Science.gov

Sample records for radar station evaluation

  1. Four Station Interferometric Radar Observations of Mars

    NASA Technical Reports Server (NTRS)

    Larsen, K. W.; Jurgens, R. F.; Arvidson, R. E.; Slade, M. A.; Haldemann, A. F.

    2002-01-01

    Planetary targets have been observed with radar since the late 1950s when it was first used for ranging experiments with the Moon. As telescope size and power increased, it became possible to observe more distant targets (Venus, Mars, and the outer satellites). Inherent to radar observations is the uncertainty as to the source of the reflection, there being two points where range and Doppler rings intersect on a sphere. The use of interferometric methods, first used on the moon with two stations and later on Venus and Mars, solved this problem. We extend the method through the addition of a fourth receiving telescope (thus doubling the number of projected baselines) and integration of the newly available Mars Orbiter Laser Altimeter (MOLA) topographic datasets.

  2. Location plan for Signal Corps Radar (S.C.R.) 296 Station 5, ...

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

    Location plan for Signal Corps Radar (S.C.R.) 296 Station 5, October 8, 1943 - Fort Barry, Signal Corps Radar 296, Station 5, Transmitter Building Foundation, Point Bonita, Marin Headlands, Sausalito, Marin County, CA

  3. Comparison Between Radar and Automatic Weather Station Refractivity Variability

    NASA Astrophysics Data System (ADS)

    Hallali, Ruben; Dalaudier, Francis; Parent du Chatelet, Jacques

    2016-08-01

    Weather radars measure changes in the refractive index of air in the atmospheric boundary layer. The technique uses the phase of signals from ground targets located around the radar to provide information on atmospheric refractivity related to meteorological quantities such as temperature, pressure and humidity. The approach has been successfully implemented during several field campaigns using operational S-band radars in Canada, UK, USA and France. In order to better characterize the origins of errors, a recent study has simulated temporal variations of refractivity based on Automatic Weather Station (AWS) measurements. This reveals a stronger variability of the refractivity during the summer and in the afternoon when the refractivity is the most sensitive to humidity, probably because of turbulence close to the ground. This raises the possibility of retrieving information on the turbulent state of the atmosphere from the variability in radar refractivity. An analysis based on a 1-year dataset from the operational C-band radar at Trappes (near Paris, France) and AWS refractivity variability measurements was used to measure those temporal and spatial variabilities. Particularly during summer, a negative bias increasing with range is observed between radar and AWS estimations, and is well explained by a model based on Taylor's hypotheses. The results demonstrate the possibility of establishing, depending on season, a quantitative and qualitative link between radar and AWS refractivity variability that reflects low-level coherent turbulent structures.

  4. Performance of radar wind profilers, radiosondes, and surface flux stations at the SGP CART site

    SciTech Connect

    Coulter, R.L.; Lesht, B.M.; Wesely, M.L.; Cook, D.R.; Holdridge, D.J.; Martin, T.J.

    1995-06-01

    The performance of several routinely operating observational systems at the Southern Great Plains (SGP) Cloud and Radiation Testbed (CART) site has been evaluated. The results of a few specific investigations are shown here for Radar Wind Profilers (RWPs) and Radio Acoustic Sounding Systems (RASSs), Balloon-Borne Sounding Systems (BBSSs), and Energy Balance Bowen Ratio (EBBR) stations.

  5. 2-D inner-shelf current observations from a single VHF WEllen RAdar (WERA) station

    USGS Publications Warehouse

    Voulgaris, G.; Kumar, N.; Gurgel, K.-W.; Warner, J.C.; List, J.H.

    2011-01-01

    The majority of High Frequency (HF) radars used worldwide operate at medium to high frequencies (8 to 30 MHz) providing spatial resolutions ranging from 3 to 1.5 km and ranges from 150 to 50 km. This paper presents results from the deployment of a single Very High Frequency (VHF, 48 MHz) WEllen RAdar (WERA) radar with spatial resolution of 150 m and range 10-15 km, used in the nearshore off Cape Hatteras, NC, USA. It consisted of a linear array of 12 antennas operating in beam forming mode. Radial velocities were estimated from radar backscatter for a variety of wind and nearshore wave conditions. A methodology similar to that used for converting acoustically derived beam velocities to an orthogonal system is presented for obtaining 2-D current fields from a single station. The accuracy of the VHF radar-derived radial velocities is examined using a new statistical technique that evaluates the system over the range of measured velocities. The VHF radar velocities showed a bias of 3 to 7 cm/s over the experimental period explainable by the differences in radar penetration and in-situ measurement height. The 2-D current field shows good agreement with the in-situ measurements. Deviations and inaccuracies are well explained by the geometric dilution analysis. ?? 2011 IEEE.

  6. The 50-MHz meteor radar observation at Syowa Station, Antarctica

    NASA Technical Reports Server (NTRS)

    Tanaka, T.; Ogawa, T.; Igarashi, K.; Fujii, R.

    1985-01-01

    The 50-MHz Doppler radar installed at Syowa Station (69 deg 00'S, 39 deg 35'E), Antarctica, in 1982 can detect continuously a meteor echo if an operator assigns the meteor mode operation to the radar. The radar has two narrow antenna beams (4 deg in the horizontal plane), one toward geomagnetic south and the other toward approximately geographic south, with a crossing angle of about 33 deg. The minicomputer annexed to the radar controls the transmission and reception of a 50-MHz wave. If the receiver detects a meteor echo, the flag signal is sent to the computer. Then the computer begins to determine the echo range with a time resolution of 1 micro s and to sample every 200 microns/s for 1 s the Doppler signal and echo intensity at the particular range (R). The line-of-sight velocity (V sub D) of the echo trail is calculated from the output from the Doppler signal detection circuit having an offset frequency by using the so-called zero-crossing method. The echo amplitude decay time calculated by a least-mean square method is used to obtain the ambipolar diffusion coefficient (D) and then to calculate the echo height (H). About 120 day observations were made during 1982-1983. Some early results are presented. magnetic tapes together with V sub D, D, H and R for later analysis in Japan. About 120 day observation were made during 1982-1983. Some early results are presented.

  7. View of Signal Corps Radar (S.C.R.) 296 Station 5 Transmitter ...

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

    View of Signal Corps Radar (S.C.R.) 296 Station 5 Transmitter Building foundation, showing Fire Control Stations (Buildings 621 and 622) and concrete stairway (top left) camera facing southwest - Fort Barry, Signal Corps Radar 296, Station 5, Transmitter Building Foundation, Point Bonita, Marin Headlands, Sausalito, Marin County, CA

  8. Topography adjacent to Signal Corps Radar (S.C.R.) 296 Station 5, ...

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

    Topography adjacent to Signal Corps Radar (S.C.R.) 296 Station 5, showing conditions before construction, May 28, 1943, this drawing shows the Bonita Ridge access road retaining wall and general conditions at Bonita Ridge before the construction of Signal Corps Radar (S.C.R.) 296 Station 5 - Fort Barry, Signal Corps Radar 296, Station 5, Transmitter Building Foundation, Point Bonita, Marin Headlands, Sausalito, Marin County, CA

  9. View looking down on Signcal Corps Radar (S.C.R.) 296 Station ...

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

    View looking down on Signcal Corps Radar (S.C.R.) 296 Station 5 Transmitter Building foundation from ridge, camera facing south - Fort Barry, Signal Corps Radar 296, Station 5, Transmitter Building Foundation, Point Bonita, Marin Headlands, Sausalito, Marin County, CA

  10. Telescope Array Radar (TARA) Remote Station Design and Development

    NASA Astrophysics Data System (ADS)

    Kunwar, Samridha

    2014-03-01

    The TARA project is a novel attempt utilizing a bi - static radar configuration in conjunction with a set of conventional cosmic ray detectors in the low - noise environment in Millard County, Utah, to detect Ultra - High Energy Cosmic Ray induced Extensive Air Showers. We present the design and development of the remote radar receiver system using a technique where the Doppler-shifted reflected signal off of the ionization trail from the cosmic ray is de - chirped. The approach is based on an analog frequency mixing technique whereby the input signal is mixed with a delayed copy of itself i.e s (t) ⊗ s (t - τ) , resulting in a beat frequency, f, which is proportional to the delay time multiplied by the cosmic ray-induced RF chirp rate. With appropriate filtering, the problem of chirp detection is ultimately reduced to that of detecting the down - converted monotone. In contrast to conventional signal processing via digital matched filtering, this is a mostly analog data acquisition system and has lower power consumption at a cost which is also comparatively inexpensive. The remote station is also subject to less radio interference, and adds stereoscopic measurement capabilities which allows unique determination of cosmic ray geometry and core location.

  11. Bird Activity Analysis Using Avian Radar Information in Naval Air Station airport, WA

    NASA Astrophysics Data System (ADS)

    Wang, J.; Herricks, E.

    2010-12-01

    The number of bird strikes on aircraft has increased sharply over recent years and airport bird hazard management has gained increasing attention in wildlife management and control. Evaluation of bird activity near airport is very critical to analyze the hazard of bird strikes. Traditional methods for bird activity analysis using visual counting provide a direct approach to bird hazard assessment. However this approach is limited to daylight and good visual conditions. Radar has been proven to be a useful and effective tool for bird detection and movement analysis. Radar eliminates observation bias and supports consistent data collection for bird activity analysis and hazard management. In this study bird activity data from the Naval Air Station Whidbey Island was collected by Accipiter Avian Radar System. Radar data was pre-processed by filtering out non-bird noises, including traffic vehicle, aircraft, insects, wind, rainfall, ocean waves and so on. Filtered data is then statistically analyzed using MATLAB programs. The results indicated bird movement dynamics in target areas near the airport, which includes (1) the daily activity varied at dawn and dusk; (2) bird activity varied by target area due to the habitat difference; and (3) both temporal and spatial movement patterns varied by bird species. This bird activity analysis supports bird hazard evaluation and related analysis and modeling to provide very useful information in airport bird hazard management planning.

  12. Application of ground-penetrating radar at McMurdo Station, Antarctica

    SciTech Connect

    Stefano, J.E.

    1992-05-01

    Argonne National Laboratory initiated a site investigation program at McMurdo Station, Antarctica, to characterize environmental contamination. The performance and usefulness of ground-penetrating radar (GPR) was evaluated under antarctic conditions during the initial site investigation in January 1991. Preliminary surveys were successful in defining the contact between reworked pyroclastic material and in the prefill, undisturbed pyroclastics and basalts at some sites. Interference from radio traffic at McMurdo Station was not observed, but interference was a problem in work with unshielded antennas near buildings. In general, the results of this field test suggest that high-quality, high-resolution, continuous subsurface profiles can be produced with GPR over most of McMurdo Station.

  13. Application of ground-penetrating radar at McMurdo Station, Antarctica

    SciTech Connect

    Stefano, J.E.

    1992-01-01

    Argonne National Laboratory initiated a site investigation program at McMurdo Station, Antarctica, to characterize environmental contamination. The performance and usefulness of ground-penetrating radar (GPR) was evaluated under antarctic conditions during the initial site investigation in January 1991. Preliminary surveys were successful in defining the contact between reworked pyroclastic material and in the prefill, undisturbed pyroclastics and basalts at some sites. Interference from radio traffic at McMurdo Station was not observed, but interference was a problem in work with unshielded antennas near buildings. In general, the results of this field test suggest that high-quality, high-resolution, continuous subsurface profiles can be produced with GPR over most of McMurdo Station.

  14. Generic evaluation tracker database for OTH radar

    NASA Astrophysics Data System (ADS)

    Flanders, Lorraine E.; Hartnett, Michael P.; Vannicola, Vincent C.

    1999-10-01

    This paper provides a real world target and clutter model for evaluation of radar signal processing algorithms. The procedure is given for target and clutter data collection which is then followed by the equalization and superposition method. We show how the model allows one to vary the target signal to clutter noise ratio so that system performance may be assessed over a wide range of target amplitudes, i.e. detection probability versus target signal to noise ratio. Three candidate pre-track algorithms are evaluated and compared using this model as input in conjunction with an advanced tracker algorithm as a post processor. Data used for the model represents airborne traffic operating over the body of water bounded by North, Central, and South America. The processors relate to the deployment of Over the Horizon Radar for drug interdiction. All the components of this work, model as well as the processors, are in software.

  15. Science program for an imaging radar receiving station in Alaska. Report of the science working group

    NASA Technical Reports Server (NTRS)

    1983-01-01

    It is argued that there would be broad scientific benefit in establishing in Alaska an imaging radar receiving station that would collect data from the European Space Agency's Remote Sensing Satellite, ERS-1. This station would acquire imagery of the ice cover from the American territorial waters of the Beaufort, Chukchi, and Bering Seas. This station, in conjunction with similar stations proposed for Kiruna, Sweden, and Prince Albert, Canada would provide synoptic coverage of nearly the entire Arctic. The value of such coverage to aspects of oceanography, geology, glaciology, and botany is considered.

  16. The study of single station inverting the sea surface current by HF ground wave radar based on adjoint assimilation technology

    NASA Astrophysics Data System (ADS)

    Han, Shuzong; Yang, Hua; Xue, Wenhu; Wang, Xingchi

    2016-10-01

    This paper introduces the assimilation technology in an ocean dynamics model and discusses the feasibility of inverting the sea surface current in the detection zone by assimilating the sea current radial velocity detected by single station HF ground wave radar in ocean dynamics model. Based on the adjoint assimilation and POM model, the paper successfully inverts the sea surface current through single station HF ground wave radar in the Zhoushan sea area. The single station HF radar inversion results are also compared with the bistatic HF radar composite results and the fixed point measured results by Annderaa current meter. The error analysis shows that acquisition of flow velocity and flow direction data from the single station HF radar based on adjoint assimilation and POM model is viable and the data obtained have a high correlation and consistency with the flow field observed by HF radar.

  17. Ground penetrating radar field evaluation in Angola

    NASA Astrophysics Data System (ADS)

    Walls, Richard; Brown, Todd; Clodfelter, Fred; Coors, Jeff; Laudato, Stephen; Lauziere, Steve; Patrikar, Ajay; Poole, Michael; Price, Mike

    2006-05-01

    Deminers around the globe are still using handheld metal detectors that lack the capability to distinguish mines from clutter, detect mines containing very little metal, or find mines buried at deeper depths. In the southern African country of Angola, many areas and roads are impassable due to the threat of anti-tank landmines. Some of these mines are undetectable using current metal detector technology. The US Army has funded the development of the NIITEK ground penetrating radar (GPR) for detection of anti-tank (AT) landmines. This radar detects metal and plastic mines as well as mines that are buried too deep for handheld metal detectors to find. The US Department of Defense Humanitarian Demining (HD) Research & Development Program focuses on developing, testing, demonstrating, and validating new technology for immediate use in humanitarian demining operations around the globe. The HD team provided funding and guidance to NIITEK Incorporated for development of a prototype system called Mine Stalker - a relatively light-weight, remote-controlled vehicle outfitted with the NIITEK GPR, detection algorithms, and a marking system. Individuals from the HD team, NIITEK Inc, and the non-governmental organization Meschen Gegen Minen (MgM) participated in a field evaluation of the Mine Stalker in Angola. The primary aim was to evaluate the effectiveness and reliability of the NIITEK GPR under field conditions. The Mine Stalker was extremely reliable during the evaluation with no significant maintenance issues. All AT mines used to verify GPR performance were detected, even when buried to depths as deep as 25-33cm.

  18. Road evaluation with ground penetrating radar

    NASA Astrophysics Data System (ADS)

    Saarenketo, Timo; Scullion, Tom

    2000-03-01

    This paper provides a status report of the Ground Penetrating Radar (GPR) highway applications based on studies conducted in both Scandinavia and the USA. After several years of research local transportation agencies are now beginning to implement GPR technology for both network and project level surveys. This paper summarizes the principles of operation of both ground-coupled and air-launched GPR systems together with a discussion of both signal processing and data interpretation techniques. In the area of subgrade soil evaluation GPR techniques have been used to nondestructively identify soil type, to estimate the thickness of overburden and to evaluate the compressibility and frost susceptibility of subgrade soil. In road structure surveys, GPR has been used to measure layer thickness, to detect subsurface defects and to evaluate base course quality. In quality control surveys, GPR techniques have been used for thickness measurements, to estimate air void content of asphalt surfaces and to detect mix segregation. Future developments are described where the technique has great potential in assisting pavement engineers with their new pavement designs and in determining the optimal repair strategies for deteriorated roadways.

  19. Maintenance evaluation for space station liquid systems

    NASA Technical Reports Server (NTRS)

    Flugel, Charles

    1987-01-01

    Many of the thermal and environmental control life support subsystems as well as other subsystems of the space station utilize various liquids and contain components which are either expendables or are life-limited in some way. Since the space station has a 20-year minimum orbital lifetime requirement, there will also be random failures occurring within the various liquid-containing subsystems. These factors as well as the planned space station build-up sequence require that maintenance concepts be developed prior to the design phase. This applies to the equipment which needs maintenance as well as the equipment which may be required at a maintenance work station within the space station. This paper presents several maintenance concepts for liquid-containing items and a flight experiment program which would allow for evaluation and improvement of these concepts so they can be incorporated in the space station designs at the outset of its design phase.

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

    SciTech Connect

    Catechis, Christopher Spyros

    2013-02-01

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

  1. Evaluation of Various Radar Data Quality Control Algorithms Based on Accumulated Radar Rainfall Statistics

    NASA Technical Reports Server (NTRS)

    Robinson, Michael; Steiner, Matthias; Wolff, David B.; Ferrier, Brad S.; Kessinger, Cathy; Einaudi, Franco (Technical Monitor)

    2000-01-01

    The primary function of the TRMM Ground Validation (GV) Program is to create GV rainfall products that provide basic validation of satellite-derived precipitation measurements for select primary sites. A fundamental and extremely important step in creating high-quality GV products is radar data quality control. Quality control (QC) processing of TRMM GV radar data is based on some automated procedures, but the current QC algorithm is not fully operational and requires significant human interaction to assure satisfactory results. Moreover, the TRMM GV QC algorithm, even with continuous manual tuning, still can not completely remove all types of spurious echoes. In an attempt to improve the current operational radar data QC procedures of the TRMM GV effort, an intercomparison of several QC algorithms has been conducted. This presentation will demonstrate how various radar data QC algorithms affect accumulated radar rainfall products. In all, six different QC algorithms will be applied to two months of WSR-88D radar data from Melbourne, Florida. Daily, five-day, and monthly accumulated radar rainfall maps will be produced for each quality-controlled data set. The QC algorithms will be evaluated and compared based on their ability to remove spurious echoes without removing significant precipitation. Strengths and weaknesses of each algorithm will be assessed based on, their abilit to mitigate both erroneous additions and reductions in rainfall accumulation from spurious echo contamination and true precipitation removal, respectively. Contamination from individual spurious echo categories will be quantified to further diagnose the abilities of each radar QC algorithm. Finally, a cost-benefit analysis will be conducted to determine if a more automated QC algorithm is a viable alternative to the current, labor-intensive QC algorithm employed by TRMM GV.

  2. An effective method for incoherent scattering radar's detecting ability evaluation

    NASA Astrophysics Data System (ADS)

    Lu, Ziqing; Yao, Ming; Deng, Xiaohua

    2016-06-01

    Ionospheric incoherent scatter radar (ISR), which is used to detect ionospheric electrons and ions, generally, has megawatt class transmission power and hundred meter level antenna aperture. The crucial purpose of this detecting technology is to get ionospheric parameters by acquiring the autocorrelation function and power spectrum of the target ionospheric plasma echoes. Whereas the ISR's echoes are very weak because of the small radar cross section of its target, estimating detecting ability will be significantly instructive and meaningful for ISR system design. In this paper, we evaluate the detecting ability through signal-to-noise ratio (SNR). The soft-target radar equation is deduced to be applicable to ISR, through which we use data from International Reference Ionosphere model to simulate signal-to-noise ratio (SNR) of echoes, and then comparing the measured SNR from European Incoherent Scatter Scientific Association and Advanced Modular Incoherent Scatter Radar with the simulation. The simulation results show good consistency with the measured SNR. For ISR, the topic of this paper is the first comparison between the calculated SNR and radar measurements; the detecting ability can be improved through increasing SNR. The effective method for ISR's detecting ability evaluation provides basis for design of radar system.

  3. Evaluation of hail suppression programme effectiveness using radar derived parameters

    NASA Astrophysics Data System (ADS)

    Tani, Satyanarayana; Paulitsch, Helmut; Teschl, Reinhard; Süsser-Rechberger, Barbara

    2016-04-01

    The objective of this study is evaluating "the operational hail suppression programme" in the province of Styria, Austria "for the year 2015". For the evaluation purpose the HAILSYS software tool was developed by integrating single polarization C-band weather radar data, aircraft trajectory, radiosonde freezing level data, hail events and crop damages information from the ground. The hail related radar derived parameters are: hail mass aloft, hail mass flux, probability of hail, vertical integrated hail mass, hail kinetic energy flux, and storm severity index. The spatial maps of hail kinetic energy and hail mass were developed to evaluate the seeding effect. The time history plots of vertical integrated hail mass, hail mass aloft and the probability of hail are drawn over an entire cell lifetime. The sensitivity and variation of radar hail parameters over time and associated changes due to cloud seeding will be presented.

  4. Solvent extraction treatment of PCB contaminated soil at Sparrevohn Long Range Radar Station, Alaska

    SciTech Connect

    Weimer, L.D.

    1999-07-01

    This technical paper describes an on-site soil treatment project at the Sparrevohn Long-Range Radar Station (LRRS), Alaska. The project was conducted during the summer of 1996. Sparrevohn LLRS is located approximately 200 miles west of Anchorage, Alaska and is accessible only by aircraft. Polychlorinated biphenyls (PCB) contaminated soil containing between 50 and 350 milligrams/kilogram (mg/kg) was stockpiled on-site. Terra Kleen Response Group, Inc.'s (Terra Kleen's) solvent extraction process successfully treated the stockpiled PCB contaminated soil ({approximately}290 yd{sup 3}). The PCB concentrations in the treated soil were reduced below the target treatment level of 15 mg/kg. On-site solvent extraction treatment realized considerable savings ({gt}$1,000,000) to the Government over the traditional method of hauling and off-site disposal.

  5. 94 GHz pulsed coherent radar for high power amplifier evaluation

    NASA Astrophysics Data System (ADS)

    Robertson, Duncan A.; Hunter, Robert I.; Gallacher, Thomas F.

    2016-05-01

    We present the design and characterization of a 94 GHz pulsed coherent radar to be used for the evaluation and demonstration of novel wideband, high power vacuum tube amplifier technology. The radar is designed to be fully coherent and exploits a low phase noise architecture to maximize Doppler performance. We selected to use horn-fed Fresnel zone plate lens antennas (FZPs) with 4-level phase quantization as a low cost method of realizing large aperture (0.5 m) antennas. The measured performance of these FZPs agrees closely with the design predictions and exceeds that obtainable with a Cassegrain of an equivalent size.

