Hydrometeorological processes vary over comparatively short length scales in regions of complex terrain such as the southern Rocky Mountains. Changes in temperature, precipitation, wind and solar radiation can vary significantly across elevation gradients, terrain landform and land cover conditions throughout the region. Capturing such variability in hydrologic models can necessitate the utilization of so-called `hyper-resolution' spatial meshes with effective element spacings of less than 100m. However, it is often difficult to obtain meteorological forcings of high quality in such regions at those resolutions which can result in significant uncertainty in fundamental in hydrologic model inputs. In this study we examine the comparative influences of meteorological forcing data fidelity and spatial resolution on seasonal simulations of snowpack evolution, runoff and streamflow in a set of high mountain watersheds in southern Colorado. We utilize the operational, NOAA National Water Model configuration of the community WRF-Hydro system as a baseline and compare against it, additional model scenarios with differing specifications of meteorological forcing data, with and without topographic downscaling adjustments applied, with and without experimental high resolution radar derived precipitation estimates and with WRF-Hydro configurations of progressively finer spatial resolution. The results suggest significant influence from and importance of meteorological downscaling techniques in controlling spatial distributions of meltout and runoff timing. The use of radar derived precipitation exhibits clear sensitivity on hydrologic simulation skill compared with the use of coarser resolution, background precipitation analyses. Advantages and disadvantages of the utilization of progressively higher resolution model configurations both in terms of computational requirements and model fidelity are also discussed.

Diagnosing the Meteorological Conditions Associated with Sprites and Lightning with Large Change Moment Charges (CMC) over Oklahoma

NASA Technical Reports Server (NTRS)

Rivera Lizxandra Flores; Lang, Timothy

2013-01-01

Sprites are a category of Transient Luminous Events (TLE's) that occur in the upper atmosphere above the tops of Mesoscale Convective Systems (MCSs). They are commonly associated with lightning strokes that produce large charge moment changes (CMCs). Synergistic use of satellite and radar-retrieved observations together with sounding data, forecasts, and lightning-detection-networks allowed the diagnosis and analysis of the meteorological conditions associated with sprites as well as large-CMC lightning over Oklahoma

Assessment of virtual towers performed with scanning wind lidars and Ka-band radars during the XPIA experiment

DOE PAGES

Debnath, Mithu; Iungo, Giacomo Valerio; Brewer, W. Alan; ...

2017-03-29

During the eXperimental Planetary boundary layer Instrumentation Assessment (XPIA) campaign, which was carried out at the Boulder Atmospheric Observatory (BAO) in spring 2015, multiple-Doppler scanning strategies were carried out with scanning wind lidars and Ka-band radars. Specifically, step–stare measurements were collected simultaneously with three scanning Doppler lidars, while two scanning Ka-band radars carried out simultaneous range height indicator (RHI) scans. The XPIA experiment provided the unique opportunity to compare directly virtual-tower measurements performed simultaneously with Ka-band radars and Doppler wind lidars. Furthermore, multiple-Doppler measurements were assessed against sonic anemometer data acquired from the meteorological tower (met-tower) present at the BAOmore » site and a lidar wind profiler. As a result, this survey shows that – despite the different technologies, measurement volumes and sampling periods used for the lidar and radar measurements – a very good accuracy is achieved for both remote-sensing techniques for probing horizontal wind speed and wind direction with the virtual-tower scanning technique.« less

Analysis of the Meteorology Associated with the 1998 NASA Glenn Twin Otter Icing Flights

NASA Technical Reports Server (NTRS)

Bernstein, Ben C.

2000-01-01

This document contains a basic analysis of the meteorology associated with the NASA Glenn Twin Otter icing encounters between December 1997 and March 1998. The purpose of this analysis is to provide a meteorological context for the aircraft data collected during these flights. For each case, the following data elements are presented: (1) A brief overview of the Twin Otter encounter, including locations, liquid water contents, temperatures and microphysical makeup of the clouds and precipitation aloft, (2) Upper-air charts, providing hand-analyzed locations of lows, troughs, ridges, saturated/unsaturated air, temperatures, warm/cold advection, and jet streams, (3) Balloon-borne soundings, providing vertical profiles of temperature, moisture and winds, (4) Infrared and visible satellite data, providing cloud locations and cloud top temperature, (5) 3-hourly surface charts, providing hand-analyzed locations of lows, highs, fronts, precipitation (including type) and cloud cover, (6) Hourly, regional radar mosaics, providing fine resolution of the locations of precipitation (including intensity and type), pilot reports of icing (including intensity and type), surface observations of precipitation type and Twin Otter tracks for a one hour window centered on the time of the radar data, and (7) Hourly plots of icing pilot reports, providing the icing intensity, icing type, icing altitudes and aircraft type. Outages occurred in nearly every dataset at some point. All relevant data that was available is presented here. All times are in UTC and all heights are in feet above mean sea level (MSL).

The design and development of signal-processing algorithms for an airborne x-band Doppler weather radar

NASA Technical Reports Server (NTRS)

Nicholson, Shaun R.

1994-01-01

Improved measurements of precipitation will aid our understanding of the role of latent heating on global circulations. Spaceborne meteorological sensors such as the planned precipitation radar and microwave radiometers on the Tropical Rainfall Measurement Mission (TRMM) provide for the first time a comprehensive means of making these global measurements. Pre-TRMM activities include development of precipitation algorithms using existing satellite data, computer simulations, and measurements from limited aircraft campaigns. Since the TRMM radar will be the first spaceborne precipitation radar, there is limited experience with such measurements, and only recently have airborne radars become available that can attempt to address the issue of the limitations of a spaceborne radar. There are many questions regarding how much attenuation occurs in various cloud types and the effect of cloud vertical motions on the estimation of precipitation rates. The EDOP program being developed by NASA GSFC will provide data useful for testing both rain-retrieval algorithms and the importance of vertical motions on the rain measurements. The purpose of this report is to describe the design and development of real-time embedded parallel algorithms used by EDOP to extract reflectivity and Doppler products (velocity, spectrum width, and signal-to-noise ratio) as the first step in the aforementioned goals.

2. VIEW SOUTHWEST, prime search radar tower, height finder radar ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. VIEW SOUTHWEST, prime search radar tower, height finder radar towards, height finder radar towers, and radar tower (unknown function) - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

EUMETCast: The Meteorological Data Dissemination Service

NASA Astrophysics Data System (ADS)

Gaertner, V. K.; Koenig, M.

2006-05-01

EUMETCast is EUMETSAT's broadcast system for environmental data. It utilises telecommunications satellites and the services of telecommunication providers to distribute data files using Digital Video Broadcast (DVB) standards to a wide audience located within the combined geographical coverage zones of the individual telecommunication satellites used to transmit the data. The telecommunication zones are now covering Europe, Africa, South America and parts of Asia and North America. This service has been established to provide the meteorological communities with satellite data and other meteorological products in near real-time for operational, but also research, education and training purposes. The following EUMETSAT services are currently available via EUMETCast: - Second Generation Meteosat - High Rate SEVIRI Image Data (every 15 minutes) - First Generation Meteosat - Indian Ocean Data Coverage (IODC) (every 30 minutes) - Other Geostationary Data from NOAA (GOES E/W) and JMA (MTSAT), (every 3 hours) - Data Collection and Retransmission (DCP) and Meteorological Data Dissemination (MDD) - Basic Meteorological Data (BMD) (Ku-band Europe only) - Meteorological Products (including some Satellite Application Facility products) - EUMETSAT Advanced Retransmission Service (EARS) (Ku-band Europe only) - DWDSAT (Ku-band Europe only) - VEGETATION data (C-band Africa only) Progressively during 2006 users will find an increasing amount of polar satellite data and products available on EUMETCast. As part of the extension of the EUMETCast Advanced Retransmission Service (EARS), ERS scatterometer data and NOAA satellite AVHRR data have already been introduced in early 2006. The ERS- SCAT demonstration service is a forerunner for the future pilot EARS-ASCAT service and the pilot EARS- AVHRR service will continue to expand during 2006 with the inclusion of data from additional AVHRR stations in the EARS network. The EUMETCast System will be also be used to provide dissemination of

The rise of active-element phased-array radar

NASA Astrophysics Data System (ADS)

Chang, Ike

The War in the Persian Gulf has recently underscored the vast leverage of advanced electronics to U.S. military power. Advanced electronics will likely play an even greater role in the U.S. military in the future. Under declining budgets, the U.S. forces are experiencing drastic reductions in manpower and resources. To offset these reductions, the military has turned to high technology in general as a force multiplier. In terms of projecting air power, a key force multiplier involves the use of electronic sensors for reconnaissance, surveillance, and tracking. One type of sensor for tactical aircraft, fire control radar, has proven to be a crucial element in establishing air superiority over potential adversaries in war. The advantages, history of development, and enabling technologies of a superior and emerging technology for fire control radars are discussed.

2. SOUTH FACE OF METEOROLOGICAL SHED (BLDG. 756) WITH METEOROLOGICAL ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

2. SOUTH FACE OF METEOROLOGICAL SHED (BLDG. 756) WITH METEOROLOGICAL DATA ACQUISITION TERMINAL (MDAT) INSIDE BUILDING - Vandenberg Air Force Base, Space Launch Complex 3, Meteorological Shed & Tower, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

A System for Distributing Real-Time Customized (NEXRAD-Radar) Geosciences Data

NASA Astrophysics Data System (ADS)

Singh, Satpreet; McWhirter, Jeff; Krajewski, Witold; Kruger, Anton; Goska, Radoslaw; Seo, Bongchul; Domaszczynski, Piotr; Weber, Jeff

2010-05-01

Hydrometeorologists and hydrologists can benefit from (weather) radar derived rain products, including rain rates and accumulations. The Hydro-NEXRAD system (HNX1) has been in operation since 2006 at IIHR-Hydroscience and Engineering at The University of Iowa. It provides rapid and user-friendly access to such user-customized products, generated using archived Weather Surveillance Doppler Radar (WSR-88D) data from the NEXRAD weather radar network in the United States. HNX1 allows researchers to deal directly with radar-derived rain products, without the burden of the details of radar data collection, quality control, processing, and format conversion. A number of hydrologic applications can benefit from a continuous real-time feed of customized radar-derived rain products. We are currently developing such a system, Hydro-NEXRAD 2 (HNX2). HNX2 collects real-time, unprocessed data from multiple NEXRAD radars as they become available, processes them through a user-configurable pipeline of data-processing modules, and then publishes processed products at regular intervals. Modules in the data processing pipeline encapsulate algorithms such as non-meteorological echo detection, range correction, radar-reflectivity-rain rate (Z-R) conversion, advection correction, merging products from multiple radars, and grid transformations. HNX2's implementation presents significant challenges, including quality-control, error-handling, time-synchronization of data from multiple asynchronous sources, generation of multiple-radar metadata products, distribution of products to a user base with diverse needs and constraints, and scalability. For content management and distribution, HNX2 uses RAMADDA (Repository for Archiving, Managing and Accessing Diverse Data), developed by the UCAR/Unidata Program Center in the Unites States. RAMADDA allows HNX2 to publish products through automation and gives users multiple access methods to the published products, including simple web-browser based

Vertical Variability of Rain Drop Size Distribution from Micro Rain Radar Measurements during IFloodS

NASA Astrophysics Data System (ADS)

Adirosi, Elisa; Tokay, Ali; Roberto, Nicoletta; Gorgucci, Eugenio; Montopoli, Mario; Baldini, Luca

2017-04-01

Ground based weather radars are highly used to generate rainfall products for meteorological and hydrological applications. However, weather radar quantitative rainfall estimation is obtained at a certain altitude that depends mainly on the radar elevation angle and on the distance from the radar. Therefore, depending on the vertical variability of rainfall, a time-height ambiguity between radar measurement and rainfall at the ground can affect the rainfall products. The vertically pointing radars (such as the Micro Rain Radar, MRR) are great tool to investigate the vertical variability of rainfall and its characteristics and ultimately, to fill the gap between the ground level and the first available radar elevation. Furthermore, the knowledge of rain Drop Size Distribution (DSD) variability is linked to the well-known problem of the non-uniform beam filling that is one of the main uncertainties of Global Precipitation Measurement (GPM) mission Dual frequency Precipitation Radar (DPR). During GPM Ground Validation Iowa Flood Studies (IFloodS) field experiment, data collected with 2D video disdrometers (2DVD), Autonomous OTT Parsivel2 Units (APU), and MRR profilers at different sites were available. In three different sites co-located APU, 2DVD and MRR are available and covered by the S-band Dual Polarimetric Doppler radar (NPOL). The first elevation height of the radar beam varies, among the three sites, between 70 m and 1100 m. The IFloodS set-up has been used to compare disdrometers, MRR and NPOL data and to evaluate the uncertainties of those measurements. First, the performance of disdrometers and MRR in determining different rainfall parameters at ground has been evaluated and then the MRR based parameters have been compared with the ones obtained from NPOL data at the lowest elevations. Furthermore, the vertical variability of DSD and integral rainfall parameters within the MRR bins (from ground to 1085 m each 35 m) has been investigated in order to provide

Compressed Sensing in On-Grid MIMO Radar.

PubMed

Minner, Michael F

2015-01-01

The accurate detection of targets is a significant problem in multiple-input multiple-output (MIMO) radar. Recent advances of Compressive Sensing offer a means of efficiently accomplishing this task. The sparsity constraints needed to apply the techniques of Compressive Sensing to problems in radar systems have led to discretizations of the target scene in various domains, such as azimuth, time delay, and Doppler. Building upon recent work, we investigate the feasibility of on-grid Compressive Sensing-based MIMO radar via a threefold azimuth-delay-Doppler discretization for target detection and parameter estimation. We utilize a colocated random sensor array and transmit distinct linear chirps to a small scene with few, slowly moving targets. Relying upon standard far-field and narrowband assumptions, we analyze the efficacy of various recovery algorithms in determining the parameters of the scene through numerical simulations, with particular focus on the ℓ 1-squared Nonnegative Regularization method.

Nowcasting Aircraft Icing Conditions in Moscow Region Using Geostationary Meteorological Satellite Data

NASA Astrophysics Data System (ADS)

Barabanova, Olga

2013-04-01

Nowadays the Main Aviation Meteorological Centre in Moscow (MAMC) provides forecasts of icing conditions in Moscow Region airports using information of surface observation network, weather radars and atmospheric sounding. Unfortunately, satellite information is not used properly in aviation meteorological offices in Moscow Region: weather forecasters deal with satellites images of cloudiness only. The main forecasters of MAMC realise that it is necessary to employ meteorological satellite numerical data from different channels in aviation forecasting and especially in nowcasting. Algorithm of nowcasting aircraft in-flight icing conditions has been developed using data from geostationary meteorological satellites "Meteosat-7" and "Meteosat-9". The algorithm is based on the brightness temperature differences. Calculation of brightness temperature differences help to discriminate clouds with supercooled large drops where severe icing conditions are most likely. Due to the lack of visible channel data, the satellite icing detection methods will be less accurate at night. Besides this method is limited by optically thick ice clouds where it is not possible to determine the extent to which supercooled large drops exists within the underlying clouds. However, we determined that most of the optically thick cases are associated with convection or mid-latitude cyclones and they will nearly always have a layer where which supercooled large drops exists with an icing threat. This product is created hourly for the Moscow Air Space and mark zones with moderate or severe icing hazards. The results were compared with mesoscale numerical atmospheric model COSMO-RU output. Verification of the algorithms results using aircraft pilot reports shows that this algorithm is a good instrument for the operational practise in aviation meteorological offices in Moscow Region. The satellite-based algorithms presented here can be used in real time to diagnose areas of icing for pilots to avoid.

Validation of attenuation, beam blockage, and calibration estimation methods using two dual polarization X band weather radars

NASA Astrophysics Data System (ADS)

Diederich, M.; Ryzhkov, A.; Simmer, C.; Mühlbauer, K.

2011-12-01

The amplitude a of radar wave reflected by meteorological targets can be misjudged due to several factors. At X band wavelength, attenuation of the radar beam by hydro meteors reduces the signal strength enough to be a significant source of error for quantitative precipitation estimation. Depending on the surrounding orography, the radar beam may be partially blocked when scanning at low elevation angles, and the knowledge of the exact amount of signal loss through beam blockage becomes necessary. The phase shift between the radar signals at horizontal and vertical polarizations is affected by the hydrometeors that the beam travels through, but remains unaffected by variations in signal strength. This has allowed for several ways of compensating for the attenuation of the signal, and for consistency checks between these variables. In this study, we make use of several weather radars and gauge network measuring in the same area to examine the effectiveness of several methods of attenuation and beam blockage corrections. The methods include consistency checks of radar reflectivity and specific differential phase, calculation of beam blockage using a topography map, estimating attenuation using differential propagation phase, and the ZPHI method proposed by Testud et al. in 2000. Results show the high effectiveness of differential phase in estimating attenuation, and potential of the ZPHI method to compensate attenuation, beam blockage, and calibration errors.

Automatic Real-Time Estimation of Plume Height and Mass Eruption Rate Using Radar Data During Explosive Volcanism

NASA Astrophysics Data System (ADS)

Arason, P.; Barsotti, S.; De'Michieli Vitturi, M.; Jónsson, S.; Arngrímsson, H.; Bergsson, B.; Pfeffer, M. A.; Petersen, G. N.; Bjornsson, H.

2016-12-01

Plume height and mass eruption rate are the principal scale parameters of explosive volcanic eruptions. Weather radars are important instruments in estimating plume height, due to their independence of daylight, weather and visibility. The Icelandic Meteorological Office (IMO) operates two fixed position C-band weather radars and two mobile X-band radars. All volcanoes in Iceland can be monitored by IMO's radar network, and during initial phases of an eruption all available radars will be set to a more detailed volcano scan. When the radar volume data is retrived at IMO-headquarters in Reykjavík, an automatic analysis is performed on the radar data above the proximity of the volcano. The plume height is automatically estimated taking into account the radar scanning strategy, beam width, and a likely reflectivity gradient at the plume top. This analysis provides a distribution of the likely plume height. The automatically determined plume height estimates from the radar data are used as input to a numerical suite that calculates the eruptive source parameters through an inversion algorithm. This is done by using the coupled system DAKOTA-PlumeMoM which solves the 1D plume model equations iteratively by varying the input values of vent radius and vertical velocity. The model accounts for the effect of wind on the plume dynamics, using atmospheric vertical profiles extracted from the ECMWF numerical weather prediction model. Finally, the resulting estimates of mass eruption rate are used to initialize the dispersal model VOL-CALPUFF to assess hazard due to tephra fallout, and communicated to London VAAC to support their modelling activity for aviation safety purposes.

New Cloud and Precipitation Research Avenues Enabled by low-cost Phased-array Radar Technology

NASA Astrophysics Data System (ADS)

Kollias, P.; Oue, M.; Fridlind, A. M.; Matsui, T.; McLaughlin, D. J.

2017-12-01

For over half a century, radars operating in a wide range of frequencies have been the primary source of observational insights of clouds and precipitation microphysics and dynamics and contributed to numerous significant advancements in the field of cloud and precipitation physics. The development of multi-wavelength and polarization diversity techniques has further strengthened the quality of microphysical and dynamical retrievals from radars and has assisted in overcoming some of the limitations imposed by the physics of scattering. Atmospheric radars have historically employed a mechanically-scanning dish antenna and their ability to point to, survey, and revisit specific points or regions in the atmosphere is limited by mechanical inertia. Electronically scanned, or phased-array, radars capable of high-speed, inertialess beam steering, have been available for several decades, but the cost of this technology has limited its use to military applications. During the last 10 years, lower power and lower-cost versions of electronically scanning radars have been developed, and this presents an attractive and affordable new tool for the atmospheric sciences. The operational and research communities are currently exploring phased array advantages in signal processing (i.e. beam multiplexing, improved clutter rejection, cross beam wind estimation, adaptive sensing) and science applications (i.e. tornadic storm morphology studies). Here, we will present some areas of atmospheric research where inertia-less radars with ability to provide rapid volume imaging offers the potential to advance cloud and precipitation research. We will discuss the added value of single phased-array radars as well as networks of these radars for several problems including: multi-Doppler wind retrieval techniques, cloud lifetime studies and aerosol-convection interactions. The performance of current (dish) and future (e-scan) radar systems for these atmospheric studies will be evaluated using

Creating Interactive Graphical Overlays in the Advanced Weather Interactive Processing System (AWIPS) Using Shapefiles and DGM Files

NASA Technical Reports Server (NTRS)

Barrett, Joe H., III; Lafosse, Richard; Hood, Doris; Hoeth, Brian

2007-01-01

Graphical overlays can be created in real-time in the Advanced Weather Interactive Processing System (AWIPS) using shapefiles or DARE Graphics Metafile (DGM) files. This presentation describes how to create graphical overlays on-the-fly for AWIPS, by using two examples of AWIPS applications that were created by the Applied Meteorology Unit (AMU). The first example is the Anvil Threat Corridor Forecast Tool, which produces a shapefile that depicts a graphical threat corridor of the forecast movement of thunderstorm anvil clouds, based on the observed or forecast upper-level winds. This tool is used by the Spaceflight Meteorology Group (SMG) and 45th Weather Squadron (45 WS) to analyze the threat of natural or space vehicle-triggered lightning over a location. The second example is a launch and landing trajectory tool that produces a DGM file that plots the ground track of space vehicles during launch or landing. The trajectory tool can be used by SMG and the 45 WS forecasters to analyze weather radar imagery along a launch or landing trajectory. Advantages of both file types will be listed.

Network connectivity paradigm for the large data produced by weather radar systems

NASA Astrophysics Data System (ADS)

Guenzi, Diego; Bechini, Renzo; Boraso, Rodolfo; Cremonini, Roberto; Fratianni, Simona

2014-05-01

The traffic over Internet is constantly increasing; this is due in particular to social networks activities but also to the enormous exchange of data caused especially by the so-called "Internet of Things". With this term we refer to every device that has the capability of exchanging information with other devices on the web. In geoscience (and, in particular, in meteorology and climatology) there is a constantly increasing number of sensors that are used to obtain data from different sources (like weather radars, digital rain gauges, etc.). This information-gathering activity, frequently, must be followed by a complex data analysis phase, especially when we have large data sets that can be very difficult to analyze (very long historical series of large data sets, for example), like the so called big data. These activities are particularly intensive in resource consumption and they lead to new computational models (like cloud computing) and new methods for storing data (like object store, linked open data, NOSQL or NewSQL). The weather radar systems can be seen as one of the sensors mentioned above: it transmit a large amount of raw data over the network (up to 40 megabytes every five minutes), with 24h/24h continuity and in any weather condition. Weather radar are often located in peaks and in wild areas where connectivity is poor. For this reason radar measurements are sometimes processed partially on site and reduced in size to adapt them to the limited bandwidth currently available by data transmission systems. With the aim to preserve the maximum flow of information, an innovative network connectivity paradigm for the large data produced by weather radar system is here presented. The study is focused on the Monte Settepani operational weather radar system, located over a wild peak summit in north-western Italy.

Doppler radar sensing of fish physiological motion

NASA Astrophysics Data System (ADS)

Hafner, Noah

The monitoring vital of signs for fish is critical for advancing the study of trophic and energetic strategies, distributions and behavior, environmental impact, and aquaculture approaches. Presented here is a new approach for monitoring fish metabolic state without the trauma and stress associated with capture, surgical ECG, or other implanted sensing systems. Original research contributions include analysis for radar operation under water, development of radar systems for aquatic operation, and application of these systems to non invasively sense the heart and gill motion of fish. Tilapia and Sturgeon were studied to test the efficacy across varied fish body shapes and sizes, ranging from 0.1 to 1.3m in snout to tail length. Monitoring experiments were conducted with eleven tilapia and three sturgeons to assess activity level participated in these experiments, the results from which include activity level monitoring (tilapia: still or fidgeting 94% of time observed), ventilation rate (tilapia: 42 bpm, sturgeon: 145 bpm), and heart rate (tilapia: 41 bpm, sturgeon: 35 bpm). Bland-Altman analysis of radar and ECG measured heart rate indicate agreement between the two measurement techniques and the suitability of radar as an alternative to ECG. The initial steps for developing a system for practical application is also presented including designs for radar system miniaturization and discussion on further characterization steps with less constrained environments.

Research and technology developments in aeronautics, atmospheric and oceanographic measurements, radar applications, and remote sensing of insects using radar

NASA Technical Reports Server (NTRS)

Oberholtzer, J. D. (Editor)

1980-01-01

Highlights of the year's activities and accomplishments are reported in the areas of aircraft safety, scientific ballooning, mid-air payload retrieval, and the design of a microwave power reception and conversion system for on use on a high altitude powered platform. The development and application of an agro-environmental system to provide crop management advisory information to Virginia farmers, and the radar tracking of insects are described. Aircraft systems, developed for measuring atmospheric ozone and nitric acid were used to sample emissions from Mount St. Helens. Investigations of the reliability and precision of the U.S. standard meteorological rocketsonde, applications of the microwave altimeter and airborne lidar system in oceanography, and the development of a multibeam altimeter concept are also summarized.

Hughes integrated synthetic aperture radar: High performance at low cost

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bayma, R.W.

1996-11-01

This paper describes the background and development of the low cost high-performance Hughes Integrated Synthetic Aperture Radar (HISAR{trademark}) which has a full range of capabilities for real-time reconnaissance, surveillance and earth resource mapping. HISAR uses advanced Synthetic Aperture Radar (SAR) technology to make operationally effective images of near photo quality, day or night and in all weather conditions. This is achieved at low cost by maximizing the use of commercially available radar and signal-processing equipment in the fabrication. Furthermore, HISAR is designed to fit into an executive-class aircraft making it available for a wide range of users. 4 refs., 8more » figs.« less

Airline meteorological requirements

NASA Technical Reports Server (NTRS)

Chandler, C. L.; Pappas, J.

1985-01-01

A brief review of airline meteorological/flight planning is presented. The effects of variations in meteorological parameters upon flight and operational costs are reviewed. Flight path planning through the use of meteorological information is briefly discussed.

Merging Radar Quantitative Precipitation Estimates (QPEs) from the High-resolution NEXRAD Reanalysis over CONUS with Rain-gauge Observations

NASA Astrophysics Data System (ADS)

Prat, O. P.; Nelson, B. R.; Stevens, S. E.; Nickl, E.; Seo, D. J.; Kim, B.; Zhang, J.; Qi, Y.

2015-12-01

The processing of radar-only precipitation via the reanalysis from the National Mosaic and Multi-Sensor Quantitative (NMQ/Q2) based on the WSR-88D Next-generation Radar (Nexrad) network over the Continental United States (CONUS) is completed for the period covering from 2002 to 2011. While this constitutes a unique opportunity to study precipitation processes at higher resolution than conventionally possible (1-km, 5-min), the long-term radar-only product needs to be merged with in-situ information in order to be suitable for hydrological, meteorological and climatological applications. The radar-gauge merging is performed by using rain gauge information at daily (Global Historical Climatology Network-Daily: GHCN-D), hourly (Hydrometeorological Automated Data System: HADS), and 5-min (Automated Surface Observing Systems: ASOS; Climate Reference Network: CRN) resolution. The challenges related to incorporating differing resolution and quality networks to generate long-term large-scale gridded estimates of precipitation are enormous. In that perspective, we are implementing techniques for merging the rain gauge datasets and the radar-only estimates such as Inverse Distance Weighting (IDW), Simple Kriging (SK), Ordinary Kriging (OK), and Conditional Bias-Penalized Kriging (CBPK). An evaluation of the different radar-gauge merging techniques is presented and we provide an estimate of uncertainty for the gridded estimates. In addition, comparisons with a suite of lower resolution QPEs derived from ground based radar measurements (Stage IV) are provided in order to give a detailed picture of the improvements and remaining challenges.

4. VIEW NORTHEAST, radar tower (unknown function), prime search radar ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

4. VIEW NORTHEAST, radar tower (unknown function), prime search radar tower, emergency power building, and height finder radar tower - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

Development of observed meteorological database to understand the deposition and dispersion processes over Fukushima and Kanto plain of Japan in March 2011

NASA Astrophysics Data System (ADS)

Yatagai, A. I.; Ishihara, M.; Watanabe, A.; Yamauchi, M.

2015-12-01

Meteorological simulations and understanding of the distribution of radioactive compounds depends on the accurate simulation of precipitation and on information regarding the timing of the emission of these radioactive pollutants from the power plant. Furthermore, three-dimensional rain drop and even fog information should be essentially important for understanding the wet deposition processes, since the initial drizzle is not measured by the tipping bucket-type raingauge. We have developed various meteorological information links (http://www.chikyu.ac.jp/akiyo/firis/) and original radar and precipitation data will be released from the page. Here we present various radar images that we have prepared for March 2011. We prepared three-dimensional radar reflectivity of the C-band radar of JMA in every 10 minutes over all Kanto Plain centered at Tokyo and Fukushima prefecture centered at Sendai. We have released images of each altitude (1km interval) for 15th - 16thand 21th March (http://sc-web.nict.go.jp/fukushima/). The vertical structure of the rainfall is almost the same at 4km with the surface and sporadic high precipitation is observed at 6 km height for 15-16th. While, generally precipitation pattern that is similar to the surface is observed at 5km height on 21th. On the other hand, an X-band radar centered at Fukushima university is also used to know more localized raindrop patterns at zenith angle of 4 degree. We prepared 10-minutes/120m mesh precipitation patterns for March 15th, 16th, 17th, 18th, 20th, 21th, 22th and 23th. Quantitative estimate is difficult from this X-band radar, but localized structure, especially for the rain-band along Nakadori (middle valley in Fukushima prefecture), that is considered to determine the highly contaminated zone, is observed with only this X-band radar in the mid-night (JST) of 15th. We will show the movie of how precipitation systems were moved at the meeting. We are preparing rain/snow amount information and fog

Radar rainfall estimation in the context of post-event analysis of flash-flood events

NASA Astrophysics Data System (ADS)

Delrieu, G.; Bouilloud, L.; Boudevillain, B.; Kirstetter, P.-E.; Borga, M.