  6. Statistical Analysis for VHF Radar Parameters at SÃO LUÍS, Jicamarca and Christmas Island Equatorial Stations

    NASA Astrophysics Data System (ADS)

    de la cruz cueva, R. Y.; Paula, E. R.; Kherani, E. A.

    2013-05-01

    Equatorial Spread F (ESF) is a manifestation of ionospheric interchange instabilities in the nighttime equatorial F region. These instabilities generate plasma density irregularities with scale sizes ranging from kilometers to thousands of kilometers. The irregularities can be detected from varieties of instruments such as digisonde, coherent and incoherent scatter radars, in situ space probes, and airglow photometers. In the present study, statistics of various aspects of spread F occurrence are presented from HF/VHF radar and incoherent scatter radar located at three equatorial stations: Christmas Island (2oN, 202.6oE, 2.9oN dip latitude, VHF radar), São Luís (2.59oS, 315.8oE, 0.5oS dip latitude, HF radar) and Jicamarca (12oS, 283.1oE, 0.6oN dip latitude, ISR). The radar parameters presented here are the onset altitude and onset time of the bottom-type and plume, and the peak altitude of the plume which are known to be associated with the spread F occurrence characteristics. The study reveals novel features namely, seasonal and solar flux dependence of spread F occurrence over Christmas island /São Luís, and longitudinal dependence of spread F occurrence characteristics from these three stations based on the chosen parameters. The importance of this work lies in the radar parameter empirical model developed combining statistical analysis of three equatorial and longitudinally separated stations, which is important to study the irregularity generation mechanisms, for space weather forecasting and nowcasting programs, and improving scintillation warning models. These parameters show generally linear correlation with solar flux index (F10.7 cm) and variation with season and magnetic declination angle. The fit correlation with F10.7cm is shown as useful information to implement one spread-F development empirical model based on small scale irregularities detected by VHF radars.

  7. Evaluating and managing Cold War era historic properties : the cultural significance of U.S. Air Force defensive radar systems.

    SciTech Connect

    Whorton, M.

    1999-01-20

    Aircraft and later missile radar early warning stations played an important role in the Cold War. They are associated with important technological, social, political, and military themes of the Cold War and are worthy of preservation. The scope and scale of these systems make physical preservation impractical, but the U.S. Air Force program of historical evaluation and documentation of these systems will provide valuable information to future generations studying this historic period.

  8. Evaluation of TRMM Ground-Validation Radar-Rain Errors Using Rain Gauge Measurements

    NASA Technical Reports Server (NTRS)

    Wang, Jianxin; Wolff, David B.

    2009-01-01

    Ground-validation (GV) radar-rain products are often utilized for validation of the Tropical Rainfall Measuring Mission (TRMM) spaced-based rain estimates, and hence, quantitative evaluation of the GV radar-rain product error characteristics is vital. This study uses quality-controlled gauge data to compare with TRMM GV radar rain rates in an effort to provide such error characteristics. The results show that significant differences of concurrent radar-gauge rain rates exist at various time scales ranging from 5 min to 1 day, despite lower overall long-term bias. However, the differences between the radar area-averaged rain rates and gauge point rain rates cannot be explained as due to radar error only. The error variance separation method is adapted to partition the variance of radar-gauge differences into the gauge area-point error variance and radar rain estimation error variance. The results provide relatively reliable quantitative uncertainty evaluation of TRMM GV radar rain estimates at various times scales, and are helpful to better understand the differences between measured radar and gauge rain rates. It is envisaged that this study will contribute to better utilization of GV radar rain products to validate versatile spaced-based rain estimates from TRMM, as well as the proposed Global Precipitation Measurement, and other satellites.

  9. Determination of U, V, and W from single station Doppler radar radial velocities

    NASA Technical Reports Server (NTRS)

    Clark, W. L.; Green, J. L.; Warnock, J. M.

    1986-01-01

    The ST/MST (stratosphere troposphere/mesosphere stratosphere troposphere) clear air Doppler radar, or wind profiler, is an important tool in observational meteorology because of its capability to remote observe dynamic parameters of the atmosphere. There are difficulties in transforming the observed radial velocities into meteorological wind components. How this problem has been treated in the past is reviewed, and some of the analysis is recast to a form more suited to the high diagnostic abilities of a number of fixed beam configurations with reference to a linear wind field. The results, in conjunction with other works which treats problems such as the effects of finite sample volumes in the presence of nonhomogeneous atmospheric reflectivity, have implications important to the design of both individual MST/ST radars and MST/ST radar networks. The key parameters to uncoupling terms in the scaling equations are w sub x and w sub y. Whenever the stratiform condition, which states that these two parameters are negligible, is satisfied, a five beam ST radar may determine unbiased values of u, v, and w for sample volumes directly above the radar. The divergence and partial deformation of the flow may also be determined. Three beam systems can determine w and w sub z, but are unable to obtain u and v wind components uncontaminated by vertical sheer terms, even when the stratiform condition is satisfied.

  10. Antenna evaluation study for the shuttle multispectral radar, phase 2

    NASA Technical Reports Server (NTRS)

    Coffey, E. L., III; Carver, K. R.

    1977-01-01

    The results of the second phase of the Antenna Evaluation Study for the Shuttle Imaging Radar are presented. The objectives of Phase II were (1) to complete the specifications for the subarray test panels, (2) to begin a study of the effects of electrical and mechanical tolerance variations on overall SIRA performance, (3) to initiate the development of a mathematical model which adequately described the array performance and (4) to begin the development of a comprehensive computer program which will eventually simulate the performance characteristics of the antenna in a spaceborne environment. Items (2), (3), and (4) were begun in Phase I (ahead of schedule), and because of this, it has been possible to accelerate the Phase II modeling/simulation objectives to the point where simulations of expected mechanical/electrical errors have already been produced.

  11. Technology evaluation for space station atmospheric leakage

    SciTech Connect

    Lemon, D.K.; Friesel, M.A.; Griffin, J.W.; Skorpik, J.R.; Shepard, C.L.; Antoniak, Z.I.; Kurtz, R.J.

    1990-02-01

    A concern in operation of a space station is leakage of atmosphere through seal points and through the walls as a result of damage from particle (space debris and micrometeoroid) impacts. This report describes a concept for a monitoring system to detect atmosphere leakage and locate the leak point. The concept is based on analysis and testing of two basic methods selected from an initial technology survey of potential approaches. 18 refs., 58 figs., 5 tabs.

  12. Evaluation Digital Elevation Model Generated by Synthetic Aperture Radar Data

    NASA Astrophysics Data System (ADS)

    Makineci, H. B.; Karabörk, H.

    2016-06-01

    Digital elevation model, showing the physical and topographical situation of the earth, is defined a tree-dimensional digital model obtained from the elevation of the surface by using of selected an appropriate interpolation method. DEMs are used in many areas such as management of natural resources, engineering and infrastructure projects, disaster and risk analysis, archaeology, security, aviation, forestry, energy, topographic mapping, landslide and flood analysis, Geographic Information Systems (GIS). Digital elevation models, which are the fundamental components of cartography, is calculated by many methods. Digital elevation models can be obtained terrestrial methods or data obtained by digitization of maps by processing the digital platform in general. Today, Digital elevation model data is generated by the processing of stereo optical satellite images, radar images (radargrammetry, interferometry) and lidar data using remote sensing and photogrammetric techniques with the help of improving technology. One of the fundamental components of remote sensing radar technology is very advanced nowadays. In response to this progress it began to be used more frequently in various fields. Determining the shape of topography and creating digital elevation model comes the beginning topics of these areas. It is aimed in this work , the differences of evaluation of quality between Sentinel-1A SAR image ,which is sent by European Space Agency ESA and Interferometry Wide Swath imaging mode and C band type , and DTED-2 (Digital Terrain Elevation Data) and application between them. The application includes RMS static method for detecting precision of data. Results show us to variance of points make a high decrease from mountain area to plane area.

  13. Passive all-sky imaging radar in the HF regime with WWV and the first station of the Long Wavelength Array

    NASA Astrophysics Data System (ADS)

    Helmboldt, J. F.; Clarke, T. E.; Craig, J.; Dowell, J. D.; Ellingson, S. W.; Hartman, J. M.; Hicks, B. C.; Kassim, N. E.; Taylor, G. B.; Wolfe, C. N.

    2013-09-01

    We present a new passive, bistatic high-frequency (HF) radar system consisting of the transmitters for the radio station WWV and the dipole antenna array that comprises the first station of the Long Wavelength Array (LWA) or "LWA1." We demonstrate that these two existing facilities, which are operated for separate purposes, can be used together as a unique HF radar imager, capable of monitoring the entire visible sky. In this paper, we describe in detail the techniques used to develop all-sky radar capability at 10, 15, and 20 MHz. We show that this radar system can be a useful tool for probing ionospheric structure and its effect on over-the-horizon (OTH) geolocation. The LWA1+WWV radar system appears to be especially adept at detecting and characterizing structures associated with sporadic-E. In addition, we also demonstrate how this system may be used for long-distance, OTH mapping of terrain/ocean HF reflectivity. Finally, we discuss the potential improvements in the utility of these applications as more LWA stations are added.

  14. Multiscale Hydrologic Evaluation of Radar Rainfall for Flow Simulations

    NASA Astrophysics Data System (ADS)

    Quintero, Felipe; Krajewski, Witold; Seo, Bong-Chul; Mantilla, Ricardo

    2016-04-01

    We made an evaluation of the performance of a hydrologic model to produce real-time flow forecasts. The model has been developed by the Iowa Flood Center (IFC), and it is implemented operationally to produce streamflow forecast for the communities of the State of Iowa in the United States. The model parameters are calibration-free. It has a parsimonious structure, that reproduces the more significant processes involved in the transformation from rainfall to runoff. The operational model uses a rainfall forcing produced by IFC, derived from the combination of rainfall fields of seven NEXRAD radars. However, this rainfall forcing does not include bias adjustment from rain gauges, due to the non-existence of a raingage network that enable the correction in real-time. In consideration, the model is also run offline using bias-adjusted rainfall products as Stage IV, and more recently MRMS. We used an extensive record of five years of IFC rainfall product and Stage IV, to evaluate the performance of the hydrologic model and the sensitivity of the flow simulations to model input. The model is not calibrated to any particular rainfall product. The distributed structure of the model allows to obtain results at any channel of the drainage network. We obtained simulated hydrographs at about 150 locations with different sub-basin spatial scales, where there are available USGS gages with streamflow observations. We obtained error metrics as Nash Sutcliffe efficiency and root mean square error, by comparing flow simulations to observations. We evaluated also the number of occurrences of hits and false alarms of discharge forecasts exceeding flood stage.

  15. Angkor site monitoring and evaluation by radar remote sensing

    NASA Astrophysics Data System (ADS)

    Chen, Fulong; Jiang, Aihui; Ishwaran, Natarajan

    2014-11-01

    Angkor, in the northern province of Siem Reap, Cambodia, is one of the most important world heritage sites of Southeast Asia. Seasonal flood and ground sinking are two representative hazards in Angkor site. Synthetic Aperture Radar (SAR) remote sensing has played an important role for the Angkor site monitoring and management. In this study, 46 scenes of TerraSAR data acquired in the span of February, 2011 to December, 2013 were used for the time series analysis and hazard evaluation; that is, two-fold classification for flood area extracting and Multi-Temporal SAR Interferometry (MT-InSAR) for ground subsidence monitoring. For the flood investigation, the original Single Look Complex (SLC) TerraSAR-X data were transferred into amplitude images. Water features in dry and flood seasons were firstly extracted using a proposed mixed-threshold approach based on the backscattering; and then for the correlation analysis between water features and the precipitation in seasonally and annually. Using the MT-InSAR method, the ground subsidence was derived with values ranging from -50 to +12 mm/yr in the observation period of February, 2011 to June, 2013. It is clear that the displacement on the Angkor site was evident, implying the necessity of continuous monitoring.

  16. Radar reflectivity

    NASA Astrophysics Data System (ADS)

    1986-07-01

    This TOP describes a method for measuring the radar reflectivity characteristics of aircraft. It uses a rotating platform and various radar systems to obtain calibrated radar Automatic Gain Control values for each degree of aspect angle for the aircraft. The purpose of this test is to provide comparable values of radar reflectivity for Army aircraft at various radar frequencies and parameter for fixed positions and aspect angles on the aircraft. Data collected on each specific aircraft can be used to evaluate radar reflectivity characteristics of aircraft skin material, paint, and structural changes such as flat versus curved surfaces.

  17. 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

  18. Evaluation of multifrequency range-imaging technique implemented on the Chung-Li VHF atmospheric radar

    NASA Astrophysics Data System (ADS)

    Chen, J.-S.; Tsai, S.-C.; Su, C.-L.; Chu, Y.-H.

    2015-09-01

    Multifrequency range imaging technique (RIM) has been implemented on the Chung-Li VHF-array radar since 2008 after its renovation. This study made a more complete examination and evaluation of the RIM technique to facilitate the performance of the radar for atmospheric studies. Various experiments of RIM with different radar parameters such as pulse length, pulse shape, receiver bandwidth, transmitter frequency set, and so on, were conducted. The radar data employed for the study were collected from 2008 to 2013. It has been shown that two factors, the range/time delay of the signal traveling in the media and the standard deviation of Gaussian-shaped range-weighting function, play crucial roles in ameliorating the RIM-produced brightness (or power distribution); the two factors are associated with some radar parameters. In addition to radar parameters, long-term RIM data show that the aging of cable lines or key components of the radar system may result in an increase of the range/time delay of signal. It is also found that the range/time delay was visibly different for the echoes from the atmosphere with and without the presence of significant precipitation. A procedure of point-by-point correction of range/time delay was thus conducted to minimize the bogus brightness discontinuity at range gate boundaries. With the RIM technique, the Chung-Li VHF radar demonstrates its first successful observation of double-layer structures as well as their temporal and spatial variations with time.

  19. Evaluation of space station solar array technology

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The research concerning lightweight solar array assemblies since 1970 is reported. A bibliography of abstracts of documents used for reference during this period is included along with an evaluation of available solar array technology. A list of recommended technology programs is presented.

  20. 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

    ... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Doppler Radar and Inertial Navigation... OPERATIONS Pt. 121, App. G Appendix G to Part 121—Doppler Radar and Inertial Navigation System (INS): Request... Radar or Inertial Navigation System must submit a request for evaluation of the system to the...

  1. 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

    ... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Doppler Radar and Inertial Navigation... OPERATIONS Pt. 121, App. G Appendix G to Part 121—Doppler Radar and Inertial Navigation System (INS): Request... Radar or Inertial Navigation System must submit a request for evaluation of the system to the...

  2. 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

    ... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Doppler Radar and Inertial Navigation... OPERATIONS Pt. 121, App. G Appendix G to Part 121—Doppler Radar and Inertial Navigation System (INS): Request... Radar or Inertial Navigation System must submit a request for evaluation of the system to the...

  3. 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

  4. Polychlorinated biphenyl profiles in ringed seals (Pusa Hispida) reveal historical contamination by a military radar station in Labrador, Canada.

    PubMed

    Brown, Tanya M; Fisk, Aaron T; Helbing, Caren C; Reimer, Ken J

    2014-03-01

    Significant amounts of soil contaminated with polychlorinated biphenyls (PCBs) were discovered at a military radar station in Saglek Bay, Labrador, Canada, in 1996. Subsequent work showed elevated PCB concentrations in local marine sediments, in the benthic-associated food web, and in some ringed seals (Pusa hispida). The benthic-associated food web clearly reflected local PCB contamination, but the high PCB concentrations found in some ringed seals remained unexplained. In the present study, the authors assess the extent to which this local PCB source at Saglek Bay is contributing to the contamination of ringed seals in northern Labrador. Among 63 ringed seals sampled along the northern Labrador coast, 5 (8%) had PCB levels that were higher than recorded anywhere else in the Canadian Arctic. In addition, compared with seals exhibiting a long-range signal, 45% and 60% of subadults and adult males, respectively, exhibited heavier PCB congener profiles as characterized by principal components analysis, >1.6-fold higher PCB/organochlorine pesticides ratios, and higher PCB concentration-weighted average log octanol-water partition coefficient values, consistent with a local source. Despite the spatially confined nature of contaminated sediments in Saglek Bay, the influence of this PCB source is not inconsequential; PCB concentrations in locally contaminated adult males are 2-fold higher than concentrations in those exposed only to long-range PCB sources and exceed an established threshold of 1.3 mg/kg for adverse health effects in seals.

  5. PQLX: A Software Tool to Evaluate Seismic Station Performance

    NASA Astrophysics Data System (ADS)

    McNamara, D. E.; Boaz, R. I.

    2006-12-01

    We present a new tool that will allow users to evaluate seismic station performance and characteristics by providing quick and easy transitions between visualizations of the frequency and time domains. The software is based on the probability density functions (PDF) of power spectral densities (PSD) (McNamara and Buland, 2004). The computed PSDs are stored in a MySQL database, allowing a user to access specific time periods of PSDs (PDF subsets) and time series segments through a GUI-driven interface. The power of the method and software lies in the fact that there is no need to screen the data for system transients, earthquakes or general data artifacts since they map into a background probability level. In fact, examination of artifacts related to station operation and episodic cultural noise allow us to estimate both the overall station quality and a baseline level of earth noise at each site. The output of this analysis tool is useful for both operational and scientific applications. Operationally, it is useful for characterizing the current and past performance of existing broadband stations, for conducting tests on potential new seismic station locations, for detecting problems with the recording system or sensors, and for evaluating the overall quality of data and meta-data. Scientifically, the tool allows for mining of PSDs for investigations on the evolution of seismic noise (see Aster et al., Hutt et al., Leeds et al., and Oneel et al., this meeting). The PDF algorithm and initial software were developed by the USGS as a part of the ANSS/GSN data and network QC system. Further development, supported by the IRIS Data Management Center, integrated the PDF algorithm into the IRIS QUACK system. The newest version, PQLX, combines the PDF system with the PQL time series viewing tool developed with support from IRIS PASSCAL. Currently, PQLX is operational at the USGS ANSS NOC and ASL for station performance monitoring.

  6. Evaluation of radar-based precipitation estimates for flash flood forecasting in the Three Gorges Region

    NASA Astrophysics Data System (ADS)

    Li, Z.; Yang, D.; Hong, Y.; Qi, Y.; Cao, Q.

    2015-05-01

    Spatial rainfall pattern plays a critical role in determining hydrological responses in mountainous areas, especially for natural disasters such as flash floods. In this study, to improve the skills of flood forecasting in the mountainous Three Gorges Region (TGR) of the Yangtze River, we developed a first version of a high-resolution (1 km) radar-based quantitative precipitation estimation (QPE) consideration of many critical procedures, such as beam blockage analysis, ground-clutter filter, rain type identification and adaptive Z-R relations. A physically-based distributed hydrological model (GBHM) was established and further applied to evaluate the performance of radar-based QPE for regional flood forecasting, relative to the gauge-driven simulations. With two sets of input data (gauge and radar) collected during summer 2010, the applicability of the current radar-based QPE to rainstorm monitoring and flash flood forecasting in the TGR is quantitatively analysed and discussed.

  7. Technology transfer and evaluation for Space Station telerobotics

    NASA Technical Reports Server (NTRS)

    Price, Charles R.; Stokes, Lebarian; Diftler, Myron A.

    1994-01-01

    The international space station (SS) must take advantage of advanced telerobotics in order to maximize productivity and safety and to reduce maintenance costs. The Automation and Robotics Division at the NASA Lyndon B. Johnson Space Center (JSC) has designed, developed, and constructed the Automated Robotics Maintenance of Space Station (ARMSS) facility for the purpose of transferring and evaluating robotic technology that will reduce SS operation costs. Additionally, JSC had developed a process for expediting the transfer of technology from NASA research centers and evaluating these technologies in SS applications. Software and hardware system developed at the research centers and NASA sponsored universities are currently being transferred to JSC and integrated into the ARMSS for flight crew personnel testing. These technologies will be assessed relative to the SS baseline, and, after refinements, those technologies that provide significant performance improvements will be recommended as upgrades to the SS. Proximity sensors, vision algorithms, and manipulator controllers are among the systems scheduled for evaluation.

  8. 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.

  9. Linking the Annual Variation of Snow Radar-derived Accumulation in West Antarctica to Long-term Automatic Weather Station Measurements

    NASA Astrophysics Data System (ADS)

    Feng, B.; Braaten, D. A.; Gogineni, P.; Paden, J. D.; Leuschen, C.; Purdon, K.

    2013-12-01

    Understanding the snow accumulation rate on polar ice sheets is important in assessing mass balance and ice sheet contribution to sea level rise. Measuring annual accumulation on a regional scale and extending back in time several decades has been accomplished using the Center for Remote Sensing of Ice Sheets (CReSIS) Snow Radar on the NASA DC-8 that is part of NASA's Ice-Bridge project. The Snow Radar detects and maps near-surface internal layers in polar firn, operating from 2- 6 GHz and providing a depth resolution of ~4 cm. During November 2011, Snow Radar data were obtained for large areas of West Antarctica, including a flight segment that passed within ~70 km of Byrd Station (80°S, 119°W). Byrd Station has a very long automatic weather station (AWS) record, extending from present to 1980, with 3 relatively brief gaps in the record. The AWS data for Byrd Station were obtained from the Antarctic Meteorological Research Center (AMRC) at the University of Wisconsin. The L1B Snow Radar data products, available from the National Snow and Ice Data Center (NSIDC), were analyzed using layer picking software to obtain the depth of reflectors in the firn that are detected by the radar. These reflectors correspond to annual markers in the firn, and allow annual accumulation to be determined. Using the distance between the reflectors and available density profiles from ice cores, water equivalent accumulation for each annual layer back to 1980 is obtained. We are analyzing spatial variations of accumulation along flight lines, as well as variations in the time series of annual accumulation. We are also analyzing links between annual accumulation and surface weather observations from the Byrd Station AWS. Our analyses of surface weather observations have focused on annual temperature, atmospheric pressure and wind extremes (e.g. 5th and 95th percentiles) and links to annual snow accumulation. We are also examining satellite-derived sea ice extent records for the

  10. Study to investigate and evaluate means of optimizing the radar function. [systems engineering of pulse radar for the space shuttle

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The investigations for a rendezvous radar system design and an integrated radar/communication system design are presented. Based on these investigations, system block diagrams are given and system parameters are optimized for the noncoherent pulse and coherent pulse Doppler radar modulation types. Both cooperative (transponder) and passive radar operation are examined including the optimization of the corresponding transponder design for the cooperative mode of operation.