2009-09-01

Meteorology and Climatology, in press. Dinku, T., E.N. Anagnostou, and M. Borga, 2002: Improving Radar-Based Estimation of Rainfall over Complex Terrain. J. Appl. Meteor., 41, 1163-1178. Pellarin, T., G. Delrieu, G. M. Saulnier, H. Andrieu, B. Vignal, and J. D. Creutin, 2002: Hydrologic visibility of weather radar systems operating in mountainous regions: Case study for the Ardeche Catchment (France). Journal of Hydrometeorology, 3, 539-555.

5. VIEW EAST, height finder radar towers, radar tower (unknown ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

5. VIEW EAST, height finder radar towers, radar tower (unknown function), prime search radar tower, operations building, and central heating plant - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

Rainwater content estimated using polarimetric radar parameters in the Heihe River Basin

NASA Astrophysics Data System (ADS)

Zhao, Guo; Chu, Rongzhong; Zhang, Tong; Jia, Wei

2013-02-01

The rainwater content of cold and arid regions has strong spatial and temporal heterogeneity. Representing rainwater content at high resolution can help us understand the characteristics of inland river basin water cycles and improve the prediction accuracy of hydrological models. Data were used from the Watershed Allied Telemetry Experimental Research (WATER) project of the Heihe River Basin, which is the second largest inland river basin in the arid regions of northwest China. We used raindrop size distributions to improve the rain water content estimation of meteorological radar and to obtain accurate rain water content data in this area. Subsequently, four estimation methods applied in the polarimetric radar were tested. The results of a non-linear regression method show that M(KDP, ZH, ZDR) has the highest accuracy for measuring rain water content. Finally, the formula for measuring the spatial rain water content was applied to a polarimetric radar with an X-band (714XDP). The influence of raindrop size distribution (DSD) on the formula M(KDP, ZH, ZDR) is lowest sensitivity, and it can be explained as follows. On the one hand, the horizontal and vertical front reflection cross sections of the radar are different, so KDP is proportional to the 3rd power of the raindrop diameter. On the other hand, the rear cross section of the radar is proportional to the sixth power of the raindrop diameter. The rainfall's spatial water content M is proportional to the 3rd power of the raindrop diameter, so the influence of the drop size distribution (DSD) on KDP is much smaller than that of ZH.

Radar research at The Pennsylvania State University Radar and Communications Laboratory

NASA Astrophysics Data System (ADS)

Narayanan, Ram M.

2017-05-01

The Radar and Communications Laboratory (RCL) at The Pennsylvania State University is at the forefront of radar technology and is engaged in cutting edge research in all aspects of radar, including modeling and simulation studies of novel radar paradigms, design and development of new types of radar architectures, and extensive field measurements in realistic scenarios. This paper summarizes the research at The Pennsylvania State University's Radar and Communications Laboratory and relevant collaborative research with several groups over the past 15 years in the field of radar and related technologies, including communications, radio frequency identification (RFID), and spectrum sensing.

Radar-driven High-resolution Hydrometeorological Forecasts of the 26 September 2007 Venice flash flood

NASA Astrophysics Data System (ADS)

Massimo Rossa, Andrea; Laudanna Del Guerra, Franco; Borga, Marco; Zanon, Francesco; Settin, Tommaso; Leuenberger, Daniel

2010-05-01

Space and time scales of flash floods are such that flash flood forecasting and warning systems depend upon the accurate real-time provision of rainfall information, high-resolution numerical weather prediction (NWP) forecasts and the use of hydrological models. Currently available high-resolution NWP model models can potentially provide warning forecasters information on the future evolution of storms and their internal structure, thereby increasing convective-scale warning lead times. However, it is essential that the model be started with a very accurate representation of on-going convection, which calls for assimilation of high-resolution rainfall data. This study aims to assess the feasibility of using carefully checked radar-derived quantitative precipitation estimates (QPE) for assimilation into NWP and hydrological models. The hydrometeorological modeling chain includes the convection-permitting NWP model COSMO-2 and a hydrologic-hydraulic models built upon the concept of geomorphological transport. Radar rainfall observations are assimilated into the NWP model via the latent heat nudging method. The study is focused on 26 September 2007 extreme flash flood event which impacted the coastal area of north-eastern Italy around Venice. The hydro-meteorological modeling system is implemented over the Dese river, a 90 km2 catchment flowing to the Venice lagoon. The radar rainfall observations are carefully checked for artifacts, including beam attenuation, by means of physics-based correction procedures and comparison with a dense network of raingauges. The impact of the radar QPE in the assimilation cycle of the NWP model is very significant, in that the main individual organized convective systems were successfully introduced into the model state, both in terms of timing and localization. Also, incorrectly localized precipitation in the model reference run without rainfall assimilation was correctly reduced to about the observed levels. On the other hand, the

Equatorial radar system

NASA Technical Reports Server (NTRS)

Rukao, S.; Tsuda, T.; Sato, T.; Kato, S.

1989-01-01

A large clear air radar with the sensitivity of an incoherent scatter radar for observing the whole equatorial atmosphere up to 1000 km altitude is now being designed in Japan. The radar, called the Equatorial Radar, will be built in Pontianak, Kalimantan Island, Indonesia (0.03 N, 109.3 E). The system is a 47 MHz monostatic Doppler radar with an active phased array configuration similar to that of the MU radar in Japan, which has been in successful operation since 1983. It will have a PA product of more than 5 x 10(9) sq. Wm (P = average transmitter power, A = effective antenna aperture) with sensitivity more than 10 times that of the MU radar. This system configuration enables pulse-to-pulse beam steering within 25 deg from the zenith. As is the case of the MU radar, a variety of sophisticated operations will be made feasible under the supervision of the radar controller. A brief description of the system configuration is presented.

Monsoon Convection during the South China Sea Monsoon Experiment Observed from Shipboard Radar and the TRMM Satellite

NASA Technical Reports Server (NTRS)

Rickenbach, Tom; Cifelli, Rob; Halverson, Jeff; Kucera, Paul; Atkinson, Lester; Fisher, Brad; Gerlach, John; Harris, Kathy; Kaufman, Cristina; Liu, Ching-Hwang;

Radar sensing via a Micro-UAV-borne system

NASA Astrophysics Data System (ADS)

Catapano, Ilaria; Ludeno, Giovanni; Gennarelli, Gianluca; Soldovieri, Francesco; Rodi Vetrella, Amedeo; Fasano, Giancarmine

2017-04-01

-equipped drone. The system is made by a commercial radar system, whose mass, size, power and cost budgets is compatible with the installation on micro-UAV. The radar system has been mounted on a DJI 550 UAV, a flexible hexacopter allowing both complex flight operations and static flight, and has been equipped with small size log-periodic antennas, having a 6 dB gain over the frequency range from 2 GHz to 11 GHz. An ad-hoc signal processing chain has been adopted to process the collected raw data and obtain an image of the investigated scenario providing an accurate target detection and localization. This chain involves a SVD-based noise filter procedure and an advanced data processing approach, which assumes a linear model of the underlying scattering phenomenon. REFERENCES [1] K. Whitehead, C. H. Hugenholtz, "Remote sensing of the environment with small unmanned aircraft systems (UASs), part 1: a review of progress and challenges", J. Unmanned Vehicle Systems, vol.2, pp. 69-85, 2014. [2] K. Ouchi, Recent trend and advance of synthetic aperture radar with selected topics, Remote Sens, vol.5, pp.716-807, 2013. [3] D. Altdor et al., UAV-borne electromagnetic induction and ground-penetrating radar measurements: a feasibility test, 74th Annual Meeting of the Deutsche Geophysikalische Gesellschaft in Karlsruhe, Germany, March 9 - 13, 2014.

Ground penetrating radar for underground sensing in agriculture: a review

NASA Astrophysics Data System (ADS)

Liu, Xiuwei; Dong, Xuejun; Leskovar, Daniel I.

2016-10-01

Belowground properties strongly affect agricultural productivity. Traditional methods for quantifying belowground properties are destructive, labor-intensive and pointbased. Ground penetrating radar can provide non-invasive, areal, and repeatable underground measurements. This article reviews the application of ground penetrating radar for soil and root measurements and discusses potential approaches to overcome challenges facing ground penetrating radar-based sensing in agriculture, especially for soil physical characteristics and crop root measurements. Though advanced data-analysis has been developed for ground penetrating radar-based sensing of soil moisture and soil clay content in civil engineering and geosciences, it has not been used widely in agricultural research. Also, past studies using ground penetrating radar in root research have been focused mainly on coarse root measurement. Currently, it is difficult to measure individual crop roots directly using ground penetrating radar, but it is possible to sense root cohorts within a soil volume grid as a functional constituent modifying bulk soil dielectric permittivity. Alternatively, ground penetrating radarbased sensing of soil water content, soil nutrition and texture can be utilized to inversely estimate root development by coupling soil water flow modeling with the seasonality of plant root growth patterns. Further benefits of ground penetrating radar applications in agriculture rely on the knowledge, discovery, and integration among differing disciplines adapted to research in agricultural management.

The Next Generation Airborne Polarimetric Doppler Radar

NASA Astrophysics Data System (ADS)

Vivekanandan, J.; Lee, Wen-Chau; Loew, Eric; Salazar, Jorge; Chandrasekar, V.

2013-04-01

aircraft in its fleet for airborne atmospheric measurements, including dropsonde, and in situ sampling and remote sensing of clouds, chemistry and aerosols. Therefore, the addition of a precipitation radar to the NSF/NCAR C-130 platform will produce transformational change in its mission. This new design can be cloned for C-130s operated by a number of agencies, including NOAA and the Air Force hurricane reconnaissance fleet. This paper presents a possible configuration of a novel, airborne phased array radar (APAR) to be installed on the NSF/NCAR C-130 aircraft with improved spatial resolution and polarimetric capability to meet or exceed that of ELDORA. The preliminary design, an update of the APAR project, and a future plan will be presented. References: Bell, M. M. , M. T. Montgomery, 2008: Observed Structure, Evolution, and Potential Intensity of Category 5 Hurricane Isabel (2003) from 12 to 14 September. Monthly Weather Review, Vol. 136, Issue 6, pp. 2023-2046. Hildebrand, P. H., W.-C. Lee, C. A. Walther, C. Frush, M. Randall, E. Loew, R. Neitzel, R. Parsons, J. Testud, F. Baudin, and A. LeCornec, 1996: The ELDORA/ASTRAIA airborne Doppler weather radar: High resolution observations from TOGA COARE. Bull. Amer. Metoro. Soc., 77, 213-232 Howard B. Bluestein, Roger M. Wakimoto, 2003: Mobile Radar Observations of Severe Convective Storms re Convective Storms. Meteorological Monographs, Vol. 30, Issue 52, pp. 105-105. Montgomery, M. T., M. M. Bell, S. D. Aberson, M. L. Black, 2006: Hurricane Isabel (2003): New Insights into the Physics of Intense Storms. Part I: Mean Vortex Structure and Maximum Intensity Estimates. Bull. of the American Meteorl. Soc., Vol. 87, Issue 10, pp. 1335-1347.

Polarization differences in airborne ground penetrating radar performance for landmine detection

NASA Astrophysics Data System (ADS)

Dogaru, Traian; Le, Calvin

2016-05-01

The U.S. Army Research Laboratory (ARL) has investigated the ultra-wideband (UWB) radar technology for detection of landmines, improvised explosive devices and unexploded ordnance, for over two decades. This paper presents a phenomenological study of the radar signature of buried landmines in realistic environments and the performance of airborne synthetic aperture radar (SAR) in detecting these targets as a function of multiple parameters: polarization, depression angle, soil type and burial depth. The investigation is based on advanced computer models developed at ARL. The analysis includes both the signature of the targets of interest and the clutter produced by rough surface ground. Based on our numerical simulations, we conclude that low depression angles and H-H polarization offer the highest target-to-clutter ratio in the SAR images and therefore the best radar performance of all the scenarios investigated.

Application of wind-profiling radar data to the analysis of dust weather in the Taklimakan Desert.

PubMed

Wang, Minzhong; Wei, Wenshou; Ruan, Zheng; He, Qing; Ge, Runsheng

2013-06-01

The Urumqi Institute of Desert Meteorology of the China Meteorological Administration carried out an atmospheric scientific experiment to detect dust weather using a wind-profiling radar in the hinterland of the Taklimakan Desert in April 2010. Based on the wind-profiling data obtained from this experiment, this paper seeks to (a) analyze the characteristics of the horizontal wind field and vertical velocity of a breaking dust weather in a desert hinterland; (b) calculate and give the radar echo intensity and vertical distribution of a dust storm, blowing sand, and floating dust weather; and (c) discuss the atmosphere dust counts/concentration derived from the wind-profiling radar data. Studies show that: (a) A wind-profiling radar is an upper-air atmospheric remote sensing system that effectively detects and monitors dust. It captures the beginning and ending of a dust weather process as well as monitors the sand and dust being transported in the air in terms of height, thickness, and vertical intensity. (b) The echo intensity of a blowing sand and dust storm weather episode in Taklimakan is about -1~10 dBZ while that of floating dust -1~-15 dBZ, indicating that the dust echo intensity is significantly weaker than that of precipitation but stronger than that of clear air. (c) The vertical shear of horizontal wind and the maintenance of low-level east wind are usually dynamic factors causing a dust weather process in Taklimakan. The moment that the low-level horizontal wind field finds a shear over time, it often coincides with the onset of a sand blowing and dust storm weather process. (d) When a blowing sand or dust storm weather event occurs, the atmospheric vertical velocity tends to be of upward motion. This vertical upward movement of the atmosphere supported with a fast horizontal wind and a dry underlying surface carries dust particles from the ground up to the air to form blown sand or a dust storm.

Extraction of advanced geospatial intelligence (AGI) from commercial synthetic aperture radar imagery

NASA Astrophysics Data System (ADS)

Kanberoglu, Berkay; Frakes, David

2017-04-01

The extraction of objects from advanced geospatial intelligence (AGI) products based on synthetic aperture radar (SAR) imagery is complicated by a number of factors. For example, accurate detection of temporal changes represented in two-color multiview (2CMV) AGI products can be challenging because of speckle noise susceptibility and false positives that result from small orientation differences between objects imaged at different times. These cases of apparent motion can result in 2CMV detection, but they obviously differ greatly in terms of significance. In investigating the state-of-the-art in SAR image processing, we have found that differentiating between these two general cases is a problem that has not been well addressed. We propose a framework of methods to address these problems. For the detection of the temporal changes while reducing the number of false positives, we propose using adaptive object intensity and area thresholding in conjunction with relaxed brightness optical flow algorithms that track the motion of objects across time in small regions of interest. The proposed framework for distinguishing between actual motion and misregistration can lead to more accurate and meaningful change detection and improve object extraction from a SAR AGI product. Results demonstrate the ability of our techniques to reduce false positives up to 60%.

Fusion of radar and ultrasound sensors for concealed weapons detection

NASA Astrophysics Data System (ADS)

Felber, Franklin S.; Davis, Herbert T., III; Mallon, Charles E.; Wild, Norbert C.

1996-06-01

An integrated radar and ultrasound sensor, capable of remotely detecting and imaging concealed weapons, is being developed. A modified frequency-agile, mine-detection radar is intended to specify with high probability of detection at ranges of 1 to 10 m which individuals in a moving crowd may be concealing metallic or nonmetallic weapons. Within about 1 to 5 m, the active ultrasound sensor is intended to enable a user to identify a concealed weapon on a moving person with low false-detection rate, achieved through a real-time centimeter-resolution image of the weapon. The goal for sensor fusion is to have the radar acquire concealed weapons at long ranges and seamlessly hand over tracking data to the ultrasound sensor for high-resolution imaging on a video monitor. We have demonstrated centimeter-resolution ultrasound images of metallic and non-metallic weapons concealed on a human at ranges over 1 m. Processing of the ultrasound images includes filters for noise, frequency, brightness, and contrast. A frequency-agile radar has been developed by JAYCOR under the U.S. Army Advanced Mine Detection Radar Program. The signature of an armed person, detected by this radar, differs appreciably from that of the same person unarmed.

Worldwide Weather Radar Imagery May Allow Substantial Increase in Meteorite Fall Recovery

NASA Technical Reports Server (NTRS)

Fries, Marc; Matson, Robert; Schaefer, Jacob; Fries, Jeffery; Hankey, Mike; Anderson, Lindsay

2014-01-01

Weather radar imagery is a valuable new technique for the rapid recovery of meteorite falls, to include falls which would not otherwise be recovered (e.g. Battle Mountain). Weather radar imagery reveals about one new meteorite fall per year (18 falls since 1998), using weather radars in the United States alone. However, an additional 75 other nations operate weather radar networks according to the UN World Meteorological Organization (WMO). If the imagery of those radars were analyzed, the current rate of meteorite falls could be improved considerably, to as much as 3.6 times the current recovery rate based on comparison of total radar areal coverage. Recently, the addition of weather radar imagery, seismometry and internet-based aggregation of eyewitness reports has improved the speed and accuracy of fresh meteorite fall recovery [e.g. 1,2]. This was demonstrated recently with the radar-enabled recovery of the Sutter's Mill fall [3]. Arguably, the meteorites recovered via these methods are of special scientific value as they are relatively unweathered, fresh falls. To illustrate this, a recent SAO/NASA ADS search using the keyword "meteorite" shows that all 50 of the top search results included at least one named meteorite recovered from a meteorite fall. This is true even though only 1260 named meteorite falls are recorded among the >49,000 individual falls recorded in the Meteoritical Society online database. The US NEXRAD system used thus far to locate meteorite falls covers most of the United States' surface area. Using a WMO map of the world's weather radars, we estimate that the total coverage of the other 75 national weather radar networks equals about 3.6x NEXRAD's coverage area. There are two findings to draw from this calculation: 1) For the past 16 years during which 18 falls are seen in US radar data, there should be an additional 65 meteorite falls recorded in worldwide radar imagery. Also: 2) if all of the world's radar data could be analyzed, the

Pathfinder radar development at Sandia National Laboratories

NASA Astrophysics Data System (ADS)

Castillo, Steven

2016-05-01

Since the invention of Synthetic Aperture Radar imaging in the 1950's, users or potential users have sought to exploit SAR imagery for a variety of applications including the earth sciences and defense. At Sandia Laboratories, SAR Research and Development and associated defense applications grew out of the nuclear weapons program in the 1980's and over the years has become a highly viable ISR sensor for a variety of tactical applications. Sandia SAR systems excel where real-­-time, high-­-resolution, all-­-weather, day or night surveillance is required for developing situational awareness. This presentation will discuss the various aspects of Sandia's airborne ISR capability with respect to issues related to current operational success as well as the future direction of the capability as Sandia seeks to improve the SAR capability it delivers into multiple mission scenarios. Issues discussed include fundamental radar capabilities, advanced exploitation techniques and human-­-computer interface (HMI) challenges that are part of the advances required to maintain Sandia's ability to continue to support ever changing and demanding mission challenges.

Radar stage uncertainty

USGS Publications Warehouse

Fulford, J.M.; Davies, W.J.

2005-01-01

The U.S. Geological Survey is investigating the performance of radars used for stage (or water-level) measurement. This paper presents a comparison of estimated uncertainties and data for radar water-level measurements with float, bubbler, and wire weight water-level measurements. The radar sensor was also temperature-tested in a laboratory. The uncertainty estimates indicate that radar measurements are more accurate than uncorrected pressure sensors at higher water stages, but are less accurate than pressure sensors at low stages. Field data at two sites indicate that radar sensors may have a small negative bias. Comparison of field radar measurements with wire weight measurements found that the radar tends to measure slightly lower values as stage increases. Copyright ASCE 2005.

Motivational Meteorology.

ERIC Educational Resources Information Center

Benjamin, Lee

1993-01-01

Describes an introductory meteorology course for nonacademic high school students. The course is made hands-on by the use of an educational software program offered by Accu-Weather. The program contains a meteorology database and instructional modules. (PR)

Technology Needs Assessment of an Atmospheric Observation System for Multidisciplinary Air Quality/Meteorology Missions, Part 2

NASA Technical Reports Server (NTRS)

Alvarado, U. R.; Bortner, M. H.; Grenda, R. N.; Brehm, W. F.; Frippel, G. G.; Alyea, F.; Kraiman, H.; Folder, P.; Krowitz, L.

1982-01-01

The technology advancements that will be necessary to implement the atmospheric observation systems are considered. Upper and lower atmospheric air quality and meteorological parameters necessary to support the air quality investigations were included. The technology needs were found predominantly in areas related to sensors and measurements of air quality and meteorological measurements.

Improving Navigation information for the Rotterdam Harbour access through a 3D Model and HF radar

NASA Astrophysics Data System (ADS)

Schroevers, Marinus

2015-04-01

The Port of Rotterdam is one of the largest harbours in the world and a gateway to Europe. For the access to Rotterdam harbour, information on hydrodynamic and meteorological conditions is of vital importance for safe and swift navigation. This information focuses on the deep navigation channel in the shallow foreshore, which accommodates large seagoing vessels. Due to a large seaward extension of the Port of Rotterdam area in 2011, current patterns have changed. A re-evaluation of the information needed, showed a need for an improved accuracy of the cross channel currents and swell, and an extended forecast horizon. To obtain this, new information system was designed based on a three dimensional hydrodynamic model which produces a 72 hour forecast. Furthermore, the system will assimilate HF radars surface current to optimize the short term forecast. The project has started in 2013 by specifying data needed from the HF radar. At the same time (temporary) buoys were deployed to monitor vertical current profiles. The HF radar will be operational in July 2015, while the model development starts beginning 2015. A pre operational version of the system is presently planned for the end of 2016. A full operational version which assimilates the HF radar data is planned for 2017.

Processing for spaceborne synthetic aperture radar imagery

NASA Technical Reports Server (NTRS)

Lybanon, M.

1973-01-01

The data handling and processing in using synthetic aperture radar as a satellite-borne earth resources remote sensor is considered. The discussion covers the nature of the problem, the theory, both conventional and potential advanced processing techniques, and a complete computer simulation. It is shown that digital processing is a real possibility and suggests some future directions for research.

Capturing atmospheric effects on 3D millimeter wave radar propagation patterns

NASA Astrophysics Data System (ADS)

Cook, Richard D.; Fiorino, Steven T.; Keefer, Kevin J.; Stringer, Jeremy

2016-05-01

Traditional radar propagation modeling is done using a path transmittance with little to no input for weather and atmospheric conditions. As radar advances into the millimeter wave (MMW) regime, atmospheric effects such as attenuation and refraction become more pronounced than at traditional radar wavelengths. The DoD High Energy Laser Joint Technology Offices High Energy Laser End-to-End Operational Simulation (HELEEOS) in combination with the Laser Environmental Effects Definition and Reference (LEEDR) code have shown great promise simulating atmospheric effects on laser propagation. Indeed, the LEEDR radiative transfer code has been validated in the UV through RF. Our research attempts to apply these models to characterize the far field radar pattern in three dimensions as a signal propagates from an antenna towards a point in space. Furthermore, we do so using realistic three dimensional atmospheric profiles. The results from these simulations are compared to those from traditional radar propagation software packages. In summary, a fast running method has been investigated which can be incorporated into computational models to enhance understanding and prediction of MMW propagation through various atmospheric and weather conditions.

Distributions of Orbital Elements for Meteoroids on Near-Parabolic Orbits According to Radar Observational Data

NASA Technical Reports Server (NTRS)

Kolomiyets, S. V.

2011-01-01

Some results of the International Heliophysical Year (IHY) Coordinated Investigation Program (CIP) number 65 Meteors in the Earth Atmosphere and Meteoroids in the Solar System are presented. The problem of hyperbolic and near-parabolic orbits is discussed. Some possibilities for the solution of this problem can be obtained from the radar observation of faint meteors. The limiting magnitude of the Kharkov, Ukraine, radar observation program in the 1970 s was +12, resulting in a very large number of meteors being detected. 250,000 orbits down to even fainter limiting magnitude were determined in the 1972-78 period in Kharkov (out of them 7,000 are hyperbolic). The hypothesis of hyperbolic meteors was confirmed. In some radar meteor observations 1 10% of meteors are hyperbolic meteors. Though the Advanced Meteor Orbit Radar (AMOR, New Zealand) and Canadian Meteor Orbit Radar (CMOR, Canada) have accumulated millions of meteor orbits, there are difficulties in comparing the radar observational data obtained from these three sites (New Zealand, Canada, Kharkov). A new global program International Space Weather Initiative (ISWI) has begun in 2010 (http://www.iswi-secretariat.org). Today it is necessary to create the unified radar catalogue of nearparabolic and hyperbolic meteor orbits in the framework of the ISWI, or any other different way, in collaboration of Ukraine, Canada, New Zealand, the USA and, possibly, Japan. Involvement of the Virtual Meteor Observatory (Netherlands) and Meteor Data Centre (Slovakia) is desirable too. International unified radar catalogue of near-parabolic and hyperbolic meteor orbits will aid to a major advance in our understanding of the ecology of meteoroids within the Solar System and beyond.

Development of NASA's Next Generation L-Band Digital Beamforming Synthetic Aperture Radar (DBSAR-2)

NASA Technical Reports Server (NTRS)

Rincon, Rafael; Fatoyinbo, Temilola; Osmanoglu, Batuhan; Lee, Seung-Kuk; Ranson, K. Jon; Marrero, Victor; Yeary, Mark

2014-01-01

NASA's Next generation Digital Beamforming SAR (DBSAR-2) is a state-of-the-art airborne L-band radar developed at the NASA Goddard Space Flight Center (GSFC). The instrument builds upon the advanced architectures in NASA's DBSAR-1 and EcoSAR instruments. The new instrument employs a 16-channel radar architecture characterized by multi-mode operation, software defined waveform generation, digital beamforming, and configurable radar parameters. The instrument has been design to support several disciplines in Earth and Planetary sciences. The instrument was recently completed, and tested and calibrated in a anechoic chamber.

Radar backscatter from the sea: Controlled experiments

NASA Astrophysics Data System (ADS)

Moore, R. K.

1992-04-01

The subwindowing method of modelling synthetic-aperture-radar (SAR) imaging of ocean waves was extended to allow wave propagation in arbitrary directions. Simulated images show that the SAR image response to swells that are imaged by velocity bunching is reduced by random smearing due to wind-generated waves. The magnitude of this response is not accurately predicted by introducing a finite coherence time in the radar backscatter. The smearing does not affect the imaging of waves by surface radar cross-section modulation, and is independent of the wind direction. Adjusting the focus of the SAR processor introduces an offset in the image response of the surface scatters. When adjusted by one-half the azimuthal phase velocity of the wave, this compensates the incoherent advance of the wave being imaged, leading to a higher image contrast. The azimuthal cut-off and range rotation of the spectral peak are predicted when the imaging of wind-generated wave trains is simulated. The simulated images suggest that velocity bunching and azimuthal smearing are strongly interdependent, and cannot be included in a model separately.

3. VIEW NORTHWEST, height finder radar towers, and radar tower ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. VIEW NORTHWEST, height finder radar towers, and radar tower (unknown function) - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

Earth Observing System/Meteorological Satellite (EOS/METSAT). Advanced Microwave Sounding Unit-A (AMSU-A) Contamination Control Plan

NASA Technical Reports Server (NTRS)

Fay, M.

1998-01-01

This Contamination Control Plan is submitted in response the Contract Document requirements List (CDRL) 007 under contract NAS5-32314 for the Earth Observing System (EOS) Advanced Microwave Sounding Unit A (AMSU-A). In response to the CDRL instructions, this document defines the level of cleanliness and methods/procedures to be followed to achieve adequate cleanliness/contamination control, and defines the required approach to maintain cleanliness/contamination control through shipping, observatory integration, test, and flight. This plan is also applicable to the Meteorological Satellite (METSAT) except where requirements are identified as EOS-specific. This plan is based on two key factors: a. The EOS/METSAT AMSU-A Instruments are not highly contamination sensitive. b. Potential contamination of other EOS Instruments is a key concern as addressed in Section 9/0 of the Performance Assurance Requirements for EOS/METSAT Integrated Programs AMSU-A Instrument (MR) (NASA Specification S-480-79).

A Wing Pod-based Millimeter Wave Cloud Radar on HIAPER

NASA Astrophysics Data System (ADS)

Vivekanandan, Jothiram; Tsai, Peisang; Ellis, Scott; Loew, Eric; Lee, Wen-Chau; Emmett, Joanthan

2014-05-01

observed sensitivity as low as -37 dBZ at 1 km range and resolved linear depolarization ratio (LDR) signature better than -29 dB during its latest test flights. References: Kollias, P., and B. A. Albrecht, 2000: The turbulence structure in a continental stratocumulus cloud from millimeter wavelength radar observation. J. Atmos. Sci., 57, 2417-2434. Kollias, P., B.A. Albrecht, R. Lhermitte, and A. Savtchenko, 2001: Radar observations of updrafts, downdrafts, and turbulence in fair weather cumuli. J. Atmos. Sci. 58, 1750-1766. Laursen, K. K., D. P. Jorgensen, G. P. Brasseur, S. L. Ustin, and J. Hunning, 2006: HIAPER: The next generation NSF/NCAR research aircraft. Bulletin of the American Meteorological Society, 87, 896-909. Pazmany, A. L., R. E. McIntosh, R. Kelly, and V. G., 1994: An airborne 95-GHz dual-polarized radar for cloud studies. IEEE Trans. Geosci. Remote Sens., 32, 731-739. Vali, G., Kelly, R.D., French, J., Haimov, S., Leon, D., McIntosh, R., Pazmany, A., 1998. Fine-scale structure and microphysics of coastal stratus. J. Atmos. Sci. 55, 3540-3564.

Application of Radar Data to Remote Sensing and Geographical Information Systems

NASA Technical Reports Server (NTRS)

vanZyl, Jakob J.

2000-01-01

The field of synthetic aperture radar changed dramatically over the past decade with the operational introduction of advance radar techniques such as polarimetry and interferometry. Radar polarimetry became an operational research tool with the introduction of the NASA/JPL AIRSAR system in the early 1980's, and reached a climax with the two SIR-C/X-SAR flights on board the space shuttle Endeavour in April and October 1994. Radar interferometry received a tremendous boost when the airborne TOPSAR system was introduced in 1991 by NASA/JPL, and further when data from the European Space Agency ERS-1 radar satellite became routinely available in 1991. Several airborne interferometric SAR systems are either currently operational, or are about to be introduced. Radar interferometry is a technique that allows one to map the topography of an area automatically under all weather conditions, day or night. The real power of radar interferometry is that the images and digital elevation models are automatically geometrically resampled, and could be imported into GIS systems directly after suitable reformatting. When combined with polarimetry, a technique that uses polarization diversity to gather more information about the geophysical properties of the terrain, a very rich multi-layer data set is available to the remote sensing scientist. This talk will discuss the principles of radar interferometry and polarimetry with specific application to the automatic categorization of land cover. Examples will include images acquired with the NASA/JPL AIRSAR/TOPSAR system in Australia and elsewhere.

Debris Flux Comparisons From The Goldstone Radar, Haystack Radar, and Hax Radar Prior, During, and After the Last Solar Maximum

NASA Technical Reports Server (NTRS)

Stokely, C. L.; Stansbery, E. G.; Goldstein, R. M.

2006-01-01

The continual monitoring of low Earth orbit (LEO) debris environment using highly sensitive radars is essential for an accurate characterization of these dynamic populations. Debris populations are continually evolving since there are new debris sources, previously unrecognized debris sources, and debris loss mechanisms that are dependent on the dynamic space environment. Such radar data are used to supplement, update, and validate existing orbital debris models. NASA has been utilizing radar observations of the debris environment for over a decade from three complementary radars: the NASA JPL Goldstone radar, the MIT Lincoln Laboratory (MIT/LL) Long Range Imaging Radar (known as the Haystack radar), and the MIT/LL Haystack Auxiliary radar (HAX). All of these systems are highly sensitive radars that operate in a fixed staring mode to statistically sample orbital debris in the LEO environment. Each of these radars is ideally suited to measure debris within a specific size region. The Goldstone radar generally observes objects with sizes from 2 mm to 1 cm. The Haystack radar generally measures from 5 mm to several meters. The HAX radar generally measures from 2 cm to several meters. These overlapping size regions allow a continuous measurement of cumulative debris flux versus diameter from 2 mm to several meters for a given altitude window. This is demonstrated for all three radars by comparing the debris flux versus diameter over 200 km altitude windows for 3 nonconsecutive years from 1998 through 2003. These years correspond to periods before, during, and after the peak of the last solar cycle. Comparing the year to year flux from Haystack for each of these altitude regions indicate statistically significant changes in subsets of the debris populations. Potential causes of these changes are discussed. These analysis results include error bars that represent statistical sampling errors, and are detailed in this paper.

Planetary radar studies

NASA Technical Reports Server (NTRS)

Thompson, T. W.; Cutts, J. A.

1981-01-01

A catalog of lunar and radar anomalies was generated to provide a base for comparison with Venusian radar signatures. The relationships between lunar radar anomalies and regolith processes were investigated, and a consortium was formed to compare lunar and Venusian radar images of craters. Time was scheduled at the Arecibo Observatory to use the 430 MHz radar to obtain high resolution radar maps of six areas of the lunar suface. Data from 1978 observations of Mare Serenitas and Plato are being analyzed on a PDP 11/70 computer to construct the computer program library necessary for the eventual reduction of the May 1981 and subsequent data acquisitions. Papers accepted for publication are presented.

Investigation of the relationships between DCS cloud properties, lifecycle, and precipitation with meteorological regimes and aerosol sources at the ARM SGP Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dong, Xiquan

In this proposed research, we will investigate how different meteorological regimes and aerosol sources affect DCS properties, diurnal and life cycles, and precipitation using multiple observational platforms (surface, satellite, and aircraft) and NARR reanalysis at the ARM SGP site. The Feng et al. (2011, 2012) DCS results will serve as a starting point for this proposed research, and help us to address some fundamental issues of DCSs, such as convective initiation, rain rate, areal extent (including stratiform and convective regions), and longevity. Convective properties will be stratified by meteorological regime (synoptic/mesoscale patterns) identified by reanalysis. Aerosol information obtained from themore » ARM SGP site will also be stratified by meteorological regimes to understand their effects on convection. Finally, the aircraft in-situ measurements and various radar observations and retrievals during the MC3E campaign will provide a “cloud-truth” dataset and are an invaluable data source for verifying the findings and investigating the proposed hypotheses in Objective 1.« less

Planetary radar studies. [radar mapping of the Moon and radar signatures of lunar and Venus craters

NASA Technical Reports Server (NTRS)

Thompson, T. W.; Cutts, J. A.

1981-01-01

Progress made in studying the evolution of Venusian craters and the evolution of infrared and radar signatures of lunar crater interiors is reported. Comparison of radar images of craters on Venus and the Moon present evidence for a steady state Venus crater population. Successful observations at the Arecibo Observatory yielded good data on five nights when data for a mix of inner and limb areas were acquired. Lunar craters with radar bright ejects are discussed. An overview of infrared radar crater catalogs in the data base is included.

An advanced stochastic weather generator for simulating 2-D high-resolution climate variables

NASA Astrophysics Data System (ADS)

Peleg, Nadav; Fatichi, Simone; Paschalis, Athanasios; Molnar, Peter; Burlando, Paolo

2017-07-01

A new stochastic weather generator, Advanced WEather GENerator for a two-dimensional grid (AWE-GEN-2d) is presented. The model combines physical and stochastic approaches to simulate key meteorological variables at high spatial and temporal resolution: 2 km × 2 km and 5 min for precipitation and cloud cover and 100 m × 100 m and 1 h for near-surface air temperature, solar radiation, vapor pressure, atmospheric pressure, and near-surface wind. The model requires spatially distributed data for the calibration process, which can nowadays be obtained by remote sensing devices (weather radar and satellites), reanalysis data sets and ground stations. AWE-GEN-2d is parsimonious in terms of computational demand and therefore is particularly suitable for studies where exploring internal climatic variability at multiple spatial and temporal scales is fundamental. Applications of the model include models of environmental systems, such as hydrological and geomorphological models, where high-resolution spatial and temporal meteorological forcing is crucial. The weather generator was calibrated and validated for the Engelberg region, an area with complex topography in the Swiss Alps. Model test shows that the climate variables are generated by AWE-GEN-2d with a level of accuracy that is sufficient for many practical applications.

Apollo experience report: Lunar module landing radar and rendezvous radar

NASA Technical Reports Server (NTRS)

Rozas, P.; Cunningham, A. R.

1972-01-01

A developmental history of the Apollo lunar module landing and rendezvous radar subsystems is presented. The Apollo radar subsystems are discussed from initial concept planning to flight configuration testing. The major radar subsystem accomplishments and problems are discussed.

30. Perimeter acquisition radar building room #318, showing radar control. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

30. Perimeter acquisition radar building room #318, showing radar control. Console and line printers - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

Planetary Radar

NASA Technical Reports Server (NTRS)

Neish, Catherine D.; Carter, Lynn M.

2015-01-01

This chapter describes the principles of planetary radar, and the primary scientific discoveries that have been made using this technique. The chapter starts by describing the different types of radar systems and how they are used to acquire images and accurate topography of planetary surfaces and probe their subsurface structure. It then explains how these products can be used to understand the properties of the target being investigated. Several examples of discoveries made with planetary radar are then summarized, covering solar system objects from Mercury to Saturn. Finally, opportunities for future discoveries in planetary radar are outlined and discussed.

Radar orthogonality and radar length in Finsler and metric spacetime geometry

NASA Astrophysics Data System (ADS)

Pfeifer, Christian

2014-09-01

The radar experiment connects the geometry of spacetime with an observers measurement of spatial length. We investigate the radar experiment on Finsler spacetimes which leads to a general definition of radar orthogonality and radar length. The directions radar orthogonal to an observer form the spatial equal time surface an observer experiences and the radar length is the physical length the observer associates to spatial objects. We demonstrate these concepts on a forth order polynomial Finsler spacetime geometry which may emerge from area metric or premetric linear electrodynamics or in quantum gravity phenomenology. In an explicit generalization of Minkowski spacetime geometry we derive the deviation from the Euclidean spatial length measure in an observers rest frame explicitly.

A Technique for Real-Time Ionospheric Ranging Error Correction Based On Radar Dual-Frequency Detection

NASA Astrophysics Data System (ADS)

Lyu, Jiang-Tao; Zhou, Chen

2017-12-01

Ionospheric refraction is one of the principal error sources for limiting the accuracy of radar systems for space target detection. High-accuracy measurement of the ionospheric electron density along the propagation path of radar wave is the most important procedure for the ionospheric refraction correction. Traditionally, the ionospheric model and the ionospheric detection instruments, like ionosonde or GPS receivers, are employed for obtaining the electron density. However, both methods are not capable of satisfying the requirements of correction accuracy for the advanced space target radar system. In this study, we propose a novel technique for ionospheric refraction correction based on radar dual-frequency detection. Radar target range measurements at two adjacent frequencies are utilized for calculating the electron density integral exactly along the propagation path of the radar wave, which can generate accurate ionospheric range correction. The implementation of radar dual-frequency detection is validated by a P band radar located in midlatitude China. The experimental results present that the accuracy of this novel technique is more accurate than the traditional ionospheric model correction. The technique proposed in this study is very promising for the high-accuracy radar detection and tracking of objects in geospace.

Calibration of a 35-GHz Airborne Cloud Radar: Lessons Learned and Intercomparison with a 94-GHz Airborne Cloud Radar

NASA Astrophysics Data System (ADS)

Ewald, Florian; Gross, Silke; Hagen, Martin; Hirsch, Lutz; Delanoë, Julien

2017-04-01

Clouds play an important role in the climate system since they have a profound influence on Earth's radiation budget and the water cycle. Uncertainties associated with their spatial characteristics as well as their microphysics still introduce large uncertainties in climate change predictions. In recent years, our understanding of the inner workings of clouds has been greatly advanced by the deployment of cloud profiling microwave radars from ground as well as from space like CloudSat or the upcoming EarthCARE satellite mission. In order to validate and assess the limitations of these spaceborne missions, a well-calibrated, airborne cloud radar with known sensitivity to clouds is indispensable. Within this context, the German research aircraft HALO was equipped with the high-power (30kW peak power) cloud radar operating at 35 GHz and a high spectral resolution lidar (HSRL) system at 532 nm. During a number of flight experiments over Europe and over the tropical and extra-tropical North-Atlantic, several radar calibration efforts have been made using the ocean surface backscatter. Moreover, CloudSat underflights have been conducted to compare the radar reflectivity and measurement sensitivity between the air- and spaceborne instruments. Additionally, the influence of different radar wavelengths was explored with joint flights of HALO and the French Falcon 20 aircraft, which was equipped with the RASTA cloud radar at 94 GHz and a HSRL at 355 nm. In this presentation, we will give an overview of lessons learned from different calibration strategies using the ocean surface backscatter. Additional measurements of signal linearity and signal saturation will complement this characterization. Furthermore, we will focus on the coordinated airborne measurements regarding the different sensitivity for clouds at 35 GHz and 94 GHz. By using the highly sensitive lidar signals, we show if the high-power cloud radar at 35 GHz can be used to validate spaceborne and airborne

Development of a synthetic aperture radar design approach for wide-swath implementation

NASA Technical Reports Server (NTRS)

Jean, B. R.

1981-01-01

The first phase of a study program to develop an advanced synthetic aperture radar design concept is presented. Attributes of particular importance for the system design include wide swath coverage, reduced power requirements, and versatility in the selection of frequency, polarization and incident angle. The multiple beam configuration provides imaging at a nearly constant angle of incidence and offers the potential of realizing a wide range of the attributes desired for an orbital imaging radar for Earth resources applications.

Using microwave Doppler radar in automated manufacturing applications

NASA Astrophysics Data System (ADS)

Smith, Gregory C.

Since the beginning of the Industrial Revolution, manufacturers worldwide have used automation to improve productivity, gain market share, and meet growing or changing consumer demand for manufactured products. To stimulate further industrial productivity, manufacturers need more advanced automation technologies: "smart" part handling systems, automated assembly machines, CNC machine tools, and industrial robots that use new sensor technologies, advanced control systems, and intelligent decision-making algorithms to "see," "hear," "feel," and "think" at the levels needed to handle complex manufacturing tasks without human intervention. The investigator's dissertation offers three methods that could help make "smart" CNC machine tools and industrial robots possible: (1) A method for detecting acoustic emission using a microwave Doppler radar detector, (2) A method for detecting tool wear on a CNC lathe using a Doppler radar detector, and (3) An online non-contact method for detecting industrial robot position errors using a microwave Doppler radar motion detector. The dissertation studies indicate that microwave Doppler radar could be quite useful in automated manufacturing applications. In particular, the methods developed may help solve two difficult problems that hinder further progress in automating manufacturing processes: (1) Automating metal-cutting operations on CNC machine tools by providing a reliable non-contact method for detecting tool wear, and (2) Fully automating robotic manufacturing tasks by providing a reliable low-cost non-contact method for detecting on-line position errors. In addition, the studies offer a general non-contact method for detecting acoustic emission that may be useful in many other manufacturing and non-manufacturing areas, as well (e.g., monitoring and nondestructively testing structures, materials, manufacturing processes, and devices). By advancing the state of the art in manufacturing automation, the studies may help

Radar Range Sidelobe Reduction Using Adaptive Pulse Compression Technique

NASA Technical Reports Server (NTRS)

Li, Lihua; Coon, Michael; McLinden, Matthew

2013-01-01

Pulse compression has been widely used in radars so that low-power, long RF pulses can be transmitted, rather than a highpower short pulse. Pulse compression radars offer a number of advantages over high-power short pulsed radars, such as no need of high-power RF circuitry, no need of high-voltage electronics, compact size and light weight, better range resolution, and better reliability. However, range sidelobe associated with pulse compression has prevented the use of this technique on spaceborne radars since surface returns detected by range sidelobes may mask the returns from a nearby weak cloud or precipitation particles. Research on adaptive pulse compression was carried out utilizing a field-programmable gate array (FPGA) waveform generation board and a radar transceiver simulator. The results have shown significant improvements in pulse compression sidelobe performance. Microwave and millimeter-wave radars present many technological challenges for Earth and planetary science applications. The traditional tube-based radars use high-voltage power supply/modulators and high-power RF transmitters; therefore, these radars usually have large size, heavy weight, and reliability issues for space and airborne platforms. Pulse compression technology has provided a path toward meeting many of these radar challenges. Recent advances in digital waveform generation, digital receivers, and solid-state power amplifiers have opened a new era for applying pulse compression to the development of compact and high-performance airborne and spaceborne remote sensing radars. The primary objective of this innovative effort is to develop and test a new pulse compression technique to achieve ultrarange sidelobes so that this technique can be applied to spaceborne, airborne, and ground-based remote sensing radars to meet future science requirements. By using digital waveform generation, digital receiver, and solid-state power amplifier technologies, this improved pulse compression

The instrumental principles of MST radars and incoherent scatter radars and the configuration of radar system hardware

NASA Technical Reports Server (NTRS)

Roettger, Juergen

1989-01-01

The principle of pulse modulation used in the case of coherent scatter radars (MST radars) is discussed. Coherent detection and the corresponding system configuration is delineated. Antenna requirements and design are outlined and the phase-coherent transmitter/receiver system is described. Transmit/receive duplexers, transmitters, receivers, and quadrature detectors are explained. The radar controller, integrator, decoder and correlator design as well as the data transfer and the control and monitoring by the host computer are delineated. Typical operation parameters of some well-known radars are summarized.

Sub-Seasonal Variability of Tropical Rainfall Observed by TRMM and Ground-based Polarimetric Radar

NASA Astrophysics Data System (ADS)

Dolan, Brenda; Rutledge, Steven; Lang, Timothy; Cifelli, Robert; Nesbitt, Stephen

2010-05-01

Studies of tropical precipitation characteristics from the TRMM-LBA and NAME field campaigns using ground-based polarimetric S-band data have revealed significant differences in microphysical processes occurring in the various meteorological regimes sampled in those projects. In TRMM-LMA (January-February 1999 in Brazil; a TRMM ground validation experiment), variability is driven by prevailing low-level winds. During periods of low-level easterlies, deeper and more intense convection is observed, while during periods of low-level westerlies, weaker convection embedded in widespread stratiform precipitation is common. In the NAME region (North American Monsoon Experiment, summer 2004 along the west coast of Mexico), strong terrain variability drives differences in precipitation, with larger drops and larger ice mass aloft associated with convection occurring over the coastal plain compared to convection over the higher terrain of the Sierra Madre Occidental, or adjacent coastal waters. Comparisons with the TRMM precipitation radar (PR) indicate that such sub-seasonal variability in these two regions are not well characterized by the TRMM PR reflectivity and rainfall statistics. TRMM PR reflectivity profiles in the LBA region are somewhat lower than S-Pol values, particularly in the more intense easterly regime convection. In NAME, mean reflectivities are even more divergent, with TRMM profiles below those of S-Pol. In both regions, the TRMM PR does not capture rain rates above 80 mm hr-1 despite much higher rain rates estimated from the S-Pol polarimetric data, and rain rates are generally lower for a given reflectivity from TRMM PR compared to S-Pol. These differences between TRMM PR and S-Pol may arise from the inability of Z-R relationships to capture the full variability of microphysical conditions or may highlight problems with TRMM retrievals over land. In addition to the TRMM-LBA and NAME regions, analysis of sub-seasonal precipitation variability and

Removing interfering clutter associated with radar pulses that an airborne radar receives from a radar transponder

DOEpatents

Ormesher, Richard C.; Axline, Robert M.

2008-12-02

Interfering clutter in radar pulses received by an airborne radar system from a radar transponder can be suppressed by developing a representation of the incoming echo-voltage time-series that permits the clutter associated with predetermined parts of the time-series to be estimated. These estimates can be used to estimate and suppress the clutter associated with other parts of the time-series.

Recommendation on Transition from Primary/Secondary Radar to Secondary- Only Radar Capability

DTIC Science & Technology

1994-10-01

Radar Beacon Performance Monitor RCIU Remote Control Interface Unit RCL Remote Communications Link R E&D Research, Engineering and Development RML Radar...rate. 3.1.2.5 Maintenance The current LRRs have limited remote maintenance monitoring (RMM) capabilities via the Remote Control Interface Unit ( RCIU ...1, -2 and FPS-20 radars required an upgrade of some of the radar subsystems, namely the RCIU to respond as an RMS and the CD to interface with radar

New Techniques for Radar Altimetry of Sea Ice and the Polar Oceans

NASA Astrophysics Data System (ADS)

Armitage, T. W. K.; Kwok, R.; Egido, A.; Smith, W. H. F.; Cullen, R.

2017-12-01

Satellite radar altimetry has proven to be a valuable tool for remote sensing of the polar oceans, with techniques for estimating sea ice thickness and sea surface height in the ice-covered ocean advancing to the point of becoming routine, if not operational, products. Here, we explore new techniques in radar altimetry of the polar oceans and the sea ice cover. First, we present results from fully-focused SAR (FFSAR) altimetry; by accounting for the phase evolution of scatterers in the scene, the FFSAR technique applies an inter-burst coherent integration, potentially over the entire duration that a scatterer remains in the altimeter footprint, which can narrow the effective along track resolution to just 0.5m. We discuss the improvement of using interleaved operation over burst-more operation for applying FFSAR processing to data acquired by future missions, such as a potential CryoSat follow-on. Second, we present simulated sea ice retrievals from the Ka-band Radar Interferometer (KaRIn), the instrument that will be launched on the Surface Water and Ocean Topography (SWOT) mission in 2021, that is capable of producing swath images of surface elevation. These techniques offer the opportunity to advance our understanding of the physics of the ice-covered oceans, plus new insight into how we interpret more conventional radar altimetry data in these regions.

Instrument concepts and technologies for future spaceborne atmospheric radars

NASA Astrophysics Data System (ADS)

Im, Eastwood; Durden, Stephen L.

2005-01-01

In conjunction with the implementation of spaceborne atmospheric radar flight missions, NASA is developing advanced instrument concepts and technologies for future spaceborne atmospheric radars, with the over-arching objectives of making such instruments more capable in supporting future science needs, and more cost effective. Two such examples are the Second-Generation Precipitation Radar (PR-2) and the Nexrad-In-Space (NIS). PR-2 is a 14/35-GHz dual-frequency rain radar with a deployable 5-meter, wide-swath scanned membrane antenna, a dual-polarized/dual-frequency receiver, and a real-time digital signal processor. It is intended for Low Earth Orbit (LEO) operations to provide greatly enhanced rainfall profile retrieval accuracy while using only a fraction of the mass of the current TRMM PR. NIS is designed to be a 35-GHz Geostationary Earth Orbiting (GEO) radar with the intent of providing hourly monitoring of the life cycle of hurricanes and tropical storms. It uses a 35-m, spherical, lightweight membrane antenna and Doppler processing to acquire 3-dimensional information on the intensity and vertical motion of hurricane rainfall. Technologies for NIS are synergistic with those for PR-2. During the last two years, several of the technology items associated with these notional instruments have also been prototyped. This paper will give an overview of these instrument design concepts and their associated technologies.

Reconfigurable L-Band Radar

NASA Technical Reports Server (NTRS)

Rincon, Rafael F.

2008-01-01

The reconfigurable L-Band radar is an ongoing development at NASA/GSFC that exploits the capability inherently in phased array radar systems with a state-of-the-art data acquisition and real-time processor in order to enable multi-mode measurement techniques in a single radar architecture. The development leverages on the L-Band Imaging Scatterometer, a radar system designed for the development and testing of new radar techniques; and the custom-built DBSAR processor, a highly reconfigurable, high speed data acquisition and processing system. The radar modes currently implemented include scatterometer, synthetic aperture radar, and altimetry; and plans to add new modes such as radiometry and bi-static GNSS signals are being formulated. This development is aimed at enhancing the radar remote sensing capabilities for airborne and spaceborne applications in support of Earth Science and planetary exploration This paper describes the design of the radar and processor systems, explains the operational modes, and discusses preliminary measurements and future plans.

Assessment of NASA's Physiographic and Meteorological Datasets as Input to HSPF and SWAT Hydrological Models

NASA Technical Reports Server (NTRS)

Alacron, Vladimir J.; Nigro, Joseph D.; McAnally, William H.; OHara, Charles G.; Engman, Edwin Ted; Toll, David

2011-01-01

This paper documents the use of simulated Moderate Resolution Imaging Spectroradiometer land use/land cover (MODIS-LULC), NASA-LIS generated precipitation and evapo-transpiration (ET), and Shuttle Radar Topography Mission (SRTM) datasets (in conjunction with standard land use, topographical and meteorological datasets) as input to hydrological models routinely used by the watershed hydrology modeling community. The study is focused in coastal watersheds in the Mississippi Gulf Coast although one of the test cases focuses in an inland watershed located in northeastern State of Mississippi, USA. The decision support tools (DSTs) into which the NASA datasets were assimilated were the Soil Water & Assessment Tool (SWAT) and the Hydrological Simulation Program FORTRAN (HSPF). These DSTs are endorsed by several US government agencies (EPA, FEMA, USGS) for water resources management strategies. These models use physiographic and meteorological data extensively. Precipitation gages and USGS gage stations in the region were used to calibrate several HSPF and SWAT model applications. Land use and topographical datasets were swapped to assess model output sensitivities. NASA-LIS meteorological data were introduced in the calibrated model applications for simulation of watershed hydrology for a time period in which no weather data were available (1997-2006). The performance of the NASA datasets in the context of hydrological modeling was assessed through comparison of measured and model-simulated hydrographs. Overall, NASA datasets were as useful as standard land use, topographical , and meteorological datasets. Moreover, NASA datasets were used for performing analyses that the standard datasets could not made possible, e.g., introduction of land use dynamics into hydrological simulations

Identification of atmospheric boundary layer thickness using doppler radar datas and WRF - ARW model in Merauke

NASA Astrophysics Data System (ADS)

Putri, R. J. A.; Setyawan, T.

2017-01-01

In the synoptic scale, one of the important meteorological parameter is the atmospheric boundary layer. Aside from being a supporter of the parameters in weather and climate models, knowing the thickness of the layer of the atmosphere can help identify aerosols and the strength of the vertical mixing of pollutants in it. The vertical wind profile data from C-band Doppler radar Mopah-Merauke which is operated by BMKG through Mopah-Merauke Meteorological Station can be used to identify the peak of Atmospheric Boundaryu Layer (ABL). ABL peak marked by increasing wind shear over the layer blending. Samples in January 2015 as a representative in the wet and in July 2015 as the representation of a dry month, shows that ABL heights using WRF models show that in July (sunny weather) ABL height values higher than in January (cloudy)

Social Radar

DTIC Science & Technology

2012-01-01

RTA HFM-201/RSM PAPER 3 - 1 © 2012 The MITRE Corporation. All Rights Reserved. Social Radar Barry Costa and John Boiney MITRE Corporation...defenders require an integrated set of capabilities that we refer to as a “ social radar.” Such a system would support strategic- to operational-level...situation awareness, alerting, course of action analysis, and measures of effectiveness for each action undertaken. Success of a social radar

Simulation of meteorological satellite (METSAT) data using LANDSAT data

NASA Technical Reports Server (NTRS)

Austin, W. W.; Ryland, W. E.

1983-01-01

The information content which can be expected from the advanced very high resolution radiometer system, AVHRR, on the NOAA-6 satellite was assessed, and systematic techniques of data interpretation for use with meteorological satellite data were defined. In-house data from LANDSAT 2 and 3 were used to simulate the spatial, spectral, and sampling methods of the NOAA-6 satellite data.

Coupled hydro-meteorological modelling on a HPC platform for high-resolution extreme weather impact study

NASA Astrophysics Data System (ADS)

Zhu, Dehua; Echendu, Shirley; Xuan, Yunqing; Webster, Mike; Cluckie, Ian

2016-11-01

Impact-focused studies of extreme weather require coupling of accurate simulations of weather and climate systems and impact-measuring hydrological models which themselves demand larger computer resources. In this paper, we present a preliminary analysis of a high-performance computing (HPC)-based hydrological modelling approach, which is aimed at utilizing and maximizing HPC power resources, to support the study on extreme weather impact due to climate change. Here, four case studies are presented through implementation on the HPC Wales platform of the UK mesoscale meteorological Unified Model (UM) with high-resolution simulation suite UKV, alongside a Linux-based hydrological model, Hydrological Predictions for the Environment (HYPE). The results of this study suggest that the coupled hydro-meteorological model was still able to capture the major flood peaks, compared with the conventional gauge- or radar-driving forecast, but with the added value of much extended forecast lead time. The high-resolution rainfall estimation produced by the UKV performs similarly to that of radar rainfall products in the first 2-3 days of tested flood events, but the uncertainties particularly increased as the forecast horizon goes beyond 3 days. This study takes a step forward to identify how the online mode approach can be used, where both numerical weather prediction and the hydrological model are executed, either simultaneously or on the same hardware infrastructures, so that more effective interaction and communication can be achieved and maintained between the models. But the concluding comments are that running the entire system on a reasonably powerful HPC platform does not yet allow for real-time simulations, even without the most complex and demanding data simulation part.

Radar volume reflectivity estimation using an array of ground-based rainfall drop size detectors

NASA Astrophysics Data System (ADS)

Lane, John; Merceret, Francis; Kasparis, Takis; Roy, D.; Muller, Brad; Jones, W. Linwood

2000-08-01

Rainfall drop size distribution (DSD) measurements made by single disdrometers at isolated ground sites have traditionally been used to estimate the transformation between weather radar reflectivity Z and rainfall rate R. Despite the immense disparity in sampling geometries, the resulting Z-R relation obtained by these single point measurements has historically been important in the study of applied radar meteorology. Simultaneous DSD measurements made at several ground sites within a microscale area may be used to improve the estimate of radar reflectivity in the air volume surrounding the disdrometer array. By applying the equations of motion for non-interacting hydrometers, a volume estimate of Z is obtained from the array of ground based disdrometers by first calculating a 3D drop size distribution. The 3D-DSD model assumes that only gravity and terminal velocity due to atmospheric drag within the sampling volume influence hydrometer dynamics. The sampling volume is characterized by wind velocities, which are input parameters to the 3D-DSD model, composed of vertical and horizontal components. Reflectivity data from four consecutive WSR-88D volume scans, acquired during a thunderstorm near Melbourne, FL on June 1, 1997, are compared to data processed using the 3D-DSD model and data form three ground based disdrometers of a microscale array.

Multidisciplinary studies of the social, economic and political impact resulting from recent advances in satellite meteorology, volume 1

NASA Technical Reports Server (NTRS)

1971-01-01

The multidisciplinary studies explore and evaluate the impact of the meteorological satellite and the concomitant impact of the data derived from it on various user groups. As expected, the primary impact related to those who would use satellite data for weather prediction and related purposes. A secondary impact was in the area of international concerns where GARP and other international meteorological activities were affected and international law was developed. A tertiary impact was exemplified by satellite photographs utilized in advertisements and related materials. The case studies, supporting studies, and independent studies all emphasize the potential of the meteorological satellite.

33. Perimeter acquisition radar building room #320, perimeter acquisition radar ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

33. Perimeter acquisition radar building room #320, perimeter acquisition radar operations center (PAROC), contains the tactical command and control group equipment required to control the par site. Showing spacetrack monitor console - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

Fly eye radar or micro-radar sensor technology

NASA Astrophysics Data System (ADS)

Molchanov, Pavlo; Asmolova, Olga

2014-05-01

To compensate for its eye's inability to point its eye at a target, the fly's eye consists of multiple angularly spaced sensors giving the fly the wide-area visual coverage it needs to detect and avoid the threats around him. Based on a similar concept a revolutionary new micro-radar sensor technology is proposed for detecting and tracking ground and/or airborne low profile low altitude targets in harsh urban environments. Distributed along a border or around a protected object (military facility and buildings, camp, stadium) small size, low power unattended radar sensors can be used for target detection and tracking, threat warning, pre-shot sniper protection and provides effective support for homeland security. In addition it can provide 3D recognition and targets classification due to its use of five orders more pulses than any scanning radar to each space point, by using few points of view, diversity signals and intelligent processing. The application of an array of directional antennas eliminates the need for a mechanical scanning antenna or phase processor. It radically decreases radar size and increases bearing accuracy several folds. The proposed micro-radar sensors can be easy connected to one or several operators by point-to-point invisible protected communication. The directional antennas have higher gain, can be multi-frequency and connected to a multi-functional network. Fly eye micro-radars are inexpensive, can be expendable and will reduce cost of defense.