  11. Evaluation of multifrequency range imaging technique implemented on the Chung-Li VHF atmospheric radar

    NASA Astrophysics Data System (ADS)

    Chen, Jenn-Shyong; Tsai, Shih-Chiao; Su, Ching-Lun; Chu, Yen-Hsyang

    2016-05-01

    The multifrequency range imaging technique (RIM) has been implemented on the Chung-Li VHF array radar since 2008 after its renovation. This study made a more complete examination and evaluation of the RIM technique to facilitate the performance of the radar for atmospheric studies. RIM experiments with various radar parameters such as pulse length, pulse shape, receiver bandwidth, transmitter frequency set, and so on were conducted. The radar data employed for the study were collected from 2008 to 2013. It has been shown that two factors, the range/time delay of the signal traveling in the media and the standard deviation of Gaussian-shaped range-weighting function, play crucial roles in ameliorating the RIM-produced brightness (or power distribution); the two factors are associated with some radar parameters and system characteristics. The range/time delay of the signal was found to increase with time; moreover, it was slightly different for the echoes from the atmosphere with and without the presence of significant precipitation. A procedure of point-by-point correction of range/time delay was thus executed for the presence of precipitation to minimize the bogus brightness discontinuity at range gate boundaries. With the RIM technique, the Chung-Li VHF radar demonstrates its first successful observation of double-layer structures as well as their temporal and spatial variations with time.

  12. Evaluation of selected surface-water-quality stations in Wyoming

    USGS Publications Warehouse

    Rucker, S.J.; DeLong, L.L.

    1987-01-01

    The U.S. Geological Survey, in cooperation with the Wyoming Department of Agriculture, has conducted a surface-water-quality program in Wyoming since 1965. The purpose has been to determine the chemical quality of the water in terms of the major dissolved constituents (salinity). Changing agricultural techniques and energy development have stimulated a need for an expanded program involving additional types of data. This report determines the adequacy of the data collected thus far to describe the chemical quality. The sampling program was evaluated by determining how well the data describe the dissolved-solids load of the streams. Monthly mean loads were estimated at 16 stations throughout the network where daily streamflow and daily specific conductance were available. Monthly loads were then compared with loads estimated from daily streamflow and data derived from analyses of samples collected on a monthly basis at these same stations. Agreement was good. Solute-load hydrographs were constructed for 37 stations and from some reaches where streamflow records were available. Because stations where no discharge records are available are not amenable to this type of analysis, data collected at these stations are of limited usefulness. This report covers analyses of data for all qualifying sites in Wyoming except those in the Green River Basin, which were analyzed in U.S. Geological Survey Water Resources Investigations 77-103. The salinity in most of the streams evaluated is adequately described by the data collected. Reduced sampling is feasible, and time and money can be diverted to collecting other data. (USGS)

  13. ERS-1 radar altimeter system performance evaluation and calibration

    NASA Astrophysics Data System (ADS)

    Braun, H. M.; Groebke, H.; Hans, P.

    1984-08-01

    The ERS-1 (ESA) radar altimeter system simulation philosophy and simulator development are described. The simulator models system geometry, echo process, uplink/downlink, platform characteristics, instrument processing, ground processing, system errors, and special target characteristics (e.g., reflections from ice surfaces). It supports pre and post launch system-calibration; refinement of the engineering specifications during the ERS-1 development phase; monitoring and controlling of instrument design and development; prelaunch verification of system performance; investigation of inflight malfunctions and compensation of errors during nominal operations; development of echo models; and demonstration of system capabilities in operational cases.

  14. Antenna evaluation study for the shuttle multispectral radar, phase 1

    NASA Technical Reports Server (NTRS)

    Coffey, E. L., III; Carver, K. R.

    1976-01-01

    Critical parameters of the shuttle multispectral radar antenna (SMRA) which most affect antenna performance were identified. A preliminary methematical model is presented for describing SMRA performance under the influence of various physical and environmental factors which might degrade performance. Because user groups have not agreed on optimum frequencies best suited for the broadest range of application, the study incorporates frequencies ranging from 1.2 to 14.5 GHz, as well as a consideration of incidence angles from near nadir to nearly 50 deg.

  15. Evaluating Pseudorange Multipath at CGPS Stations Spanning Mexico

    NASA Astrophysics Data System (ADS)

    Vazquez, G.; Bennett, R. A.; Spinler, J. C.

    2013-12-01

    A research study was conducted in order to quantify and analyze the amount of pseudorange multipath at continuous Global Positioning System (CGPS) stations spanning Mexico. These CGPS stations are administered by a variety of organizations, including government agencies and public universities, and thus serve a wide range of positioning needs. Despite the diversity of the networks and their intended audiences, a core function of all of the networks is to provide a stable framework for high-precision positioning in support of diverse commercial and scientific applications. CGPS data from a large number of publicly available networks located in Mexico were studied. These include the RGNA (National Active Geodetic Network) administered by INEGI (National Institute of Statistics and Geography), the PBO network (Plate Boundary Observatory) funded by the National Science Foundation (NSF) and operated by UNAVCO (University NAVstar Consortium), the Southern California Integrated GPS Network (SCIGN), which is a collaboration effort of the United States Geological Survey (USGS), Scripps Institution of Oceanography and the Jet Propulsion Laboratory (JPL), the UNAM network, operated by the National Seismological System (SSN) and the Institute of Geophysics of the National Autonomous University of Mexico (UNAM), the Suominet Geodetic Network (SNG) and the CORS (Continuously Operating Reference Station) network, operated by the Federal Aviation Administration (FAA). A total of 54 CGPS stations were evaluated, where dual-frequency geodetic-grade receivers collected GPS data continuously during the period from 1994 to 2013. It is usually assumed that despite carefully selected locations, all CGPS stations are to some extent, affected by the presence of signal multipath. In addition, the geographic distribution of stations provides a nation-wide access to the International Terrestrial Reference Frame (ITRF). For real-time kinematic (RTK) and rapid static applications that depend on

  16. Natural gas vehicle fueling station dispenser meter evaluations

    SciTech Connect

    Rowley, P.F.; Kriha, K.; Blazek, C.F.

    1995-12-31

    The Institute of Gas Technology (IGT) has constructed a multi-purpose meter evaluation facility capable of testing metering technologies for high flow rate and high pressure NGV dispenser applications. The objective of IGT`s meter evaluation program, sponsored by IGT`s Sustaining Membership Program and the Gas Research Institute, is to assist the industry in evaluating the performance and accuracy of currently available flowmeters that are being used or could be applied to CNG gas dispensing. These meters are tested at various flow rates and pressures to determine their performance under NGV fueling station operating conditions and to identify the performance characteristics and limitations for each meter. The metering technologies which are being evaluated under this program include Coriolis meter, sonic nozzle meter, and turbine meter designs.

  17. Implementation and evaluation of the new wind algorithm in NASA's 50 MHz doppler radar wind profiler

    NASA Technical Reports Server (NTRS)

    Taylor, Gregory E.; Manobianco, John T.; Schumann, Robin S.; Wheeler, Mark M.; Yersavich, Ann M.

    1993-01-01

    The purpose of this report is to document the Applied Meteorology Unit's implementation and evaluation of the wind algorithm developed by Marshall Space Flight Center (MSFC) on the data analysis processor (DAP) of NASA's 50 MHz doppler radar wind profiler (DRWP). The report also includes a summary of the 50 MHz DRWP characteristics and performance and a proposed concept of operations for the DRWP.

  18. System Performance Evaluation and Improvement by Using KSGC Radar Data of Space Debris Observations

    NASA Astrophysics Data System (ADS)

    Nakamura, Shinichi; Tajima, Toru; Kudoh, Noduo; Abe, Jyunya; Someya, Kazunori; Ono, Katsuhiro; Kameyama, Masaya; Adachi, Gaku; Aoki, Sadao

    2013-08-01

    Since 2003, an active phased array radar at Kamisaibara Space Guard Centre (KSGC) has been used for LEO debris observation in Japan. JAXA evaluated the performance of the KSGC radar at its 10-year anniversary of debris observation. This paper presents the evaluation of detection ability, measurement accuracy and tracking ability, and the improvement of tracking ability of the KSGC radar by tuning parameters. It is well known that the evaluation of the abilities and accuracy are comparatively simple. However, improvement of tracking ability requires know-how that can only be attained through accumulation of observation facts and their analytical results. For example, there are some non-negligible differences between debris tracking and usual flying objects (i.e. airplanes) tracking. Namely, debris tracking can be characterized by the fact that its detective distance is extremely long, velocity is extremely high, fluctuation of relative attitude is unstable, etc. This paper describes the above points, and more specifically, the evaluation method and logic for improving system performance of the KSGC radar by using debris observation data.

  19. A review of selected ground penetrating radar applications to mineral resource evaluations

    NASA Astrophysics Data System (ADS)

    Francke, Jan

    2012-06-01

    Since the commercialisation of ground penetrating radar (GPR) in the 1970s, the technology has been relegated to niche applications in the mining industry. Advances in radar technology, such as flexible collinear antennas and the integration of live differential GPS positioning, have spurred GPR's acceptance in recent years as a standard exploration method for a number of deposit types. Provided herein is an overview of commercialised GPR applications for surface mineral resource evaluations, covering examples of alluvial channels, nickel and bauxitic laterites, iron ore deposits, mineral sands, coal and kimberlites.

  20. Evaluation of synthetic aperture radar for oil-spill response. Final report, June 1992-September 1993

    SciTech Connect

    Hover, G.L.; Mastin, G.A.; Axline, R.M.; Bradley, J.D.

    1993-10-01

    This report provides a detailed evaluation of synthetic aperture radar (SAR) as a potential technology improvement over the Coast Guard's existing side-looking airborne radar (SLAR) for oil-spill surveillance applications. The U.S. Coast Guard Research and Development Center (RD Center), Environmental Safety Branch, sponsored a joint experiment including the U.S. Coast Guard, Sandia National Laboratories, and the National Oceanographic and Atmospheric Administration (NOAA), Hazardous Materials Division. Radar imaging missions were flown on six days over the coastal waters off Santa Barbara, CA, where there are constant natural seeps of oil. Both the Coast Guard SLAR and the Sandia National Laboratories SAR were employed to acquire simultaneous images of oil slicks and other natural sea surface features that impact oil-spill interpretation. Surface truth and other environmental data were also recorded during the experiment. The experiment data were processed at Sandia National Laboratories and delivered to the RD Center on a PC-based computer workstation for analysis by experiment participants. Synthetic aperture radar, Side looking airborne radar, Oil slicks.

  1. 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

  2. 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

  3. Evaluation plan for space station network interface units

    NASA Technical Reports Server (NTRS)

    Weaver, Alfred C.

    1990-01-01

    Outlined here is a procedure for evaluating network interface units (NIUs) produced for the Space Station program. The procedures should be equally applicable to the data management system (DMS) testbed NIUs produced by Honeywell and IBM. The evaluation procedures are divided into four areas. Performance measurement tools are hardware and software that must be developed in order to evaluate NIU performance. Performance tests are a series of tests, each of which documents some specific characteristic of NIU and/or network performance. In general, these performance tests quantify the speed, capacity, latency, and reliability of message transmission under a wide variety of conditions. Functionality tests are a series of tests and code inspections that demonstrate the functionality of the particular subset of ISO protocols which have been implemented in a given NIU. Conformance tests are a series of tests which would expose whether or not selected features within the ISO protocols are present and interoperable.

  4. Summary of monitoring station component evaluation project 2009-2011.

    SciTech Connect

    Hart, Darren M.

    2012-02-01

    Sandia National Laboratories (SNL) is regarded as a center for unbiased expertise in testing and evaluation of geophysical sensors and instrumentation for ground-based nuclear explosion monitoring (GNEM) systems. This project will sustain and enhance our component evaluation capabilities. In addition, new sensor technologies that could greatly improve national monitoring system performance will be sought and characterized. This work directly impacts the Ground-based Nuclear Explosion Monitoring mission by verifying that the performance of monitoring station sensors and instrumentation is characterized and suitable to the mission. It enables the operational monitoring agency to deploy instruments of known capability and to have confidence in operational success. This effort will ensure that our evaluation capabilities are maintained for future use.

  5. Shuttle orbiter Ku-band radar/communications system design evaluation

    NASA Technical Reports Server (NTRS)

    Dodds, J.; Holmes, J.; Huth, G. K.; Iwasaki, R.; Maronde, R.; Polydoros, A.; Weber, C.; Broad, P.

    1980-01-01

    Tasks performed in an examination and critique of a Ku-band radar communications system for the shuttle orbiter are reported. Topics cover: (1) Ku-band high gain antenna/widebeam horn design evaluation; (2) evaluation of the Ku-band SPA and EA-1 LRU software; (3) system test evaluation; (4) critical design review and development test evaluation; (5) Ku-band bent pipe channel performance evaluation; (6) Ku-band LRU interchangeability analysis; and (7) deliverable test equipment evaluation. Where discrepancies were found, modifications and improvements to the Ku-band system and the associated test procedures are suggested.

  6. Evaluating the Potential of Radar-based Rainfall Estimates for Stream Flow Simulation in the Philippines

    NASA Astrophysics Data System (ADS)

    Abon, C. C.; Kneis, D.; Bronstert, A.; Crisologo, I.; David, C. P. C.; Heistermann, M.

    2014-12-01

    This study evaluates the suitability of radar-based quantitative precipitation estimates (QPE) for the simulation of stream flow in the Marikina River Basin (535 km2), The Philippines. We used observed reflectivity from the wet season period of 2012 and 2013 from an S-band radar near Subic. Radar data processing and precipitation estimation were carried out using the Open Source library wradlib. To evaluate the potential added value of radar-based QPE, we generated a benchmark precipitation product based on the interpolation of rain gauge observations (GO product). The GO product was also used to quantify rainfall estimation errors at the point scale. For stream flow simulation, we used a semi-distributed conceptual hydrological model based on the Open Source ECHSE framework. At the point scale, the radar-based QPE was benchmarked against the GO product at daily and hourly accumulation intervals. It turned out that the radar-based QPE outperformed the GO product in the 2012 while the performance was similar in the 2013. For both periods, estimation errors substantially increased from the daily to the hourly accumulation intervals, most likely due to a lack of representativeness at the point scale. Interestingly, though, the hourly rainfall estimates allowed for a good simulation of observed stream flow when used to force the hydrological model. In particular, the two main flood events, induced by an enhanced South-West monsoon, are well represented using both hourly rainfall products. The results show that the quality of the simulated stream flow was well in line with the point-based verification: while the radar-based QPE clearly outperforms the GO product in 2012, both perform similarly in 2013. The hydrological model had been recalibrated for each rainfall product to allow for a fair comparison of the two competing rainfall products. As the Marikina River Basin has a comparatively dense rain gauge network, the results of this study are encouraging with respect

  7. Application of 50 MHz doppler radar wind profiler to launch operations at Kennedy Space Center and Cape Canaveral Air Station

    NASA Technical Reports Server (NTRS)

    Schumann, Robin S.; Taylor, Gregory E.; Smith, Steve A.; Wilfong, Timothy L.

    1994-01-01

    This paper presents a case study where a significant wind shift, not detected by jimspheres, was detected by the 50 MHz DRWP (Doppler Radar Wind Profiler) and evaluated to be acceptable prior to the launch of a Shuttle. This case study illustrates the importance of frequent upper air wind measurements for detecting significant rapidly changing features as well as for providing confidence that the features really exist and are not due to instrumentation error. Had the release of the jimsphere been timed such that it would have detected the entire wind shift, there would not have been sufficient time to release another jimsphere to confirm the existence of the feature prior to the scheduled launch. We found that using a temporal median filter on the one minute spectral estimates coupled with a constraining window about a first guess velocity effectively removes nearly all spurious signals from the velocity profile generated by NASA's 50 MHz DRWP while boosting the temporal resolution to as high as one profile every 3 minutes. The higher temporal resolution of the 50 MHz DRWP using the signal processing algorithm described in this paper ensures the detection of rapidly changing features as well as provides the confidence that the features are genuine. Further benefit is gained when the profiles generated by the DRWP are examined in relation to the profiles measured by jimspheres and/or rawinsondes. The redundancy offered by using two independent measurements can dispel or confirm any suspicion regarding instrumentation error or malfunction and wind profiles can be examined in light of their respective instruments' strengths and weaknesses.

  8. Combination of Radar Altimeter and In-Situ Measurements to deduce Rating-Curves at Some Virtual Stations in the Ungauged Amazon and Orinoco Basins

    NASA Astrophysics Data System (ADS)

    Leon, J.; Seyler, F.; Calmant, S.; Bonnet, M.

    2008-12-01

    In the last two years, virtual gauged stations have been proposed to increase the density of hydrological network in ungauged or very poorly monitored basins (Leon, 2006). In spatial hydrology a virtual station is considered as any crossing of water body surface (i.e., large rivers) by radar altimeter satellite tracks. The main objective of this study is to review the usefulness of altimetric data presenting rating curves obtained for some virtual stations at the poorly gauged basins of Caqueta (Colombian Amazon basin), Uaupes and Upper Negro (Brazilian Amazon basin) and Upper Orinoco. Rating curve parameters at virtual stations are estimated by fitting with a power law distribution the temporal series of water surface altitude derived from ENVISAT satellite measurements and modeled discharges. The applied methodology (Leon et al. 2006a) allows the ellipsoidal height of effective zero flow to be estimated. This parameter is a good proxy of the mean water depth from which the river bed slope can be computed. These quantities combined with rating-curve parameters are highly valuable for understanding hydrological behaviour, especially at ungauged basins where hydrodynamical studies had always been prevented by the lack of in-situ data. The results obtained allow to propose a new insight into the hydrological behaviour of the region shared by Colombia, Brazil and Venezuela, which is very difficult to access, and then very poorly known.

  9. Operational and technical evaluation of the full digital Automated Radar Terminal Systems (ARTS) display (FDAD)

    NASA Astrophysics Data System (ADS)

    Clark, R.; Roditi, S.

    1982-10-01

    This report discusses the operational and technical evaluation of the Full Digital Automated Radar Terminal Systems (ARTS) Display (FDAD). The FDAD was capable of providing data entry, data display, data refresh, and input/output functions of either ARTS II, ARTS III or ARTS IIIA computer. Three different cathode ray tube phosphors, including color, were evaluated. Data were displayed either in a full digital mode or a time share mode. During the time share mode, the display of digital data was time shared with analog radar/beacon target reports. Modifications to software, hardware, and display firmware would be required to make the FDAD's operationally suitable. The technical evaluation conditionally accepts the displays, as tested, and it recommends their use as field displays, provided certain modifications are made.

  10. Microbial Diversity Aboard Spacecraft: Evaluation of the International Space Station

    NASA Technical Reports Server (NTRS)

    Castro, Victoria A.; Thrasher, Adrianna N.; Healy, Mimi; Ott, C. Mark; Pierson, Duane L.

    2003-01-01

    An evaluation of the microbial flora from air, water, and surface samples provided a baseline of microbial diversity onboard the International Space Station (ISS) to gain insight into bacterial and fungal contamination during the initial stages of construction and habitation. Using 16S genetic sequencing and rep-PeR, 63 bacterial strains were isolated for identification and fingerprinted for microbial tracking. The use of these molecular tools allowed for the identification of bacteria not previously identified using automated biochemical analysis and provided a clear indication of the source of several ISS contaminants. Fungal and bacterial data acquired during monitoring do not suggest there is a current microbial hazard to the spacecraft, nor does any trend indicate a potential health risk. Previous spacecraft environmental analysis indicated that microbial contamination will increase with time and require continued surveillance.

  11. Shuttle imaging radar-A (SIR-A) data analysis. [geology of the Ozark Plateau of southern Missouri, land use in western Illinois, and vegetation types at Koonamore Station, Australia

    NASA Technical Reports Server (NTRS)

    Arvidson, R. E.

    1983-01-01

    The utility of shuttle imaging radar (SIR-A) data was evaluated in several geological and environmental contexts. For the Ozark Plateau of southern Missouri, SIR-A data were of little use in mapping structural features, because of generally uniform returns. For western Illinois, little was to be gained in terms of identifying land use categories by examining differences between overlapping passes. For southern Australia (Koonamore Station), information ion vegetation types that was not obtainable from LANDSAT MSS data alone was obtained. Specifically, high SIR-A returns in the Australian site were found to correlate with locations where shrubs increase surface roughness appreciably. The Australian study site results demonstrate the synergy of acquiring spectral reflectance and radar data over the same location and time. Such data are especially important in that region, since grazing animals have substantially altered and are continuing to alter the distribution of shrublands, grasslands, and soil exposures. Periodic, synoptic acquisition of MSS and SAR data would be of use in monitoring the dynamics of land-cover change in this environment.

  12. State-space adjustment of radar rainfall and skill score evaluation of stochastic volume forecasts in urban drainage systems.

    PubMed

    Löwe, Roland; Mikkelsen, Peter Steen; Rasmussen, Michael R; Madsen, Henrik

    2013-01-01

    Merging of radar rainfall data with rain gauge measurements is a common approach to overcome problems in deriving rain intensities from radar measurements. We extend an existing approach for adjustment of C-band radar data using state-space models and use the resulting rainfall intensities as input for forecasting outflow from two catchments in the Copenhagen area. Stochastic grey-box models are applied to create the runoff forecasts, providing us with not only a point forecast but also a quantification of the forecast uncertainty. Evaluating the results, we can show that using the adjusted radar data improves runoff forecasts compared with using the original radar data and that rain gauge measurements as forecast input are also outperformed. Combining the data merging approach with short-term rainfall forecasting algorithms may result in further improved runoff forecasts that can be used in real time control.

  13. Combined observations of meteors by image-orthicon television camera and multi-station radar. [to compare ionization with luminosity

    NASA Technical Reports Server (NTRS)

    Cook, A. F.; Forti, G.; Mccrosky, R. E.; Posen, A.; Southworth, R. B.; Williams, J. T.

    1973-01-01

    Observations from multiple sites of a radar network and by television of 29 individual meteors from February 1969 through June 1970 are reported. Only 12 of the meteors did not appear to fragment over all the observed portion of their trajectories. From these 12, the relation for the radar magnitude to the panchromatic absolute magnitude was found in terms of velocity of the meteor. A very tentative fit to the data on the duration of long enduring echoes versus visual absolute magnitude is made. The exponential decay characteristics of the later parts of several of the light curves are pointed out as possible evidence of mutual coalescence of droplets into which the meteoroid has completely broken.