Interference-Detection Module in a Digital Radar Receiver

NASA Technical Reports Server (NTRS)

Fischman, Mark; Berkun, Andrew; Chu, Anhua; Freedman, Adam; Jourdan, Michael; McWatters, Dalia; Paller, Mimi

2009-01-01

A digital receiver in a 1.26-GHz spaceborne radar scatterometer now undergoing development includes a module for detecting radio-frequency interference (RFI) that could contaminate scientific data intended to be acquired by the scatterometer. The role of the RFI-detection module is to identify time intervals during which the received signal is likely to be contaminated by RFI and thereby to enable exclusion, from further scientific data processing, of signal data acquired during those intervals. The underlying concepts of detection of RFI and rejection of RFI-contaminated signal data are also potentially applicable in advanced terrestrial radio receivers, including software-defined radio receivers in general, receivers in cellular telephones and other wireless consumer electronic devices, and receivers in automotive collision-avoidance radar systems.

Assimilation of radar quantitative precipitation estimations in the Canadian Precipitation Analysis (CaPA)

NASA Astrophysics Data System (ADS)

Fortin, Vincent; Roy, Guy; Donaldson, Norman; Mahidjiba, Ahmed

2015-12-01

The Canadian Precipitation Analysis (CaPA) is a data analysis system used operationally at the Canadian Meteorological Center (CMC) since April 2011 to produce gridded 6-h and 24-h precipitation accumulations in near real-time on a regular grid covering all of North America. The current resolution of the product is 10-km. Due to the low density of the observational network in most of Canada, the system relies on a background field provided by the Regional Deterministic Prediction System (RDPS) of Environment Canada, which is a short-term weather forecasting system for North America. For this reason, the North American configuration of CaPA is known as the Regional Deterministic Precipitation Analysis (RDPA). Early in the development of the CaPA system, weather radar reflectivity was identified as a very promising additional data source for the precipitation analysis, but necessary quality control procedures and bias-correction algorithms were lacking for the radar data. After three years of development and testing, a new version of CaPA-RDPA system was implemented in November 2014 at CMC. This version is able to assimilate radar quantitative precipitation estimates (QPEs) from all 31 operational Canadian weather radars. The radar QPE is used as an observation source and not as a background field, and is subject to a strict quality control procedure, like any other observation source. The November 2014 upgrade to CaPA-RDPA was implemented at the same time as an upgrade to the RDPS system, which brought minor changes to the skill and bias of CaPA-RDPA. This paper uses the frequency bias indicator (FBI), the equitable threat score (ETS) and the departure from the partial mean (DPM) in order to assess the improvements to CaPA-RDPA brought by the assimilation of radar QPE. Verification focuses on the 6-h accumulations, and is done against a network of 65 synoptic stations (approximately two stations per radar) that were withheld from the station data assimilated by Ca

Coherent Doppler Laser Radar: Technology Development and Applications

NASA Technical Reports Server (NTRS)

Kavaya, Michael J.; Arnold, James E. (Technical Monitor)

2000-01-01

NASA's Marshall Space Flight Center has been investigating, developing, and applying coherent Doppler laser radar technology for over 30 years. These efforts have included the first wind measurement in 1967, the first airborne flights in 1972, the first airborne wind field mapping in 1981, and the first measurement of hurricane eyewall winds in 1998. A parallel effort at MSFC since 1982 has been the study, modeling and technology development for a space-based global wind measurement system. These endeavors to date have resulted in compact, robust, eyesafe lidars at 2 micron wavelength based on solid-state laser technology; in a factor of 6 volume reduction in near diffraction limited, space-qualifiable telescopes; in sophisticated airborne scanners with full platform motion subtraction; in local oscillator lasers capable of rapid tuning of 25 GHz for removal of relative laser radar to target velocities over a 25 km/s range; in performance prediction theory and simulations that have been validated experimentally; and in extensive field campaign experience. We have also begun efforts to dramatically improve the fundamental photon efficiency of the laser radar, to demonstrate advanced lower mass laser radar telescopes and scanners; to develop laser and laser radar system alignment maintenance technologies; and to greatly improve the electrical efficiency, cooling technique, and robustness of the pulsed laser. This coherent Doppler laser radar technology is suitable for high resolution, high accuracy wind mapping; for aerosol and cloud measurement; for Differential Absorption Lidar (DIAL) measurements of atmospheric and trace gases; for hard target range and velocity measurement; and for hard target vibration spectra measurement. It is also suitable for a number of aircraft operations applications such as clear air turbulence (CAT) detection; dangerous wind shear (microburst) detection; airspeed, angle of attack, and sideslip measurement; and fuel savings through

Analysis of Active Lava Flows on Kilauea Volcano, Hawaii, Using SIR-C Radar Correlation Measurements

NASA Technical Reports Server (NTRS)

Zebker, H. A.; Rosen, P.; Hensley, S.; Mouginis-Mark, P. J.

1995-01-01

Precise eruption rates of active pahoehoe lava flows on Kilauea volcano, Hawaii, have been determined using spaceborne radar data acquired by the Space Shuttle Imaging Radar-C (SIR-C). Measurement of the rate of lava flow advance, and the determination of the volume of new material erupted in a given period of time, are among the most important observations that can be made when studying a volcano.

Solar Radar Experiments

DTIC Science & Technology

1998-01-01

communications satellites and electric power grids. RELATED PROJECTS Studies with the HAARP radar facility being constructed in Alaska are conducted with...on wave-plasma interactions and also are assessing the possible use of HAARP as a solar radar. REFERENCES James, J. C., Radar studies of the sun, in

Assimilating Thor: How Airmen Integrate Weather Prediction

DTIC Science & Technology

2010-06-01

atmosphere and the earth from the air and from space widened the aperture of data so as to overexpose humans to the panoply of information coming...endurance record flights circled the earth without stopping; aircraft climbed through the atmosphere into space. Weather surveillance radar...advances found congruence in the meteorological advance of ensemble weather modeling. Complex, adaptive systems like the atmosphere lend themselves to

Meteorology for public

NASA Astrophysics Data System (ADS)

Špoler Čanić, Kornelija; Rasol, Dubravka; Milković, Janja

2013-04-01

The Meteorological and Hydrological Service in Croatia (MHSC) is, as a public service, open to and concentrated on public. The organization of visits to the MHSC for groups started in 1986. The GLOBE program in Croatia started in 1995 and after that interest for the group tours at the MHSC has increased. The majority of visitors are school and kindergarten children, students and groups of teachers. For each group tour we try to prepare the content that is suitable for the age and interest of a group. Majority of groups prefer to visit the meteorological station where they can see meteorological instruments and learn how they work. It is organized as a little workshop, where visitors can ask questions and discuss with a guide not only about the meteorological measurements but also about weather and climate phenomena they are interested in. Undoubtedly the highlight of a visit is the forecaster's room where visitors can talk to the forecasters (whom they can also see giving a weather forecast on the national TV station) and learn how weather forecasts are made. Sometimes we offer to visitors to make some meteorological experiments but that is still not in a regular program of the group tours due to the lack of performing space. Therefore we give them the instructions for making instruments and simulations of meteorological phenomena from household items. Visits guides are meteorologists with profound experience in the popularization of science.

The Miniaturization of the AFIT Random Noise Radar

DTIC Science & Technology

2013-03-01

RANDOM NOISE RADAR I. Introduction Recent advances in technology and signal processing techniques have opened thedoor to using an ultra-wide band random...AIR FORCE INSTITUTE OF TECHNOLOGY Wright-Patterson Air Force Base, Ohio DISTRIBUTION STATEMENT A. APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED...and Computer Engineering Graduate School of Engineering and Management Air Force Institute of Technology Air University Air Education and Training

Radiosonde pressure sensor performance - Evaluation using tracking radars

NASA Technical Reports Server (NTRS)

Parsons, C. L.; Norcross, G. A.; Brooks, R. L.

1984-01-01

The standard balloon-borne radiosonde employed for synoptic meteorology provides vertical profiles of temperature, pressure, and humidity as a function of elapsed time. These parameters are used in the hypsometric equation to calculate the geopotential altitude at each sampling point during the balloon's flight. It is important that the vertical location information be accurate. The present investigation was conducted with the objective to evaluate the altitude determination accuracy of the standard radiosonde throughout the entire balloon profile. The tests included two other commercially available pressure sensors to see if they could provide improved accuracy in the stratosphere. The pressure-measuring performance of standard baroswitches, premium baroswitches, and hypsometers in balloon-borne sondes was correlated with tracking radars. It was found that the standard and premium baroswitches perform well up to about 25 km altitude, while hypsometers provide more reliable data above 25 km.

Meteorological satellite accomplishments

NASA Technical Reports Server (NTRS)

Allison, L. J.; Arking, A.; Bandeen, W. R.; Shenk, W. E.; Wexler, R.

1974-01-01

The various types of meteorological satellites are enumerated. Vertical sounding, parameter extraction technique, and both macroscale and mesoscale meteorological phenomena are discussed. The heat budget of the earth-atmosphere system is considered, along with ocean surface and hydrology.

Space Radar Image of Ubar Optical/Radar

NASA Image and Video Library

1998-04-28

This pair of images from space shows a portion of the southern Empty Quarter of the Arabian Peninsula in the country of Oman. On the left is a radar image of the region around the site of the fabled Lost City of Ubar, discovered in 1992 with the aid of remote sensing data. On the right is an enhanced optical image taken by the shuttle astronauts. Ubar existed from about 2800 BC to about 300 AD. and was a remote desert outpost where caravans were assembled for the transport of frankincense across the desert. The actual site of the fortress of the Lost City of Ubar, currently under excavation, is too small to show in either image. However, tracks leading to the site, and surrounding tracks, show as prominent, but diffuse, reddish streaks in the radar image. Although used in modern times, field investigations show many of these tracks were in use in ancient times as well. Mapping of these tracks on regional remote sensing images provided by the Landsat satellite was a key to recognizing the site as Ubar. The prominent magenta colored area is a region of large sand dunes. The green areas are limestone rocks, which form a rocky desert floor. A major wadi, or dry stream bed, runs across the scene and appears as a white line. The radar images, and ongoing field investigations, will help shed light on an early civilization about which little in known. The radar image was taken by the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) and is centered at 18 degrees North latitude and 53 degrees East longitude. The image covers an area about 50 kilometers by 100 kilometers (31 miles by 62 miles). The colors in the image are assigned to different frequencies and polarizations of the radar as follows: red is L-band, horizontally transmitted, horizontally received; blue is C-band horizontally transmitted, horizontally received; green is L-band horizontally transmitted, vertically received. SIR-C/X-SAR, a joint mission of the German, Italian and the United

The New Meteor Radar at Penn State: Design and First Observations

NASA Technical Reports Server (NTRS)

Urbina, J.; Seal, R.; Dyrud, L.

2011-01-01

In an effort to provide new and improved meteor radar sensing capabilities, Penn State has been developing advanced instruments and technologies for future meteor radars, with primary objectives of making such instruments more capable and more cost effective in order to study the basic properties of the global meteor flux, such as average mass, velocity, and chemical composition. Using low-cost field programmable gate arrays (FPGAs), combined with open source software tools, we describe a design methodology enabling one to develop state-of-the art radar instrumentation, by developing a generalized instrumentation core that can be customized using specialized output stage hardware. Furthermore, using object-oriented programming (OOP) techniques and open-source tools, we illustrate a technique to provide a cost-effective, generalized software framework to uniquely define an instrument s functionality through a customizable interface, implemented by the designer. The new instrument is intended to provide instantaneous profiles of atmospheric parameters and climatology on a daily basis throughout the year. An overview of the instrument design concepts and some of the emerging technologies developed for this meteor radar are presented.

Analysis of airborne Doppler lidar, Doppler radar and tall tower measurements of atmospheric flows in quiescent and stormy weather

NASA Technical Reports Server (NTRS)

Bluestein, H. B.; Doviak, R. J.; Eilts, M. D.; Mccaul, E. W.; Rabin, R.; Sundara-Rajan, A.; Zrnic, D. S.

1986-01-01

The first experiment to combine airborne Doppler Lidar and ground-based dual Doppler Radar measurements of wind to detail the lower tropospheric flows in quiescent and stormy weather was conducted in central Oklahoma during four days in June-July 1981. Data from these unique remote sensing instruments, coupled with data from conventional in-situ facilities, i.e., 500-m meteorological tower, rawinsonde, and surface based sensors, were analyzed to enhance understanding of wind, waves and turbulence. The purposes of the study were to: (1) compare winds mapped by ground-based dual Doppler radars, airborne Doppler lidar, and anemometers on a tower; (2) compare measured atmospheric boundary layer flow with flows predicted by theoretical models; (3) investigate the kinematic structure of air mass boundaries that precede the development of severe storms; and (4) study the kinematic structure of thunderstorm phenomena (downdrafts, gust fronts, etc.) that produce wind shear and turbulence hazardous to aircraft operations. The report consists of three parts: Part 1, Intercomparison of Wind Data from Airborne Lidar, Ground-Based Radars and Instrumented 444 m Tower; Part 2, The Structure of the Convective Atmospheric Boundary Layer as Revealed by Lidar and Doppler Radars; and Part 3, Doppler Lidar Observations in Thunderstorm Environments.

Aercibo S-band radar program

NASA Technical Reports Server (NTRS)

Campbell, Donald B.

1988-01-01

The high powered 12.6 cm wavelength radar on the 1000-ft Arecibo reflector is utilized for a number of solar system studies. Chief among these are: (1) surface reflectivity mapping of Venus, Mercury and the Moon. Resolutions achievable on Venus are less than 1.5 km over some areas, for Mercury about 30 km and for the Moon 200 m at present, (2) high time resolution ranging measurements to the surfaces of the terrestrial planets. These measurements are used to obtain profiles and scattering parameters in the equatorial region. They can also be used to test relativistic and gravitational theories by monitoring the rate of advance of the perihelion of the orbit of Mercury and placing limits on the stability of the gravitational constant, (3) measurements of the orbital parameters, figure, spin vector and surface properties of asteroids and comets, and (4) observations of the Galilean Satellites of Jupiter and the satellites of Mars, Phobos and Deimos. The Galilean Satellites of Jupiter were re-observed with the 12.6 cm radar for the first time since 1981. Much more accurate measurements of the scattering properties of the three icy satellites were obtained that generally confirmed previous observations. Unambiguous measurements of the cross section and circular polarizations ratio of Io were also obtained for the first time. The radar scattering properties of four mainbelt asteroids and one near-earth asteroid were studied.

Advanced Doppler radar physiological sensing technique for drone detection

NASA Astrophysics Data System (ADS)

Yoon, Ji Hwan; Xu, Hao; Garcia Carrillo, Luis R.

2017-05-01

A 24 GHz medium-range human detecting sensor, using the Doppler Radar Physiological Sensing (DRPS) technique, which can also detect unmanned aerial vehicles (UAVs or drones), is currently under development for potential rescue and anti-drone applications. DRPS systems are specifically designed to remotely monitor small movements of non-metallic human tissues such as cardiopulmonary activity and respiration. Once optimized, the unique capabilities of DRPS could be used to detect UAVs. Initial measurements have shown that DRPS technology is able to detect moving and stationary humans, as well as largely non-metallic multi-rotor drone helicopters. Further data processing will incorporate pattern recognition to detect multiple signatures (motor vibration and hovering patterns) of UAVs.

Meteorological operational services for civil protection in Veneto region (North-eastern Italy).

NASA Astrophysics Data System (ADS)

Barbi, A.; Monai, M.; Zardini, F.

2009-09-01

The Meteorological Centre of Teolo (CMT), part of the Regional Agency for Environmental Prevention and Protection of the North-eastern Italian region Veneto (ARPAV), is the operational regional meteorological service. Since April 2009 the Centre is linked to and supplies meteorological monitoring and forecasting to the recently constituted Functional Centre of the regional civil protection (CFD Veneto), which operates in the framework of National Civil Protection. The CFD Veneto supplies a multi-disciplinary, technical-scientific support to civil protection activities, to early warnings of natural hazards, in particular related to hydrogeological, hydraulic, and avalanches risks. The north-eastern part of Italy is known to be one of the rainiest regions in Europe. The region Veneto, due to its topographic configuration which includes Alpine reliefs, plans and a coast exposed to the Adriatic Sea, is conducive to heavy and long-lasting precipitation events. Also, strong thunderstorm activity with high precipitation rates, hail, wind gusts, and even tornadoes are relatively frequent occurrences. In this contribution two recent examples of different types of extreme events are briefly analysed by means of the ARPAV multi-sensor observing system which includes weather radar and a dense surface network. We show some of the impacts of such weather events on the territory, the services provided by CFD Veneto, in terms of meteorological forecasting and nowcasting products, and hydrogeologic/hydraulic hazard bullettins. The analysis highlights the difficulty of an efficient wheather forecast for civil defence purposes in a complex situation as ours, where many types of different events are possible. Especially cases of rapid convective events with their intense and very localized phenomena are a significant challenge. It is well-known that such events can bring remarkable material damages and serious danger for the people. For this reason an effective warning system which

41. Perimeter acquisition radar building radar element and coaxial display, ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

41. Perimeter acquisition radar building radar element and coaxial display, with drawing of typical antenna section. Drawing, from left to right, shows element, aluminum ground plane, cable connectors and hardware, cable, and back-up ring. Grey area is the concrete wall - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

IIth AMS Conference on Satellite Meteorology and Oceanography.

NASA Astrophysics Data System (ADS)

Velden, Christopher; Digirolamo, Larry; Glackin, Mary; Hawkins, Jeffrey; Jedlovec, Gary; Lee, Thomas; Petty, Grant; Plante, Robert; Reale, Anthony; Zapotocny, John

2002-11-01

The American Meteorological Society (AMS) held its 11th Conference on Satellite Meteorology and Oceanography at the Monona Terrace Convention Center in Madison, Wisconsin, during 15-18 October 2001. The purpose of the conference, typically held every 18 months, is to promote a forum for AMS membership, international scientists, and student members to present and discuss the latest advances in satellite remote sensing for meteorological and oceanographical applications. This year, surrounded by inspirational designs by famed architect Frank Lloyd Wright, the meeting focused on several broad topics related to remote sensing from space, including environmental applications of land and oceanic remote sensing, climatology and long-term satellite data studies, operational applications, radiances and retrievals, and new technology and methods. A vision of an increasing convergence of satellite systems emerged that included operational and research satellite programs and interdisciplinary user groups.The conference also hosted NASA's Electronic Theater, which was presented to groups of middle and high school students totaling over 5500. It was truly a successful public outreach event. The conference banquet was held on the final evening, where a short tribute to satellite pioneer Verner Suomi was given by Joanne Simpson. Suomi was responsible for establishing the Space Science and Engineering Center at the University of Wisconsin in Madison.

Use of Dual Polarization Radar in Validation of Satellite Precipitation Measurements: Rationale and Opportunities

NASA Technical Reports Server (NTRS)

Chandrasekar, V.; Hou, Arthur; Smith, Eric; Bringi, V. N.; Rutledge, S. A.; Gorgucci, E.; Petersen, W. A.; SkofronickJackson, Gail

2008-01-01

Dual-polarization weather radars have evolved significantly in the last three decades culminating in the operational deployment by the National Weather Service. In addition to operational applications in the weather service, dual-polarization radars have shown significant potential in contributing to the research fields of ground based remote sensing of rainfall microphysics, study of precipitation evolution and hydrometeor classification. Furthermore the dual-polarization radars have also raised the awareness of radar system aspects such as calibration. Microphysical characterization of precipitation and quantitative precipitation estimation are important applications that are critical in the validation of satellite borne precipitation measurements and also serves as a valuable tool in algorithm development. This paper presents the important role played by dual-polarization radar in validating space borne precipitation measurements. Starting from a historical evolution, the various configurations of dual-polarization radar are presented. Examples of raindrop size distribution retrievals and hydrometeor type classification are discussed. The quantitative precipitation estimation is a product of direct relevance to space borne observations. During the TRMM program substantial advancement was made with ground based polarization radars specially collecting unique observations in the tropics which are noted. The scientific accomplishments of relevance to space borne measurements of precipitation are summarized. The potential of dual-polarization radars and opportunities in the era of global precipitation measurement mission is also discussed.

ICT approaches to integrating institutional and non-institutional data services for better understanding of hydro-meteorological phenomena

NASA Astrophysics Data System (ADS)

Bedrina, T.; Parodi, A.; Quarati, A.; Clematis, A.

2012-06-01

It is widely recognised that an effective exploitation of Information and Communication Technologies (ICT) is an enabling factor to achieve major advancements in Hydro-Meteorological Research (HMR). Recently, a lot of attention has been devoted to the use of ICT in HMR activities, e.g. in order to facilitate data exchange and integration, to improve computational capabilities and consequently model resolution and quality. Nowadays, ICT technologies have demonstrated that it is possible to extend monitoring networks by integrating sensors and other sources of data managed by volunteer's communities. These networks are constituted by peers that span a wide portion of the territory in many countries. The peers are "location aware" in the sense that they provide information strictly related with their geospatial location. The coverage of these networks, in general, is not uniform and the location of peers may follow random distribution. The ICT features used to set up the network are lightweight and user friendly, thus, permitting the peers to join the network without the necessity of specialised ICT knowledge. In this perspective it is of increasing interest for HMR activities to elaborate of Personal Weather Station (PWS) networks, capable to provide almost real-time, location aware, weather data. Moreover, different big players of the web arena are now providing world-wide backbones, suitable to present on detailed map location aware information, obtained by mashing up data from different sources. This is the case, for example, with Google Earth and Google Maps. This paper presents the design of a mashup application aimed at aggregating, refining and visualizing near real-time hydro-meteorological datasets. In particular, we focused on the integration of instant precipitation depths, registered either by widespread semi-professional weather stations and official ones. This sort of information has high importance and usefulness in decision support systems and Civil

Evaluation of radar and automatic weather station data assimilation for a heavy rainfall event in southern China

NASA Astrophysics Data System (ADS)

Hou, Tuanjie; Kong, Fanyou; Chen, Xunlai; Lei, Hengchi; Hu, Zhaoxia

2015-07-01

To improve the accuracy of short-term (0-12 h) forecasts of severe weather in southern China, a real-time storm-scale forecasting system, the Hourly Assimilation and Prediction System (HAPS), has been implemented in Shenzhen, China. The forecasting system is characterized by combining the Advanced Research Weather Research and Forecasting (WRF-ARW) model and the Advanced Regional Prediction System (ARPS) three-dimensional variational data assimilation (3DVAR) package. It is capable of assimilating radar reflectivity and radial velocity data from multiple Doppler radars as well as surface automatic weather station (AWS) data. Experiments are designed to evaluate the impacts of data assimilation on quantitative precipitation forecasting (QPF) by studying a heavy rainfall event in southern China. The forecasts from these experiments are verified against radar, surface, and precipitation observations. Comparison of echo structure and accumulated precipitation suggests that radar data assimilation is useful in improving the short-term forecast by capturing the location and orientation of the band of accumulated rainfall. The assimilation of radar data improves the short-term precipitation forecast skill by up to 9 hours by producing more convection. The slight but generally positive impact that surface AWS data has on the forecast of near-surface variables can last up to 6-9 hours. The assimilation of AWS observations alone has some benefit for improving the Fractions Skill Score (FSS) and bias scores; when radar data are assimilated, the additional AWS data may increase the degree of rainfall overprediction.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Karlson, Benjamin; LeBlanc, Bruce Philip.; Minster, David G

2014-10-01

Wind turbines have grown in size and capacity with today's average turbine having a power capacity of around 1.9 MW, reaching to heights of over 495 feet from ground to blade tip, and operating with speeds at the tip of the blade up to 200 knots. When these machines are installed within the line-of-sight of a radar system, they can cause significant clutter and interference, detrimentally impacting the primary surveillance radar (PSR) performance. The Massachusetts Institute of Technology's Lincoln Laboratory (MIT LL) and Sandia National Laboratories (SNL) were co-funded to conduct field tests and evaluations over two years in ordermore » 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.« less

OBJECTIVE METEOROLOGICAL CLASSIFICATION SCHEME DESIGNED TO ELUCIDATE OZONE'S DEPENDENCE ON METEOROLOGY

EPA Science Inventory

This paper utilizes a two-stage clustering approach as part of an objective classification scheme designed to elucidate 03's dependence on meteorology. hen applied to ten years (1981-1990) of meteorological data for Birmingham, Alabama, the classification scheme identified seven ...

Monsoon Convective During the South China Sea Monsoon Experiment: Observations from Ground-Based Radar and the TRMM Satellite

NASA Technical Reports Server (NTRS)

Cifelli, Rob; Rickenbach, Tom; Halverson, Jeff; Keenan, Tom; Kucera, Paul; Atkinson, Lester; Fisher, Brad; Gerlach, John; Harris, Kathy; Kaufman, Cristina

1999-01-01

A main goal of the recent South China Sea Monsoon Experiment (SCSMEX) was to study convective processes associated with the onset of the Southeast Asian summer monsoon. The NASA TOGA C-band scanning radar was deployed on the Chinese research vessel Shi Yan #3 for two 20 day cruises, collecting dual-Doppler measurements in conjunction with the BMRC C-Pol dual-polarimetric radar on Dongsha Island. Soundings and surface meteorological data were also collected with an NCAR Integrated Sounding System (ISS). This experiment was the first major tropical field campaign following the launch of the Tropical Rainfall Measuring Mission (TRMM) satellite. These observations of tropical oceanic convection provided an opportunity to make comparisons between surface radar measurements and the Precipitation Radar (PR) aboard the TRMM satellite in an oceanic environment. Nearly continuous radar operations were conducted during two Intensive Observing Periods (IOPS) straddling the onset of the monsoon (5-25 May 1998 and 5-25 June 1998). Mesoscale lines of convection with widespread regions of both trailing and forward stratiform precipitation were observed following the onset of the active monsoon in the northern South China Sea region. The vertical structure of the convection during periods of strong westerly flow and relatively moist environmental conditions in the lower to mid-troposphere contrasted sharply with convection observed during periods of low level easterlies, weak shear, and relatively dry conditions in the mid to upper troposphere. Several examples of mesoscale convection will be shown from the ground (ship)-based and spaceborne radar data during times of TRMM satellite overpasses. Examples of pre-monsoon convection, characterized by isolated cumulonimbus and shallow, precipitating congestus clouds, will also be discussed.

51. View of upper radar scanner switch in radar scanner ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

51. View of upper radar scanner switch in radar scanner building 105 from upper catwalk level showing emanating waveguides from upper switch (upper one-fourth of photograph) and emanating waveguides from lower radar scanner switch in vertical runs. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

Spaceborne radar observations: A guide for Magellan radar-image analysis

NASA Technical Reports Server (NTRS)

Ford, J. P.; Blom, R. G.; Crisp, J. A.; Elachi, Charles; Farr, T. G.; Saunders, R. Stephen; Theilig, E. E.; Wall, S. D.; Yewell, S. B.

1989-01-01

Geologic analyses of spaceborne radar images of Earth are reviewed and summarized with respect to detecting, mapping, and interpreting impact craters, volcanic landforms, eolian and subsurface features, and tectonic landforms. Interpretations are illustrated mostly with Seasat synthetic aperture radar and shuttle-imaging-radar images. Analogies are drawn for the potential interpretation of radar images of Venus, with emphasis on the effects of variation in Magellan look angle with Venusian latitude. In each landform category, differences in feature perception and interpretive capability are related to variations in imaging geometry, spatial resolution, and wavelength of the imaging radar systems. Impact craters and other radially symmetrical features may show apparent bilateral symmetry parallel to the illumination vector at low look angles. The styles of eruption and the emplacement of major and minor volcanic constructs can be interpreted from morphological features observed in images. Radar responses that are governed by small-scale surface roughness may serve to distinguish flow types, but do not provide unambiguous information. Imaging of sand dunes is rigorously constrained by specific angular relations between the illumination vector and the orientation and angle of repose of the dune faces, but is independent of radar wavelength. With a single look angle, conditions that enable shallow subsurface imaging to occur do not provide the information necessary to determine whether the radar has recorded surface or subsurface features. The topographic linearity of many tectonic landforms is enhanced on images at regional and local scales, but the detection of structural detail is a strong function of illumination direction. Nontopographic tectonic lineaments may appear in response to contrasts in small-surface roughness or dielectric constant. The breakpoint for rough surfaces will vary by about 25 percent through the Magellan viewing geometries from low to high

Diagnosing Meteorological Conditions Associated with Sprites and Lightning with Large Charge Moment Changes (CMC) over Oklahoma

NASA Technical Reports Server (NTRS)

Rivera, Lizxandra Flores; Lang, Timothy

2014-01-01

Sprites are a category of Transient Luminous Events (TLEs) that occur in the upper atmosphere above the tops of Mesoscale Convective Systems (MCSs). They are commonly associated with lightning strokes that produce large charge moment changes (CMCs). Synergistic use of satellite and radar-retrieved observations together with sounding data, forecasts, and lightning-detection networks allowed the diagnosis and analysis of the meteorological conditions associated with sprites as well as large-CMC lightning over Oklahoma. One goal of the NASA-funded effort reported herein is the investigation of the potential for sprite interference with aerospace activities in the 20- 100km altitude range, including research balloons, space missions and other aviation transports.

New Cloud Science from the New ARM Cloud Radar Systems (Invited)

NASA Astrophysics Data System (ADS)

Wiscombe, W. J.

2010-12-01

The DOE ARM Program is deploying over $30M worth of scanning polarimetric Doppler radars at its four fixed and two mobile sites, with the object of advancing cloud lifecycle science, and cloud-aerosol-precipitation interaction science, by a quantum leap. As of 2011, there will be 13 scanning radar systems to complement its existing array of profiling cloud radars: C-band for precipitation, X-band for drizzle and precipitation, and two-frequency radars for cloud droplets and drizzle. This will make ARM the world’s largest science user of, and largest provider of data from, ground-based cloud radars. The philosophy behind this leap is actually quite simple, to wit: dimensionality really does matter. Just as 2D turbulence is fundamentally different from 3D turbulence, so observing clouds only at zenith provides a dimensionally starved, and sometimes misleading, picture of real clouds. In particular, the zenith view can say little or nothing about cloud lifecycle and the second indirect effect, nor about aerosol-precipitation interactions. It is not even particularly good at retrieving the cloud fraction (no matter how that slippery quantity is defined). This talk will review the history that led to this development and then discuss the aspirations for how this will propel cloud-aerosol-precipitation science forward. The step by step plan for translating raw radar data into information that is useful to cloud and aerosol scientists and climate modelers will be laid out, with examples from ARM’s recent scanning cloud radar deployments in the Azores and Oklahoma . In the end, the new systems should allow cloud systems to be understood as 4D coherent entities rather than dimensionally crippled 2D or 3D entities such as observed by satellites and zenith-pointing radars.

Space Radar Image of Long Island Optical/Radar

NASA Technical Reports Server (NTRS)

1994-01-01

This pair of images of the Long Island, New York region is a comparison of an optical photograph (top) and a radar image (bottom), both taken in darkness in April 1994. The photograph at the top was taken by the Endeavour astronauts at about 3 a.m. Eastern time on April 20, 1994. The image at the bottom was acquired at about the same time four days earlier on April 16,1994 by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) system aboard the space shuttle Endeavour. Both images show an area approximately 100 kilometers by 40 kilometers (62 miles by 25 miles) that is centered at 40.7 degrees North latitude and 73.5 degrees West longitude. North is toward the upper right. The optical image is dominated by city lights, which are particularly bright in the densely developed urban areas of New York City located on the left half of the photo. The brightest white zones appear on the island of Manhattan in the left center, and Central Park can be seen as a darker area in the middle of Manhattan. To the northeast (right) of the city, suburban Long Island appears as a less densely illuminated area, with the brightest zones occurring along major transportation and development corridors. Since radar is an active sensing system that provides its own illumination, the radar image shows a great amount of surface detail, despite the night-time acquisition. The colors in the radar image were obtained using the following radar channels: red represents the L-band (horizontally transmitted and received); green represents the L-band (horizontally transmitted and vertically received); blue represents the C-band (horizontally transmitted and vertically received). In this image, the water surface - the Atlantic Ocean along the bottom edge and Long Island Sound shown at the top edge - appears red because small waves at the surface strongly reflect the horizontally transmitted and received L-band radar signal. Networks of highways and railroad lines are clearly

Space Radar Image of Long Island Optical/Radar

NASA Image and Video Library

1999-05-01

This pair of images of the Long Island, New York region is a comparison of an optical photograph (top) and a radar image (bottom), both taken in darkness in April 1994. The photograph at the top was taken by the Endeavour astronauts at about 3 a.m. Eastern time on April 20, 1994. The image at the bottom was acquired at about the same time four days earlier on April 16,1994 by the Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) system aboard the space shuttle Endeavour. Both images show an area approximately 100 kilometers by 40 kilometers (62 miles by 25 miles) that is centered at 40.7 degrees North latitude and 73.5 degrees West longitude. North is toward the upper right. The optical image is dominated by city lights, which are particularly bright in the densely developed urban areas of New York City located on the left half of the photo. The brightest white zones appear on the island of Manhattan in the left center, and Central Park can be seen as a darker area in the middle of Manhattan. To the northeast (right) of the city, suburban Long Island appears as a less densely illuminated area, with the brightest zones occurring along major transportation and development corridors. Since radar is an active sensing system that provides its own illumination, the radar image shows a great amount of surface detail, despite the night-time acquisition. The colors in the radar image were obtained using the following radar channels: red represents the L-band (horizontally transmitted and received); green represents the L-band (horizontally transmitted and vertically received); blue represents the C-band (horizontally transmitted and vertically received). In this image, the water surface - the Atlantic Ocean along the bottom edge and Long Island Sound shown at the top edge - appears red because small waves at the surface strongly reflect the horizontally transmitted and received L-band radar signal. Networks of highways and railroad lines are clearly

On the Creation of An Urban Boundary Layer Product Using The Radar Wind Profiler of the New York City Meteorological Network

NASA Astrophysics Data System (ADS)

Dempsey, M. J.; Booth, J.; Arend, M.; Melecio-Vazquez, D.

2016-12-01

The radar wind profiler (RWP) located on the Liberty Science Center in Jersey City, NJ is a part of the New York City Meteorological Network (NYCMetNet). An automatic algorithm based on those by Angevine [1] and Molod [2] is expanded upon and implemented to take RWP signal to noise ratio data and create an urban boundary layer (UBL) height product. Time series of the RWP UBL heights from clear and cloudy days are examined and compared to UBL height time series calculated from thermal data obtained from a NYCMetNet radiometer located on the roof of the Grove School of Engineering at The City College of New York. UBL data from the RWP are also compared to the MERRA (Modern Era Retrospective Analysis for Research and Applications) planetary boundary layer height time series product. A limited seasonal climatology is created from the available RWP data for clear and cloudy days and then compared to a limited seasonal climatology produced from boundary layer data obtained from MERRA and boundary layer data calculated from the CCNY radiometer. As with wind profilers in the NOAA wind profiler network, the signal return to the lowest range gates is not always the result of turbulent scattering, but from scattering from other targets such as the building itself, birds and insects. The algorithm attempts to address this during the daytime, when strong signal returns at the lowest range gates mask the SNR maxima above which are representative of the actual UBL height. Detecting the collapse and fall of the boundary layer meets with limited success, also, from the hours of 2:30pm to 5:00pm. Upper and lower range gates from the wind profiler limit observation of the nighttime boundary layer for heights falling below the lowest range gate and daytime convective boundary layer maxima rising above the highest. Due to the constraints of the instrument and the algorithm it is recommended that the boundary layer height product be constrained to the hours of 8am to 7pm.

Development of Spaceborne Radar Simulator by NICT and JAXA using JMA Cloud-resolving Model

NASA Astrophysics Data System (ADS)

Kubota, T.; Eito, H.; Aonashi, K.; Hashimoto, A.; Iguchi, T.; Hanado, H.; Shimizu, S.; Yoshida, N.; Oki, R.

2009-12-01

We are developing synthetic spaceborne radar data toward a simulation of the Dual-frequency Precipitation Radar (DPR) aboard the Global Precipitation Measurement (GPM) core-satellite. Our purposes are a production of test-bed data for higher level DPR algorithm developers, in addition to a diagnosis of a cloud resolving model (CRM). To make the synthetic data, we utilize the CRM by the Japan Meteorological Agency (JMA-NHM) (Ikawa and Saito 1991, Saito et al. 2006, 2007), and the spaceborne radar simulation algorithm by the National Institute of Information and Communications Technology (NICT) and the Japan Aerospace Exploration Agency (JAXA) named as the Integrated Satellite Observation Simulator for Radar (ISOSIM-Radar). The ISOSIM-Radar simulates received power data in a field of view of the spaceborne radar with consideration to a scan angle of the radar (Oouchi et al. 2002, Kubota et al. 2009). The received power data are computed with gaseous and hydrometeor attenuations taken into account. The backscattering and extinction coefficients are calculated assuming the Mie approximation for all species. The dielectric constants for solid particles are computed by the Maxwell-Garnett model (Bohren and Battan 1982). Drop size distributions are treated in accordance with those of the JMA-NHM. We assume a spherical sea surface, a Gaussian antenna pattern, and 49 antenna beam directions for scan angles from -17 to 17 deg. in the PR. In this study, we report the diagnosis of the JMA-NHM with reference to the TRMM Precipitation Radar (PR) and CloudSat Cloud Profiling Radar (CPR) using the ISOSIM-Radar from the view of comparisons in cloud microphysics schemes of the JMA-NHM. We tested three kinds of explicit bulk microphysics schemes based on Lin et al. (1983), that is, three-ice 1-moment scheme, three-ice 2-moment scheme (Eito and Aonashi 2009), and newly developed four-ice full 2-moment scheme (Hashimoto 2008). The hydrometeor species considered here are rain, graupel

Amplification of radar and lidar signatures using quantum sensors

NASA Astrophysics Data System (ADS)

Lanzagorta, Marco

2013-05-01

One of the major scientific thrusts from recent years has been to try to harness quantum phenomena to dramat­ ically increase the performance of a wide variety of classical devices. These advances in quantum information science have had a considerable impact on the development of photonic-based quantum sensors. Even though quantum radar and quantum lidar remain theoretical proposals, preliminary results suggest that these sensors have the potential of becoming disruptive technologies able to revolutionize reconnaissance systems. In this paper we will discuss how quantum entanglement can be exploited to increase the radar and lidar signature of rectangular targets. In particular, we will show how the effective visibility of the target is increased if observed with an entangled multi-photon quantum sensor.

Systems and Methods for Radar Data Communication

NASA Technical Reports Server (NTRS)

Bunch, Brian (Inventor); Szeto, Roland (Inventor); Miller, Brad (Inventor)

2013-01-01

A radar information processing system is operable to process high bandwidth radar information received from a radar system into low bandwidth radar information that may be communicated to a low bandwidth connection coupled to an electronic flight bag (EFB). An exemplary embodiment receives radar information from a radar system, the radar information communicated from the radar system at a first bandwidth; processes the received radar information into processed radar information, the processed radar information configured for communication over a connection operable at a second bandwidth, the second bandwidth lower than the first bandwidth; and communicates the radar information from a radar system, the radar information communicated from the radar system at a first bandwidth.

Java Radar Analysis Tool

NASA Technical Reports Server (NTRS)

Zaczek, Mariusz P.

2005-01-01

Java Radar Analysis Tool (JRAT) is a computer program for analyzing two-dimensional (2D) scatter plots derived from radar returns showing pieces of the disintegrating Space Shuttle Columbia. JRAT can also be applied to similar plots representing radar returns showing aviation accidents, and to scatter plots in general. The 2D scatter plots include overhead map views and side altitude views. The superposition of points in these views makes searching difficult. JRAT enables three-dimensional (3D) viewing: by use of a mouse and keyboard, the user can rotate to any desired viewing angle. The 3D view can include overlaid trajectories and search footprints to enhance situational awareness in searching for pieces. JRAT also enables playback: time-tagged radar-return data can be displayed in time order and an animated 3D model can be moved through the scene to show the locations of the Columbia (or other vehicle) at the times of the corresponding radar events. The combination of overlays and playback enables the user to correlate a radar return with a position of the vehicle to determine whether the return is valid. JRAT can optionally filter single radar returns, enabling the user to selectively hide or highlight a desired radar return.

Comparison of cloud boundaries measured with 8.6 mm radar and 10.6 micrometer lidar

NASA Technical Reports Server (NTRS)

Uttal, Taneil; Intrieri, Janet M.

1993-01-01

One of the most basic cloud properties is location; the height of cloud base and the height of cloud top. The glossary of meteorology defines cloud base (top) as follows: 'For a given cloud or cloud layer, that lowest (highest) level in the atmosphere at which the air contains a perceptible quantity of cloud particles.' Our studies show that for a 8.66 mm radar, and a 10.6 micrometer lidar, the level at which cloud hydrometers become 'perceptible' can vary significantly as a function of the different wavelengths, powers, beamwidths and sampling rates of the two remote sensors.

Current Scientific Progress and Future Scientific Prospects Enabled by Spaceborne Precipitation Radar Measurements

NASA Technical Reports Server (NTRS)

Smith, Eric A.; Im, Eastwood; Tripoli, Gregory J.; Yang, Song

2008-01-01

First, we examine current scientific progress and understanding that have been possible through use of spaceborne precipitation radar measurements being provided by the TRMM and CloudSat satellites. Second, we look across a future 20-year time frame to assess how and why anticipated improvements in space radar systems will further advance scientific progress into topic areas once considered beyond the realm of space-based remote sensing. JAXA's 13.8 GHz Ku-band cross-track scanning Precipitation Radar (PR) developed for flight on NASA's non-sun-synchronous, diurnally-precessing TRMM satellite, was the first Earth radar flown in space that was designed specifically for precipitation measurement. Its proven accuracy in measuring global rainfall in the tropics and sub-tropics and its unanticipated longevity in continuing these measurements beyond a full decade have established the standards against which all follow-up and future space radars will be evaluated. In regards to the current PR measurement time series, we will discuss a selection of major scientific discoveries and impacts which have set the stage for future radar measuring systems. In fact, the 2nd contemporary space radar applicable for terrestrial precipitation measurement, i.e., JPL-CSA's 94 GHz nadir-staring Cloud Profiling Radar (CPR) flown on NASA's sun-synchronous CloudSat satellite, although designed primarily for measurement of non-precipitating cloud hydrometeors and aerosols, has also unquestionably advanced precipitation measurement because CPR's higher frequency and greatly increased sensitivity (approximately 30 dBZ) has enabled global observations of light rain rate spectrum processes (i.e., rain rates below 0.05 mm per hourand of precipitation processes in the high troposphere (particularly ice phase processes). These processes are beyond reach of the TRMM radar because the PR sensitivity limit is approximately 17 dBZ which means its lower rain rate cutoff is around 0.3 mm per hour and its

A variational technique to estimate snowfall rate from coincident radar, snowflake, and fall-speed observations

NASA Astrophysics Data System (ADS)

Cooper, Steven J.; Wood, Norman B.; L'Ecuyer, Tristan S.

2017-07-01

Estimates of snowfall rate as derived from radar reflectivities alone are non-unique. Different combinations of snowflake microphysical properties and particle fall speeds can conspire to produce nearly identical snowfall rates for given radar reflectivity signatures. Such ambiguities can result in retrieval uncertainties on the order of 100-200 % for individual events. Here, we use observations of particle size distribution (PSD), fall speed, and snowflake habit from the Multi-Angle Snowflake Camera (MASC) to constrain estimates of snowfall derived from Ka-band ARM zenith radar (KAZR) measurements at the Atmospheric Radiation Measurement (ARM) North Slope Alaska (NSA) Climate Research Facility site at Barrow. MASC measurements of microphysical properties with uncertainties are introduced into a modified form of the optimal-estimation CloudSat snowfall algorithm (2C-SNOW-PROFILE) via the a priori guess and variance terms. Use of the MASC fall speed, MASC PSD, and CloudSat snow particle model as base assumptions resulted in retrieved total accumulations with a -18 % difference relative to nearby National Weather Service (NWS) observations over five snow events. The average error was 36 % for the individual events. Use of different but reasonable combinations of retrieval assumptions resulted in estimated snowfall accumulations with differences ranging from -64 to +122 % for the same storm events. Retrieved snowfall rates were particularly sensitive to assumed fall speed and habit, suggesting that in situ measurements can help to constrain key snowfall retrieval uncertainties. More accurate knowledge of these properties dependent upon location and meteorological conditions should help refine and improve ground- and space-based radar estimates of snowfall.

FIRE_CI2_ETL_RADAR

Atmospheric Science Data Center

2015-11-25

FIRE_CI2_ETL_RADAR Project Title:  FIRE II CIRRUS Discipline:  ... Platform:  Ground Station Instrument:  Radar Spatial Coverage:  (37.06, -95.34) Spatial ... Order Data Guide Documents:  ETL_RADAR Guide Readme Files:  Readme ETL_RADAR (PS) ...

Combination of radar and daily precipitation data to estimate meaningful sub-daily point precipitation extremes

NASA Astrophysics Data System (ADS)

Bárdossy, András; Pegram, Geoffrey

2017-01-01

The use of radar measurements for the space time estimation of precipitation has for many decades been a central topic in hydro-meteorology. In this paper we are interested specifically in daily and sub-daily extreme values of precipitation at gauged or ungauged locations which are important for design. The purpose of the paper is to develop a methodology to combine daily precipitation observations and radar measurements to estimate sub-daily extremes at point locations. Radar data corrected using precipitation-reflectivity relationships lead to biased estimations of extremes. Different possibilities of correcting systematic errors using the daily observations are investigated. Observed gauged daily amounts are interpolated to unsampled points and subsequently disaggregated using the sub-daily values obtained by the radar. Different corrections based on the spatial variability and the subdaily entropy of scaled rainfall distributions are used to provide unbiased corrections of short duration extremes. Additionally a statistical procedure not based on a matching day by day correction is tested. In this last procedure as we are only interested in rare extremes, low to medium values of rainfall depth were neglected leaving a small number of L days of ranked daily maxima in each set per year, whose sum typically comprises about 50% of each annual rainfall total. The sum of these L day maxima is first iterpolated using a Kriging procedure. Subsequently this sum is disaggregated to daily values using a nearest neighbour procedure. The daily sums are then disaggregated by using the relative values of the biggest L radar based days. Of course, the timings of radar and gauge maxima can be different, so the method presented here uses radar for disaggregating daily gauge totals down to 15 min intervals in order to extract the maxima of sub-hourly through to daily rainfall. The methodologies were tested in South Africa, where an S-band radar operated relatively continuously at

A simple biota removal algorithm for 35 GHz cloud radar measurements

NASA Astrophysics Data System (ADS)

Kalapureddy, Madhu Chandra R.; Sukanya, Patra; Das, Subrata K.; Deshpande, Sachin M.; Pandithurai, Govindan; Pazamany, Andrew L.; Ambuj K., Jha; Chakravarty, Kaustav; Kalekar, Prasad; Krishna Devisetty, Hari; Annam, Sreenivas

2018-03-01

Cloud radar reflectivity profiles can be an important measurement for the investigation of cloud vertical structure (CVS). However, extracting intended meteorological cloud content from the measurement often demands an effective technique or algorithm that can reduce error and observational uncertainties in the recorded data. In this work, a technique is proposed to identify and separate cloud and non-hydrometeor echoes using the radar Doppler spectral moments profile measurements. The point and volume target-based theoretical radar sensitivity curves are used for removing the receiver noise floor and identified radar echoes are scrutinized according to the signal decorrelation period. Here, it is hypothesized that cloud echoes are observed to be temporally more coherent and homogenous and have a longer correlation period than biota. That can be checked statistically using ˜ 4 s sliding mean and standard deviation value of reflectivity profiles. The above step helps in screen out clouds critically by filtering out the biota. The final important step strives for the retrieval of cloud height. The proposed algorithm potentially identifies cloud height solely through the systematic characterization of Z variability using the local atmospheric vertical structure knowledge besides to the theoretical, statistical and echo tracing tools. Thus, characterization of high-resolution cloud radar reflectivity profile measurements has been done with the theoretical echo sensitivity curves and observed echo statistics for the true cloud height tracking (TEST). TEST showed superior performance in screening out clouds and filtering out isolated insects. TEST constrained with polarimetric measurements was found to be more promising under high-density biota whereas TEST combined with linear depolarization ratio and spectral width perform potentially to filter out biota within the highly turbulent shallow cumulus clouds in the convective boundary layer (CBL). This TEST technique is

The Applied Meteorology Unit: Nineteen Years Successfully Transitioning Research into Operations for America's Space Program

NASA Technical Reports Server (NTRS)

Madura, John T.; Bauman, William H.; Merceret, Francis J.; Roeder, William P.; Brody, Frank C.; Hagemeyer, Bartlett C.

2010-01-01

The Applied Meteorology Unit (AMU) provides technology transition and technique development to improve operational weather support to the Space Shuttle and the entire American space program. The AMU is funded and managed by NASA and operated by a contractor that provides five meteorologists with a diverse mix of advanced degrees, operational experience, and associated skills including data processing, statistics, and the development of graphical user interfaces. The AMU's primary customers are the U.S. Air Force 45th Weather Squadron at Patrick Air Force Base, the National Weather Service Spaceflight Meteorology Group at NASA Johnson Space Center, and the National Weather Service Melbourne FL Forecast Office. The AMU has transitioned research into operations for nineteen years and worked on a wide range of topics, including new forecasting techniques for lightning probability, synoptic peak winds,.convective winds, and summer severe weather; satellite tools to predict anvil cloud trajectories and evaluate camera line of sight for Space Shuttle launch; optimized radar scan strategies; evaluated and implemented local numerical models; evaluated weather sensors; and many more. The AMU has completed 113 projects with 5 more scheduled to be completed by the end of 2010. During this rich history, the AMU and its customers have learned many lessons on how to effectively transition research into operations. Some of these lessons learned include collocating with the operational customer and periodically visiting geographically separated customers, operator submitted projects, consensus tasking process, use of operator primary advocates for each project, customer AMU liaisons with experience in both operations and research, flexibility in adapting the project plan based on lessons learned during the project, and incorporating training and other transition assistance into the project plans. Operator involvement has been critical to the AMU's remarkable success and many awards

A High Resolution Radar Altimeter to Measure the Topography of Ice Sheets

NASA Technical Reports Server (NTRS)

Pawul, Rudolf A.

1997-01-01

This thesis is a reference for the Advanced Application Flight Experiment (AAFE) altimeter. The transmitter and receiver subsections are described and measurements of their current state is provided. During the 1994 NASA Greenland Experiment, the altimeter experienced several hardware malfunctions. The process of returning the radar to its fully operational state is presented in detail and necessary design modifications are explained. An updated radar user's manual is included along with various circuit designs which need to be implemented. The thesis is intended to provide an incoming graduate student with a solid foundation of the fundamentals of AAFE altimeter operation.

A Radar-Enabled Collaborative Sensor Network Integrating COTS Technology for Surveillance and Tracking

PubMed Central

Kozma, Robert; Wang, Lan; Iftekharuddin, Khan; McCracken, Ernest; Khan, Muhammad; Islam, Khandakar; Bhurtel, Sushil R.; Demirer, R. Murat

2012-01-01

The feasibility of using Commercial Off-The-Shelf (COTS) sensor nodes is studied in a distributed network, aiming at dynamic surveillance and tracking of ground targets. Data acquisition by low-cost (<$50 US) miniature low-power radar through a wireless mote is described. We demonstrate the detection, ranging and velocity estimation, classification and tracking capabilities of the mini-radar, and compare results to simulations and manual measurements. Furthermore, we supplement the radar output with other sensor modalities, such as acoustic and vibration sensors. This method provides innovative solutions for detecting, identifying, and tracking vehicles and dismounts over a wide area in noisy conditions. This study presents a step towards distributed intelligent decision support and demonstrates effectiveness of small cheap sensors, which can complement advanced technologies in certain real-life scenarios. PMID:22438713

A radar-enabled collaborative sensor network integrating COTS technology for surveillance and tracking.

PubMed

Kozma, Robert; Wang, Lan; Iftekharuddin, Khan; McCracken, Ernest; Khan, Muhammad; Islam, Khandakar; Bhurtel, Sushil R; Demirer, R Murat

2012-01-01

The feasibility of using Commercial Off-The-Shelf (COTS) sensor nodes is studied in a distributed network, aiming at dynamic surveillance and tracking of ground targets. Data acquisition by low-cost (<$50 US) miniature low-power radar through a wireless mote is described. We demonstrate the detection, ranging and velocity estimation, classification and tracking capabilities of the mini-radar, and compare results to simulations and manual measurements. Furthermore, we supplement the radar output with other sensor modalities, such as acoustic and vibration sensors. This method provides innovative solutions for detecting, identifying, and tracking vehicles and dismounts over a wide area in noisy conditions. This study presents a step towards distributed intelligent decision support and demonstrates effectiveness of small cheap sensors, which can complement advanced technologies in certain real-life scenarios.

RADAR performance experiments

NASA Technical Reports Server (NTRS)

Leroux, C.; Bertin, F.; Mounir, H.

1991-01-01

Theoretical studies and experimental results obtained at Coulommiers airport showed the capability of Proust radar to detect wind shears, in clear air condition as well as in presence of clouds or rain. Several examples are presented: in a blocking highs situation an atmospheric wave system at the Brunt-Vaisala frequency can be clearly distinguished; in a situation of clouds without rain the limit between clear air and clouds can be easily seen; and a windshear associated with a gust front in rainy conditions is shown. A comparison of 30 cm clear air radar Proust and 5 cm weather Doppler radar Ronsard will allow to select the best candidate for wind shear detection, taking into account the low sensibility to ground clutter of Ronsard radar.

Triple-frequency radar retrievals of snowfall properties from the OLYMPEX field campaign

NASA Astrophysics Data System (ADS)

Leinonen, J. S.; Lebsock, M. D.; Sy, O. O.; Tanelli, S.

2017-12-01

Retrieval of snowfall properties with radar is subject to significant errors arising from the uncertainties in the size and structure of snowflakes. Recent modeling and theoretical studies have shown that multi-frequency radars can potentially constrain the microphysical properties and thus reduce the uncertainties in the retrieved snow water content. So far, there have only been limited efforts to leverage the theoretical advances in actual snowfall retrievals. In this study, we have implemented an algorithm that retrieves the snowfall properties from triple-frequency radar data using the radar scattering properties from a combination of snowflake scattering databases, which were derived using numerical scattering methods. Snowflake number concentration, characteristic size and density are derived using a combination of optimal estimation and Kalman smoothing; the snow water content and other bulk properties are then derived from these. The retrieval framework is probabilistic and thus naturally provides error estimates for the retrieved quantities. We tested the retrieval algorithm using data from the APR3 airborne radar flown onboard the NASA DC-8 aircraft during the Olympic Mountain Experiment (OLYMPEX) in late 2015. We demonstrated consistent retrieval of snow properties and smooth transition from single- and dual-frequency retrievals to using all three frequencies simultaneously. The error analysis shows that the retrieval accuracy is improved when additional frequencies are introduced. We also compare the findings to in situ measurements of snow properties as well as measurements by polarimetric ground-based radar.

46 CFR 121.404 - Radars.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Radars. 121.404 Section 121.404 Shipping COAST GUARD... Navigation Equipment § 121.404 Radars. (a) Except as allowed by paragraph (b) of this section, all self... radar system for surface navigation with a radar screen mounted at the primary operating station. (b...

46 CFR 121.404 - Radars.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Radars. 121.404 Section 121.404 Shipping COAST GUARD... Navigation Equipment § 121.404 Radars. (a) Except as allowed by paragraph (b) of this section, all self... radar system for surface navigation with a radar screen mounted at the primary operating station. (b...

46 CFR 121.404 - Radars.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Radars. 121.404 Section 121.404 Shipping COAST GUARD... Navigation Equipment § 121.404 Radars. (a) Except as allowed by paragraph (b) of this section, all self... radar system for surface navigation with a radar screen mounted at the primary operating station. (b...

46 CFR 121.404 - Radars.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Radars. 121.404 Section 121.404 Shipping COAST GUARD... Navigation Equipment § 121.404 Radars. (a) Except as allowed by paragraph (b) of this section, all self... radar system for surface navigation with a radar screen mounted at the primary operating station. (b...

46 CFR 121.404 - Radars.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Radars. 121.404 Section 121.404 Shipping COAST GUARD... Navigation Equipment § 121.404 Radars. (a) Except as allowed by paragraph (b) of this section, all self... radar system for surface navigation with a radar screen mounted at the primary operating station. (b...

Radar remote sensing in biology

USGS Publications Warehouse

Moore, Richard K.; Simonett, David S.

1967-01-01

The present status of research on discrimination of natural and cultivated vegetation using radar imaging systems is sketched. The value of multiple polarization radar in improved discrimination of vegetation types over monoscopic radars is also documented. Possible future use of multi-frequency, multi-polarization radar systems for all weather agricultural survey is noted.

Inter-comparison of Rainfall Estimation from Radar and Satellite During 2016 June 23 Yancheng Tornado Event over Eastern China

NASA Astrophysics Data System (ADS)

Huang, C.; Chen, S.; Liang, Z.; Hu, B.

2017-12-01

ABSTRACT: On the afternoon of June 23, 2016, Yancheng city in eastern China was hit by a severe thunderstorm that produced a devastating tornado. This tornado was ranked as an EF4 on the Enhanced Fujita scale by China Meteorological Administration, and killed at least 99 people and injured 846 others (152 seriously). This study evaluates rainfall estimates from ground radar network and four satellite algorithms with a relatively dense rain gauge network over eastern China including Jiangsu province and its adjacent regions for the Yancheng June 23 Tornado extreme convective storm in different spatiotemporal scales (from 0.04° to 0.1° and hourly to event total accumulation). The radar network is composed of about 6 S-band Doppler weather radars. Satellite precipitation products include Integrated Multi-satellitE Retrievals for GPM (IMERG), Climate Prediction Center morphing technique (CMORPH), Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Cloud Classification System (PERSIANN-CCS), and Global Satellite Mapping of Precipitation (GSMap). Relative Bias (RB), Root-Mean-Squared Error (RMSE), Correlation Coefficient (CC), Probability Of Detection (POD), False Alarm Ratio (FAR), and Critical Success Index (CSI) are used to quantify the performance of these precipitation products.

Hybrid Radar Emitter Recognition Based on Rough k-Means Classifier and Relevance Vector Machine

PubMed Central

Yang, Zhutian; Wu, Zhilu; Yin, Zhendong; Quan, Taifan; Sun, Hongjian

2013-01-01

Due to the increasing complexity of electromagnetic signals, there exists a significant challenge for recognizing radar emitter signals. In this paper, a hybrid recognition approach is presented that classifies radar emitter signals by exploiting the different separability of samples. The proposed approach comprises two steps, namely the primary signal recognition and the advanced signal recognition. In the former step, a novel rough k-means classifier, which comprises three regions, i.e., certain area, rough area and uncertain area, is proposed to cluster the samples of radar emitter signals. In the latter step, the samples within the rough boundary are used to train the relevance vector machine (RVM). Then RVM is used to recognize the samples in the uncertain area; therefore, the classification accuracy is improved. Simulation results show that, for recognizing radar emitter signals, the proposed hybrid recognition approach is more accurate, and presents lower computational complexity than traditional approaches. PMID:23344380

A New Type of Captive Balloon for Vertical Meteorological Observation in Urban Area

NASA Astrophysics Data System (ADS)

Nakamura, M.; Sakai, S.; Ono, K.

2010-12-01

Many meteorological observations in urban area have been made in recent years in order to investigate the mechanism of heat island. However, there are few data of cooling process in urban area. For this purpose, high density observations in both space and time are required. Generally vertical meteorological observations can be made by towers, radars, balloons. These methods are limited by urban area conditions. Among these methods, a captive balloon is mainly used to about a hundred meter from ground in a vertical meteorological observation. Small airships called kytoons or advertising balloons, for example. Conventional balloons are, however, influenced by the wind and difficult to keep the specified position. Moreover, it can be dangerous to conduct such observations in the highly build-up area. To overcome these difficulties, we are developing a new type of captive balloon. It has a wing form to gain lift and keep its position. It is also designed small to be kept in a carport. It is made of aluminum film and polyester cloth in order to attain lightweight solution. We have tried floating a balloon like NACA4424 for several years. It was difficult to keep a wing form floating up over 100 meters from ground because internal pressure was decreased by different temperature. The design is changed in this year. The balloon that has wing form NACA4415 is similar in composition to an airplane. It has a big gasbag with airship form and two wing form. It is able to keep form of a wing by high internal pressure. We will report a plan for the balloon and instances of some observations.