  14. A study of an orbital radar mapping mission to Venus. Volume 2: Configuration comparisons and systems evaluation

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Configuration comparisons and systems evaluation for the orbital radar mapping mission of the planet Venus are discussed. Designs are recommended which best satisfy the science objectives of the Venus radar mapping concept. Attention is given to the interaction and integration of those specific mission-systems recommendations with one another, and the final proposed designs are presented. The feasibility, cost, and scheduling of these configurations are evaluated against assumptions of reasonable state-of-the-art growth and space funding expectations.

  15. An evaluation of the accuracy of some radar wind profiling techniques

    NASA Astrophysics Data System (ADS)

    Koscielny, A. J.; Doviak, R. J.

    1983-12-01

    Major advances in Doppler radar measurement in optically clear air have made it feasible to monitor radial velocities in the troposphere and lower stratosphere. For most applications the three dimensional wind vector is monitored rather than the radial velocity. Measurement of the wind vector with a single radar can be made assuming a spatially linear, time invariant wind field. The components and derivatives of the wind are estimated by the parameters of a linear regression of the radial velocities on functions of their spatial locations. The accuracy of the wind measurement thus depends on the locations of the radial velocities. The suitability is evaluated of some of the common retrieval techniques for simultaneous measurement of both the vertical and horizontal wind components. The techniques considered for study are fixed beam, azimuthal scanning (VAD) and elevation scanning (VED).

  16. Evaluation of surface clutter for the design of spaceborne rain radar

    NASA Astrophysics Data System (ADS)

    Hanado, Hiroshi; Ihara, Toshio

    Effects of surface clutter interference through antenna sidelobe on rainfall measurements, which is one of the most important technological issues to realize spaceborne rain radar, are quantitatively examined in order to clarify the antenna design criteria. The received intensities of both rain echo and sea clutter are evaluated by numerically integrating both radar equations, assuming appropriate precipitation and sea surface scattering property models and realistic antenna pattern of phased array antenna, which is fed with the Taylor distribution of sidelobe level -30 dB with exciting currents errors being superimposed. The results illustrate that there exists a severely interfered region directly adjacent to the sea surface due to antenna mainlobe-sea clutter coupling. They also demonstrate the feasibility of quantitative measurements of rainfall, except the above region, with the planar array antenna fed according to the Taylor distribution of sidelobe level -30 dB.

  17. An evaluation of the accuracy of some radar wind profiling techniques

    NASA Technical Reports Server (NTRS)

    Koscielny, A. J.; Doviak, R. J.

    1983-01-01

    Major advances in Doppler radar measurement in optically clear air have made it feasible to monitor radial velocities in the troposphere and lower stratosphere. For most applications the three dimensional wind vector is monitored rather than the radial velocity. Measurement of the wind vector with a single radar can be made assuming a spatially linear, time invariant wind field. The components and derivatives of the wind are estimated by the parameters of a linear regression of the radial velocities on functions of their spatial locations. The accuracy of the wind measurement thus depends on the locations of the radial velocities. The suitability is evaluated of some of the common retrieval techniques for simultaneous measurement of both the vertical and horizontal wind components. The techniques considered for study are fixed beam, azimuthal scanning (VAD) and elevation scanning (VED).

  18. In-Service Evaluation of the Turbulence Auto-PIREP System and Enhanced Turbulence Radar Technologies

    NASA Technical Reports Server (NTRS)

    Prince, Jason B.; Buck, Bill K.; Robinson, Paul A.; Ryan, Tim

    2007-01-01

    From August 2003 to December 2006, In-Service Evaluations (ISE) of the Turbulence Auto-PIREP System (TAPS) and Enhanced Turbulence (E-Turb) Radar, technologies developed in NASA's Turbulence Prediction and Warning System (TPAWS) element of its Aviation Safety and Security Program (AvSSP), were conducted. NASA and AeroTech Research established an industry team comprising AeroTech, Delta Air Lines, Rockwell Collins, and ARINC to conduct the ISEs. The technologies were installed on Delta aircraft and their effectiveness was evaluated in day-to-day operations. This report documents the establishment and conduct of the ISEs and presents results and feedback from various users.

  19. Evaluation of bridge decks and pavements at highway speed using ground-penetrating radar

    NASA Astrophysics Data System (ADS)

    Maser, Kenneth R.

    1995-05-01

    Ground penetrating radar has been developed as an economical alternative for evaluating pavement layer properties and estimating quantities of deterioration in bridge decks. These highway applications are based on the use of vehicle-mounted radar systems traveling at normal driving speed. Surveys are conducted without lane closures, and extensive coverage can be obtained in a short survey period. Customized software has been specifically developed to handle and interpret the large quantities of data collected by this system. Two integrated software systems have been developed and extensively tested for pavement layer thickness and bridge deck condition evaluation. PAVLAYER, for pavements, has demonstrated an accuracy of +/- 7% for asphalt layer thickness evaluation based on tests on 150 pavement sections and correlation with over 700 cores. DECAR, for evaluating quantities of deteriorated concrete in bridge decks, has demonstrated an accuracy of +/- 4.4% of the total deck area based on ground truth evaluation of 64 bridge decks. The paper describes the details of the hardware and software components and the analytic methods used in these two systems. Also presented are descriptions of three field evaluation programs, in which the PAVLAYER and DECAR results are correlated with ground truth. Typical output and ground truth correlations are presented.

  20. [Evaluation of medication advertising broadcast on radio stations].

    PubMed

    Batista, Almária Mariz; Carvalho, Maria Cleide Ribeiro Dantas de

    2013-02-01

    The scope of this paper was to evaluate advertising for medication broadcast on radio stations in Natal, State of Rio Grande do Norte, Brazil, from April to September 2008 and from April to September 2010. The advertising was recorded and transcribed in order to conduct legal analysis and content analysis based on the precepts of Laurence Bardin. Both the advertising recorded during the first stage (regulated by RDC 102/00) and the second stage (regulated by RDC 96/08) contained some form of legal violation. Content analysis detected practically the same violations in both stages, namely the lack of information regarding adverse effects of the medication, appeal to consumption, exaggeration of efficiency/effectiveness and abusive exploitation of illness. Despite the inclusion of more modern and restrictive legislation, radio advertising continues to violate the law blatantly, committing abuse and disrespecting the population's entitlement to good health. The study reveals the need for medication advertising to be dealt with in a broader context, in other words to be treated as a public health concern. It must take into consideration the socio-historical scenario in which it evolved, since the legislation alone is insufficient to combat abuse committed to the detriment of public health.

  1. [Evaluation of medication advertising broadcast on radio stations].

    PubMed

    Batista, Almária Mariz; Carvalho, Maria Cleide Ribeiro Dantas de

    2013-02-01

    The scope of this paper was to evaluate advertising for medication broadcast on radio stations in Natal, State of Rio Grande do Norte, Brazil, from April to September 2008 and from April to September 2010. The advertising was recorded and transcribed in order to conduct legal analysis and content analysis based on the precepts of Laurence Bardin. Both the advertising recorded during the first stage (regulated by RDC 102/00) and the second stage (regulated by RDC 96/08) contained some form of legal violation. Content analysis detected practically the same violations in both stages, namely the lack of information regarding adverse effects of the medication, appeal to consumption, exaggeration of efficiency/effectiveness and abusive exploitation of illness. Despite the inclusion of more modern and restrictive legislation, radio advertising continues to violate the law blatantly, committing abuse and disrespecting the population's entitlement to good health. The study reveals the need for medication advertising to be dealt with in a broader context, in other words to be treated as a public health concern. It must take into consideration the socio-historical scenario in which it evolved, since the legislation alone is insufficient to combat abuse committed to the detriment of public health. PMID:23358781

  2. Evaluation of Ground Radar Snowfall Products Using SNOTEL Measurements over Mountainous Regions in Western United States

    NASA Astrophysics Data System (ADS)

    Wen, Y.; Kirstetter, P.; Gourley, J. J.; Hong, Y.; Behrangi, A.

    2015-12-01

    Snow contributes to regional and global water budgets and is of critical importance to our society. Snow can also cause potentially hazardous weather, and rapidly-melting snowpack may cause flooding. For large-scale weather monitoring, snowfall observations from ground radar have become highly desirable. However, verification and refinement of these retrievals requires ground-validation datasets. This study conducts a comprehensive evaluation of NOAA/NSSL Multi-Radar/ Multi-Sensor (MRMS) snowfall products using the Snow Telemetry (SNOTEL) hourly and daily precipitation and Snow Water Equivalent (SWE) datasets. The statistical analysis reveals that the MRMS snowfall estimation has bias compared to SNOTEL in-situ measurements. The bias between MRMS and SNOTEL is studied by considering environmental variables, radar beam sampling characteristics (blockage, beam height and width) and snow density. We expect a step forward towards establishing a robust surface-based snowfall reference database in West Mountainous Region, which can be shared with the satellite snowfall and snowpack community.

  3. Off the Radar: Comparative Evaluation of Radial Visualization Solutions for Composite Indicators.

    PubMed

    Albo, Yael; Lanir, Joel; Bak, Peter; Rafaeli, Sheizaf

    2016-01-01

    A composite indicator (CI) is a measuring and benchmark tool used to capture multi-dimensional concepts, such as Information and Communication Technology (ICT) usage. Individual indicators are selected and combined to reflect a phenomena being measured. Visualization of a composite indicator is recommended as a tool to enable interested stakeholders, as well as the public audience, to better understand the indicator components and evolution over time. However, existing CI visualizations introduce a variety of solutions and there is a lack in CI's visualization guidelines. Radial visualizations are popular among these solutions because of CI's inherent multi-dimensionality. Although in dispute, Radar-charts are often used for CI presentation. However, no empirical evidence on Radar's effectiveness and efficiency for common CI tasks is available. In this paper, we aim to fill this gap by reporting on a controlled experiment that compares the Radar chart technique with two other radial visualization methods: Flower-charts as used in the well-known OECD Betterlife index, and Circle-charts which could be adopted for this purpose. Examples of these charts in the current context are shown in Figure 1. We evaluated these charts, showing the same data with each of the mentioned techniques applying small multiple views for different dimensions of the data. We compared users' performance and preference empirically under a formal task-taxonomy. Results indicate that the Radar chart was the least effective and least liked, while performance of the two other options were mixed and dependent on the task. Results also showed strong preference of participants toward the Flower chart. Summarizing our results, we provide specific design guidelines for composite indicator visualization. Fig. 1: Three radial solutions for composite indicator visualizations compared empirically for users' performance and preferences.

  4. Off the Radar: Comparative Evaluation of Radial Visualization Solutions for Composite Indicators.

    PubMed

    Albo, Yael; Lanir, Joel; Bak, Peter; Rafaeli, Sheizaf

    2016-01-01

    A composite indicator (CI) is a measuring and benchmark tool used to capture multi-dimensional concepts, such as Information and Communication Technology (ICT) usage. Individual indicators are selected and combined to reflect a phenomena being measured. Visualization of a composite indicator is recommended as a tool to enable interested stakeholders, as well as the public audience, to better understand the indicator components and evolution over time. However, existing CI visualizations introduce a variety of solutions and there is a lack in CI's visualization guidelines. Radial visualizations are popular among these solutions because of CI's inherent multi-dimensionality. Although in dispute, Radar-charts are often used for CI presentation. However, no empirical evidence on Radar's effectiveness and efficiency for common CI tasks is available. In this paper, we aim to fill this gap by reporting on a controlled experiment that compares the Radar chart technique with two other radial visualization methods: Flower-charts as used in the well-known OECD Betterlife index, and Circle-charts which could be adopted for this purpose. Examples of these charts in the current context are shown in Figure 1. We evaluated these charts, showing the same data with each of the mentioned techniques applying small multiple views for different dimensions of the data. We compared users' performance and preference empirically under a formal task-taxonomy. Results indicate that the Radar chart was the least effective and least liked, while performance of the two other options were mixed and dependent on the task. Results also showed strong preference of participants toward the Flower chart. Summarizing our results, we provide specific design guidelines for composite indicator visualization. Fig. 1: Three radial solutions for composite indicator visualizations compared empirically for users' performance and preferences. PMID:26529525

  5. Site evaluation for laser satellite-tracking stations

    NASA Technical Reports Server (NTRS)

    Mao, N. H.; Mohr, P. A.

    1976-01-01

    Twenty-six locations for potential laser satellite-tracking stations, four of them actually already occupied in this role, are reviewed in terms of their known local and regional geology and geophysics. The sites are also considered briefly in terms of weather and operational factors. Fifteen of the sites qualify as suitable for a stable station whose motions are likely to reflect only gross plate motion. The others, including two of the present laser station sites (Arequipa and Athens), fail to qualify unless extra monitoring schemes can be included, such as precise geodetic surveying of ground deformation.

  6. Conceptual design and evaluation of selected Space Station concepts, volume 1

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Space Station configuration concepts are defined to meet the NASA Headquarters Concept Development Group (CDG) requirements. Engineering and programmatic data are produced on these concepts suitable for NASA and industry dissemination. A data base is developed for input to the CDG's evaluation of generic Space Station configurations and for use in the critique of the CDG's generic configuration evaluation process.

  7. The design and evaluation of a 5.8 ghz laptop-based radar system

    NASA Astrophysics Data System (ADS)

    Teng, Kevin Chi-Ming

    This project involves design and analysis of a 5.8 GHz laptop-based radar system. The radar system measures Doppler, ranging and forming Synthetic Aperture Radar (SAR) images utilizing Matlab software provided from MIT Open Courseware and performs data acquisition and signal processing. The main purpose of this work is to bring new perspective to the existing radar project by increasing the ISM band frequency from 2.4 GHz to 5.8 GHz and to carry out a series of experiments on the implementation of the radar kit. Demonstrating the radar at higher operating frequency is capable of providing accurate data results in Doppler, ranging and SAR images.

  8. Ranger Station Solar-Energy System Receives Economic Evaluation

    NASA Technical Reports Server (NTRS)

    1982-01-01

    Economic performance of Glendo Reservoir Ranger Station solar-energy system in Wyoming and extrapolated performance in four other locations around the U.S. is reviewed in report. System is a passive drain-down system using water as heat-transfer medium for space and hot-water heating.

  9. 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....

  10. 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....

  11. 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 ... Search Guide Documents:  ETL_RADAR Guide Readme Files:  Readme ETL_RADAR (PS) ...

  12. 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....

  13. 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....

  14. 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....

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

    SciTech Connect

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

    2014-08-01

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

  16. [Development of innovative methods of electromagnetic field evaluation for portable radio-station].

    PubMed

    Rubtsova, N B; Perov, S Iu; Bogacheva, E V; Kuster, N

    2013-01-01

    The results of portable radio-station "Radiy-301" electromagnetic fields (EMF) emission measurement and specific absorption rate data evaluation has shown that workers' exposure EMF levels may elevate hygienic norms and hereupon can be health risk factor. Possible way of portable radio-station EMF dosimetry enhancement by means of domestic and international approaches harmonization is considered.

  17. Evaluation of absorption cycle for space station environmental control system application

    NASA Technical Reports Server (NTRS)

    Sims, W. H.; Oneill, M. J.; Reid, H. C.; Bisenius, P. M.

    1972-01-01

    The study to evaluate an absorption cycle refrigeration system to provide environmental control for the space stations is reported. A zero-gravity liquid/vapor separator was designed and tested. The results were used to design a light-weight, efficient generator for the absorption refrigeration system. It is concluded that absorption cycle refrigeration is feasible for providing space station environmental control.

  18. 1. VIEW NORTHWEST, operations building, height finder radar tower, and ...

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

    1. VIEW NORTHWEST, operations building, height finder radar tower, 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

  19. Simulation of synthetic aperture radar 3: Evaluation of prototype digital feature analysis data

    NASA Astrophysics Data System (ADS)

    Crane, Peter M.; Bell, Herbert H.

    1989-12-01

    This experiment evaluated the suitability of the Defense Mapping Agency (DMA) prototype Level 3c Digital Feature Analysis Data (DFAD) for the simulation of Synthetic Aperture Radar (SAR). The suitability of Prototype Level 3c DFAD was evaluated by comparing simulations generated from samples of Level 3c and from samples of DFAD previously demonstrated to be adequate for SAR simulation; these products, however, were unsuitable for production in the quantities required to meet Air Force needs. B-1B Offensive Systems Officers performed a navigation update task using simulated and actual SAR images. Crosshair placement accuracy, operator confidence in the placement, and ratings of acceptability for use in a Weapon System Trainer were recorded using both simulated and actual SAR images. The results indicated that SAR simulation can be supported as well by Level 3c DFAD as by the other products.

  20. Radar target identification by natural resonances: Evaluation of signal processing algorithms

    NASA Astrophysics Data System (ADS)

    Lazarakos, Gregory A.

    1991-09-01

    When a radar pulse impinges upon a target, the resultant scattering process can be solved as a linear time-invariant (LTI) system problem. The system has a transfer function with poles and zeros. Previous work has shown that the poles are independent on the target's structure and geometry. This thesis evaluates the resonance estimation performance of two signal processing techniques: the Kumaresan-Tufts algorithm and the Cadzow-Solomon algorithm. Improvements are made to the Cadzow-Solomon algorithm. Both algorithms are programmed using MATLAB. Test data used to evaluate these algorithms includes synthetic and integral equation generated signals, with and without additive noise, in addition to new experimental scattering data from a thin wire, aluminum spheres, and scale model aircraft.

  1. Evaluation of Space Station Meteoroid/Debris Shielding Materials, Supplement

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The following Lotus 1-2-3 spreadsheets are included. They were converted from Lotus version 2.1 to version 1A, which is more common and can also be read by all subsequent versions. MS-DOS V.3.10 was used to format the diskette. Additional information can be attained by contacting: Eric L. Christiansen, Eagle Engineering, (713)338-2682. 1) IMPACT.WKS Analytical model described in Section 4.2 and Appendix A. 2) HUGONIOT.WKS Calculates peak shock pressure as described in Appendix C. 3) FIGOFMER.WKS Empirical model described in Section 4.1 and Appendix B. 4) DEB_VDIS.WKS Contains orbital debris velocity distribution for typical Space Station orbit. Calculates the fraction of debris below the velocity causing aluminum projectiles to melt as described in Section 3.3. 5) MOD_CRIT.WKS Determines the critical orbital debris and meteoroid size that a Space Station hab or lab module should be designed to protect against based on a 0.9955 probability of no penetration as described in Section 3.3. 6) SSMOD_CE.WKS Determines the number and maximum size of perforations expected in an aluminum bumper of a Space Station common module over its orbital lifetime as discussed in Section 3.3.

  2. The undersea habitat as a space station analog: Evaluation of research and training potential

    NASA Technical Reports Server (NTRS)

    Helmreich, Robert L.; Wilhelm, John A.

    1985-01-01

    An evaluation is given of the utility of undersea habitats for both research and training on behavioral issues relative to the space station. The feasibility of a particular habitat, La Chalupa, is discussed.

  3. Evaluation of SO{sub 2} control technologies for three SCE&G power stations

    SciTech Connect

    Robinson, J.A. Jr.; Wiggins, D.S.

    1995-06-01

    South Carolina Electric and Gas, Co. (SCE&G) commissioned a detailed engineering study evaluating flue gas desulphurization (FGD) equipment for three coal fired generating stations in 1993. Raytheon Engineers and Constructors performed the study evaluating wet and dry FGD processes at three of SCE&G`s generating stations. This paper presents the results and conclusions from the study. The following areas are discussed: (1) Station Descriptions; (2) Process Design Criteria; (3) Study Goals and Methodology; (4) Results from the Economic and Kepner-Tregoe Analysis; and (5) Study Recommendations. The paper concludes with a lessons learned section discussing issues which arose during the study.

  4. Tree Roots in Agroforestry: Evaluating Biomass and Distribution with Ground Penetrating Radar

    NASA Astrophysics Data System (ADS)

    Borden, Kira Alia

    The root systems of five tree species (Populus deltoides x nigra clone DN-177, Juglans nigra, Quercus rubra, Picea abies, and Thuja occidentalis) are described following non-intrusive imaging using ground penetrating radar (GPR). This research aimed to 1) assess the utility of GPR for in situ root studies and 2) employ GPR to estimate tree root biomass and distribution in an agroforestry system in southern Ontario, Canada. The mean coarse root biomass estimated from GPR analysis was 54.1 +/- 8.7 kg tree-1 (+/- S.E.; n=12), within 1 % of the mean coarse root biomass measured from matched excavations. The vertical distribution of detected roots varied among species, with T. occidentalis and P. abies roots concentrated in the top 20 cm and J. nigra and Q. rubra roots distinctly deeper. I evaluate these root systems based on their C storage potential and complementary root stratification with adjacent crops.

  5. 47 CFR 80.389 - Frequencies for maritime support stations.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... associated public coast station. (b) Shore radar and radiolocation tests. The following frequency bands are available for assignment to demonstrate radar and radiolocation equipment. The use of frequencies...

  6. 47 CFR 80.389 - Frequencies for maritime support stations.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... associated public coast station. (b) Shore radar and radiolocation tests. The following frequency bands are available for assignment to demonstrate radar and radiolocation equipment. The use of frequencies...

  7. 47 CFR 80.389 - Frequencies for maritime support stations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... associated public coast station. (b) Shore radar and radiolocation tests. The following frequency bands are available for assignment to demonstrate radar and radiolocation equipment. The use of frequencies...

  8. 47 CFR 80.389 - Frequencies for maritime support stations.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... associated public coast station. (b) Shore radar and radiolocation tests. The following frequency bands are available for assignment to demonstrate radar and radiolocation equipment. The use of frequencies...

  9. 47 CFR 80.389 - Frequencies for maritime support stations.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... associated public coast station. (b) Shore radar and radiolocation tests. The following frequency bands are available for assignment to demonstrate radar and radiolocation equipment. The use of frequencies...

  10. 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

    ... System (INS): Request for Evaluation; Equipment and Equipment Installation; Training Program; Equipment... AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR CARRIERS AND OPERATORS FOR... OPERATIONS Pt. 121, App. G Appendix G to Part 121—Doppler Radar and Inertial Navigation System (INS):...

  11. Generalized Geologic evaluation of side looking radar imagery of the Teton Range and Jackson Hole, northwestern Wyoming

    NASA Technical Reports Server (NTRS)

    Love, J. D.

    1970-01-01

    A generalized geologic evaluation of lines, localities, and features of various types that are visible on a series of radar image strips covering the Teton Range and Jackson Hole in northwestern Wyoming, is given. No attempt was made to collate a complete geologic map with the radar image at each locality. Formation names, problems of geologic interpretation, and details of stratigraphy and structure that are not directly pertinent to a study of the imagery are omitted, but reference is made to publications that contain this type of supplementary information.

  12. An evaluation of oxygen-hydrogen propulsion systems for the Space Station

    NASA Technical Reports Server (NTRS)

    Klemetson, R. W.; Garrison, P. W.; Hannum, N. P.

    1985-01-01

    Conceptual designs for O2/H2 chemical and resistojet propulsion systems for the space station was developed and evaluated. The evolution of propulsion requirements was considered as the space station configuration and its utilization as a space transportation node change over the first decade of operation. The characteristics of candidate O2/H2 auxiliary propulsion systems are determined, and opportunities for integration with the OTV tank farm and the space station life support, power and thermal control subsystems are investigated. OTV tank farm boiloff can provide a major portion of the growth station impulse requirements and CO2 from the life support system can be a significant propellant resource, provided it is not denied by closure of that subsystem. Waste heat from the thermal control system is sufficient for many propellant conditioning requirements. It is concluded that the optimum level of subsystem integration must be based on higher level space station studies.

  13. Study to investigate and evaluate means of optimizing the radar function for the space shuttle

    NASA Technical Reports Server (NTRS)

    1976-01-01

    A detailed analysis of the spiral scan was performed for antenna sizes ranging from 20 inches to 36 inches in diameter and for search angles characteristic of both the radar and the communication acquisition modes. The power budgets for passive target radar detection were calculated for antenna diameters ranging from 20 to 36 inches. Dwell times commensurate with spiral scan were used for these budget calculations. The signal design for the candidate pulse Doppler system is summarized. Ground return analysis carried out for the passive target radar mode is examined, and the details are presented. A concluding description of the proposed candidate radar/communication system configuration is given.

  14. International Space Station Bacteria Filter Element Service Life Evaluation

    NASA Technical Reports Server (NTRS)

    Perry, J. L.

    2005-01-01

    The International Space Station (ISS) uses high-efficiency particulate air filters to remove particulate matter from the cabin atmosphere. Known as bacteria filter elements (BFEs), there are 13 elements deployed on board the ISS's U.S. segment in the flight 4R assembly level. The preflight service life prediction of 1 yr for the BFEs is based upon engineering analysis of data collected during developmental testing that used a synthetic dust challenge. While this challenge is considered reasonable and conservative from a design perspective, an understanding of the actual filter loading is required to best manage the critical ISS program resources. Testing was conducted on BFEs returned from the ISS to refine the service life prediction. Results from this testing and implications to ISS resource management are provided.

  15. Development, Test, and Evaluation of Microwave Radar Water Level (MWWL) Sensors' Wave Measurement Capability

    NASA Astrophysics Data System (ADS)

    Iyer, S. K.; Heitsenrether, R.

    2015-12-01

    Waves can have a significant impact on many coastal operations including navigational safety, recreation, and even the economy. Despite this, as of 2009, there were only 181 in situ real-time wave observation networks nationwide (IOOS 2009). There has recently been interest in adding real-time wave measurement systems to already existing NOAA Center for Operational Oceanographic Products and Services (CO-OPS) stations. Several steps have already been taken in order to achieve this, such as integrating information from existing wave measurement buoys and initial testing of multiple different wave measurement systems (Heitsenrether et al. 2012). Since wave observations can be derived from high frequency water level changes, we will investigate water level sensors' capability to measure waves. Recently, CO-OPS has been transitioning to new microwave radar water level (MWWL) sensors which have higher resolution and theoretically a greater potential wave measurement capability than the acoustic sensors in stilling wells. In this study, we analyze the wave measurement capability of MWWL sensors at two high energy wave environments, Duck, NC and La Jolla, CA, and compare results to two "reference" sensors (A Nortek acoustic waves and currents profiler (AWAC) at Duck and a single point pressure sensor at La Jolla). A summary of results from the two field test sites will be presented, including comparisons of wave energy spectra, significant wave height, and peak period measured by the test MWWL sensors and both reference AWAC and pressure sensors. In addition, relationships between MWWL versus reference wave sensor differences and specific wave conditions will be discussed. Initial results from spectral analysis and the calculation of bulk wave parameters indicate that MWWL sensors set to the "NoFilter" processing setting can produce wave measurements capability that compare well to the two reference sensors. These results support continued development to enable the

  16. Remote infrared signage evaluation for transit stations and intersections.

    PubMed

    Crandall, W; Brabyn, J; Bentzen, B L; Myers, L

    1999-10-01

    Opportunities for education and employment depend upon effective and independent travel. For mainstream society, this is accomplished to a large extent by printed signs. People who are print disabled, visually impaired, or totally blind are at a disadvantage because they do not have access to signage. Remote infrared signage, such as the Talking Signs (TS) system, provides a solution to this need by labeling the environment for distant viewing. The system uses a transmitting "sign" and a hand-held receiver to tell people about their surroundings. In a seamless infrared signage environment, a visually impaired traveler could: walk safely across an intersection to an ATM or fare machine, from fare machine to bus stop, from bus stop to bus; from bus to building, from building to elevator, from elevator to office, from office to restroom, and so forth. This paper focuses on two problems that are among the most challenging and dangerous faced by blind travelers: negotiating complex transit stations and controlled intersections. We report on human factors studies of TS in these critical tasks, examining such issues as how much training is needed to use the system, its impact on performance and safety, benefits for different population subgroups and user opinions of its value. Results indicate that blind people can quickly and easily learn to use remote infrared signage effectively, and that its use improves travel safety, efficiency, and independence.

  17. Use of radars to monitor stream discharge by noncontact methods

    USGS Publications Warehouse

    Costa, J.E.; Cheng, R.T.; Haeni, F.P.; Melcher, N.; Spicer, K.R.; Hayes, E.; Plant, W.; Hayes, K.; Teague, C.; Barrick, D.

    2006-01-01

    Conventional measurements of river flows are costly, time-consuming, and frequently dangerous. This report evaluates the use of a continuous wave microwave radar, a monostatic UHF Doppler radar, a pulsed Doppler microwave radar, and a ground-penetrating radar to measure river flows continuously over long periods and without touching the water with any instruments. The experiments duplicate the flow records from conventional stream gauging stations on the San Joaquin River in California and the Cowlitz River in Washington. The purpose of the experiments was to directly measure the parameters necessary to compute flow: surface velocity (converted to mean velocity) and cross-sectional area, thereby avoiding the uncertainty, complexity, and cost of maintaining rating curves. River channel cross sections were measured by ground-penetrating radar suspended above the river. River surface water velocity was obtained by Bragg scattering of microwave and UHF Doppler radars, and the surface velocity data were converted to mean velocity on the basis of detailed velocity profiles measured by current meters and hydroacoustic instruments. Experiments using these radars to acquire a continuous record of flow were conducted for 4 weeks on the San Joaquin River and for 16 weeks on the Cowlitz River. At the San Joaquin River the radar noncontact measurements produced discharges more than 20% higher than the other independent measurements in the early part of the experiment. After the first 3 days, the noncontact radar discharge measurements were within 5% of the rating values. On the Cowlitz River at Castle Rock, correlation coefficients between the USGS stream gauging station rating curve discharge and discharge computed from three different Doppler radar systems and GPR data over the 16 week experiment were 0.883, 0.969, and 0.992. Noncontact radar results were within a few percent of discharge values obtained by gauging station, current meter, and hydroacoustic methods. Time

  18. Ground penetrating radar and direct current resistivity evaluation of the desiccation test cap, Savannah River Site

    SciTech Connect

    Wyatt, D.E.; Cumbest, R.J.

    1996-04-01

    The Savannah River Site (SRS) has a variety of waste units that may be temporarily or permanently stabilized by closure using an impermeable cover to prevent groundwater infiltration. The placement of an engineered kaolin clay layer over a waste unit is an accepted and economical technique for providing an impermeable cover but the long term stability and integrity of the clay in non-arid conditions is unknown. A simulated kaolin cap has been constructed at the SRA adjacent to the Burial Ground Complex. The cap is designed to evaluate the effects of desiccation on clay integrity, therefore half of the cap is covered with native soil to prevent drying, while the remainder of the cap is exposed. Measurements of the continuing impermeability of a clay cap are difficult because intrusive techniques may locally compromise the structure. Point measurements made to evaluate clay integrity, such as those from grid sampling or coring and made through a soil cover, may miss cracks, joints or fissures, and may not allow for mapping of the lateral extent of elongate features. Because of these problems, a non-invasive technique is needed to map clay integrity, below a soil or vegetation cover, which is capable of moderate to rapid investigation speeds. Two non-intrusive geophysical techniques, direct current resistivity and ground penetrating radar (GPR), have been successful at the SRS in geologically mapping shallow subsurface clay layers. The applicability of each technique in detecting the clay layer in the desiccation test cap and associated anomalies was investigated.

  19. 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

  20. Performance Evaluation of Target Detection with a Near-Space Vehicle-Borne Radar in Blackout Condition

    PubMed Central

    Li, Yanpeng; Li, Xiang; Wang, Hongqiang; Deng, Bin; Qin, Yuliang

    2016-01-01

    Radar is a very important sensor in surveillance applications. Near-space vehicle-borne radar (NSVBR) is a novel installation of a radar system, which offers many benefits, like being highly suited to the remote sensing of extremely large areas, having a rapidly deployable capability and having low vulnerability to electronic countermeasures. Unfortunately, a target detection challenge arises because of complicated scenarios, such as nuclear blackout, rain attenuation, etc. In these cases, extra care is needed to evaluate the detection performance in blackout situations, since this a classical problem along with the application of an NSVBR. However, the existing evaluation measures are the probability of detection and the receiver operating curve (ROC), which cannot offer detailed information in such a complicated application. This work focuses on such requirements. We first investigate the effect of blackout on an electromagnetic wave. Performance evaluation indexes are then built: three evaluation indexes on the detection capability and two evaluation indexes on the robustness of the detection process. Simulation results show that the proposed measure will offer information on the detailed performance of detection. These measures are therefore very useful in detecting the target of interest in a remote sensing system and are helpful for both the NSVBR designers and users. PMID:26751445

  1. Performance Evaluation of Target Detection with a Near-Space Vehicle-Borne Radar in Blackout Condition.

    PubMed

    Li, Yanpeng; Li, Xiang; Wang, Hongqiang; Deng, Bin; Qin, Yuliang

    2016-01-06

    Radar is a very important sensor in surveillance applications. Near-space vehicle-borne radar (NSVBR) is a novel installation of a radar system, which offers many benefits, like being highly suited to the remote sensing of extremely large areas, having a rapidly deployable capability and having low vulnerability to electronic countermeasures. Unfortunately, a target detection challenge arises because of complicated scenarios, such as nuclear blackout, rain attenuation, etc. In these cases, extra care is needed to evaluate the detection performance in blackout situations, since this a classical problem along with the application of an NSVBR. However, the existing evaluation measures are the probability of detection and the receiver operating curve (ROC), which cannot offer detailed information in such a complicated application. This work focuses on such requirements. We first investigate the effect of blackout on an electromagnetic wave. Performance evaluation indexes are then built: three evaluation indexes on the detection capability and two evaluation indexes on the robustness of the detection process. Simulation results show that the proposed measure will offer information on the detailed performance of detection. These measures are therefore very useful in detecting the target of interest in a remote sensing system and are helpful for both the NSVBR designers and users.

  2. Evaluation of river water quality monitoring stations by principal component analysis.

    PubMed

    Ouyang, Ying

    2005-07-01

    The development of a surface water monitoring network is a critical element in the assessment, restoration, and protection of stream water quality. This study applied principal component analysis (PCA) and principal factor analysis (PFA) techniques to evaluate the effectiveness of the surface water quality-monitoring network in a river where the evaluated variables are monitoring stations. The objective was to identify monitoring stations that are important in assessing annual variations of river water quality. Twenty-two stations used for monitoring physical, chemical, and biological parameters, located at the main stem of the lower St. Johns River in Florida, USA, were selected for the purpose of this study. Results show that 3 monitoring stations were identified as less important in explaining the annual variance of the data set, and therefore could be the non-principal stations. In addition, the PFA technique was also employed to identify important water quality parameters. Results reveal that total organic carbon, dissolved organic carbon, total nitrogen, dissolved nitrate and nitrite, orthophosphate, alkalinity, salinity, Mg, and Ca were the parameters that are most important in assessing variations of water quality in the river. This study suggests that PCA and PFA techniques are useful tools for identification of important surface water quality monitoring stations and parameters.

  3. Performance evaluation of the Enraf-Nonius Model 872 radar gage

    SciTech Connect

    Peters, T.J.; Park, W.R.

    1992-12-01

    There are indications that the Enraf-Nonius Radar Gage installed in Tank 241-SY-101 may not be providing an accurate reading of the true surface level in the waste tank. The Pacific Northwest Laboratory (PNL) performed an initial study to determine the effect of the following items on the distance read by the gage: Tank riser; Material permittivity and conductivity Foam; Proportion of supernatant to solid material in the field of view of the instrument; Physical geometry of the supernatant and solid material changing in the field of view with respect to time; and Varying water content in the solid material. The results of the tests indicate that distance measured by the radar gage is affected by the permittivity, conductivity, and angle of the target surface. These parameters affect the complex input impedance of the signal received by the radar gage to measure the distance to the target. In Tank 101-SY, the radar gage is placed on top of a 12 in. diameter riser. The riser affects the field of view of the instrument, and a much smaller target surface is detected when the radar beam propagates through a riser. In addition, the riser acts as a waveguide, and standing waves are enhanced between the target surface and the radar gage. The result is a change in the level measured by the radar gage due to changing properties of the target surface even when the distance to the target does not change. The test results indicate that the radar will not detect dry crust or foam. However, if the crust or foam is stirred so that it becomes wet, then the crust or foam became detectable. The level read using the radar gage decreased as the moisture in the crust or foam evaporated.

  4. Evaluating Microphysics in Cloud-Resolving Models using TRMM and Ground-based Precipitation Radar Observations

    NASA Astrophysics Data System (ADS)

    Krueger, S. K.; Zulauf, M. A.; Li, Y.; Zipser, E. J.

    2005-05-01

    Global satellite datasets such as those produced by ISCCP, ERBE, and CERES provide strong observational constraints on cloud radiative properties. Such observations have been widely used for model evaluation, tuning, and improvement. Cloud radiative properties depend primarily on small, non-precipitating cloud droplets and ice crystals, yet the dynamical, microphysical and radiative processes which produce these small particles often involve large, precipitating hydrometeors. There now exists a global dataset of tropical cloud system precipitation feature (PF) properties, collected by TRMM and produced by Steve Nesbitt, that provides additional observational constraints on cloud system properties. We are using the TRMM PF dataset to evaluate the precipitation microphysics of two simulations of deep, precipitating, convective cloud systems: one is a 29-day summertime, continental case (ARM Summer 1997 SCM IOP, at the Southern Great Plains site); the second is a tropical maritime case: the Kwajalein MCS of 11-12 August 1999 (part of a 52-day simulation). Both simulations employed the same bulk, three-ice category microphysical parameterization (Krueger et al. 1995). The ARM simulation was executed using the UCLA/Utah 2D CRM, while the KWAJEX simulation was produced using the 3D CSU CRM (SAM). The KWAJEX simulation described above is compared with both the actual radar data and the TRMM statistics. For the Kwajalein MCS of 11 to 12 August 1999, there are research radar data available for the lifetime of the system. This particular MCS was large in size and rained heavily, but it was weak to average in measures of convective intensity, against the 5-year TRMM sample of 108. For the Kwajalein MCS simulation, the 20 dBZ contour is at 15.7 km and the 40 dBZ contour at 14.5 km! Of all 108 MCSs observed by TRMM, the highest value for the 40 dBZ contour is 8 km. Clearly, the high reflectivity cores are off scale compared with observed cloud systems in this area. A similar

  5. Evaluation of X-band polarimetric radar estimation of rainfall and rain drop size distribution parameters in West Africa

    NASA Astrophysics Data System (ADS)

    Koffi, A. K.; Gosset, M.; Zahiri, E.-P.; Ochou, A. D.; Kacou, M.; Cazenave, F.; Assamoi, P.

    2014-06-01

    As part of the African Monsoon Multidisciplinary Analysis (AMMA) field campaign an X-band dual-polarization Doppler radar was deployed in Benin, West-Africa, in 2006 and 2007, together with a reinforced rain gauge network and several optical disdrometers. Based on this data set, a comparative study of several rainfall estimators that use X-band polarimetric radar data is presented. In tropical convective systems as encountered in Benin, microwave attenuation by rain is significant and quantitative precipitation estimation (QPE) at X-band is a challenge. Here, several algorithms based on the combined use of reflectivity, differential reflectivity and differential phase shift are evaluated against rain gauges and disdrometers. Four rainfall estimators were tested on twelve rainy events: the use of attenuation corrected reflectivity only (estimator R(ZH)), the use of the specific phase shift only R(KDP), the combination of specific phase shift and differential reflectivity R(KDP,ZDR) and an estimator that uses three radar parameters R(ZH,ZDR,KDP). The coefficients of the power law relationships between rain rate and radar variables were adjusted either based on disdrometer data and simulation, or on radar-gauges observations. The three polarimetric based algorithms with coefficients predetermined on observations outperform the R(ZH) estimator for rain rates above 10 mm/h which explain most of the rainfall in the studied region. For the highest rain rates (above 30 mm/h) R(KDP) shows even better scores, and given its performances and its simplicity of implementation, is recommended. The radar based retrieval of two parameters of the rain drop size distribution, the normalized intercept parameter NW and the volumetric median diameter Dm was evaluated on four rainy days thanks to disdrometers. The frequency distributions of the two parameters retrieved by the radar are very close to those observed with the disdrometer. NW retrieval based on a combination of ZH

  6. Geostatistical evaluation of satellite radar altimetry for high-resolution mapping of Lambert Glacier, Antarctica

    NASA Technical Reports Server (NTRS)

    Herzfeld, Ute C.; Lingle, Craig S.; Lee, Li-Her

    1993-01-01

    The potential of satellite radar altimetry for high-resolution mapping of Antarctic ice streams is evaluated, using retracked and slope-corrected data from the Lambert Glacier and Amery Ice Shelf area, East Antarctica, acquired by Geosat during the Exact Repeat Mission (ERM), 1986-89. The map area includes lower Lambert Glacier north of 72.18 deg S, the southern Amery Ice Shelf, and the grounded inland ice sheet on both sides. The Geosat ERM altimetry is found to provide substantially more complete coverage than the 1978 Seasat altimetry, due to improved tracking. Variogram methods are used to estimate the noise levels in the data as a function of position throughout the map area. The spatial structure in the data is quantified by constructing experimental variograms using altimetry from the area of the grounding zone of Lambert Glacier, which is the area chiefly of interest in this topographically complex region. Kriging is employed to invert the along-track height measurements onto a fine-scale 3 km grid. The unsmoothed along-track Geosat ERM altimetry yields spatially continuous maps showing the main topographic features of lower Lambert Glacier, upper Amery Ice Shelf and the adjacent inland ice sheet. The probable position of the grounding line of Lambert Glacier is identified from a break in slope at the grounded ice/floating ice transition. The approximate standard error of the kriged map is inferred from the data noise levels.

  7. Evaluation of pan evaporation modeling with two different neural networks and weather station data

    NASA Astrophysics Data System (ADS)

    Kim, Sungwon; Singh, Vijay P.; Seo, Youngmin

    2014-07-01

    This study evaluates neural networks models for estimating daily pan evaporation for inland and coastal stations in Republic of Korea. A multilayer perceptron neural networks model (MLP-NNM) and a cascade correlation neural networks model (CCNNM) are developed for local implementation. Five-input models (MLP 5 and CCNNM 5) are generally found to be the best for local implementation. The optimal neural networks models, including MLP 4, MLP 5, CCNNM 4, and CCNNM 5, perform well for homogeneous (cross-stations 1 and 2) and nonhomogeneous (cross-stations 3 and 4) weather stations. Statistical results of CCNNM are better than those of MLP-NNM during the test period for homogeneous and nonhomogeneous weather stations except for MLP 4 being better in BUS-DAE and POH-DAE, and MLP 5 being better in POH-DAE. Applying the conventional models for the test period, it is found that neural networks models perform better than the conventional models for local, homogeneous, and nonhomogeneous weather stations.

  8. Evaluation of Flexible Array Station Performance and Ambient Noise Analysis Using 500 Days of Continuous Recordings

    NASA Astrophysics Data System (ADS)

    Alvarez, M. G.; Anderson, K.; Arias-Dotson, E.; Fowler, J.; Woodward, R.

    2008-12-01

    Within the NSF funded EarthScope USArray program, the Flexible Array (FA) is a pool of campaign seismic instruments for Principal Investigator-driven studies to augment the Transportable Array footprint in imaging key geophysical targets at higher resolution. In this study we evaluate the performance of FA stations using data recorded from the EarthScope CAFÉ experiment in western Washington. Using this unique data set, we create a reference point on how well portable broadband stations perform for an extended continuous period of over 500 days (150:2006 - 50:2008) . All instrumentation that comprise the CAFE experiment is essentially new, of the same type and deployed using a uniform installation technique. The performance of 60 stations is analyzed; 46 stations are broadband, equipped with Guralp CMG 3T and Reftek R130's, the remainder equipped with short period Guralp CMG 40T1Hz and the same data acquisition system. The information used for this evaluation is derived from three sources; detailed field service notes kindly provided by the PI's (Ken Creager, Stephane Rondenay, Geoff Abers), data reports from the IRIS Data Management Center, and the actual time series data. The data return (based on data archived at the DMC w/o any problems) for this experiment is calculated to be 94.5% . The various failures through time are segregated into logical categories where trends in deployment techniques and equipment failures are quantified. Using McNamara statistical analysis to characterize background seismic noise, probability density functions were computed for 25 CAFE stations spanning over 500 days of recording beginning in mid 2006. Results from each station were then combined to produce a network wide characterization of the background noise level. For the same time period, PSD's for 35 nearby Transportable Array stations were also computed and combined into a single system wide PSD. Both installation types perform remarkable well with some differences being

  9. Planetary Radar with the Green Bank Telescope

    NASA Astrophysics Data System (ADS)

    Ford, Alyson; Ford, John M.; Watts, Galen

    2014-11-01

    The large aperture and sensitive receivers of the National Radio Astronomy Observatory's Robert C. Byrd Green Bank Telescope (GBT) make it an attractive receiving station for bistatic radar experiments. Consequently, it has been used as a receive station for radar observations since its commissioning in 2001. The GBT is equipped with receivers for all common planetary radar transmitters at P, S, and X band, as well as for future radars at up to 86 GHz. We describe the technical capabilities of the GBT and its instrumentation in terms of its tracking and RF performance, the available radar backends, and select science results obtained through the use of the GBT.

  10. Field evaluation of boric acid and fipronil based bait stations against adult mosquitoes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The effectiveness of boric acid (1%) and fipronil (0.1%) bait stations in reducing the number of laboratory-reared female Aedes aegypti and Ochlerotatus taeniorhynchus mosquitoes released in outdoor screened cages was evaluated. Both toxicants reduced landing rates of the two mosquito species on a ...