Vertical PM10 Characteristics and their Relation with Tropospheric Meteorology over Hong Kong

NASA Astrophysics Data System (ADS)

Hei Tong, Cheuk

2016-04-01

Small particulates or PM10, those with aerodynamic diameters less than 10 mm, can cause long term impairment to human health as they can penetrate deep and deposit on the wall of the respiratory system. Hong Kong receives significant concentration of cross-boundary particulates but at the same time produce domestic pollutants which altogether contribute to the total pollution problem. Recent research interest is paying more attention on the vertical characteristic of PM in the lower atmosphere as possible correlations exist along different altitude. Besides, there exists potential relationship between PM concentration aloft and the high-level weather condition. Yet, most studies focus only up to around 200 meters above sea level due to the proposed significance and the lack of technology. Undoubtedly, this is not enough in investigating the relation between vertical atmospheric profile and PM vertical characteristics. New technology development has allowed measuring PM concentration along the vertical atmospheric profile up to tropopause. This measurement relies on the Atmospheric Light Detection and Ranging (LiDAR) which operates using the radar principle to detect Rayleigh and Mie scattering from atmospheric gas and aerosols. The research involves (1) study of the seasonal vertical PM10 characteristics in five studying site of Hong Kong covering urban, suburban and rural area; (2) the relationship of the PM10 characteristics with meteorological parameters; (3) the vertical PM10 characteristics under the approach of tropical cyclones. A portable Micro Pulse Lidar (MPL) is adopted to collect PM data aloft while surface PM data is collected from ground stations. High-level meteorology data is received from Hong Kong Observatory. Statistical analyses are operated to investigate the correlation between weather conditions and PM concentration along the vertical profile. The research study is divided in phrases. The ultimate goal of the study is to develop models

Observing convection with satellite, radar, and lightning measurements

NASA Astrophysics Data System (ADS)

Hamann, Ulrich; Nisi, Luca; Clementi, Lorenzo; Ventura, Jordi Figueras i.; Gabella, Marco; Hering, Alessandro M.; Sideris, Ioannis; Trefalt, Simona; Germann, Urs

2015-04-01

Heavy precipitation, hail, and wind gusts are the fundamental meteorological hazards associated with strong convection and thunderstorms. The thread is particularly severe in mountainous areas, e.g. it is estimated that on average between 50% and 80% of all weather-related damage in Switzerland is caused by strong thunderstorms (Hilker et al., 2010). Intense atmospheric convection is governed by processes that range from the synoptic to the microphysical scale and are considered to be one of the most challenging and difficult weather phenomena to predict. Even though numerical weather prediction models have some skills to predict convection, in general the exact location of the convective initialization and its propagation cannot be forecasted by these models with sufficient precision. Hence, there is a strong interest to improve the short-term forecast by using statistical, object oriented and/or heuristic nowcasting methods. MeteoSwiss has developed several operational nowcasting systems for this purpose such as TRT (Hering, 2008) and COALITION (Nisi, 2014). In this contribution we analyze the typical development of convection using measurements of the Swiss C-band Dual Polarization Doppler weather radar network, the MSG SEVIRI satellite, and the Météorage lighting network. The observations are complemented with the analysis and forecasts of the COSMO model. Special attention is given to the typical evolutionary stages like the pre-convective environment, convective initiation, cloud top glaciation, start, maximum, and end of precipitation and lightning activity. The pre-convective environment is examined using instability indices derived from SEVIRI observations and the COSMO forecasts. During the early development satellite observations are used to observe the rise of the cloud top, the growth of the cloud droplet or crystals, and the glaciation of the cloud top. SEVIRI brightness temperatures, channel differences, and temporal trends as suggested by

Flood Monitoring using X-band Dual-polarization Radar Network

NASA Astrophysics Data System (ADS)

Chandrasekar, V.; Wang, Y.; Maki, M.; Nakane, K.

2009-09-01

A dense weather radar network is an emerging concept advanced by the Center for Collaborative Adaptive Sensing of the Atmosphere (CASA). Using multiple radars observing over a common will create different data outcomes depending on the characteristics of the radar units employed and the network topology. To define this a general framework is developed to describe the radar network space, and formulations are obtained that can be used for weather radar network characterization. Current weather radar surveillance networks are based upon conventional sensing paradigm of widely-separated, standalone sensing systems using long range radars that operate at wavelengths in 5-10 cm range. Such configuration has limited capability to observe close to the surface of the earth because of the earth's curvature but also has poorer resolution at far ranges. The dense network radar system, observes and measures weather phenomenon such as rainfall and severe weather close to the ground at higher spatial and temporal resolution compared to the current paradigm. In addition the dense network paradigm also is easily adaptable to complex terrain. Flooding is one of the most common natural hazards in the world. Especially, excessive development decreases the response time of urban watersheds and complex terrain to rainfall and increases the chance of localized flooding events over a small spatial domain. Successful monitoring of urban floods requires high spatiotemporal resolution, accurate precipitation estimation because of the rapid flood response as well as the complex hydrologic and hydraulic characteristics in an urban environment. This paper reviews various aspects in radar rainfall mapping in urban coverage using dense X-band dual-polarization radar networks. By reducing the maximum range and operating at X-band, one can ensure good azimuthal resolution with a small-size antenna and keep the radar beam closer to the ground. The networked topology helps to achieve satisfactory

Radar Remote Sensing

NASA Technical Reports Server (NTRS)

Rosen, Paul A.

2012-01-01

This lecture was just a taste of radar remote sensing techniques and applications. Other important areas include Stereo radar grammetry. PolInSAR for volumetric structure mapping. Agricultural monitoring, soil moisture, ice-mapping, etc. The broad range of sensor types, frequencies of observation and availability of sensors have enabled radar sensors to make significant contributions in a wide area of earth and planetary remote sensing sciences. The range of applications, both qualitative and quantitative, continue to expand with each new generation of sensors.

Applied Meteorology Unit (AMU) Quarterly Report Fourth Quarter FY-04

NASA Technical Reports Server (NTRS)

Bauman, William; Wheeler, Mark; Lambert, Winifred; Case, Jonathan; Short, David

2004-01-01

This report summarizes the Applied Meteorology Unit (A MU) activities for the fourth quarter of Fiscal Year 2004 (July -Sept 2004). Tasks covered are: (1) Objective Lightning Probability Forecast: Phase I, (2) Severe Weather Forecast Decision Aid, (3) Hail Index, (4) Shuttle Ascent Camera Cloud Obstruction Forecast, (5) Advanced Regional Prediction System (ARPS) Optimization and Training Extension and (5) User Control Interface for ARPS Data Analysis System (ADAS) Data Ingest.

Radar Remote Sensing of Ice and Sea State and Air-Sea Interaction in the Marginal Ice Zone

DTIC Science & Technology

2014-09-30

1 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Radar Remote Sensing of Ice and Sea State and Air-Sea...Interaction in the Marginal Ice Zone Hans C. Graber RSMAS – Department of Ocean Sciences Center for Southeastern Tropical Advanced Remote Sensing...scattering and attenuation process of ocean waves interacting with ice . A nautical X-band radar on a vessel dedicated to science would be used to follow the

Ice-type classifications from airborne pulse-limited radar altimeter return waveform characteristics

NASA Technical Reports Server (NTRS)

Fedor, L. S.; Hayne, G. S.; Walsh, E. J.

1989-01-01

During mid-March 1978, the NASA C-130 aircraft was deployed to Eielson Air Force Base in Fairbanks, Alaska, to make a series of flights over ice in the Beaufort Sea. The radar altimeter data analyzed were obtained northeast of Mackenzie Bay on March 14th in the vicinity of 69.9 deg N, 134.2 deg W. The data were obtained with a 13.9 GHz radar altimeter developed under the NASA Advanced Applications Flight Experiments (AAFE) Program. This airborne radar was built as a forerunner of the Seasat radar altimeter, and utilized the same pulse compression technique. Pulse-limited radar data taken with the altimeter from 1500-m altitude over sea ice are registered to high-quality photography. The backscattered power is statistically related the surface conductivity and to the number of facets whose surface normal is directed towards the radar. The variations of the radar return waveform shape and signal level are correlated with the variation of the ice type determined from photography. The AAFE altimeter has demonstrated that the return waveform shape and signal level of an airborne pulse-limited altimeter at 13.9 GHz respond to sea ice type. The signal level responded dramatically to even a very small fracture in the ice, as long as it occurred directly at the altimeter nadir point. Shear zones and regions of significant compression ridging consistently produced low signal levels. The return waveforms frequently evidenced the characteristics of both specular and diffuse scattering, and there was an indication that the power backscattered at 3 deg off-nadir in a shear zone was actually somewhat higher than that from nadir.

Meteorological satellites: Past, present, and future

NASA Technical Reports Server (NTRS)

1982-01-01

Past developments, accomplishments and future potential of meteorological satellites are discussed. Meteorological satellite design is described in detail. Space platforms and their meteorological applications are discussed. User needs are also discussed.

Obstacle penetrating dynamic radar imaging system

DOEpatents

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

2006-12-12

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

The Air Force Manufacturing Technology (MANTECH): Technology transfer methodology as exemplified by the radar transmit/receive module program

NASA Technical Reports Server (NTRS)

Houpt, Tracy; Ridgely, Margaret

1991-01-01

The Air Force Manufacturing Technology program is involved with the improvement of radar transmit/receive modules for use in active phased array radars for advanced fighter aircraft. Improvements in all areas of manufacture and test of these modules resulting in order of magnitude improvements in the cost of and the rate of production are addressed, as well as the ongoing transfer of this technology to the Navy.

Meteorological Support in Scientific Ballooning

NASA Technical Reports Server (NTRS)

Schwantes, Chris; Mullenax, Robert

2016-01-01

The weather affects every portion of a scientific balloon mission, from payload integration to launch, float, and impact and recovery. Forecasting for these missions is very specialized and unique in many aspects. CSBF Meteorology incorporates data from NWSNCEP, as well as several international meteorological organizations, and NCAR. This presentation will detail the tools used and specifics on how CSBF Meteorology produces its forecasts.

Meteorological Support in Scientific Ballooning

NASA Technical Reports Server (NTRS)

Schwantes, Chris; Mullenax, Robert

2017-01-01

The weather affects every portion of a scientific balloon mission, from payload integration to launch, float, and impact and recovery. Forecasting for these missions is very specialized and unique in many aspects. CSBF Meteorology incorporates data from NWSNCEP, as well as several international meteorological organizations, and NCAR. This presentation will detail the tools used and specifics on how CSBF Meteorology produces its forecasts.

Survey of Ultra-wideband Radar

NASA Astrophysics Data System (ADS)

Mokole, Eric L.; Hansen, Pete

The development of UWB radar over the last four decades is very briefly summarized. A discussion of the meaning of UWB is followed by a short history of UWB radar developments and discussions of key supporting technologies and current UWB radars. Selected UWB radars and the associated applications are highlighted. Applications include detecting and imaging buried mines, detecting and mapping underground utilities, detecting and imaging objects obscured by foliage, through-wall detection in urban areas, short-range detection of suicide bombs, and the characterization of the impulse responses of various artificial and naturally occurring scattering objects. In particular, the Naval Research Laboratory's experimental, low-power, dual-polarized, short-pulse, ultra-high resolution radar is used to discuss applications and issues of UWB radar. Some crucial issues that are problematic to UWB radar are spectral availability, electromagnetic interference and compatibility, difficulties with waveform control/shaping, hardware limitations in the transmission chain, and the unreliability of high-power sources for sustained use above 2 GHz.

Radar: Human Safety Net

ERIC Educational Resources Information Center

Ritz, John M.

2016-01-01

Radar is a technology that can be used to detect distant objects not visible to the human eye. A predecessor of radar, called the telemobiloscope, was first used to detect ships in the fog in 1904 off the German coast. Many scientists have worked on the development and refinement of radar (Hertz with electromagnetic waves; Popov with determining…

Impact of dual-polarization radar technology and Twitter on the Hattiesburg, Mississippi tornado.

PubMed

Cates, Alexis L; Arnold, Brent W; Cooper, Guy Paul; Yeager, Violet; Stake, Josh; Ali, Mohammed; Calderone, Richard C; Wilkinson, James; Hsu, Edbert; Parrillo, Steven; Piper, Steven; Subbarao, Italo

2013-12-01

Dual-Polarization Radar and Twitter were analyzed to determine the impact on injuries sustained by the Hattiesburg EF-4 tornado. Tracking data provided from the Dual-Pol radar systems in National Weather Service Jackson were reviewed. Twitter data from four local Twitter handles were obtained. The change in tweets and followers for the day of the storm were compared to historical averages. A Student t-test was utilized in determining statistical significance (p<0.05). Medical records from two local emergency departments were reviewed for patients treated up to 24 hours after the tornado. An Injury Severity Score (ISS) was calculated for trauma records related to the tornado. Radar detection of the tornado gave approximately 30 minutes of advanced warning time. Statistical significance in follower growth was seen in all four Twitter handles. Out of 50 patients, the average ISS was 3.9 with a range of 1 to 29. There were zero fatalities. An ISS average of 3.9 was significantly less than two previous tornadoes of similar strength that occurred prior to increased usage of Dual-pol radar and Twitter as a means for communicating severe weather information. Early detection from Dual-pol radar improved warning time. Tweets informed citizens to seek appropriate shelter. (Disaster Med Public Health Preparedness. 2013;7:585-592).

German Radar Observation Shuttle Experiment (ROSE)

NASA Technical Reports Server (NTRS)

Sleber, A. J.; Hartl, P.; Haydn, R.; Hildebrandt, G.; Konecny, G.; Muehlfeld, R.

1984-01-01

The success of radar sensors in several different application areas of interest depends on the knowledge of the backscatter of radar waves from the targets of interest, the variance of these interaction mechanisms with respect to changing measurement parameters, and the determination of the influence of he measuring systems on the results. The incidence-angle dependency of the radar cross section of different natural targets is derived. Problems involved by the combination of data gained with different sensors, e.g., MSS-, TM-, SPOTand SAR-images are analyzed. Radar cross-section values gained with ground-based radar spectrometers and spaceborne radar imaging, and non-imaging scatterometers and spaceborne radar images from the same areal target are correlated. The penetration of L-band radar waves into vegetated and nonvegetated surfaces is analyzed.

Using TRMM and GPM precipitation radar for calibration of weather radars in the Philippines

NASA Astrophysics Data System (ADS)

Crisologo, Irene; Bookhagen, Bodo; Smith, Taylor; Heistermann, Maik

2016-04-01

Torrential and sustained rainfall from tropical cyclones, monsoons, and thunderstorms frequently impact the Philippines. In order to predict, assess, and measure storm impact, it is imperative to have a reliable and accurate monitoring system in place. In 2011, the Philippine Atmospheric, Geophysical, and Astronomical Services Administration (PAGASA) established a weather radar network of ten radar devices, eight of which are single-polarization S-band radars and two dual-polarization C-band radars. Because of a low-density hydrometeorological monitoring networks in the Philippines, calibration of weather radars becomes a challenging, but important task. In this study, we explore the potential of scrutinizing the calibration of ground radars by using the observations from the Tropical Rainfall Measuring Mission (TRMM). For this purpose, we compare different TRMM level 1 and 2 orbital products from overpasses over the Philippines, and compare these products to reflectivities observed by the Philippine ground radars. Differences in spatial resolution are addressed by computing adequate zonal statistics of the local radar bins located within the corresponding TRMM cell in space and time. The wradlib package (Heistermann et al. 2013; Heistermann et al. 2015) is used to process the data from the Subic S-band single-polarization weather radar. These data will be analyzed in conjunction with TRMM data for June to August 2012, three months of the wet season. This period includes the enhanced monsoon of 2012, locally called Habagat 2012, which brought sustained intense rainfall and massive floods in several parts of the country including the most populated city of Metro Manila. References Heistermann, M., Jacobi, S., Pfaff, T. (2013): Technical Note: An open source library for processing weather radar data (wradlib). Hydrol. Earth Syst. Sci., 17, 863-871, doi: 10.5194/hess-17-863-2013. Heistermann, M., S. Collis, M. J. Dixon, S. Giangrande, J. J. Helmus, B. Kelley, J

A variational technique to estimate snowfall rate from coincident radar, snowflake, and fall-speed observations

DOE PAGES

Cooper, Steven J.; Wood, Norman B.; L'Ecuyer, Tristan S.

2017-07-20

Estimates of snowfall rate as derived from radar reflectivities alone are non-unique. Different combinations of snowflake microphysical properties and particle fall speeds can conspire to produce nearly identical snowfall rates for given radar reflectivity signatures. Such ambiguities can result in retrieval uncertainties on the order of 100–200% for individual events. Here, we use observations of particle size distribution (PSD), fall speed, and snowflake habit from the Multi-Angle Snowflake Camera (MASC) to constrain estimates of snowfall derived from Ka-band ARM zenith radar (KAZR) measurements at the Atmospheric Radiation Measurement (ARM) North Slope Alaska (NSA) Climate Research Facility site at Barrow. MASCmore » measurements of microphysical properties with uncertainties are introduced into a modified form of the optimal-estimation CloudSat snowfall algorithm (2C-SNOW-PROFILE) via the a priori guess and variance terms. Use of the MASC fall speed, MASC PSD, and CloudSat snow particle model as base assumptions resulted in retrieved total accumulations with a -18% difference relative to nearby National Weather Service (NWS) observations over five snow events. The average error was 36% for the individual events. The use of different but reasonable combinations of retrieval assumptions resulted in estimated snowfall accumulations with differences ranging from -64 to +122% for the same storm events. Retrieved snowfall rates were particularly sensitive to assumed fall speed and habit, suggesting that in situ measurements can help to constrain key snowfall retrieval uncertainties. Furthermore, accurate knowledge of these properties dependent upon location and meteorological conditions should help refine and improve ground- and space-based radar estimates of snowfall.« less

A variational technique to estimate snowfall rate from coincident radar, snowflake, and fall-speed observations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cooper, Steven J.; Wood, Norman B.; L'Ecuyer, Tristan S.

Estimates of snowfall rate as derived from radar reflectivities alone are non-unique. Different combinations of snowflake microphysical properties and particle fall speeds can conspire to produce nearly identical snowfall rates for given radar reflectivity signatures. Such ambiguities can result in retrieval uncertainties on the order of 100–200% for individual events. Here, we use observations of particle size distribution (PSD), fall speed, and snowflake habit from the Multi-Angle Snowflake Camera (MASC) to constrain estimates of snowfall derived from Ka-band ARM zenith radar (KAZR) measurements at the Atmospheric Radiation Measurement (ARM) North Slope Alaska (NSA) Climate Research Facility site at Barrow. MASCmore » measurements of microphysical properties with uncertainties are introduced into a modified form of the optimal-estimation CloudSat snowfall algorithm (2C-SNOW-PROFILE) via the a priori guess and variance terms. Use of the MASC fall speed, MASC PSD, and CloudSat snow particle model as base assumptions resulted in retrieved total accumulations with a -18% difference relative to nearby National Weather Service (NWS) observations over five snow events. The average error was 36% for the individual events. The use of different but reasonable combinations of retrieval assumptions resulted in estimated snowfall accumulations with differences ranging from -64 to +122% for the same storm events. Retrieved snowfall rates were particularly sensitive to assumed fall speed and habit, suggesting that in situ measurements can help to constrain key snowfall retrieval uncertainties. Furthermore, accurate knowledge of these properties dependent upon location and meteorological conditions should help refine and improve ground- and space-based radar estimates of snowfall.« less

Nowcasting of meteorological risks during the winter season using the "Integrated Meteorological Observation Network in Castilla y León, (Spain)"

NASA Astrophysics Data System (ADS)

Guerrero-Higueras, Ángel Manuel; López, Laura; Merino, Andrés; Sánchez, José Luis; Matía, Pedro; Lorente, José Manuel; Hermida, Lucía; Nafría, David; Ortiz de Galisteo, José Pablo; Marcos, José Luis; García-Ortega, Eduardo

2013-04-01

The location of Castilla y León within the Iberian Peninsula and its territorial extension make its meteorological risks diverse. The integration of various observation networks, both public and private, in the Observation Network of Castilla y León, allows us to follow the risks in real-time. One of the most frequent risks in the winter season is snow precipitation. In the present paper, we compared WRF numerical model predictions of snowfall for Castilla y León with data from the meteorological observation network and observations from the MSG satellite. Furthermore, frosts were more frequent in the area, to the point that there are parts of the study area with frost during the entire year. Thus, the data from the network allows us to determine the area where frost was registered. Finally, the situations with fog, especially with advective and radiative characteristics, are frequent in the center and south of the plateau, especially in the winter season. Additionally, the Observation Network allows us to know the areas with fog in real-time. The Observation Network is managed using a new platform, developed by Group for Atmospheric Physics, known as MeteoNet, which allows for the prompt extraction of a concrete parameter in a specific location, or, the spatial representation of a parameter determined for the entire study area. Furthermore, the management system developed for the data allows for the total representation of data from the WRF prediction model, with satellite images, observation network, radar data, etc., which is converted into a very useful tool for following risks and validating algorithms in Castilla y León. Acknowledgements The authors would like to thank the Regional Government of Castilla y León for its financial support through the project LE220A11-2.

Spaceborne Imaging Radar-C instrument

NASA Technical Reports Server (NTRS)

Huneycutt, Bryan L.

1993-01-01

The Spaceborne Imaging Radar-C is the next radar in the series of spaceborne radar experiments, which began with Seasat and continued with SIR-A and SIR-B. The SIR-C instrument has been designed to obtain simultaneous multifrequency and simultaneous multipolarization radar images from a low earth orbit. It is a multiparameter imaging radar that will be flown during at least two different seasons. The instrument operates in the squint alignment mode, the extended aperture mode, the scansar mode, and the interferometry mode. The instrument uses engineering techniques such as beam nulling for echo tracking, pulse repetition frequency hopping for Doppler centroid tracking, generating the frequency step chirp for radar parameter flexibility, block floating-point quantizing for data rate compression, and elevation beamwidth broadening for increasing the swath illumination.

Automated target recognition using passive radar and coordinated flight models

NASA Astrophysics Data System (ADS)

Ehrman, Lisa M.; Lanterman, Aaron D.

2003-09-01

Rather than emitting pulses, passive radar systems rely on illuminators of opportunity, such as TV and FM radio, to illuminate potential targets. These systems are particularly attractive since they allow receivers to operate without emitting energy, rendering them covert. Many existing passive radar systems estimate the locations and velocities of targets. This paper focuses on adding an automatic target recognition (ATR) component to such systems. Our approach to ATR compares the Radar Cross Section (RCS) of targets detected by a passive radar system to the simulated RCS of known targets. To make the comparison as accurate as possible, the received signal model accounts for aircraft position and orientation, propagation losses, and antenna gain patterns. The estimated positions become inputs for an algorithm that uses a coordinated flight model to compute probable aircraft orientation angles. The Fast Illinois Solver Code (FISC) simulates the RCS of several potential target classes as they execute the estimated maneuvers. The RCS is then scaled by the Advanced Refractive Effects Prediction System (AREPS) code to account for propagation losses that occur as functions of altitude and range. The Numerical Electromagnetic Code (NEC2) computes the antenna gain pattern, so that the RCS can be further scaled. The Rician model compares the RCS of the illuminated aircraft with those of the potential targets. This comparison results in target identification.

Study to investigate and evaluate means of optimizing the radar function for the space shuttle. [(pulse radar)

NASA Technical Reports Server (NTRS)

1975-01-01

Results are discussed of a study to define a radar and antenna system which best suits the space shuttle rendezvous requirements. Topics considered include antenna characteristics and antenna size tradeoffs, fundamental sources of measurement errors inherent in the target itself, backscattering crosssection models of the target and three basic candidate radar types. Antennas up to 1.5 meters in diameter are within specified installation constraints, however, a 1 meter diameter paraboloid and a folding, four slot backfeed on a two gimbal mount implemented for a spiral acquisition scan is recommended. The candidate radar types discussed are: (1) noncoherent pulse radar (2) coherent pulse radar and (3) pulse Doppler radar with linear FM ranging. The radar type recommended is a pulse Doppler with linear FM ranging. Block diagrams of each radar system are shown.

The Chinese FY-1 Meteorological Satellite Application in Observation on Oceanic Environment

NASA Astrophysics Data System (ADS)

Weimin, S.

meteorological satellite is stated in this paper. exploration of the ocean resources has been a very important question of global strategy in the world. The exploration of the ocean resources includes following items: Making full use of oceanic resources and space, protecting oceanic environment. to observe the ocean is by using of satellite. In 1978, US successfully launched the first ocean observation satellite in the world --- Sea Satellite. It develops ancient oceanography in to advanced space-oceanography. FY-1 B and FY- IC respectively. High quality data were acquired at home and abroad. FY-1 is Chinese meteorological satellite, but with 0.43 ~ 0.48 μm ,0.48 ~ 0.53 μm and 0.53 ~ 0.58 μm three ocean color channels, actually it is a multipurpose remote sensing satellite of meteorology and oceanography. FY-1 satellite's capability of observation on ocean partly, thus the application field is expanded and the value is increased. With the addition of oceanic channels on FY-1, the design of the satellite is changed from the original with meteorological observation as its main purpose into remote sensing satellite possessing capability of observing meteorology and ocean as well. Thus, the social and economic benefit of FY-1 is increased. the social and economic benefit of the development of the satellite is the key technique in the system design of the satellite. technically feasible but also save the funds in researching and manufacturing of the satellite, quicken the tempo of researching and manufacturing satellite. the scanning radiometer for FY-1 is conducted an aviation experiment over Chinese ocean. This experiment was of vital importance to the addition of oceanic observation channel on FY-1. FY-1 oceanic channels design to be correct. detecting ocean color. This is the unique character of Chinese FY-1 meteorological satellite. meteorological remote sensing channel on FY-1 to form detecting capability of three visible channels: red, yellow and blue

Lidars as an operational tool for meteorology and advanced atmospheric research

NASA Astrophysics Data System (ADS)

Simeonov, Valentin; Dinoev, Todor; Serikov, Ilya; Froidevaux, Martin; Bartlome, Marcel; Calpini, Bertrand; Bobrovnikov, Sergei; Ristori, Pablo; van den Bergh, Hubert; Parlange, Marc; Archinov, Yury

2010-05-01

The talk will present the concept and observation results of three advanced lidar systems developed recently at the Swiss federal Institute of Technology- Lausanne (EPFL) Switzerland. Two of the systems are Raman lidars for simultaneous water vapor, temperature and aerosol observations and the third one is an ozone UV DIAL system. The Ranan lidars use vibrational water vapor and nitrogen signals to derive water vapor mixing ratio and temperature, aerosol extinction and backscatter are measured using pure-rotational Raman and elastic signals. The first Raman lidar (RALMO) is a fully automated, water vapor /temperature/aerosol lidar developed for operational use by the Swiss meteorological office (MeteoSiss). The lidar supplies water vapor mixing ratio and temperature plus aerosol extinction and backscatter coefficients at 355 nm. The operational range of the lidar is 100-7000 m (night time) and 100- 5000 m (daytime) with time resolution of 30 min. The spatial resolution varies with height from 25 to 300 m in order to maintain the maximum measurement error of 10%. The system is designed to provide long-term database with minimal instrument-induced variations in time of the measured parameters. The lidar has been in regular operation in the main aerological station of Meteoswiss- Payerne since September 2008. The second Raman lidar is a new generation, solar-blind system with an operational range 10-500 m and high spatial (1.5 m) and temporal (1 s) resolutions designed for simultaneous humidity, temperature, and aerosol measurements in the lower atmosphere. To maintain the measurement accuracy while operating with fixed spatial and temporal resolution, the receiver is designed to provide lower than ten dynamic range of the signals within the distance range of the lidar. The lidar has 360° azimuth and 240°elevation scanning ability. The lidar was used in two field campaigns aiming to study the structure of the lower atmosphere over complex terrains and, in particular

Synergistic Measurement of Ice Cloud Microphysics using C- and Ka-Band Radars

NASA Astrophysics Data System (ADS)

Ewald, F.; Gross, S.; Hagen, M.; Li, Q.; Zinner, T.

2017-12-01

of the C-band radar and compare the results to simultaneous linear depolarization measurements with the Ka-band radar. In summary, we will explore if the scientific understanding of ice cloud microphysics can be advanced by the combination of C- and Ka-band radars.

Airborne Radar Observations of Severe Hailstorms: Implications for Future Spaceborne Radar

NASA Technical Reports Server (NTRS)

Heymsfield, Gerald M.; Tian, Lin; Li, Lihua; McLinden, Matthew; Cervantes, Jaime I.

2013-01-01

A new dual-frequency (Ku and Ka band) nadir-pointing Doppler radar on the high-altitude NASA ER-2 aircraft, called the High-Altitude Imaging Wind and Rain Airborne Profiler (HIWRAP), has collected data over severe thunderstorms in Oklahoma and Kansas during the Midlatitude Continental Convective Clouds Experiment (MC3E). The overarching motivation for this study is to understand the behavior of the dualwavelength airborne radar measurements in a global variety of thunderstorms and how these may relate to future spaceborne-radar measurements. HIWRAP is operated at frequencies that are similar to those of the precipitation radar on the Tropical Rainfall Measuring Mission (Ku band) and the upcoming Global Precipitation Measurement mission satellite's dual-frequency (Ku and Ka bands) precipitation radar. The aircraft measurements of strong hailstorms have been combined with ground-based polarimetric measurements to obtain a better understanding of the response of the Ku- and Ka-band radar to the vertical distribution of the hydrometeors, including hail. Data from two flight lines on 24 May 2011 are presented. Doppler velocities were approx. 39m/s2at 10.7-km altitude from the first flight line early on 24 May, and the lower value of approx. 25m/s on a second flight line later in the day. Vertical motions estimated using a fall speed estimate for large graupel and hail suggested that the first storm had an updraft that possibly exceeded 60m/s for the more intense part of the storm. This large updraft speed along with reports of 5-cm hail at the surface, reflectivities reaching 70 dBZ at S band in the storm cores, and hail signals from polarimetric data provide a highly challenging situation for spaceborne-radar measurements in intense convective systems. The Ku- and Ka-band reflectivities rarely exceed approx. 47 and approx. 37 dBZ, respectively, in these storms.