  11. Radar Scan Strategies for the Patrick Air Force Base Weather Surveillance Radar, Model-74C, Replacement

    NASA Technical Reports Server (NTRS)

    Short, David

    2008-01-01

    The 45th Weather Squadron (45 WS) is replacing the Weather Surveillance Radar, Model 74C (WSR-74C) at Patrick Air Force Base (PAFB), with a Doppler, dual polarization radar, the Radtec 43/250. A new scan strategy is needed for the Radtec 43/250, to provide high vertical resolution data over the Kennedy Space Center (KSC) and Cape Canaveral Air Force Station (CCAFS) launch pads, while taking advantage of the new radar's advanced capabilities for detecting severe weather phenomena associated with convection within the 45 WS area of responsibility. The Applied Meteorology Unit (AMU) developed several scan strategies customized for the operational needs of the 45 WS. The AMU also developed a plan for evaluating the scan strategies in the period prior to operational acceptance, currently scheduled for November 2008.

  12. Evaluation of emergency drug releases from the Centers for Disease Control and Prevention Quarantine Stations.

    PubMed

    Roohi, Shahrokh; Grinnell, Margaret; Sandoval, Michelle; Cohen, Nicole J; Crocker, Kimberly; Allen, Christopher; Dougherty, Cindy; Jolly, Julian; Pesik, Nicki

    2015-01-01

    The Centers for Disease Control and Prevention (CDC) Quarantine Stations distribute select lifesaving drug products that are not commercially available or are in limited supply in the United States for emergency treatment of certain health conditions. Following a retrospective analysis of shipment records, the authors estimated an average of 6.66 hours saved per shipment when drug products were distributed from quarantine stations compared to a hypothetical centralized site from CDC headquarters in Atlanta, GA. This evaluation supports the continued use of a decentralized model which leverages CDC's regional presence and maximizes efficiency in the distribution of lifesaving drugs. PMID:27149310

  13. Evaluation of emergency drug releases from the Centers for Disease Control and Prevention Quarantine Stations.

    PubMed

    Roohi, Shahrokh; Grinnell, Margaret; Sandoval, Michelle; Cohen, Nicole J; Crocker, Kimberly; Allen, Christopher; Dougherty, Cindy; Jolly, Julian; Pesik, Nicki

    2015-01-01

    The Centers for Disease Control and Prevention (CDC) Quarantine Stations distribute select lifesaving drug products that are not commercially available or are in limited supply in the United States for emergency treatment of certain health conditions. Following a retrospective analysis of shipment records, the authors estimated an average of 6.66 hours saved per shipment when drug products were distributed from quarantine stations compared to a hypothetical centralized site from CDC headquarters in Atlanta, GA. This evaluation supports the continued use of a decentralized model which leverages CDC's regional presence and maximizes efficiency in the distribution of lifesaving drugs. PMID:25779896

  14. CETF Space Station payload pointing system design and analysis feasibility study. [Critical Evaluation Task Force

    NASA Technical Reports Server (NTRS)

    Smagala, Tom; Mcglew, Dave

    1988-01-01

    The expected pointing performance of an attached payload coupled to the Critical Evaluation Task Force Space Station via a payload pointing system (PPS) is determined. The PPS is a 3-axis gimbal which provides the capability for maintaining inertial pointing of a payload in the presence of disturbances associated with the Space Station environment. A system where the axes of rotation were offset from the payload center of mass (CM) by 10 in. in the Z axis was studied as well as a system having the payload CM offset by only 1 inch. There is a significant improvement in pointing performance when going from the 10 in. to the 1 in. gimbal offset.

  15. Neutral buoyancy evaluation of technologies for space station external operations. [EVA weightlessness simulation

    NASA Technical Reports Server (NTRS)

    Akin, D. L.; Bowden, M. L.; Spofford, J. R.

    1984-01-01

    In order to perform a complete systems analysis for almost any large space program, it is vital to have a thorough understanding of human capabilities in extravehicular activity (EVA). The present investigation is concerned with the most significant results from the MIT Space Systems Lab's neutral buoyancy tests. An evaluation of neutral buoyancy is considered along with the tested structures, aspects of learning, productivity, time and motion analysis, and assembly loads. Attention is given to EVA assembly with a manned maneuvering unit, teleoperated structural assembly, an integrated control station, a beam assembly teleoperator, and space station proximity operations.

  16. Evaluation of two algorithms for a network of coastal HF radars in the Mid-Atlantic Bight

    NASA Astrophysics Data System (ADS)

    Kohut, Josh; Roarty, Hugh; Randall-Goodwin, Evan; Glenn, Scott; Lichtenwalner, C. Sage

    2012-06-01

    The National High Frequency (HF) Surface Current Mapping Radar Network is being developed as a backbone system within the U.S. Integrated Ocean Observing System. This paper focuses on the application of HF radar-derived surface current maps to U.S. Coast Guard Search and Rescue operations along the Mid-Atlantic coast of the USA. In that context, we evaluated two algorithms used to combine maps of radial currents into a single map of total vector currents. In situ data provided by seven drifter deployments and four bottom-mounted current meters were used to (1) evaluate the well-established unweighted least squares (UWLS) and the more recently adapted optimal interpolation (OI) algorithms and (2) quantify the sensitivity of the OI algorithm to varying decorrelation scales and error thresholds. Results with both algorithms were shown to depend on the location within the HF radar data footprint. The comparisons near the center of the HF radar coverage showed no significant difference between the two algorithms. The most significant distinction between the two was seen in the drifter trajectories. With these simulations, the weighting of radial velocities by distance in the OI implementation was very effective at reducing both the distance between the actual drifter and the cluster of simulated particles as well as the scale of the search area that encompasses them. In this study, the OI further reduced the already improved UWLS-based search areas by an additional factor of 2. The results also indicated that the OI output was relatively insensitive to the varying decorrelation scales and error thresholds tested.

  17. Vehicle-mounted ground penetrating radar (Mine Stalker III) field evaluation in Angola

    NASA Astrophysics Data System (ADS)

    Laudato, Stephen; Hart, Kerry; Nevard, Michael; Lauziere, Steven; Grant, Shaun

    2014-05-01

    The U.S. Department of Defense Humanitarian Demining Research and Development (HD R&D) Program, Non-Intrusive Inspection Technology (NIITEK), Inc. and The HALO Trust have over the last decade funded, developed and tested various prototype vehicle mounted ground penetrating radar (GPR) systems named the Mine Stalker. The HD R&D Program and NIITEK developed the Mine Stalker to detect low metal anti-tank (LM-AT) mines in roads. The country of Angola is severely affected by LM-AT mines in and off road, some of which are buried beyond the effective range of detection sensors current used in country. The threat from LM-AT mines such as the South African Number 8 (No. 8) and the Chinese Type 72 (72AT) still persist from Angola's 30 years of civil war. These LM-AT threats are undetectable at depths greater than 5 to 10 centimeters using metal detection technology. Clearing commerce routes are a critical requirement before Angola can rebuild its infrastructure and improve safety conditions for the local populace. The Halo Trust, a non-governmental demining organization (NGO) focused on demining and clearance of unexploded ordnance (UXO), has partnered with the HD R&D Program to conduct an operational field evaluation (OFE) of the Mine Stalker III (MS3) in Angola. Preliminary testing and training efforts yielded encouraging results. This paper presents a review of the data collected, testing results, system limitations and deficiencies while operating in a real world environment. Our goal is to demonstrate and validate this technology in live minefield environments, and to collect data to prompt future developments to the system.

  18. How Much Gravel? Use of Ground Penetrating Radar for Aggregate Resource Evaluation

    NASA Astrophysics Data System (ADS)

    McCuaig, S. J.; Ricketts, J.

    2004-05-01

    Ground penetrating radar (GPR) was tested in two gravel quarries in eastern Newfoundland, Canada, to determine its usefulness for aggregate resource evaluation. In Mercer's Pit, near Tors Cove, GPR profiles show irregular, discontinuous reflections that extend to depths of more than 30 m. Boulders are common at depth (identified on the profiles by numerous individual diffractions). The area is interpreted as a much thicker gravel deposit than had been estimated by previous methods, however, the presence of boulders could indicate a lower quality resource. Analysis of a peat bog near the pit shows a prominent contact on the GPR profiles. It is interpreted as the hummocky surface of the gravel deposit (continuous, high amplitude reflections), which underlies a much weaker reflective zone of peat. At Snow's Pit, near Bay Roberts, a series of overlapping diffractions at depth are interpreted as representing the bedrock surface, which varies from 5 to 15 m below the surface. Aggregate deposits overlie the bedrock (irregular, discontinuous reflections) and contain very few boulders. This deposit also was found to be larger than previously thought, and is low in boulder content throughout. GPR was found to be an effective tool for delineating the extent and volume of aggregate resources in these examples. It provides a detailed view of the subsurface and large amounts of information are gathered quickly and easily. GPR can be used to revise volume calculations of quarries already in operation and to estimate the volume of potential new deposits. It is also useful for planning pit development and analysing prospective areas that quarry operators do not yet own or have rights to, with virtually no environmental impact on the land surveyed.

  19. An intercomparison of radar-based liquid cloud microphysics retrievals and implication for model evaluation studies

    NASA Astrophysics Data System (ADS)

    Huang, D.; Zhao, C.; Dunn, M.; Dong, X.; Mace, G. G.; Jensen, M. P.; Xie, S.; Liu, Y.

    2011-12-01

    To assess if current radar-based liquid cloud microphysical retrievals of the Atmospheric Radiation Measurement (ARM) program can provide useful constraints for modeling studies, this paper presents intercomparison results of three cloud products at the Southern Great Plains (SGP) site: the ARM MICROBASE, University of Utah (UU), and University of North Dakota (UND) products over the nine-year period from 1998 to 2006. The probability density and spatial autocorrelation functions of the three cloud Liquid Water Content (LWC) retrievals appear to be consistent with each other, while large differences are found in the droplet effective radius retrievals. The differences in the vertical distribution of both cloud LWC and droplet effective radius retrievals are found to be alarmingly large, with the relative difference between nine-year mean cloud LWC retrievals ranging from 20% at low altitudes to 100% at high altitudes. Nevertheless, the spread in LWC retrievals is much smaller than that in cloud simulations by climate and cloud resolving models. The MICROBASE effective radius ranges from 2.0 at high altitudes to 6.0 μm at low altitudes and the UU and UND droplet effective radius is 6 μm larger. Further analysis through a suite of retrieval experiments shows that the difference between MICROBASE and UU LWC retrievals stems primarily from the partition total Liquid Water path (LWP) into supercooled and warm liquid, and from the input cloud boundaries and LWP. The large differences between MICROBASE and UU droplet effective radius retrievals are mainly due to rain/drizzle contamination and the assumptions of cloud droplet concentration used in the retrieval algorithms. The large discrepancy between different products suggests caution in model evaluation with these observational products, and calls for improved retrievals in general.

  20. Noncooperative rendezvous radar system

    NASA Technical Reports Server (NTRS)

    1974-01-01

    A fire control radar system was developed, assembled, and modified. The baseline system and modified angle tracking system are described along with the performance characteristics of the baseline and modified systems. Proposed changes to provide additional techniques for radar evaluation are presented along with flight test data.

  1. Performance Evaluation of an Autonomous Adaptive Base Station that Supports Multiple Wireless Network Systems

    NASA Astrophysics Data System (ADS)

    Akabane, Kazunori; Shiba, Hiroyuki; Matsui, Munehiro; Uehara, Kazuhiro

    Various wireless systems are being developed to meet users' needs, and the rapid increase in frequency demand that accompanies the increasing popularity of wireless services means that more effective use of frequency resources is urgently needed. However, existing base stations are making no effort to use frequency resources effectively, and cooperation among wireless system base stations is needed to use frequency resources more effectively. Base stations can cooperate more efficiently if they are able to use multiple channels of many wireless systems simultaneously. We propose an autonomous adaptive base station (AABS) that can switch among various wireless systems the way software defined radio (SDR) base stations do. AABS can autonomously select and use the most suitable wireless system on the basis of user traffic and its hardware resources. Moreover, frequency resources are used effectively because AABS prevents unnecessary radio wave transmission when the number of users in the wireless systems decreases. AABS is also suitable for “multi-link communication” because it can use multiple channels of multiple wireless systems simultaneously. We developed AABS prototype and evaluated its performance. Our experimental and computer simulation results show the performance of AABS and its efficiency.

  2. Evaluation of newly installed SWEPOS mast stations, individual vs. type PCV antenna models and comparison with pillar stations

    NASA Astrophysics Data System (ADS)

    Nilfouroushan, Faramarz; Jivall, Lotti; Lilje, Christina; Steffen, Holger; Lidberg, Martin; Johansson, Jan; Jarlemark, Per

    2016-04-01

    For about two decades, SWEPOS (the Swedish Permanent GNSS network) pillar stations have been used in different geodetic and geodynamic studies. To keep continuous measurements of these long lived pillar stations and at the same time modernizing the SWEPOS network, it has been decided to install new truss mast stations, equipped with modern and individually calibrated antennas and radomes, capable of tracking all new GNSS satellites. Installation of mast stations started in 2011. Today, each pillar station in the SWEPOS permanent GNSS network has a close-by truss mast station, mostly in 10 meters distance with individual calibrated Leica choke ring antenna and its attachment (LEIAR25.R3, LEIT). Due to their closeness to pillars, the modern mast stations may provide additional information for the analysis of ground movements in Sweden e.g. to distinguish between tectonic and geodynamic processes (e.g. land uplift in Sweden). In this study, we have used two datasets from two different seasons for 21 pillars and 21 mast stations and formed different networks. The mast network has been processed using both IGS standard (type) and individually calibrated PCV (Phase Center Variation) models and therefore the effect of these two different PCV models on height components has been investigated. In a combined network, we processed all 42 stations (21 pillars+21 mast) to see how this multi-baseline network (861 baselines) combination differs from independent mast or pillar networks with much less baselines (210 baselines). For our analysis, we used the GAMIT-GLOBK software and compared different networks. Ambiguity resolutions, daily coordinate repeatability and differences between height components in different solutions are presented. Moreover, the GAMIT and BERNESE solutions for combined mast and pillar networks are compared. Our results suggest that the SWEPOS truss mast stations can reliably be used for crustal deformation studies. The comparison between pillar and mast

  3. Lava flows in mare imbrium: An evaluation of anomalously low earth-based radar reflectivity

    USGS Publications Warehouse

    Schaber, G.G.; Thompson, T.W.; Zisk, S.H.

    1975-01-01

    The lunar maria reflect two to five times less Earth-based radar power than the highlands, the spectrally blue maria surfaces returning the lowest power levels. This effect of weakening signal return has been attributed to increased signal absorption related to the electrical and magnetic characteristics of the mineral ilmenite (FeTiO3). The surface of Mare Imbrium contains some of the most distinct red-blue colorimetric boundaries and depolarized 70 cm wavelength reflectivity variations on the near side of the Moon. The weakest levels of both 3.8 cm and 70 cm reflectivity within Imbrium are confined to regional mare surfaces of the blue spectral type that can be recognized as stratigraphically unique flow surfaces. Frequency distributions of the 70 cm polarized and depolarized radar return power for five mare surfaces within the basin indicate that signal absorption, and probably the ilmenite content, increases generally from the beginning of the Imbrian Period to the end of the Eratosthenian Period with slight reversal between the end of the Imbrian and beginning of the Eratosthenian. TiO2 calibrated radar reflectivity curves can be utilized for lunar maria geochemical mapping in the same manner as the TiO2 calibrated spectral reflectivity curves of Charette et al. (1974). The long wavelength radar data may be a sensitive indicator of mare chemical variations as it is unaffected by the normal surface rock clutter that includes ray materials from large impact craters. ?? 1975 D. Reidel Publishing Company.

  4. Evaluation of tag entanglement as a factor in harmonic radar studies of insect dispersal

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The observation of insects and other small organisms entangled in the habitat after the addition of vertical or trailing electronic tags to their body has generated concerns on the suitability of harmonic radars to track the dispersal of insects. This study compared the walking behavior of adult Co...

  5. Shuttle orbiter KU-band radar/communications system design evaluation

    NASA Technical Reports Server (NTRS)

    1979-01-01

    An expanded introduction is presented which addresses the in-depth nature of the tasks and indicates continuity of the reported effort and results with previous work and related contracts, and the two major modes of operation which exist in the Ku-band system, namely, the radar mode and the communication mode, are described. The Ku-band radar system is designed to search for a target in a designated or undesignated mode, then track the detected target, which might be cooperative (active) or passive, providing accurate, estimates of the target range, range rate, angle and angle rate to enable the orbiter to rendezvous with this target. The radar mode is described along with a summary of its predicted performance. The principal sub-unit that implements the radar function is the electronics assembly 2(EA-2). The relationship of EA-2 to the remainder of the Ku-band system is shown. A block diagram of EA-2 is presented including the main command and status signals between EA-2 and the other Ku-band units.

  6. Description and Initial Evaluation of a Computer-Based Individual Trainer for the Radar Intercept Observer.

    ERIC Educational Resources Information Center

    Rigney, Joseph W.; And Others

    An individual trainer for giving students in the radar intercept observer (RIO) schools concentrated practice in procedures for air-to-air intercepts was designed around a programmable graphics terminal with two integral minicomputers and 8k of core memory. The trainer automatically administers practice in computing values of variables in the…

  7. Evaluating the potential of X-band polarimetric radar observations in mountainous hydrology

    NASA Astrophysics Data System (ADS)

    Anagnostou, Marios; Kalogiros, John; Nikolopoulos, Efthymios; Anagnostou, Emmanouil; Marra, Francesco; Mair, Elisabeth; Bertolidi, Giacomo; Tappeiner, Ulrike; Borga, Marco

    2013-04-01

    Alpine catchments hydrology is strongly determined by orographic effects on the space-time structure of precipitation. Mountain precipitation results from a multitude of processes such as mechanical lifting, enhancement, shadowing etc. Many of these processes are poorly understood, especially at small spatial and temporal scales. Consequently, this limits the predictive capability of hydrological models and our understanding of the majority of the precipitation-related natural hazards occurring in both high- and lowlands. This lack of knowledge is mainly due to the intrinsic limitations of our best measurement techniques: raingauges and weather radars. Raingauges provide relatively accurate but only point-like observations, while weather radars produce instantaneous spatially distributed rainfall maps but their operation over complex terrain creates a number of limitations, which make their estimates reliable in a limited space-time domain. A solution to this limitation might be the use of a number of cost-effective short-range X-band radars as complement to raingauges and conventional, large and expensive weather radars. The study focuses on a 64 km2 mountainous basin located in Northern Italy. Rainfall observations from a dense network of raingauges located at different elevation, a C-band and an X-band polarimetric mobile unit are used to force a semi-distributed hydrologic model. A number of storm events are simulated and compared to investigate the potential of using high-res rainfall input from X-band polarimetric radar for simulating the hydrologic response. Events have been discriminated on the basis of rainfall intensity, snowfall limit and hydrological response. Results reveal that in contrast with the other two rainfall sources, X-band observations offer an improved representation of orographic enhancement of precipitation, which turns to have a significant impact in simulating peak flows.

  8. A volatile organic analyzer for Space Station: Description and evaluation of a gas chromatography/ ion mobility

    NASA Technical Reports Server (NTRS)

    Limero, Thomas F.; James, John T.

    1994-01-01

    A Volatile Organic Analyzer (VOA) is being developed as an essential component of the Space Station's Environmental Health System (EHS) air quality monitoring strategy to provide warning to the crew and ground personnel if volatile organic compounds exceed established exposure limits. The short duration of most Shuttle flights and the relative simplicity of the contaminant removal mechanism have lessened the concern about crew exposure to air contaminants on the Shuttle. However, the longer missions associated with the Space Station, the complex air revitalization system and the proposed number of experiments have led to a desire for real-time monitoring of the contaminants in the Space Station atmosphere. Achieving the performance requirements established for the VOA within the Space Station resource (e.g., power, weight) allocations led to a novel approach that joined a gas chromatograph (GC) to an ion mobility spectrometer (IMS). The authors of this paper will discuss the rational for selecting the GC/IMS technology as opposed to the more established gas chromatography/mass spectrometry (GC/MS) for the foundation of the VOA. The data presented from preliminary evaluations will demonstrate the versatile capability of the GC/IMS to analyze the major contaminants expected in the Space Station atmosphere. The favorable GC/IMS characteristics illustrated in this paper included excellent sensitivity, dual-mode operation for selective detection, and mobility drift times to distinguish co-eluting GC peaks. Preliminary studies have shown that the GC/IMS technology can meet surpass the performance requirements of the Space Station VOA.

  9. Characterization and evaluation of five jaboticaba accessions at the subtropical horticulture research station in Miami, Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fruit of five Jaboticaba (Myrciaria caulifloria) cultivars ‘MC-05-06’, ‘MC-05-14’, ‘MC-05-12’, ‘MC-06-15,’ and ‘MC-06-14’ were evaluated and characterized at the National Germplasm Repository, Subtropical horticulture Research Station (SHRS) Miami, Florida. Thirty fruits were harvested from clona...

  10. [The evaluation of hazardous cinder wastes in Ulan Ude thermal power stations].

    PubMed

    Borisenkova, R V; Dik, E P; Soboleva, A N; Lutsenko, L A

    2000-01-01

    Considering possibility of waste materials use in building materials production, the authors evaluated toxicity of ash and clinker waste of electric power stations in Ulan-Ude city. The ash dust and its tincture in water, when injected even in maximal amounts, induced no intoxication symptoms and death in experimental animals, therefore bear no toxicity. Using toxicity indexes to compare ash and clinker waste dust with nontoxic dust proved the studied waste to be nontoxic and acceptable for use in building industry.

  11. Space Radar Image of Star City, Russia

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This radar image shows the Star City cosmonaut training center, east of Moscow, Russia. Four American astronauts are training here for future long-duration flights aboard the Russian Mir space station. These joint flights are giving NASA and the Russian Space Agency experience necessary for the construction of the international Alpha space station, beginning in late 1997. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR), on its 62nd orbit on October 3, 1994. This Star City image is centered at 55.55 degrees north latitude and 38.0 degrees east longitude. The area shown is approximately 32 kilometers by 49 kilometers (20 miles by 30 miles). North is to the top in this image. The radar illumination is from the top of the image. The image was produced using three channels of SIR-C radar data: red indicates L-band (23 cm wavelength, horizontally transmitted and received); green indicates L-band (horizontally transmitted and vertically received); blue indicates C-band (6 cm wavelength, horizontally transmitted and vertically received). In general, dark pink areas are agricultural; pink and light blue areas are urban communities; black areas represent lakes and rivers; dark blue areas are cleared forest; and light green areas are forested. The prominent black runways just right of center are Shchelkovo Airfield, about 4 km long. The textured pale blue-green area east and southeast of Shchelkovo Airfield is forest. Just east of the runways is a thin railroad line running southeast; the Star City compound lies just east of the small bend in the rail line. Star City contains the living quarters and training facilities for Russian cosmonauts and their families. Moscow's inner loop road is visible at the lower left edge of the image. The Kremlin is just off the left edge, on the banks of the meandering Moskva River. The Klyazma River snakes to the southeast from the reservoir in the upper left (shown in bright red

  12. Retrieval and Evaluation of Wind Vectors and Advective Surface Velocities from Synthetic Aperture Radar and Infrared Radiometer Data

    NASA Astrophysics Data System (ADS)

    Carvajal, Gisela; Eriksson, Leif E. B.

    Analysis of ocean surface dynamics has been proven to be of vital importance in many areas (e.g. shipping, fishing). Two important parameters to describe the ocean dynamics are the wind velocity (speed and direction) and advective surface velocities (ocean current velocity). These parameters are currently provided operationally by forecast models, surface sensors (e.g. buoys, coastal radar) and satellite sensors. However, coverage limitations, low resolution and limited temporal availability impose a need for implementation and evaluation of new data sources and techniques for estimation of these parameters. In this paper we implement and evaluate known techniques for determination of wind and ocean current velocity from satellite data. Wind is determined from Synthetic Aperture Radar (SAR) data by applying two algo-rithms. First, the Local Gradient method is implemented to extract wind direction from the SAR data, and then the CMOD-5 Geophysical Model Function of the backscatter is inverted to obtain the wind speed as a function of the wind direction and the incidence angle. Current propagation is estimated by analyzing the Sea Surface Temperature propagation in two consec-utive infrared images of the same area from the Advanced Very High Resolution Radiometer. The evaluation shows a good agreement between estimated wind vectors from SAR and scat-terometer data. Comparison with merged ocean current estimates is addressed. The methods will be implemented in the maritime security service provided by the SECTRONIC project funded by the EU 7th framework program.

  13. Preliminary evaluation of space station transmission line in a ring configuration

    NASA Technical Reports Server (NTRS)

    Roth, Mary Ellen

    1990-01-01

    The results of a preliminary evaluation of a space station type transmission line and commercial transmission lines in a ring configuration, are reported. In a ring configuration, each node has two paths for the return current of each wire. The additional path can create an unbalanced condition, where the magnetic fields created by the forward and return currents do not cancel. This evaluation was to quantify the effects of the unbalanced case upon the external fields. The transmission lines evaluated were standard commercial coaxial cables, RG59 and RG213, and a space station designed flat Litz transmission line. Each was evaluated in a balanced and unbalanced mode of operation. Currents and their harmonic content were recorded and compared. As expected, the harmonic content of the different current (I delta) was substantial for the unbalanced case as compared to the balanced case. For the balanced case, very little difference was noted among the various transmission lines evaluated. The evaluation is discussed, and the test circuit, the measurements, and the resulting data are described.

  14. Wideband On-ground Monostatic Radar Antenna for Water Content Soil Evaluation: Modeling, Design and Testing

    NASA Astrophysics Data System (ADS)

    Vitale, Q.; Rejiba, F.; Guérin, R.

    2012-12-01

    The knowledge of soil's hydraulic properties spatial distribution is important in agricultural practice optimization and hydrological studies. Non-invasive methods of measurement of the dielectric permittivity such as time domain reflectometry (TDR) and ground penetrating radar (GPR) are increasingly used in order to asses soil water content at the field scale. In order to acquire radar data over a wide frequency range, we designed a simple on-ground radar antenna operating on the frequency range 350 MHz - 2GHz. The antenna was designed using a powerful commercial three dimensional finite-difference time-domain (FDTD) electromagnetic field solver. A prototype of the frequency type radar transmission link was constructed and laboratory measurements were first performed with calibration purpose (the antenna was placed on a 13 cm-thick sand layer of known dielectric permittivity). The antenna is used in monostatic configuration and associated with a vector network analyzer to perform measurements of the antenna-soil reflection coefficients (S11) in the frequency domain. Those measurements are compared to FDTD simulations using the root mean square criterion in order to assess the sand dielectric properties. The use of full-wave FDTD software allows simulation of the whole antenna components, thus all potential influence on the reflection coefficient are recorded. The estimated permittivity with this procedure was close to the real one. In order to test the prototype in real field conditions measurements were performed on a single profile characterized by several agricultural practices (wheat crop, vegetative buffer strip and corn crop). Reflection coefficient (S11) measurements acquired with the prototype are compared to TDR measurements and DC electrical soundings in order to validate the soil apparent dielectric permittivity as well as its apparent electrical conductivity.

  15. Radar principles

    NASA Technical Reports Server (NTRS)

    Sato, Toru

    1989-01-01

    Discussed here is a kind of radar called atmospheric radar, which has as its target clear air echoes from the earth's atmosphere produced by fluctuations of the atmospheric index of refraction. Topics reviewed include the vertical structure of the atmosphere, the radio refractive index and its fluctuations, the radar equation (a relation between transmitted and received power), radar equations for distributed targets and spectral echoes, near field correction, pulsed waveforms, the Doppler principle, and velocity field measurements.

  16. The Solid Rocket Motor Slag Population: Results of a Radar-based Regressive Statistical Evaluation

    NASA Technical Reports Server (NTRS)

    Horstman, Matthew F.; Xu, Yu-Lin

    2008-01-01

    Solid rocket motor (SRM) slag has been identified as a significant source of man-made orbital debris. The propensity of SRMs to generate particles of 100 m and larger has caused concern regarding their contribution to the debris environment. Radar observation, rather than in-situ gathered evidence, is currently the only measurable source for the NASA/ODPO model of the on-orbit slag population. This simulated model includes the time evolution of the resultant orbital populations using a historical database of SRM launches, propellant masses, and estimated locations and times of tail-off. However, due to the small amount of observational evidence, there can be no direct comparison to check the validity of this model. Rather than using the assumed population developed from purely historical and physical assumptions, a regressional approach was used which utilized the populations observed by the Haystack radar from 1996 to present. The estimated trajectories from the historical model of slag sources, and the corresponding plausible detections by the Haystack radar, were identified. Comparisons with observational data from the ensuing years were made, and the SRM model was altered with respect to size and mass production of slag particles to reflect the historical data obtained. The result is a model SRM population that fits within the bounds of the observed environment.

  17. Evaluation of tag entanglement as a factor in harmonic radar studies of insect dispersal.

    PubMed

    Boiteau, G; Vincent, C; Meloche, F; Leskey, T C; Colpitts, B G

    2011-02-01

    The observation of insects and other small organisms entangled in the habitat after the addition of vertical or trailing electronic tags to their body has generated concerns on the suitability of harmonic radars to track the dispersal of insects. This study compared the walking behavior of adult Colorado potato beetle (Leptinotarsa decemlineata (Say) Chrysomelidae), plum curculio (Conotrachelus nenuphar (Herbst) Curculionidae), and western corn rootworm (Diabrotica virgifera virgifera (LeConte) Chrysomelidae) with and without vertical and or trailing tags in field plots or arenas. The frequency of the larger Colorado potato beetles crossing bare ground or grassy plots was unaffected by the presence of an 8 cm trailing harmonic radar tag. However, plum curculios and western corn rootworms, were either unable to walk with a 4 cm trailing tag (plum curculio) or displayed a reduced ability to successfully cross a bare ground arena. Our results revealed the significant impact of vegetation on successful insect dispersal, whether tagged or not. The vertical movement of these insects on stems, stalks, and tubes was also unaffected by the presence of vertical tags. Trailing tags had a significant negative effect on the vertical movement of the western corn rootworm. Results show that harmonic radar technology is a suitable method for studying the walking paths of the three insects with appropriate tag type and size. The nuisance factor generated by appropriately sized tags was small relative to that of vegetation. PMID:22182617

  18. Ada compiler evaluation on the Space Station Freedom Software Support Environment project

    NASA Technical Reports Server (NTRS)

    Badal, D. L.

    1989-01-01

    This paper describes the work in progress to select the Ada compilers for the Space Station Freedom Program (SSFP) Software Support Environment (SSE) project. The purpose of the SSE Ada compiler evaluation team is to establish the criteria, test suites, and benchmarks to be used for evaluating Ada compilers for the mainframes, workstations, and the realtime target for flight- and ground-based computers. The combined efforts and cooperation of the customer, subcontractors, vendors, academia and SIGAda groups made it possible to acquire the necessary background information, benchmarks, test suites, and criteria used.

  19. 47 CFR 80.104 - Identification of radar transmissions not authorized.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Identification of radar transmissions not... Procedures-General § 80.104 Identification of radar transmissions not authorized. This section applies to all maritime radar transmitters except radar beacon stations. (a) Radar transmitters must not transmit...

  20. 47 CFR 80.104 - Identification of radar transmissions not authorized.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Identification of radar transmissions not... Procedures-General § 80.104 Identification of radar transmissions not authorized. This section applies to all maritime radar transmitters except radar beacon stations. (a) Radar transmitters must not transmit...

  1. 47 CFR 80.104 - Identification of radar transmissions not authorized.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Identification of radar transmissions not... Procedures-General § 80.104 Identification of radar transmissions not authorized. This section applies to all maritime radar transmitters except radar beacon stations. (a) Radar transmitters must not transmit...

  2. 47 CFR 80.104 - Identification of radar transmissions not authorized.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Identification of radar transmissions not... Procedures-General § 80.104 Identification of radar transmissions not authorized. This section applies to all maritime radar transmitters except radar beacon stations. (a) Radar transmitters must not transmit...

  3. 47 CFR 80.104 - Identification of radar transmissions not authorized.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Identification of radar transmissions not... Procedures-General § 80.104 Identification of radar transmissions not authorized. This section applies to all maritime radar transmitters except radar beacon stations. (a) Radar transmitters must not transmit...

  4. Evaluation of Algorithms for Calculating Forest Micrometeorological Variables Using an Extensive Dataset of Paired Station Recordings

    NASA Astrophysics Data System (ADS)

    Garvelmann, J.; Pohl, S.; Warscher, M.; Mair, E.; Marke, T.; Strasser, U.; Kunstmann, H.

    2015-12-01

    Forests represent significant areas of subalpine environments and their influence is crucial for the snow cover dynamics on the ground. Since measurements of major micrometeorological variables are usually lacking for forested sites, physically based or empirical parameterizations are usually applied to calculate the beneath-canopy micrometeorological conditions for snow hydrological modeling. Most of these parameterizations have been developed from observations at selected long-term climate stations. Consequently, the high spatial variability of the micrometeorological variables is usually not taken into account. The goal of this study is to evaluate existing approaches using an extensive dataset collected during five winter seasons using a stratified sampling design with pairs of snow monitoring stations (SnoMoS) at open/forested sites in three study areas (Black Forest region of SW Germany, Brixenbach catchment in the Austrian Alps and the Berchtesgadener Ache catchment in the Berchtesgaden Alps of SE Germany). In total, recordings from 110 station pairs were available for analysis. The measurements of air temperature, relative humidity, wind speed and global radiation from the open field sites were used to calculate the adjacent inside forest conditions. Calculation results are compared to the respective beneath-canopy measurements in order to evaluate the applied model algorithms. The results reveal that the algorithms surprisingly well reproduced the inside canopy conditions for wind speed and global radiation. However, air temperature and relative humidity are not well reproduced. Our study comes up with a modification of the two respective parameterizations developed from the paired measurements.

  5. Synthesized multi-station tribo-test system for bio-tribological evaluation in vitro

    NASA Astrophysics Data System (ADS)

    Wu, Tonghai; Du, Ying; Li, Yang; Wang, Shuo; Zhang, Zhinan

    2016-06-01

    Tribological tests play an important role on the evaluation of long-term bio-tribological performances of prosthetic materials for commercial fabrication. Those tests focus on the motion simulation of a real joint in vitro with only normal loads and constant velocities, which are far from the real friction behavior of human joints characterized with variable loads and multiple directions. In order to accurately obtain the bio-tribological performances of artificial joint materials, a tribological tester with a miniature four-station tribological system is proposed with four distinctive features. Firstly, comparability and repeatability of a test are ensured by four equal stations of the tester. Secondly, cross-linked scratch between tribo-pairs of human joints can be simulated by using a gear-rack meshing mechanism to produce composite motions. With this mechanism, the friction tracks can be designed by varying reciprocating and rotating speeds. Thirdly, variable loading system is realized by using a ball-screw mechanism driven by a stepper motor, by which loads under different gaits during walking are simulated. Fourthly, dynamic friction force and normal load can be measured simultaneously. The verifications of the performances of the developed tester show that the variable frictional tracks can produce different wear debris compared with one-directional tracks, and the accuracy of loading and friction force is within ±5%. Thus the high consistency among different stations can be obtained. Practically, the proposed tester system could provide more comprehensive and accurate bio-tribological evaluations for prosthetic materials.

  6. Synthesized multi-station tribo-test system for bio-tribological evaluation in vitro

    NASA Astrophysics Data System (ADS)

    Wu, Tonghai; Du, Ying; Li, Yang; Wang, Shuo; Zhang, Zhinan

    2016-07-01

    Tribological tests play an important role on the evaluation of long-term bio-tribological performances of prosthetic materials for commercial fabrication. Those tests focus on the motion simulation of a real joint in vitro with only normal loads and constant velocities, which are far from the real friction behavior of human joints characterized with variable loads and multiple directions. In order to accurately obtain the bio-tribological performances of artificial joint materials, a tribological tester with a miniature four-station tribological system is proposed with four distinctive features. Firstly, comparability and repeatability of a test are ensured by four equal stations of the tester. Secondly, cross-linked scratch between tribo-pairs of human joints can be simulated by using a gear-rack meshing mechanism to produce composite motions. With this mechanism, the friction tracks can be designed by varying reciprocating and rotating speeds. Thirdly, variable loading system is realized by using a ball-screw mechanism driven by a stepper motor, by which loads under different gaits during walking are simulated. Fourthly, dynamic friction force and normal load can be measured simultaneously. The verifications of the performances of the developed tester show that the variable frictional tracks can produce different wear debris compared with one-directional tracks, and the accuracy of loading and friction force is within ±5%. Thus the high consistency among different stations can be obtained. Practically, the proposed tester system could provide more comprehensive and accurate bio-tribological evaluations for prosthetic materials.

  7. Detail view of southeast corner of Signal Corps Radar (S.C.R.) ...

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

    Detail view of southeast corner of Signal Corps Radar (S.C.R.) 296 Station 5 Transmitter Building foundation, showing Signal Corps Radar (S.C.R.) 296 Station 5 Tower concrete pier in background, camera facing north - Fort Barry, Signal Corps Radar 296, Station 5, Transmitter Building Foundation, Point Bonita, Marin Headlands, Sausalito, Marin County, CA

  8. Performance evaluation of the retrieval of a two hours rainfall event through microwave tomography applied to a network of radio-base stations

    NASA Astrophysics Data System (ADS)

    Facheris, L.; Cuccoli, F.; Baldini, L.

    2012-04-01

    practically continuous-time basis. In the past years, we showed that new scenarios for tomographic rainfall monitoring have been disclosed by the availability of widespread networks of radio-base stations for mobile communications (i.e., GSM, GPRS, UMTS). Such networks could be employed as the backbone of a low cost system able to provide 2D estimates of rainfall in real time. Monitoring capabilities increase in more populated sites, as urban areas, where such radio links form up a dense network that can be exploited to get detailed information also about structure and evolution of rainfall phenomena. In 2010, we presented a novel tomographic processing method for rainfall rate estimation, specifically adaptable to the dense and asymmetric topologies of urban networks of radio-base stations. In this paper, we show its application to a simulated time sequence of specific attenuation (K) maps, derived from true weather radar data gathered during a rainfall event specifically selected to evaluate the performance of the tomographic retrieval in critical conditions. The event was in fact very localized and intense and lasted two hours. 12 GHz is assumed for the carrier frequency of the radio-base network. We show the reconstruction performance of the 2D K fields achieved resorting first to a symmetric, regular network and then to a couple of totally asymmetric ones.

  9. Evaluation of second-order texture parameters for sea ice classification from radar images

    NASA Astrophysics Data System (ADS)

    Shokr, Mohammed E.

    1991-06-01

    With the advent of airborne and spaceborne synthetic aperture radar (SAR) systems, sea ice classification from SAR images has become an important research subject. Since gray tone alone has proven to be of limited capability in differentiating ice types, texture has naturally become an attractive avenue to explore. Accordingly, performance of texture quantification parameters as related to their ability to discriminate ice types has to be examined. SAR image appearance depends on radar parameters involved in the image construction procedures from the doppler history record. Therefore the feasibility of using universal texture/ice type relationships that hold for all combinations of radar parameters also has to be investigated. To that end, imagery data from three different SAR systems were used in this study. Five conventional texture parameters, derived from the gray level co-occurrence matrix (GLCM), were examined. Two of them were modified to ensure their invariant character under linear gray tone transformations. Results indicated that all parameters were highly correlated. The parameters did not, in general, vary with the computational variables used in generating co-occurrence matrices. Ice types can be identified uniquely by the mean value of any texture parameter. The relatively high variability of texture parameters, however, confuses ice discrimination, particularly of smoother ice types. Ice classification was conducted using a per-pixel maximum likelihood supervised scheme. When texture was combined with gray tone, the overall average classification accuracy was improved. Texture was successful in improving the classification accuracy of multiyear ice but was less promising in discriminating first-season ice types. The best two GLCM texture parameters, according to the computed overall average classification accuracies, were the inverse difference moment and the entropy. A brief description of GLCM texture parameters as related to ice's physical

  10. Evaluation of a highway pavement using non destructive tests: Falling Weight Deflectometer and Ground Penetrating Radar

    NASA Astrophysics Data System (ADS)

    Marecos, Vania; Fontul, Simona; de Lurdes Antunes, Maria

    2015-04-01

    This paper presents the results of the application of Falling Weight Deflectometer (FWD) and Ground Penetrating Radar (GPR) to assess the bearing capacity of a rehabilitated flexible highway pavement that began to show the occurrence of cracks in the surface layer, about one year after the improvement works. A visual inspection of the surface of the pavement was performed to identify and characterize the cracks. Several core drills were done to analyse the cracks propagation in depth, these cores were also used for GPR data calibration. From the visual inspection it was concluded that the development of the cracks were top-down and that the cracks were located predominantly in the wheel paths. To determine the thickness of the bituminous and granular layers GPR tests were carried out using two horn antennas of 1,0 GHz and 1,8 GHz and a radar control unit SIR-20, both from GSSI. FWD load tests were performed on the wheel paths and structural models were established, based on the deflections measured, through back calculation. The deformation modulus of the layers was calculated and the bearing capacity of the pavement was determined. Summing up, within this study the GPR was used to continuously detect the layer thickness and the GPR survey data was calibrated with core drills. The results showed variations in the bituminous layer thickness in comparison to project data. From the load tests it was concluded that the deformation modulus of the bituminous layers were also vary variable. Limitations on the pavement bearing capacity were detected in the areas with the lower deformation modulus. This abstract is of interest for COST Action TU1208 Civil Engineering Applications of Ground Penetrating Radar.

  11. Radar-based Flood Warning System for Houston, Texas and Its Performance Evaluation

    NASA Astrophysics Data System (ADS)

    Fang, N.; Bedient, P.

    2009-12-01

    Houston has a long history of flooding problems as a serious nature. For instance, Houstonians suffered from severe flood inundation during Tropical Storm Allison in 2001 and Hurricane Ike in 2008. Radar-based flood warning systems as non-structural tools to provide accurate and timely warnings to the public and private entities are greatly needed for urban areas prone to flash floods. Fortunately, the advent of GIS, radar-based rainfall estimation using NEXRAD, and real-time delivery systems on the internet have allowed flood alert systems to provide important advanced warning of impending flood conditions. Thus, emergency personnel can take proper steps to mitigate against catastrophic losses. The Rice and Texas Medical Center (TMC) Flood Alert System (FAS2) has been delivering warning information with 2 to 3 hours of lead time to facility personnel in a readily understood format for more than 40 events since 1997. The system performed well during these major rainfall events with R square value of 93%. The current system has been improved by incorporating a new hydraulic prediction tool - FloodPlain Map Library (FPML). The FPML module aims to provide visualized information such as floodplain maps and water surface elevations instead of just showing hydrographs in real time based on NEXRAD radar rainfall data. During Hurricane Ike (September, 2008), FAS2 successfully provided precise and timely flood warning information to TMC with the peak flow difference of 3.6% and the volume difference of 5.6%; timing was excellent for this double-peaked event. With the funding from the Texas Department of Transportation, a similar flood warning system has been developed at a critical transportation pass along Highway 288 in Houston, Texas. In order to enable emergency personnel to begin flood preparation with as much lead time as possible, FAS2 is being used as a prototype to develop warning system for other flood-prone areas such as City of Sugar Land.

  12. Application of HF radar currents to oil spill modelling.

    PubMed

    Abascal, Ana J; Castanedo, Sonia; Medina, Raul; Losada, Inigo J; Alvarez-Fanjul, Enrique

    2009-02-01

    In this work, the benefits of high-frequency (HF) radar currents for oil spill modeling and trajectory analysis of floating objects are analyzed. The HF radar performance is evaluated by means of comparison between a drifter buoy trajectory and the one simulated using a Lagrangian trajectory model. A methodology to optimize the transport model performance and to calculate the search area of the predicted positions is proposed. This method is applied to data collected during the Galicia HF Radar Experience. This experiment was carried out to explore the capabilities of this technology for operational monitoring along the Spanish coast. Two long-range HF radar stations were installed and operated between November 2005 and February 2006 on the Galician coast. In addition, a drifter buoy was released inside the coverage area of the radar. The HF radar currents, as well as numerical wind data were used to simulate the buoy trajectory using the TESEO oil spill transport model. In order to evaluate the contribution of HF radar currents to trajectory analysis, two simulation alternatives were carried out. In the first one, wind data were used to simulate the motion of the buoy. In the second alternative, surface currents from the HF radar were also taken into account. For each alternative, the model was calibrated by means of the global optimization algorithm SCEM-UA (Shuffled Complex Evolution Metropolis) in order to obtain the probability density function of the model parameters. The buoy trajectory was computed for 24h intervals using a Monte Carlo approach based on the results provided in the calibration process. A bivariate kernel estimator was applied to determine the 95% confidence areas. The analysis performed showed that simulated trajectories integrating HF radar currents are more accurate than those obtained considering only wind numerical data. After a 24h period, the error in the final simulated position improves using HF radar currents. Averaging the

  13. Using SHARAD radar soundings to evaluate the origin of martian gullies and pingos

    NASA Astrophysics Data System (ADS)

    Nunes, D. C.; Smrekar, S. E.; Safaeinili, A.; Phillips, R. J.; Seu, R.