Combination of radar and daily precipitation data to estimate meaningful sub-daily point precipitation extremes

NASA Astrophysics Data System (ADS)

Pegram, Geoff; Bardossy, Andras; Sinclair, Scott

2017-04-01

The use of radar measurements for the space time estimation of precipitation has for many decades been a central topic in hydro-meteorology. In this presentation we are interested specifically in daily and sub-daily extreme values of precipitation at gauged or ungauged locations which are important for design. The purpose of the presentation is to develop a methodology to combine daily precipitation observations and radar measurements to estimate sub-daily extremes at point locations. Radar data corrected using precipitation-reflectivity relationships lead to biased estimations of extremes. Different possibilities of correcting systematic errors using the daily observations are investigated. Observed gauged daily amounts are interpolated to un-sampled points and subsequently disaggregated using the sub-daily values obtained by the radar. Different corrections based on the spatial variability and the sub-daily entropy of scaled rainfall distributions are used to provide unbiased corrections of short duration extremes. In addition, a statistical procedure not based on a matching day by day correction is tested. In this last procedure, as we are only interested in rare extremes, low to medium values of rainfall depth were neglected leaving 12 days of ranked daily maxima in each set per year, whose sum typically comprises about 50% of each annual rainfall total. The sum of these 12 day maxima is first interpolated using a Kriging procedure. Subsequently this sum is disaggregated to daily values using a nearest neighbour procedure. The daily sums are then disaggregated by using the relative values of the biggest 12 radar based days in each year. Of course, the timings of radar and gauge maxima can be different, so the new method presented here uses radar for disaggregating daily gauge totals down to 15 min intervals in order to extract the maxima of sub-hourly through to daily rainfall. The methodologies were tested in South Africa, where an S-band radar operated

Applications of high resolution rainfall radar data to quantify water temperature dynamics in urban catchments

NASA Astrophysics Data System (ADS)

Croghan, Danny; Van Loon, Anne; Bradley, Chris; Sadler, Jon; Hannnah, David

2017-04-01

Studies relating rainfall events to river water quality are frequently hindered by the lack of high resolution rainfall data. Local studies are particularly vulnerable due to the spatial variability of precipitation, whilst studies in urban environments require precipitation data at high spatial and temporal resolutions. The use of point-source data makes identifying causal effects of storms on water quality problematic and can lead to erroneous interpretations. High spatial and temporal resolution rainfall radar data offers great potential to address these issues. Here we use rainfall radar data with a 1km spatial resolution and 5 minute temporal resolution sourced from the UK Met Office Nimrod system to study the effects of storm events on water temperature (WTemp) in Birmingham, UK. 28 WTemp loggers were placed over 3 catchments on a rural-urban land use gradient to identify trends in WTemp during extreme events within urban environments. Using GIS, the catchment associated with each logger was estimated, and 5 min. rainfall totals and intensities were produced for each sub-catchment. Comparisons of rainfall radar data to meteorological stations in the same grid cell revealed the high accuracy of rainfall radar data in our catchments (<5% difference for studied months). The rainfall radar data revealed substantial differences in rainfall quantity between the three adjacent catchments. The most urban catchment generally received more rainfall, with this effect greatest in the highest intensity storms, suggesting the possibility of urban heat island effects on precipitation dynamics within the catchment. Rainfall radar data provided more accurate sub-catchment rainfall totals allowing better modelled estimates of storm flow, whilst spatial fluctuations in both discharge and WTemp can be simply related to precipitation intensity. Storm flow inputs for each sub-catchment were estimated and linked to changes in WTemp. WTemp showed substantial fluctuations (>1 �

Simulation of the Transport and Dispersion of Perfluorocarbon Tracers Released in Texas Using multiple Assimilated Meteorological Wind Fields

NASA Astrophysics Data System (ADS)

Schichtel, B.; Barna, M.; Gebhart, K.; Green, M.

2002-12-01

The Big Bend Regional Aerosol and Visibility Observational Study (BRAVO) was designed to determine the causes of visibility impairment at Big Bend National Park, located in southwestern Texas. As part of BRAVO, an intensive field study was conducted during July-October 1999. Among the features of this study was the release of unique perfluorocarbon tracers from four sites within Texas, representative of industrial/urban locations. These tracers were monitored at 21 sites, throughout Texas. Other measurements collected during the field study included upper-level winds using radar profilers, and speciated fine-particulate mass concentrations. MM5 was used to simulate the regional meteorology during BRAVO, and was run in non-hydrostatic mode using a continental-scale 36km domain with nested 12km and 4km domains. MM5 employed observational nudging by incorporating the available measured wind data from the National Weather Service and data from the radar wind profilers. Meteorological data from the National Weather Service's Eta Data Assimilation System (EDAS), archived at 80km grid spacing, were also available. Several models are being used to evaluate airmass transport to Big Bend, including CMAQ, REMSAD, HYSPLIT and the CAPITA Monte Carlo Model. This combination of tracer data, meteorological data and deployment of four models provides a unique opportunity to assess the ability of the model/wind field combinations to properly simulate the regional scale atmospheric transport and dispersion of trace gases over distances of 100 to 800km. This paper will present the tracer simulations from REMSAD using the 36 and 12 km MM5 wind fields, and results from HYSPLIT and the Monte Carlo model driven by the 36km MM5 and 80km EDAS wind fields. Preliminary results from HYSPLIT and the Monte Carlo model driven by the EDAS wind fields shows that these models are able to account for the primary features of tracer concentrations patterns in the Big Bend area. However, at times the

Development of the nowcasting system for the XVII Asiad at Korea Meteorological Administration

NASA Astrophysics Data System (ADS)

Park, Kyungjeen; Kim, Juwon; Jang, Taekyu; Hwang, Seung On; Park, Yunho; Kim, Yoonjae; Park, Seonjoo; Joo, Sangwon; Noh, Hae Mi

2014-05-01

The XVII Asiad, known as the 2014 Asian game, is the largest sporting event in Asia. It will be held in Incheon, South Korea from September 19 to October 4, with 437 events in 36 sports. To support this game, Korea Meteorological Administration developed Incheon Data Assimilation and Prediction System (IDAPS) for nowcasting and very short range forecasts. The domain is centered at Incheon city and covers the central region of the Korean peninsula and adjacent seas. It repeats analysis and forecast processes with 1 hour cycling interval. IDAPS has approximately 1 km horizontal resolution with 324 x 360 grids and 70 vertical layers. Three dimensional variational data assimilation is applied to assimilate AWS, windprofiler, buoy, sonde, aircraft, scatwinds, rain rate, and radar products. The details of IDAPS and the experiment results will be given during the conference.

Alabama Ground Operations during the Deep Convective Clouds and Chemistry Experiment

NASA Technical Reports Server (NTRS)

Carey, Lawrence; Blakeslee, Richard; Koshak, William; Bain, Lamont; Rogers, Ryan; Kozlowski, Danielle; Sherrer, Adam; Saari, Matt; Bigelbach, Brandon; Scott, Mariana;

Enhanced Weather Radar (EWxR) System

NASA Technical Reports Server (NTRS)

Kronfeld, Kevin M. (Technical Monitor)

2003-01-01

An airborne weather radar system, the Enhanced Weather Radar (EWxR), with enhanced on-board weather radar data processing was developed and tested. The system features additional weather data that is uplinked from ground-based sources, specialized data processing, and limited automatic radar control to search for hazardous weather. National Weather Service (NWS) ground-based Next Generation Radar (NEXRAD) information is used by the EWxR system to augment the on-board weather radar information. The system will simultaneously display NEXRAD and on-board weather radar information in a split-view format. The on-board weather radar includes an automated or hands-free storm-finding feature that optimizes the radar returns by automatically adjusting the tilt and range settings for the current altitude above the terrain and searches for storm cells near the atmospheric 0-degree isotherm. A rule-based decision aid was developed to automatically characterize cells as hazardous, possibly-hazardous, or non-hazardous based upon attributes of that cell. Cell attributes are determined based on data from the on-board radar and from ground-based radars. A flight path impact prediction algorithm was developed to help pilots to avoid hazardous weather along their flight plan and their mission. During development the system was tested on the NASA B757 aircraft and final tests were conducted on the Rockwell Collins Sabreliner.

Advanced Corrections for InSAR Using GPS and Numerical Weather Models

NASA Astrophysics Data System (ADS)

Cossu, F.; Foster, J. H.; Amelung, F.; Varugu, B. K.; Businger, S.; Cherubini, T.

2017-12-01

We present results from an investigation into the application of numerical weather models for generating tropospheric correction fields for Interferometric Synthetic Aperture Radar (InSAR). We apply the technique to data acquired from a UAVSAR campaign as well as from the CosmoSkyMed satellites. The complex spatial and temporal changes in the atmospheric propagation delay of the radar signal remain the single biggest factor limiting InSAR's potential for hazard monitoring and mitigation. A new generation of InSAR systems is being built and launched, and optimizing the science and hazard applications of these systems requires advanced methodologies to mitigate tropospheric noise. We use the Weather Research and Forecasting (WRF) model to generate a 900 m spatial resolution atmospheric models covering the Big Island of Hawaii and an even higher, 300 m resolution grid over the Mauna Loa and Kilauea volcanoes. By comparing a range of approaches, from the simplest, using reanalyses based on typically available meteorological observations, through to the "kitchen-sink" approach of assimilating all relevant data sets into our custom analyses, we examine the impact of the additional data sets on the atmospheric models and their effectiveness in correcting InSAR data. We focus particularly on the assimilation of information from the more than 60 GPS sites in the island. We ingest zenith tropospheric delay estimates from these sites directly into the WRF analyses, and also perform double-difference tomography using the phase residuals from the GPS processing to robustly incorporate heterogeneous information from the GPS data into the atmospheric models. We assess our performance through comparisons of our atmospheric models with external observations not ingested into the model, and through the effectiveness of the derived phase screens in reducing InSAR variance. Comparison of the InSAR data, our atmospheric analyses, and assessments of the active local and mesoscale

DOE's 449 MHz Wind Profiling Radars on the U.S. West Coast: Annual Report for Fiscal Year 2016

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flaherty, Julia E.; Shaw, William J.; Wilczak, J. M.

The three coastal wind profilers and associated meteorological instruments located in Forks, WA, Astoria, OR, and North Bend, OR, provide important observations at high temporal and vertical spatial resolution to characterize the meteorological inflow to the western region of the United States. These instruments have been operating for a year or more, and furnish boundary conditions for the modeling efforts of the WFIP2 project. The data have been delivered to archives at both NOAA and the DOE A2e DAP at a data recovery rate in excess of 98%. Site maintenance activities have been relatively minor, with a few component replacementsmore » and repairs to RASS foam. Bird mortality surveys have found no bird nests or carcasses, and the U.S. Fish and Wildlife Service has regularly been provided survey reports. This project represents a successful collaboration between PNNL and NOAA to procure, test, deploy, maintain, and operate three 449 MHz radar wind profilers.« less

Historical aspects of radar atmospheric dynamics

NASA Technical Reports Server (NTRS)

Kato, Susumu

1989-01-01

A review of the history of radar techniques which have been applied to atmospheric observation is given. The author starts with ionosphere observation with the ionosonde, symbolizing as it does the earliest history of radar observation, and proceeds to later developments in radar observation such as the use of partial reflection, meteor, and incoherent scatter radars. Mesosphere stratosphere troposphere (MST) radars are discussed in terms of lower atmosphere observation.

Radar Performance Improvement. Angle Tracking Modification to Fire Control Radar System for Space Shuttle Rendezvous

NASA Technical Reports Server (NTRS)

Little, G. R.

1976-01-01

The AN/APQ-153 fire control radar modified to provide angle tracking was evaluated for improved performance. The frequency agile modifications are discussed along with the range-rate improvement modifications, and the radar to computer interface. A parametric design and comparison of noncoherent and coherent radar systems are presented. It is shown that the shuttle rendezvous range and range-rate requirements can be made by a Ku-Band noncoherent pulse radar.

Consistency analysis and correction of ground-based radar observations using space-borne radar

NASA Astrophysics Data System (ADS)

Zhang, Shuai; Zhu, Yiqing; Wang, Zhenhui; Wang, Yadong

2018-04-01

The lack of an accurate determination of radar constant can introduce biases in ground-based radar (GR) reflectivity factor data, and lead to poor consistency of radar observations. The geometry-matching method was applied to carry out spatial matching of radar data from the Precipitation Radar (PR) on board the Tropical Rainfall Measuring Mission (TRMM) satellite to observations from a GR deployed at Nanjing, China, in their effective sampling volume, with 250 match-up cases obtained from January 2008 to October 2013. The consistency of the GR was evaluated with reference to the TRMM PR, whose stability is established. The results show that the below-bright-band-height data of the Nanjing radar can be split into three periods: Period I from January 2008 to March 2010, Period II from March 2010 to May 2013, and Period III from May 2013 to October 2013. There are distinct differences in overall reflectivity factor between the three periods, and the overall reflectivity factor in period II is smaller by a factor of over 3 dB than in periods I and III, although the overall reflectivity within each period remains relatively stable. Further investigation shows that in period II the difference between the GR and PR observations changed with echo intensity. A best-fit relation between the two radar reflectivity factors provides a linear correction that is applied to the reflectivity of the Nanjing radar, and which is effective in improving its consistency. Rain-gauge data were used to verify the correction, and the estimated precipitation based on the corrected GR reflectivity data was closer to the rain-gauge observations than that without correction.

The Dallas-Fort Worth (DFW) Urban Radar Network: Enhancing Resilience in the Presence of Floods, Tornadoes, Hail and High Winds

NASA Astrophysics Data System (ADS)

Chandra*, Chandrasekar V.; the full DFW Team

2015-04-01

Currently, the National Weather Service (NWS) Next Generation Weather Radar (NEXRAD) provides observations updated every five-six minutes across the United States. However, at the maximum NEXRAD operating range of 230 km, the 0.5 degree radar beam (lowest tilt) height is about 5.4 km above ground level (AGL) because of the effect of Earth curvature. Consequently, much of the lower atmosphere (1-3 km AGL) cannot be observed by the NEXRAD. To overcome the fundamental coverage limitations of today's weather surveillance radars, and improve the spatial and temporal resolution issues, at urban scale, the National Science Foundation Engineering Research Center (NSF-ERC) for Collaborative Adaptive Sensing of the Atmosphere (CASA) has embarked the development of Dallas-Fort worth (DFW) urban remote sensing network to conduct high-resolution sensing in the lower atmosphere for a metropolitan environment, communicate high resolution observations and nowcasting of severe weather including flash floods, hail storms and high wind events. Being one of the largest inland metropolitan areas in the U.S., the DFW Metroplex is home to over 6.5 million people by 2012 according to the North Central Texas Council of Governments (NCTCOG). It experiences a wide range of natural weather hazards, including urban flash flood, high wind, tornado, and hail, etc. Successful monitoring of the rapid changing meteorological conditions in such a region is necessary for emergency management and decision making. Therefore, it is an ideal location to investigate the impacts of hazardous weather phenomena, to enhance resilience in an urban setting and demonstrate the CASA concept in a densely populated urban environment. The DFW radar network consists of 8 dual-polarization X-band weather radars and standard NEXRAD S-band radar, covering the greater DFW metropolitan region. This paper will present high resolution observation of tornado, urban flood, hail storm and damaging wind event all within the

Studies based on global subsurface radar sounding of the Moon by SELENE (Kaguya) Lunar Radar Sounder (LRS): A summary

NASA Astrophysics Data System (ADS)

Kumamoto, A.; Yamaguchi, Y.; Yamaji, A.; Kobayashi, T.; Oshigami, S.; Ishiyama, K.; Nakamura, N.; Goto, Y.

2015-12-01

The Lunar Radar Sounder (LRS) onboard the SELENE (Kaguya) spacecraft has successfully performed radar sounder observations of the lunar subsurface structures and passive observations of natural radio and plasma waves from the lunar orbit. After the transfer of the spacecraft into the final lunar orbit and antenna deployment, the operation of LRS started on October 29, 2007. Through the operation until June 10, 2009, 130 million pulses worth of radar sounder data have been obtained [Ono et al., 2010]. Based on the datasets of the first lunar global subsurface radar sounding, Ono et al. [2009] revealed that there are distinct reflectors at a depth of several hundred meters in the nearside maria, which are inferred to be buried regolith layers covered by a basalt layer with a thickness of several hundred meters. Based on the further survey, Pommerol et al. [2010] pointed out the negative correlation of clear subsurface echoes with the maps of ilmenite, and suggested that dense ilmenite attenuates the radar pulse in the basaltic mare lava, and cause the absence of the clear subsurface echoes. That also suggests there are undetected subsurface reflectors especially below the young lava flow units with high ilmenite abundance. Kobayashi et al. [2012] applied synthetic aperture radar (SAR) processing to SELENE LRS data in order to obtain distinct radargram. Taking advantage of analyzing waveform data sent via high data rate telemetry from the Moon, we can perform advanced data analyses on the ground. We started providing the both SAR processed and waveform datasets via SELENE Data Archive (http://l2db.selene.darts.isas.jaxa.jp/index.html.en) since 2015. Oshigami et al. [2014] estimated volumes of basalt units in the ages of 2.7 Ga to 3.8 Ga in the nearside maria. The volume was derived from the depth of subsurface reflectors measured by LRS. The volumes of the geologic units were 103 to 104 km3. The average eruption rates were 10-5 to 10-3 km3 yr-1. The estimated volumes

A 10 cm Dual Frequency Doppler Weather Radar. Part I. The Radar System.

DTIC Science & Technology

1982-10-25

Evaluation System ( RAMCES )". The step attenuator required for this calibration can be programmed remotely, has low power and temperature coefficients, and...Control and Evaluation System". The Quality Assurance/Fault Location Network makes use of fault location techniques at critical locations in the radar and...quasi-con- tinuous monitoring of radar performance. The Radar Monitor, Control and Evaluation System provides for automated system calibration and

Radar data smoothing filter study

NASA Technical Reports Server (NTRS)

White, J. V.

1984-01-01

The accuracy of the current Wallops Flight Facility (WFF) data smoothing techniques for a variety of radars and payloads is examined. Alternative data reduction techniques are given and recommendations are made for improving radar data processing at WFF. A data adaptive algorithm, based on Kalman filtering and smoothing techniques, is also developed for estimating payload trajectories above the atmosphere from noisy time varying radar data. This algorithm is tested and verified using radar tracking data from WFF.

Microphysics, Meteorology, Microwave and Modeling of Mediterranean Storms: The M(sup 5) Problem

NASA Technical Reports Server (NTRS)

Smith, Eric A.; Fiorino, Steven; Mugnai, Alberto; Panegrossi, Giulia; Tripoli, Gregory; Starr, David (Technical Monitor)

2001-01-01

Comprehensive understanding of the microphysical nature of Mediterranean storms requires a combination of in situ meteorological data analysis and radar-passive microwave data analysis, effectively integrated with numerical modeling studies at various scales, particularly from synoptic scale down to mesoscale. The microphysical properties of and their controls on severe storms are intrinsically related to meteorological processes under which storms have evolved, processes which eventually select and control the dominant microphysical properties themselves. Insofar as hazardous Mediterranean storms, highlighted by the September 25-28/1992 Genova flood event, the October 5-7/1998 Friuli flood event, and the October 13-15/2000 Piemonte flood event (all taking place in northern Italy), developing a comprehensive microphysical interpretation requires an understanding of the multiple phases of storm evolution and the heterogeneous nature of precipitation fields within the storm domains. This involves convective development, stratiform transition and decay, orographic lifting, and sloped frontal lifting proc esses. This also involves vertical motions and thermodynamical instabilities governing physical processes that determine details of the liquid/ice water contents, size distributions, and fall rates of the various modes of hydrometeors found within the storm environments. This paper presents detailed 4-dimensional analyses of the microphysical elements of the three severe Mediterranean storms identified above, investigated with the aid of SSM/I and TRMM satellite measurements (and other remote sensing measurements). The analyses are guided by nonhydrostatic mesoscale model simulations at high resolution of the intense rain producing portions of the storm environments. The results emphasize how meteorological controls taking place at the large scale, coupled with localized terrain controls, ultimately determine the most salient features of the bulk microphysical

Syllabi for Instruction in Agricultural Meteorology.

ERIC Educational Resources Information Center

De Villiers, G. D. B.; And Others

A working group of the Commission for Agricultural Meteorology has prepared this report to fill a need for detailed syllabi for instruction in agricultural meteorology required by different levels of personnel. Agrometeorological personnel are classified in three categories: (1) professional meteorological personnel (graduates with basic training…

47 CFR 80.273 - Radar standards.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 5 2012-10-01 2012-10-01 false Radar standards. 80.273 Section 80.273... MARITIME SERVICES Equipment Authorization for Compulsory Ships § 80.273 Radar standards. (a) Radar... with radar must comply with the following standards (all incorporated by reference, see § 80.7): (1...

47 CFR 80.273 - Radar standards.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 5 2014-10-01 2014-10-01 false Radar standards. 80.273 Section 80.273... MARITIME SERVICES Equipment Authorization for Compulsory Ships § 80.273 Radar standards. (a) Radar... with radar must comply with the following standards (all incorporated by reference, see § 80.7): (1...

47 CFR 80.273 - Radar standards.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 5 2013-10-01 2013-10-01 false Radar standards. 80.273 Section 80.273... MARITIME SERVICES Equipment Authorization for Compulsory Ships § 80.273 Radar standards. (a) Radar... with radar must comply with the following standards (all incorporated by reference, see § 80.7): (1...

Magneto-Radar Hidden Metal Detector

DOEpatents

McEwan, Thomas E.

2005-07-05

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

Radar Soundings of the Subsurface of Mars

NASA Technical Reports Server (NTRS)

Picardi, Giovanni; Plaut, Jeffrey J.; Biccari, Daniela; Bombaci, Ornella; Calabrese, Diego; Cartacci, Marco; Cicchetti, Andrea; Clifford, Stephen M.; Edenhofer, Peter; Farrell, William M.;

Practicality of electronic beam steering for MST/ST radars, part 6.2A

NASA Technical Reports Server (NTRS)

Clark, W. L.; Green, J. L.

1984-01-01

Electronic beam steering is described as complex and expensive. The Sunset implementation of electronic steering is described, and it is demonstrated that such systems are cost effective, versatile, and no more complex than fixed beam alternatives, provided three or more beams are needed. The problem of determining accurate meteorological wind components in the presence of spatial variation is considered. A cost comparison of steerable and fixed systems allowing solution of this problem is given. The concepts and relations involved in phase steering are given, followed by the description of the Sunset ST radar steering system. The implications are discussed, references to the competing SAD method are provided, and a recommendation concerning the design of the future Doppler ST/MST systems is made.

Interception of LPI radar signals

NASA Astrophysics Data System (ADS)

Lee, Jim P.

1991-11-01

Most current radars are designed to transmit short duration pulses with relatively high peak power. These radars can be detected easily by the use of relatively modest EW intercept receivers. Three radar functions (search, anti-ship missile (ASM) seeker, and navigation) are examined to evaluate the effectiveness of potential low probability of intercept (LPI) techniques, such as waveform coding, antenna profile control, and power management that a radar may employ against current Electronic Warfare (EW) receivers. The general conclusion is that it is possible to design a LPI radar which is effective against current intercept EW receivers. LPI operation is most easily achieved at close ranges and against a target with a large radar cross section. The general system sensitivity requirement for the detection of current and projected LPI radars is found to be on the order of -100 dBmi which cannot be met by current EW receivers. Finally, three potential LPI receiver architectures, using channelized, superhet, and acousto-optic receivers with narrow RF and video bandwidths are discussed. They have shown some potential in terms of providing the sensitivity and capability in an environment where both conventional and LPI signals are present.

46 CFR 130.310 - Radar.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Radar. 130.310 Section 130.310 Shipping COAST GUARD... EQUIPMENT AND SYSTEMS Navigational Equipment § 130.310 Radar. Each vessel of 100 or more gross tons must be fitted with a general marine radar in the pilothouse. ...

46 CFR 130.310 - Radar.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Radar. 130.310 Section 130.310 Shipping COAST GUARD... EQUIPMENT AND SYSTEMS Navigational Equipment § 130.310 Radar. Each vessel of 100 or more gross tons must be fitted with a general marine radar in the pilothouse. ...

46 CFR 130.310 - Radar.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Radar. 130.310 Section 130.310 Shipping COAST GUARD... EQUIPMENT AND SYSTEMS Navigational Equipment § 130.310 Radar. Each vessel of 100 or more gross tons must be fitted with a general marine radar in the pilothouse. ...

46 CFR 130.310 - Radar.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 4 2014-10-01 2014-10-01 false Radar. 130.310 Section 130.310 Shipping COAST GUARD... EQUIPMENT AND SYSTEMS Navigational Equipment § 130.310 Radar. Each vessel of 100 or more gross tons must be fitted with a general marine radar in the pilothouse. ...

46 CFR 130.310 - Radar.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Radar. 130.310 Section 130.310 Shipping COAST GUARD... EQUIPMENT AND SYSTEMS Navigational Equipment § 130.310 Radar. Each vessel of 100 or more gross tons must be fitted with a general marine radar in the pilothouse. ...

Radar Image of Galapagos Island

NASA Image and Video Library

1996-10-23

This is an image showing part of Isla Isabella in the western Galapagos Islands. It was taken by the L-band radar in HH polarization from the Spaceborne Imaging Radar C/X-Band Synthetic Aperture Radar on the 40th orbit of NASA’s space shuttle Endeavour.

Low-Angle Radar Tracking

DTIC Science & Technology

1976-02-01

Transition from Specular Reflection to Diffuse Scattering. . . 10 Composition of the Electric-Field Vector as Seen at the Radar...r t (16) R • FIGURE P COMPOSITION OF THE ELECTRIC-FIELD VECTOR AS SEEN AT THE RADAR, R, IN FIG. 2. The electric field at the radar, E, is the sum...wavelengths in the VHP and UHF ranges even subsurface characteristics can be important. So in a field experiment one must be careful to measure

All-digital radar architecture

NASA Astrophysics Data System (ADS)

Molchanov, Pavlo A.

2014-10-01

All digital radar architecture requires exclude mechanical scan system. The phase antenna array is necessarily large because the array elements must be co-located with very precise dimensions and will need high accuracy phase processing system for aggregate and distribute T/R modules data to/from antenna elements. Even phase array cannot provide wide field of view. New nature inspired all digital radar architecture proposed. The fly's eye consists of multiple angularly spaced sensors giving the fly simultaneously thee wide-area visual coverage it needs to detect and avoid the threats around him. Fly eye radar antenna array consist multiple directional antennas loose distributed along perimeter of ground vehicle or aircraft and coupled with receiving/transmitting front end modules connected by digital interface to central processor. Non-steering antenna array allows creating all-digital radar with extreme flexible architecture. Fly eye radar architecture provides wide possibility of digital modulation and different waveform generation. Simultaneous correlation and integration of thousands signals per second from each point of surveillance area allows not only detecting of low level signals ((low profile targets), but help to recognize and classify signals (targets) by using diversity signals, polarization modulation and intelligent processing. Proposed all digital radar architecture with distributed directional antenna array can provide a 3D space vector to the jammer by verification direction of arrival for signals sources and as result jam/spoof protection not only for radar systems, but for communication systems and any navigation constellation system, for both encrypted or unencrypted signals, for not limited number or close positioned jammers.

Double Bright Band Observations with High-Resolution Vertically Pointing Radar, Lidar, and Profiles

NASA Technical Reports Server (NTRS)

Emory, Amber E.; Demoz, Belay; Vermeesch, Kevin; Hicks, Michael

2014-01-01

On 11 May 2010, an elevated temperature inversion associated with an approaching warm front produced two melting layers simultaneously, which resulted in two distinct bright bands as viewed from the ER-2 Doppler radar system, a vertically pointing, coherent X band radar located in Greenbelt, MD. Due to the high temporal resolution of this radar system, an increase in altitude of the melting layer of approximately 1.2 km in the time span of 4 min was captured. The double bright band feature remained evident for approximately 17 min, until the lower atmosphere warmed enough to dissipate the lower melting layer. This case shows the relatively rapid evolution of freezing levels in response to an advancing warm front over a 2 h time period and the descent of an elevated warm air mass with time. Although observations of double bright bands are somewhat rare, the ability to identify this phenomenon is important for rainfall estimation from spaceborne sensors because algorithms employing the restriction of a radar bright band to a constant height, especially when sampling across frontal systems, will limit the ability to accurately estimate rainfall.

Double bright band observations with high-resolution vertically pointing radar, lidar, and profilers

NASA Astrophysics Data System (ADS)

Emory, Amber E.; Demoz, Belay; Vermeesch, Kevin; Hicks, Micheal

2014-07-01

On 11 May 2010, an elevated temperature inversion associated with an approaching warm front produced two melting layers simultaneously, which resulted in two distinct bright bands as viewed from the ER-2 Doppler radar system, a vertically pointing, coherent X band radar located in Greenbelt, MD. Due to the high temporal resolution of this radar system, an increase in altitude of the melting layer of approximately 1.2 km in the time span of 4 min was captured. The double bright band feature remained evident for approximately 17 min, until the lower atmosphere warmed enough to dissipate the lower melting layer. This case shows the relatively rapid evolution of freezing levels in response to an advancing warm front over a 2 h time period and the descent of an elevated warm air mass with time. Although observations of double bright bands are somewhat rare, the ability to identify this phenomenon is important for rainfall estimation from spaceborne sensors because algorithms employing the restriction of a radar bright band to a constant height, especially when sampling across frontal systems, will limit the ability to accurately estimate rainfall.

Data fusion approach to threat assessment for radar resources management

NASA Astrophysics Data System (ADS)

Komorniczak, Wojciech; Pietrasinski, Jerzy; Solaiman, Basel

2002-03-01

The paper deals with the problem of the multifunction radar resources management. The problem consists of target/tasks ranking and tasks scheduling. The paper is focused on the target ranking, with the data fusion approach. The data from the radar (object's velocity, range, altitude, direction etc.), IFF system (Identification Friend or Foe) and ESM system (Electronic Support Measures - information concerning threat's electro - magnetic activities) is used to decide of the importance assignment for each detected target. The main problem consists of the multiplicity of various types of the input information. The information from the radar is of the probabilistic or ambiguous imperfection type and the IFF information is of evidential type. To take the advantage of these information sources the advanced data fusion system is necessary. The system should deal with the following situations: fusion of the evidential and fuzzy information, fusion of the evidential information and a'priori information. The paper describes the system which fuses the fuzzy and the evidential information without previous change to the same type of information. It is also described the proposal of using of the dynamic fuzzy qualifiers. The paper shows the results of the preliminary system's tests.

An affordable modular vehicle radar for landmine and IED detection

NASA Astrophysics Data System (ADS)

Daniels, David; Curtis, Paul; Dittmer, Jon; Hunt, Nigel; Graham, Blair; Allan, Robert

2009-05-01

This paper describes a vehicle mounted 8-channel radar system suitable for buried landmine and IED detection. The system is designed to find Anti Tank (AT) landmines and buried Improvised Explosive Devices (IEDs). The radar uses field-proven ground penetrating radar sub-system modules and is scalable to 16, 32 or 64 channels, for covering greater swathe widths and for providing higher cross track resolution. This offers the capability of detecting smaller targets down to a minimum dimension of 100mm. The current rate of advance of the technology demonstrator is 10 kph; this can be increased to 20 kph where required. The data output is triggered via shaft encoder or via GPS and, for each forward increment; the data output is variable from a single byte per channel through to the 512 samples per channel. Trials using an autonomous vehicle, combined with a COFDM wireless link for data and telemetry back to a base station, have proven successful and the system architecture is described in this paper. The GPR array can be used as a standalone sensor or can be integrated with off-the-shelf software and a metal detection array.

Comparison of radar data versus rainfall data

PubMed Central

Espinosa, B.; Hromadka, T.V.; Perez, R.

2015-01-01

Doppler radar data are increasingly used in rainfall-runoff synthesis studies, perhaps due to radar data availability, among other factors. However, the veracity of the radar data are often a topic of concern. In this paper, three Doppler radar outcomes developed by the United States National Weather Service at three radar sites are examined and compared to actual rain gage data for two separate severe storm events in order to assess accuracy in the published radar estimates of rainfall. Because the subject storms were very intense rainfall events lasting approximately one hour in duration, direct comparisons between the three radar gages themselves can be made, as well as a comparison to rain gage data at a rain gage location subjected to the same storm cells. It is shown that topographic interference with the radar outcomes can be a significant factor leading to differences between radar and rain gage readings, and that care is needed in calibrating radar outcomes using available rain gage data in order to interpolate rainfall estimates between rain gages using the spatial variation observed in the radar readings. The paper establishes and describes•the need for “ground-truthing” of radar data, and•possible errors due to topographic interference. PMID:26649276

Fire and forest meteorology

Treesearch

SA Ferguson; T.J. Brown; M. Flannigan

2005-01-01

The American Meteorological Society symposia series on Fire and Forest Meteorology provides biennial forums for atmospheric and fire scientists to introduce and discuss the latest and most relevant research on weather, climate and fire. This special issue highlights significant work that was presented at the Fifth Symposium in Orlando, Florida during 16-20 November...

Coherent Laser Radar System Theory.

DTIC Science & Technology

1987-11-05

This program is aimed at developing a system theory for the emerging technology of multifunction coherent CO2 laser radars. It builds upon previous...work funded by U.S. Army Research Office contract DAAG29-80-K-0022. Keywords include: Laser radar theory, Radar system theory , and Laser speckle.

Recommendation on transition from primary/secondary radar to secondary-only radar capability

DOT National Transportation Integrated Search

1994-10-01

This recommendation has been prepared to support the FAA decision to deactivate primary Long-range radars and presents a : transition strategy and implementation plan for the transformation of the existing primary/secondary en route radar : system to...

Meteoroid Fragmentation as Revealed in Head- and Trail-Echoes Observed with the Arecibo UHF and VHF Radars

NASA Technical Reports Server (NTRS)

Mathews, J. D.; Malhorta, A.

2011-01-01

We report recent 46.8/430 MHz (VHF/UHF) radar meteor observations at Arecibo Observatory (AO) that reveal many previously unreported features in the radar meteor return - including flare-trails at both UHF and VHF - that are consistent with meteoroid fragmentation. Signature features of fragmentation include strong intra-pulse and pulse-to-pulse fading as the result of interference between or among multiple meteor head-echo returns and between head-echo and impulsive flare or "point" trail-echoes. That strong interference fading occurs implies that these scatterers exhibit well defined phase centers and are thus small compared with the wavelength. These results are consistent with and offer advances beyond a long history of optical and radar meteoroid fragmentation studies. Further, at AO, fragmenting and flare events are found to be a large fraction of the total events even though these meteoroids are likely the smallest observed by the major radars. Fragmentation is found to be a major though not dominate component of the meteors observed at other HPLA radars that are sensitive to larger meteoroids.

Microphysics in West African squall line with an Xband polarimetric radar and an Hydrometeor Identification Scheme: comparison with in situ measurements

NASA Astrophysics Data System (ADS)

Cazenave, F.; Gosset, M.; Kacou, M.; Alcoba, M.; Fontaine, E.

2015-12-01

A better knowledge on the microphysics of tropical continental convective systems is needed in order to improve quantitative precipitation measurements in the Tropics. Satellite passive microwave estimation of tropical rainfall could be improved with a better parameterization of the icy hydrometeors in the Bayesian RAIN estimation algorithm (BRAIN, Viltard et al., 2006) used over continental tropics. To address this important issue specific campaigns that combine aircraft based in situ microphysics probing and polarimetric radar have been organized as part of the CNES/ISRO satellite mission Megha-Tropiques. The first microphysics validation campaign was set up in Niamey in August 2010. The field deployment included the AMMA-CATH 56 rain gages, 3 disdrometers, 2 meteorological radars including the C-band MIT and the Xport X-band dual polarisation radar, and a 4 weeks campaign with the instrumented Falcon 20 from the french operator for environmental research aircrafts equipped with several microphysics probes and the 94Ghz cloud radar RASTA. The objective is to combine scales and methods to converge towards a parameterization of the ice size, mass and density laws inside continental Mesoscale Convective System (MCS). The Particle IDentification algorithm (PID) developed by the Colorado State University (CSU) adapted to the band X by B. Dolan (Dolan et al. 2009) is used to classify seven kind of particles: drizzle or light rain, moderate to heavy rain, wet and dry graupel, wet and dry aggregates and ice crystals. On a limited number of systems, the airborne microphysics sensors provide a detailed in situ reference on the Particle Size Distribution (PSD) that can be compared with the radar PID in the radar pixels located along the flight trajectory. An original approach has been developed for the radar - in situ comparison: it consists in simulating synthetic radar variables from the microphysics probe information and compare the 2 data sets in a common 'radar space

Lunar and Venusian radar bright rings

NASA Technical Reports Server (NTRS)

Thompson, T. W.; Saunders, R. S.; Weissman, D. E.

1986-01-01

Twenty-one lunar craters have radar bright ring appearances which are analogous to eleven complete ring features in the earth-based 12.5 cm observations of Venus. Radar ring diameters and widths for the lunar and Venusian features overlap for sizes from 45 to 100 km. Radar bright areas for the lunar craters are associated with the slopes of the inner and outer rim walls, while level crater floors and level ejecta fields beyond the raised portion of the rim have average radar backscatter. It is proposed that the radar bright areas of the Venusian rings are also associated with the slopes on the rims of craters. The lunar craters have evolved to radar bright rings via mass wasting of crater rim walls and via post-impact flooding of crater floors. Aeolian deposits of fine-grained material on Venusian crater floors may produce radar scattering effects similar to lunar crater floor flooding. These Venusian aeolian deposits may preferentially cover blocky crater floors producing a radar bright ring appearance. It is proposed that the Venusian features with complete bright ring appearances and sizes less than 100 km are impact craters. They have the same sizes as lunar craters and could have evolved to radar bright rings via analogous surface processes.

Meteorological Satellites (METSAT) and Earth Observing System (EOS) Advanced Microwave Sounding Unit-A (AMSU-A) Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL)

NASA Technical Reports Server (NTRS)

1996-01-01

This Failure Modes and Effects Analysis (FMEA) is for the Advanced Microwave Sounding Unit-A (AMSU-A) instruments that are being designed and manufactured for the Meteorological Satellites Project (METSAT) and the Earth Observing System (EOS) integrated programs. The FMEA analyzes the design of the METSAT and EOS instruments as they currently exist. This FMEA is intended to identify METSAT and EOS failure modes and their effect on spacecraft-instrument and instrument-component interfaces. The prime objective of this FMEA is to identify potential catastrophic and critical failures so that susceptibility to the failures and their effects can be eliminated from the METSAT/EOS instruments.

Lithological and textural controls on radar and diurnal thermal signatures of weathered volcanic deposits, Lunar Crater region, Nevada

NASA Technical Reports Server (NTRS)

Plaut, Jeffrey J.; Rivard, Benoit

1992-01-01

Radar backscatter intensity as measured by calibrated synthetic aperture radar (SAR) systems is primarily controlled by three factors: local incidence angle, wavelength-scale roughness, and dielectric permittivity of surface materials. Radar observations may be of limited use for geological investigations of surface composition, unless the relationships between lithology and the above characteristics can be adequately understood. In arid terrains, such as the Southwest U.S., weathering signatures (e.g. soil development, fracturing, debris grain size and shape, and hill slope characteristics) are controlled to some extent by lithologic characteristics of the parent bedrock. These textural features of outcrops and their associated debris will affect radar backscatter to varying degrees, and the multiple-wavelength capability of the JPL Airborne SAR (AIRSAR) system allows sampling of textures at three distinct scales. Diurnal temperature excursions of geologic surfaces are controlled primarily by the thermal inertia of surface materials, which is a measure of the resistance of a material to a change in temperature. Other influences include albedo, surface slopes affecting insolation, local meteorological conditions and surface emissivity at the relevant thermal wavelengths. To first order, thermal inertia variations on arid terrain surfaces result from grain size distribution and porosity differences, at scales ranging from micrometers to tens of meters. Diurnal thermal emission observations, such as those made by the JPL Thermal Infrared Multispectral Scanner (TIMS) airborne instrument, are thus influenced by geometric surface characteristics at scales comparable to those controlling radar backscatter. A preliminary report on a project involving a combination of field, laboratory and remote sensing observations of weathered felsic-to basaltic volcanic rock units exposed in the southern part of the Lunar Crater Volcanic Field, in the Pancake Range of central Nevada is

46 CFR 184.404 - Radars.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Radars. 184.404 Section 184.404 Shipping COAST GUARD... MISCELLANEOUS SYSTEMS AND EQUIPMENT Navigation Equipment § 184.404 Radars. (a) A vessel must be fitted with a Federal Communications Commission (FCC) type accepted general marine radar system for surface navigation...

46 CFR 184.404 - Radars.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Radars. 184.404 Section 184.404 Shipping COAST GUARD... MISCELLANEOUS SYSTEMS AND EQUIPMENT Navigation Equipment § 184.404 Radars. (a) A vessel must be fitted with a Federal Communications Commission (FCC) type accepted general marine radar system for surface navigation...

46 CFR 184.404 - Radars.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 46 Shipping 7 2014-10-01 2014-10-01 false Radars. 184.404 Section 184.404 Shipping COAST GUARD... MISCELLANEOUS SYSTEMS AND EQUIPMENT Navigation Equipment § 184.404 Radars. (a) A vessel must be fitted with a Federal Communications Commission (FCC) type accepted general marine radar system for surface navigation...

46 CFR 184.404 - Radars.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 7 2012-10-01 2012-10-01 false Radars. 184.404 Section 184.404 Shipping COAST GUARD... MISCELLANEOUS SYSTEMS AND EQUIPMENT Navigation Equipment § 184.404 Radars. (a) A vessel must be fitted with a Federal Communications Commission (FCC) type accepted general marine radar system for surface navigation...

46 CFR 184.404 - Radars.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 7 2013-10-01 2013-10-01 false Radars. 184.404 Section 184.404 Shipping COAST GUARD... MISCELLANEOUS SYSTEMS AND EQUIPMENT Navigation Equipment § 184.404 Radars. (a) A vessel must be fitted with a Federal Communications Commission (FCC) type accepted general marine radar system for surface navigation...

A radar-based hydrological model for flash flood prediction in the dry regions of Israel

NASA Astrophysics Data System (ADS)

Ronen, Alon; Peleg, Nadav; Morin, Efrat

2014-05-01

Flash floods are floods which follow shortly after rainfall events, and are among the most destructive natural disasters that strike people and infrastructures in humid and arid regions alike. Using a hydrological model for the prediction of flash floods in gauged and ungauged basins can help mitigate the risk and damage they cause. The sparsity of rain gauges in arid regions requires the use of radar measurements in order to get reliable quantitative precipitation estimations (QPE). While many hydrological models use radar data, only a handful do so in dry climate. This research presents a robust radar-based hydro-meteorological model built specifically for dry climate. Using this model we examine the governing factors of flash floods in the arid and semi-arid regions of Israel in particular and in dry regions in general. The hydrological model built is a semi-distributed, physically-based model, which represents the main hydrological processes in the area, namely infiltration, flow routing and transmission losses. Three infiltration functions were examined - Initial & Constant, SCS-CN and Green&Ampt. The parameters for each function were found by calibration based on 53 flood events in three catchments, and validation was performed using 55 flood events in six catchments. QPE were obtained from a C-band weather radar and adjusted using a weighted multiple regression method based on a rain gauge network. Antecedent moisture conditions were calculated using a daily recharge assessment model (DREAM). We found that the SCS-CN infiltration function performed better than the other two, with reasonable agreement between calculated and measured peak discharge. Effects of storm characteristics were studied using synthetic storms from a high resolution weather generator (HiReS-WG), and showed a strong correlation between storm speed, storm direction and rain depth over desert soils to flood volume and peak discharge.

Space Shuttle interactive meteorological data system study

NASA Technical Reports Server (NTRS)

Young, J. T.; Fox, R. J.; Benson, J. M.; Rueden, J. P.; Oehlkers, R. A.

1985-01-01

Although focused toward the operational meteorological support review and definition of an operational meteorological interactive data display systems (MIDDS) requirements for the Space Meteorology Support Group at NASA/Johnson Space Center, the total operational meteorological support requirements and a systems concept for the MIDDS network integration of NASA and Air Force elements to support the National Space Transportation System are also addressed.

Improved estimation of heavy rainfall by weather radar after reflectivity correction and accounting for raindrop size distribution variability

NASA Astrophysics Data System (ADS)

Hazenberg, Pieter; Leijnse, Hidde; Uijlenhoet, Remko

2015-04-01

Between 25 and 27 August 2010 a long-duration mesoscale convective system was observed above the Netherlands, locally giving rise to rainfall accumulations exceeding 150 mm. Correctly measuring the amount of precipitation during such an extreme event is important, both from a hydrological and meteorological perspective. Unfortunately, the operational weather radar measurements were affected by multiple sources of error and only 30% of the precipitation observed by rain gauges was estimated. Such an underestimation of heavy rainfall, albeit generally less strong than in this extreme case, is typical for operational weather radar in The Netherlands. In general weather radar measurement errors can be subdivided into two groups: (1) errors affecting the volumetric reflectivity measurements (e.g. ground clutter, radar calibration, vertical profile of reflectivity) and (2) errors resulting from variations in the raindrop size distribution that in turn result in incorrect rainfall intensity and attenuation estimates from observed reflectivity measurements. A stepwise procedure to correct for the first group of errors leads to large improvements in the quality of the estimated precipitation, increasing the radar rainfall accumulations to about 65% of those observed by gauges. To correct for the second group of errors, a coherent method is presented linking the parameters of the radar reflectivity-rain rate (Z-R) and radar reflectivity-specific attenuation (Z-k) relationships to the normalized drop size distribution (DSD). Two different procedures were applied. First, normalized DSD parameters for the whole event and for each precipitation type separately (convective, stratiform and undefined) were obtained using local disdrometer observations. Second, 10,000 randomly generated plausible normalized drop size distributions were used for rainfall estimation, to evaluate whether this Monte Carlo method would improve the quality of weather radar rainfall products. Using the

Radar network communication through sensing of frequency hopping

DOEpatents

Dowla, Farid; Nekoogar, Faranak

2013-05-28

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

Demonstration of solar echoes using the Air Force OTH-B radar

NASA Technical Reports Server (NTRS)

Pizzo, V. J.; Hildner, E.; Georges, T.; Fraser-Smith, A.; Kelly, F.

1995-01-01

From the late 50s to early 70s, attempts were made by at least two different groups to obtain information on physical conditions in the corona by means of active radar soundings. While echoes from the Sun were unquestionably detected. difficulties in their interpretation led to inconclusive results. A major hindrance to these efforts was the limited understanding of the day-to-day structure of the corona then available (e.g., pioneering work in solar wind studies were just underway. and coronal holes had not yet been discovered). With the end of the Cold War, the very large over-the-horizon (OTH) radars operated by the Air Force have been opened up to basic science research through the end of the fiscal year. In light of advances made in coronal physics and in signal processing technology since these early experiments were undertaken. access to the state-of-the art OTH-B radar offers a rare opportunity to gauge anew the scientific potential for radar sounding of the Sun. In principle, it should be possible to obtain useful data on plasma densities and motions over a range of heights in the corona near 0.5R(solar mass) above the solar surface We report here the preliminary findings from a sequence of observations taken over the course of a solar rotation.

Sensor management in RADAR/IRST track fusion

NASA Astrophysics Data System (ADS)

Hu, Shi-qiang; Jing, Zhong-liang

2004-07-01

In this paper, a novel radar management strategy technique suitable for RADAR/IRST track fusion, which is based on Fisher Information Matrix (FIM) and fuzzy stochastic decision approach, is put forward. Firstly, optimal radar measurements' scheduling is obtained by the method of maximizing determinant of the Fisher information matrix of radar and IRST measurements, which is managed by the expert system. Then, suggested a "pseudo sensor" to predict the possible target position using the polynomial method based on the radar and IRST measurements, using "pseudo sensor" model to estimate the target position even if the radar is turned off. At last, based on the tracking performance and the state of target maneuver, fuzzy stochastic decision is used to adjust the optimal radar scheduling and retrieve the module parameter of "pseudo sensor". The experiment result indicates that the algorithm can not only limit Radar activity effectively but also keep the tracking accuracy of active/passive system well. And this algorithm eliminates the drawback of traditional Radar management methods that the Radar activity is fixed and not easy to control and protect.

Radar data processing and analysis

NASA Technical Reports Server (NTRS)

Ausherman, D.; Larson, R.; Liskow, C.

1976-01-01

Digitized four-channel radar images corresponding to particular areas from the Phoenix and Huntington test sites were generated in conjunction with prior experiments performed to collect X- and L-band synthetic aperture radar imagery of these two areas. The methods for generating this imagery are documented. A secondary objective was the investigation of digital processing techniques for extraction of information from the multiband radar image data. Following the digitization, the remaining resources permitted a preliminary machine analysis to be performed on portions of the radar image data. The results, although necessarily limited, are reported.

Ultra-wideband radar motion sensor

DOEpatents

McEwan, Thomas E.

1994-01-01

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

Ultra-wideband radar motion sensor

DOEpatents

McEwan, T.E.

1994-11-01

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

Automatic system for radar echoes filtering based on textural features and artificial intelligence

NASA Astrophysics Data System (ADS)

Hedir, Mehdia; Haddad, Boualem

2017-10-01

Among the very popular Artificial Intelligence (AI) techniques, Artificial Neural Network (ANN) and Support Vector Machine (SVM) have been retained to process Ground Echoes (GE) on meteorological radar images taken from Setif (Algeria) and Bordeaux (France) with different climates and topologies. To achieve this task, AI techniques were associated with textural approaches. We used Gray Level Co-occurrence Matrix (GLCM) and Completed Local Binary Pattern (CLBP); both methods were largely used in image analysis. The obtained results show the efficiency of texture to preserve precipitations forecast on both sites with the accuracy of 98% on Bordeaux and 95% on Setif despite the AI technique used. 98% of GE are suppressed with SVM, this rate is outperforming ANN skills. CLBP approach associated to SVM eliminates 98% of GE and preserves precipitations forecast on Bordeaux site better than on Setif's, while it exhibits lower accuracy with ANN. SVM classifier is well adapted to the proposed application since the average filtering rate is 95-98% with texture and 92-93% with CLBP. These approaches allow removing Anomalous Propagations (APs) too with a better accuracy of 97.15% with texture and SVM. In fact, textural features associated to AI techniques are an efficient tool for incoherent radars to surpass spurious echoes.

Analysis of Meteorological Satellite location and data collection system concepts

NASA Technical Reports Server (NTRS)

Wallace, R. G.; Reed, D. L.

1981-01-01

A satellite system that employs a spaceborne RF interferometer to determine the location and velocity of data collection platforms attached to meteorological balloons is proposed. This meteorological advanced location and data collection system (MALDCS) is intended to fly aboard a low polar orbiting satellite. The flight instrument configuration includes antennas supported on long deployable booms. The platform location and velocity estimation errors introduced by the dynamic and thermal behavior of the antenna booms and the effects of the presence of the booms on the performance of the spacecraft's attitude control system, and the control system design considerations critical to stable operations are examined. The physical parameters of the Astromast type of deployable boom were used in the dynamic and thermal boom analysis, and the TIROS N system was assumed for the attitude control analysis. Velocity estimation error versus boom length was determined. There was an optimum, minimum error, antenna separation distance. A description of the proposed MALDCS system and a discussion of ambiguity resolution are included.

Shuttle Imaging Radar - Geologic applications

NASA Technical Reports Server (NTRS)

Macdonald, H.; Bridges, L.; Waite, W.; Kaupp, V.

1982-01-01

The Space Shuttle, on its second flight (November 12, 1981), carried the first science and applications payload which provided an early demonstration of Shuttle's research capabilities. One of the experiments, the Shuttle Imaging Radar-A (SIR-A), had as a prime objective to evaluate the capability of spaceborne imaging radars as a tool for geologic exploration. The results of the experiment will help determine the value of using the combination of space radar and Landsat imagery for improved geologic analysis and mapping. Preliminary analysis of the Shuttle radar imagery with Seasat and Landsat imagery from similar areas provides evidence that spaceborne radars can significantly complement Landsat interpretation, and vastly improve geologic reconnaissance mapping in those areas of the world that are relatively unmapped because of perpetual cloud cover.

The PROUST radar

NASA Technical Reports Server (NTRS)

Bertin, F.; Glass, M.; Ney, R.; Petitdidier, M.

1986-01-01

The Stratosphere-Troposphere (ST) radar called PROUST works at 935 MHz using the same klystron and antenna as the coherent-scatter radar. The use of this equipment for ST work has required some important modifications of the transmitting system and the development of receiving, data processing and acquisition (1984,1985) equipment. The modifications are discussed.

Mapping three-dimensional surface deformation caused by the 2010 Haiti earthquake using advanced satellite radar interferometry.

PubMed

Jung, Hyung-Sup; Hong, Soo-Min

2017-01-01

Mapping three-dimensional (3D) surface deformation caused by an earthquake is very important for the environmental, cultural, economic and social sustainability of human beings. Synthetic aperture radar (SAR) systems made it possible to measure precise 3D deformations by combining SAR interferometry (InSAR) and multiple aperture interferometry (MAI). In this paper, we retrieve the 3D surface deformation field of the 2010 Haiti earthquake which occurred on January 12, 2010 by a magnitude 7.0 Mw by using the advanced interferometric technique that integrates InSAR and MAI data. The surface deformation has been observed by previous researchers using the InSAR and GPS method, but 3D deformation has not been measured yet due to low interferometric coherence. The combination of InSAR and MAI were applied to the ALOS PALSAR ascending and descending pairs, and were validated with the GPS in-situ measurements. The archived measurement accuracy was as little as 1.85, 5.49 and 3.08 cm in the east, north and up directions, respectively. This result indicates that the InSAR/MAI-derived 3D deformations are well matched with the GPS deformations. The 3D deformations are expected to allow us to improve estimation of the area affected by the 2010 Haiti earthquake.

Mapping three-dimensional surface deformation caused by the 2010 Haiti earthquake using advanced satellite radar interferometry

PubMed Central

Jung, Hyung-Sup; Hong, Soo-Min

2017-01-01

Mapping three-dimensional (3D) surface deformation caused by an earthquake is very important for the environmental, cultural, economic and social sustainability of human beings. Synthetic aperture radar (SAR) systems made it possible to measure precise 3D deformations by combining SAR interferometry (InSAR) and multiple aperture interferometry (MAI). In this paper, we retrieve the 3D surface deformation field of the 2010 Haiti earthquake which occurred on January 12, 2010 by a magnitude 7.0 Mw by using the advanced interferometric technique that integrates InSAR and MAI data. The surface deformation has been observed by previous researchers using the InSAR and GPS method, but 3D deformation has not been measured yet due to low interferometric coherence. The combination of InSAR and MAI were applied to the ALOS PALSAR ascending and descending pairs, and were validated with the GPS in-situ measurements. The archived measurement accuracy was as little as 1.85, 5.49 and 3.08 cm in the east, north and up directions, respectively. This result indicates that the InSAR/MAI-derived 3D deformations are well matched with the GPS deformations. The 3D deformations are expected to allow us to improve estimation of the area affected by the 2010 Haiti earthquake. PMID:29145475

Radar-aeolian roughness project

NASA Technical Reports Server (NTRS)

Greeley, Ronald; Dobrovolskis, A.; Gaddis, L.; Iversen, J. D.; Lancaster, N.; Leach, Rodman N.; Rasnussen, K.; Saunders, S.; Vanzyl, J.; Wall, S.

1991-01-01

The objective is to establish an empirical relationship between measurements of radar, aeolian, and surface roughness on a variety of natural surfaces and to understand the underlying physical causes. This relationship will form the basis for developing a predictive equation to derive aeolian roughness from radar backscatter. Results are given from investigations carried out in 1989 on the principal elements of the project, with separate sections on field studies, radar data analysis, laboratory simulations, and development of theory for planetary applications.

Advancing migratory bird conservation and management by using radar: An interagency collaboration

USGS Publications Warehouse

Ruth, Janet M.; Barrow, Wylie C.; Sojda, Richard S.; Dawson, Deanna K.; Diehl, Robert H.; Manville, Albert; Green, Michael T.; Krueper, David J.; Johnston, Scott

2005-01-01

Many technical issues make this work difficult, including complex data structures, massive data sets, digital recognition of birds, large areas not covered by weather radar, and model validation; however, progress will only be furthered by tackling the challenge. The new coalition will meets its goals by: (1) facilitating a productive collaboration with NOAA, Department of the Interior bureaus, state wildlife agencies, universities, power companies, and other potential partners; (2) building and strengthening scientific capabilities within USGS; (3) addressing key migratory bird management issues; and (4) ensuring full funding for the collaborative effort.

Space Radar Image of San Rafael Glacier, Chile

NASA Image and Video Library

1999-04-15

A NASA radar instrument has been successfully used to measure some of the fastest moving and most inaccessible glaciers in the world -- in Chile's huge, remote Patagonia ice fields -- demonstrating a technique that could produce more accurate predictions of glacial response to climate change and corresponding sea level changes. This image, produced with interferometric measurements made by the Spaceborne Imaging Radar-C and X-band Synthetic Aperture Radar (SIR-C/X-SAR) flown on the Space Shuttle last fall, has provided the first detailed measurements of the mass and motion of the San Rafael Glacier. Very few measurements have been made of the Patagonian ice fields, which are the world's largest mid-latitude ice masses and account for more than 60 percent of the Southern Hemisphere's glacial area outside of Antarctica. These features make the area essential for climatologists attempting to understand the response of glaciers on a global scale to changes in climate, but the region's inaccessibility and inhospitable climate have made it nearly impossible for scientists to study its glacial topography, meteorology and changes over time. Currently, topographic data exist for only a few glaciers while no data exist for the vast interior of the ice fields. Velocity has been measured on only five of the more than 100 glaciers, and the data consist of only a few single-point measurements. The interferometry performed by the SIR-C/X-SAR was used to generate both a digital elevation model of the glaciers and a map of their ice motion on a pixel-per-pixel basis at very high resolution for the first time. The data were acquired from nearly the same position in space on October 9, 10 and 11, 1994, at L-band frequency (24-cm wavelength), vertically transmitted and received polarization, as the Space Shuttle Endeavor flew over several Patagonian outlet glaciers of the San Rafael Laguna. The area shown in these two images is 50 kilometers by 30 kilometers (30 miles by 18 miles) in

46 CFR 108.717 - Radar.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Radar. 108.717 Section 108.717 Shipping COAST GUARD... Miscellaneous Equipment § 108.717 Radar. Each self-propelled unit of 1,600 gross tons and over in ocean or coastwise service must have— (a) A marine radar system for surface navigation; and (b) Facilities on the...

46 CFR 108.717 - Radar.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Radar. 108.717 Section 108.717 Shipping COAST GUARD... Miscellaneous Equipment § 108.717 Radar. Each self-propelled unit of 1,600 gross tons and over in ocean or coastwise service must have— (a) A marine radar system for surface navigation; and (b) Facilities on the...

46 CFR 108.717 - Radar.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Radar. 108.717 Section 108.717 Shipping COAST GUARD... Miscellaneous Equipment § 108.717 Radar. Each self-propelled unit of 1,600 gross tons and over in ocean or coastwise service must have— (a) A marine radar system for surface navigation; and (b) Facilities on the...

46 CFR 108.717 - Radar.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Radar. 108.717 Section 108.717 Shipping COAST GUARD... Miscellaneous Equipment § 108.717 Radar. Each self-propelled unit of 1,600 gross tons and over in ocean or coastwise service must have— (a) A marine radar system for surface navigation; and (b) Facilities on the...

46 CFR 108.717 - Radar.

Code of Federal Regulations, 2014 CFR

2014-10-01