    2008-12-01

    Gullies are some of the geologically youngest features on Mars (< 10 Myr), and their morphology, defined normally by alcove-channel-aprons, led instantly to the hypothesis of formation by the action of fluid water. Hence, gullies might offer an opportunity to constrain the recent history of water on the planet. Different models propose a variety of mechanisms to produce the liquid, with sources generally falling into either surficial (mantling) deposits or ground water/ice. The SHARAD sounding radar aboard the Mars Reconnaissance Orbiter, with a ~10 m subsurface vertical resolution, may have a strong role to play in testing the water hypothesis for the origin of gullies and in characterizing the source of the fluid. We have surveyed radar data for nearly 50 gullies, which occur predominantly at mid-latitudes on both hemispheres of Mars. In most of these cases, strong subsurface reflectors are not observed. In the few cases where strong subsurface reflections are observed, they possibly relate to volcanic units (e.g. Amazonis and Arcadia Planitiae). Weak, near-surface (< 200 m) reflectors appear to be present at some but not all gullies. We are also examining another type of feature postulated to arise from subsurface water/ice activity: pingos. These are nearly circular mounds hundreds of meters across and tens of meters high that are characterized by fractures or collapsed pits on their crests. On Earth, pressurization at depth leads to injection and subsequent freezing of water into the shallow subsurface. The uplifted layer of permafrost cracks as the mound grows and collapse pits form over time due to ice loss. As in the case of gullies, weak shallow subsurface reflections are present in some of the pingo occurrences. Up to this point, however, our limited survey of gullies and pingos is not supportive of shallow aquifers, as the high dielectric constant of liquid water would produce strong reflections, according to simple propagation models. The weak

  14. The Solid Rocket Motor Slag Population: Results of a Radar-Based Regressive Statistical Evaluation

    NASA Technical Reports Server (NTRS)

    Horstman, Matthew F.; Xu, Yu-Lin

    2008-01-01

    Solid rocket motor (SRM) slag has been identified as a potential source of man-made orbital debris. The possibility that SRMs (in addition to generating dust particles in the sub-millimeter range) may generate particles up to centimeters in size has caused concern regarding their contribution to the debris environment. Returned surfaces from space do not have sufficient area or exposure time to provide a clear picture of the SRM millimeter and centimeter debris population. Currently, radar observation is probably the only way to collect data showing the debris contribution from SRMs. Such observation is used to sample the debris environment, but it is difficult to obtain accurate orbital elements for the detected debris objects. NASA has developed several models to describe the different orbital debris populations, based on assumed debris production mechanisms to create clouds of debris objects that can be propagated in time. The NASA model, LEGEND (LEO-to-GEO Environment Debris), functions as a time-tested debris model for most debris sources. However, the current LEGEND model does not include contributions from the SRM population. An SRM model has recently been developed by NASA, based on purely theoretical details of SRM production and known SRM launches, but verification with hard data is needed. Because the detections of individual SRM objects cannot be deterministically separated from the total debris observed by radar, the validation of the SRM model can only be done by combining it with the LEGEND breakup model and comparing it with data. By applying observational constraints, the degree of SRM slag contribution to the environment may be estimated. This serves as an observationally sound method from which to calibrate a purely theoretical model into something more realistic. For this study, we use the populations observed by the Haystack radar from 1996 to present. For the SRM debris, we use a historical database of SRM launches, propellant masses, and

  15. An evaluation of International Reference Ionosphere electron density in the polar cap and cusp using EISCAT Svalbard radar measurements

    NASA Astrophysics Data System (ADS)

    Merete Bjoland, Lindis; Belyey, Vasyl; Løvhaug, Unni Pia; La Hoz, Cesar

    2016-09-01

    Incoherent scatter radar measurements are an important source for studies of ionospheric plasma parameters. In this paper the EISCAT Svalbard radar (ESR) long-term database is used to evaluate the International Reference Ionosphere (IRI) model. The ESR started operations in 1996, and the accumulated database up to 2012 thus covers 16 years, giving an overview of the ionosphere in the polar cap and cusp during more than one solar cycle. Data from ESR can be used to obtain information about primary plasma parameters: electron density, electron and ion temperature, and line-of-sight plasma velocity from an altitude of about 50 and up to 1600 km. Monthly averages of electron density and temperature and ion temperature and composition are also provided by the IRI model from an altitude of 50 to 2000 km. We have compared electron density data obtained from the ESR with the predicted electron density from the IRI-2016 model. Our results show that the IRI model in general fits the ESR data well around the F2 peak height. However, the model seems to underestimate the electron density at lower altitudes, particularly during winter months. During solar minimum the model is also less accurate at higher altitudes. The purpose of this study is to validate the IRI model at polar latitudes.

  16. Stress Corrosion Evaluation of Various Metallic Materials for the International Space Station Water Recycling System

    NASA Technical Reports Server (NTRS)

    Torres, P. D.

    2015-01-01

    A stress corrosion evaluation was performed on Inconel 625, Hastelloy C276, titanium commercially pure (TiCP), Ti-6Al-4V, Ti-6Al-4V extra low interstitial, and Cronidur 30 steel as a consequence of a change in formulation of the pretreatment for processing the urine in the International Space Station Environmental Control and Life Support System Urine Processing Assembly from a sulfuric acid-based to a phosphoric acid-based solution. The first five listed were found resistant to stress corrosion in the pretreatment and brine. However, some of the Cronidur 30 specimens experienced reduction in load-carrying ability.

  17. Evaluation of genotoxic effects of benzene and its derivatives in workers of gas stations.

    PubMed

    Trevisan, Patrícia; da Silva, Juliane Nascimento; da Silva, Alessandra Pawelec; Rosa, Rafael Fabiano Machado; Paskulin, Giorgio Adriano; Thiesen, Flávia Valladão; de Oliveira, Ceres Andréia Vieira; Zen, Paulo Ricardo Gazzola

    2014-04-01

    The search for reliable biomarkers of human exposure to benzene and its derivatives is still subject of research. Many of the proposed biomarkers have limitations ranging from the low sensitivity to the wide variability of results. Thus, the aim of our study was to assess the frequencies of chromosomal abnormalities (CA) and sister chromatid exchanges (SCE) in workers of gas stations, with (cases, n = 19) and without (local controls, n = 6) risk of exposure to benzene and its derivatives, comparing them with the results from the general population (external controls, n = 38). The blood dosages of benzene, toluene, and xylenes were measured in all participants. Blood solvent levels were compared with the findings obtained in cytogenetic evaluation and a research protocol which included data of the workplace, lifestyle, and health of the individuals. We did not detect the presence of benzene and its derivatives and did not find chromosomal damage that may be associated with the gas station activity in cases. Moreover, although we found an association of increased SCE and the working time in the local controls, the values found for SCE are within normal limits. Thus, our evaluation of SCE and CA reflected the levels of benzene and its derivatives observed in the blood. We believe, therefore, that SCE and CA may actually constitute possible tests for the evaluation of these exposures. However, we believe that further studies, including individuals at risk, are important to confirm this assertion.

  18. Evaluation of auxiliary tempering pump effectiveness at Chalk Point Steam Electric Station

    SciTech Connect

    Wendling, L.C.; Holland, A.F.

    1989-08-01

    The effectiveness of auxiliary tempering pump operation at Chalk Point Steam Electric Station (SES) at reducing plant-induced mortality of aquatic biota was evaluated. Several Representative Important Species (RIS) and dominant benthic and zooplankton species were used in the evaluation as indicators of overall system-wide responses. Expected mortality with and without auxiliary pump operation was estimated using thermal tolerance data available from the scientific literature for blue crabs, white perch, striped bass, spot, Macoma balthica and Acartia tonsa. The evaluation led to the conclusion that the operation of auxiliary tempering pumps at Chalk Point SES increases plant-induced mortality of spot, white perch, striped bass, and zooplankton. Operation of the tempering pumps may reduce blue crab mortality slightly under certain circumstances, and Macoma balthica mortality is probably largely unaffected by their operation.

  19. Evaluating the Global Precipitation Measurement Mission with NOAA/NSSL Multi-Radar Multisensor: Past, Current Status and Future Directions.

    NASA Astrophysics Data System (ADS)

    Kirstetter, P. E.; Hong, Y.; Gourley, J. J.; Carr, N.; Petersen, W. A.; Schwaller, M.; Anagnostou, E. N.; Kummerow, C. D.; Ferraro, R. R.; Wang, N. Y.

    2014-12-01

    Accurate characterization of uncertainties in precipitation estimates derived from space-borne measurements is critical for many applications including water budget studies or prediction of natural hazards caused by extreme rainfall events. GPM precipitation level II estimates are compared to the NEXRAD-based precipitation estimates derived from NOAA/NSSL's Multi-Radar, Multisensor (MRMS) platform. The NEXRAD network has undergone an upgrade in technology with dual-polarization capabilities. These new polarimetric variables are being incorporated in MRMS to improve quality control of reflectivity data and to correct for partial beam blockages. The MRMS products, after having been adjusted by rain gauges and passing several quality controls and filtering procedures, are 1) accurate with known uncertainty bounds and 2) measured at a resolution below the pixel sizes of the GPM radar and radiometer observations. They are used by a number of NASA investigators to evaluate level II and level III satellite rainfall algorithms. The at-launch GPM Radiometer algorithm uses matches of coincident overpasses of various radiometers with surface rainfall from the MRMS database developed for the GPM project. Statistics from TRMM level II products serve as a benchmark to evaluate GPM precipitation estimates. Comparisons have been carried out at fine scale (e.g. instantaneous and 5 km for DPR) within a comparison framework developed to examine the consistency of the ground and space-based sensors in term of precipitation detection, characterization (e.g. convective, stratiform) and quantification. Specific error factors for passive (e.g. surface conditions for GMI) and active (e.g. attenuation of the radar signal, non uniform beam filling for DPR) sensors are investigated. Systematic biases and random errors quantified at the satellite estimation scale are useful for satellite-based Level III precipitation products. An online validation tool was designed to provide, for the first

  20. Weather Radar

    NASA Astrophysics Data System (ADS)

    Vivekanandan, Jothiram

    2004-10-01

    Weather radar is an indispensable component for remote sensing of the atmosphere, and the data and products derived from weather radar are routinely used in climate and weather-related studies to examine trends, structure, and evolution. The need for weather remote sensing is driven by the necessity to understand and explain a specific atmospheric science phenomenon. The importance of remote sensing is especially evident in high-profile observational programs, such as the WSR-88D (Weather Surveillance Radar) network, TRMM (Tropical Rainfall Measuring Mission), and ARM (Atmospheric Radiation Measurement). A suite of ground-based and airborne radar instruments is maintained and deployed for observing wind, clouds, and precipitation. Weather radar observation has become an integral component of weather forecasting and hydrology and climate studies. The inclusion of weather radar observations in numerical weather modeling has enhanced severe storm forecasting, aviation weather, hurricane intensity and movement, and the global water cycle.

  1. Evaluation of the biological effects of police radar RAMER 7F

    SciTech Connect

    Rotkovska, D.; Kautska, J.; Bartonickova, A.; Keprtova, J.; Hofer, M. ); Moc, J. )

    1993-06-01

    This paper presents results of experiments on the effects of electromagnetic radiation in the millimeter range (frequency 34.0 [+-] 0.1 GHz, power density 20 [mu]W/cm[sup 2]) emitted by a police radar device. Considering the physical properties of the radiation in millimeter range (skin effects), the experiments were carried out on hairless mice. The main physiological parameters tested were body mass, body temperature, peripheral blood, and mass and cellularity of several important organs. Critical organs, the skin, and cornea were examined by electron microscopy. Differentiation ability of hematopoietic cells, progenitors of granulocytes and macrophages, and DNA synthesis in the cornea were compared in irradiated and nonirradiated animals. None of the parameters tested was affected to an extent that would indicate the start of a pathological process or the risk of damage to genetic material.

  2. Preliminary geologic evaluation of L-band radar imagery: Arkansas test site

    NASA Technical Reports Server (NTRS)

    Macdonald, H.; Waite, W. P.

    1977-01-01

    The relatively small angles of incidence (steep depression angles) of the L-band system provide minimal shadowing on terrain back-slopes and considerable foreshortening on terrain fore-slopes which sacrifice much of the topographic enhancement afforded by a more oblique angle of illumination. In addition, the dynamic range of the return from vegetated surfaces is substantially less for the L-band system, and many surface features defined primarily by subtle changes in vegetation are lost. In areas having terrain conditions similar to those of northern Arkansas, and where LANDSAT and shorter wavelength aircraft radar data are available, the value of the JPL L-band imagery as either a complimentary or supplementary geologic data source is not obvious.

  3. Evaluation of environmental levels of aromatic hydrocarbons in gasoline service stations by gas chromatography.

    PubMed

    Periago, J F; Zambudio, A; Prado, C

    1997-08-22

    The volume of gasoline sold in refuelling operations and the ambient temperature, can increase significantly the environmental levels of aromatic hydrocarbon vapours and subsequently, the occupational risk of gasoline service station attendants, specially in the case of benzene. We have evaluated the occupational exposure to aromatic hydrocarbons by means of personal-breathing-zone samples of gasoline vapours in a service station attendant population. This evaluation was carried out using diffusive samplers, in two periods at quite different temperatures (March and July). A significant relationship between the volume of gasoline sold during the shift and the ambient concentration of benzene, toluene, and xylenes was found for each worker sampled. Furthermore a significant difference was found between the time-weighted average concentration of aromatic compounds measured in March, with ambient temperatures of 14-15 degrees C and July, with temperatures of 28-30 degrees C. In addition, 20% of the population sampled in the last period were exposed to a time-weighted average concentration of benzene above the proposed Threshold Limit Value of 960 micrograms/m(3) of the American Conference of Governmental Industrial Hygienists (ACGIH).

  4. The Evaluation of Methicillin Resistance in Staphylococcus aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    Ott, C. M.; Bassinger, V. J.; Fontenot, S. L.; Castro, V. A.; Pierson, D. L.

    2005-01-01

    The International Space Station (ISS) represents a semi-closed environment with a high level of crewmember interaction. As community-acquired methicillin-resistant Staphylococcus aureus (MRSA) has emerged as a health concern in environments with susceptible hosts in close proximity, an evaluation of isolates of clinical and environmental Staphylococcus aureus and coagulase negative Staphylococcus was performed to determine if this trend was also present in astronauts aboard ISS or the space station itself. Rep-PCR fingerprinting analysis of archived ISS isolates confirmed our earlier studies indicating a transfer of S. aureus between crewmembers. In addition, this fingerprinting also indicated a transfer between crewmembers and their environment. While a variety of S. aureus were identified from both the crewmembers and the environment, phenotypic evaluations indicated minimal methicillin resistance. However, positive results for the Penicillin Binding Protein, indicative of the presence of the mecA gene, were detected in multiple isolates of archived Staphylococcus epidermidis and Staphylococcus haemolyticus. Phenotypic analysis of these isolates confirmed their resistance to methicillin. While MRSA has not been isolated aboard ISS, the potential exists for the transfer of the gene, mecA, from coagulase negative environmental Staphylococcus to S. aureus creating MRSA strains. This study suggests the need to expand environmental monitoring aboard long duration exploration spacecraft to include antibiotic resistance profiling.

  5. Evaluation of environmental levels of aromatic hydrocarbons in gasoline service stations by gas chromatography.

    PubMed

    Periago, J F; Zambudio, A; Prado, C

    1997-08-22

    The volume of gasoline sold in refuelling operations and the ambient temperature, can increase significantly the environmental levels of aromatic hydrocarbon vapours and subsequently, the occupational risk of gasoline service station attendants, specially in the case of benzene. We have evaluated the occupational exposure to aromatic hydrocarbons by means of personal-breathing-zone samples of gasoline vapours in a service station attendant population. This evaluation was carried out using diffusive samplers, in two periods at quite different temperatures (March and July). A significant relationship between the volume of gasoline sold during the shift and the ambient concentration of benzene, toluene, and xylenes was found for each worker sampled. Furthermore a significant difference was found between the time-weighted average concentration of aromatic compounds measured in March, with ambient temperatures of 14-15 degrees C and July, with temperatures of 28-30 degrees C. In addition, 20% of the population sampled in the last period were exposed to a time-weighted average concentration of benzene above the proposed Threshold Limit Value of 960 micrograms/m(3) of the American Conference of Governmental Industrial Hygienists (ACGIH). PMID:9299740

  6. An intercomparison of radar-based liquid cloud microphysics retrievals and implications for model evaluation studies

    NASA Astrophysics Data System (ADS)

    Huang, D.; Zhao, C.; Dunn, M.; Dong, X.; Mace, G. G.; Jensen, M. P.; Xie, S.; Liu, Y.

    2012-06-01

    This paper presents a statistical comparison of three cloud retrieval products of the Atmospheric Radiation Measurement (ARM) program at the Southern Great Plains (SGP) site from 1998 to 2006: MICROBASE, University of Utah (UU), and University of North Dakota (UND) products. The probability density functions of the various cloud liquid water content (LWC) retrievals appear to be consistent with each other. While the mean MICROBASE and UU cloud LWC retrievals agree well in the middle of cloud, the discrepancy increases to about 0.03 gm-3 at cloud top and cloud base. Alarmingly large differences are found in the droplet effective radius (re) retrievals. The mean MICROBASE re is more than 6 μm lower than the UU re, whereas the discrepancy is reduced to within 1 μm if columns containing raining and/or mixed-phase layers are excluded from the comparison. A suite of stratified comparisons and retrieval experiments reveal that the LWC difference stems primarily from rain contamination, partitioning of total liquid later path (LWP) into warm and supercooled liquid, and the input cloud mask and LWP. The large discrepancy among the re retrievals is mainly due to rain contamination and the presence of mixed-phase layers. Since rain or ice particles are likely to dominate radar backscattering over cloud droplets, the large discrepancy found in this paper can be thought of as a physical limitation of single-frequency radar approaches. It is therefore suggested that data users should use the retrievals with caution when rain and/or mixed-phase layers are present in the column.

  7. 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.

  8. Evaluation of polarimetric parameters from a new dual-polarization C-band weather radar in an alpine region

    NASA Astrophysics Data System (ADS)

    Paulitsch, H.; Teschl, F.; Teschl, R.

    2009-04-01

    The first weather radar with dual polarization capabilities was recently installed in Austria. In contrast to conventional weather radars, where the reflectivity is measured in one polarization plane only, a dual polarization radar provides transmission in either horizontal, vertical, or both polarizations while receiving both the horizontal and vertical channels simultaneously. The back-scatter from precipitation particles is different for horizontal and vertical polarization, because these particles are usually far from being spherical. Information on size, shape, and material density of precipitation particles is obtained by comparing the reflected horizontal and vertical power returns and their ratio and correlation. The use of polarimetric radar variables can therefore increase the accuracy of the rain rate estimation compared to standard Z-R relationship of non-polarimetric radars. For the new weather radar different polarimetric rain rate estimators, which are based on the horizontal polarization radar reflectivity, Zh, the differential reflectivity, Zdr, and the specific differential phase shift, Kdp, are used. The rain rate estimators are further combined with an attenuation correction schema. In this study several radar observations of rainfall events are used to test the rain rate estimators and the attenuation correction. The results of the different algorithm are presented and a comparison with rain gauge measurements is made. Also the operational quality of the radar parameters is discussed and the implication of radar measurement errors on the accuracy of polarimetric rain rate estimations is shown.

  9. Evaluation of prototype air/fluid separator for Space Station Freedom Health Maintenance Facility

    NASA Technical Reports Server (NTRS)

    Billica, Roger; Smith, Maureen; Murphy, Linda; Kizzee, Victor D.

    1991-01-01

    A prototype air/fluid separator suction apparatus proposed as a possible design for use with the Health Maintenance Facility aboard Space Station Freedom (SSF) was evaluated. A KC-135 parabolic flight test was performed for this purpose. The flights followed the standard 40 parabola profile with 20 to 25 seconds of near-zero gravity in each parabola. A protocol was prepared to evaluate the prototype device in several regulator modes (or suction force), using three fluids of varying viscosity, and using either continuous or intermittent suction. It was felt that a matrixed approach would best approximate the range of utilization anticipated for medical suction on SSF. The protocols were performed in one-gravity in a lab setting to familiarize the team with procedures and techniques. Identical steps were performed aboard the KC-135 during parabolic flight.

  10. Evaluating the Global Precipitation Measurement mission with NOAA/NSSL Multi-Radar Multisensor: current status and future directions.

    NASA Astrophysics Data System (ADS)

    Kirstetter, P. E.; Hong, Y.; Gourley, J. J.; Carr, N.; Petersen, W. A.; Schwaller, M.; Anagnostou, E. N.; Kummerow, C. D.; Ferraro, R. R.; Wang, N. Y.; Tanelli, S.; Turk, J.; Huffman, G. J.

    2015-12-01

    Accurate characterization of uncertainties in precipitation estimates derived from space-borne measurements is critical for many applications including water budget studies or prediction of natural hazards caused by extreme rainfall events. The GPM precipitation Level II (active and passive) and Level III (IMERG) estimates are compared to the NEXRAD-based precipitation estimates derived from NOAA/NSSL's Multi-Radar, Multi-Sensor (MRMS) platform. The NEXRAD network has undergone an upgrade in technology with dual-polarization capabilities and the MRMS products, after having been adjusted by rain gauges and passing several quality controls and filtering procedures, are 1) accurate with known uncertainty bounds and 2) measured at a resolution below the pixel sizes any GPM estimates. They are used by a number of NASA investigators to evaluate Level II and Level III satellite precipitation algorithms. A comparison framework was developed to examine the consistency of the ground and space-based sensors in term of precipitation detection, typology (e.g. convective, stratiform) and quantification. At the Level II precipitation features are introduced to analyze satellite estimates under various precipitation processes. Specific factors for passive (e.g. surface conditions for GMI) and active (e.g. attenuation of the radar signal, non uniform beam filling for DPR) sensors are investigated. Prognostic analysis directly provides feedback to algorithm developers on how to improve the satellite estimates. Comparison with TRMM products serves as a benchmark to evaluate GPM precipitation estimates. A the Level III the contribution of Level II is explicitly characterized and a rigorous characterization is performed to migrate across scales fully understanding the propagation of errors. This cross products characterization acts as a bridge to intercalibrate microwave measurements from the GPM constellation satellites and propagate to the combined and global precipitation estimates

  11. Summary of Turbulence Data Obtained During United Air Lines Flight Evaluation of an Experimental C Band (5.5 cm) Airborne Weather Radar

    NASA Technical Reports Server (NTRS)

    Coe, E. C.; Fetner, M. W.

    1954-01-01

    Data on atmospheric turbulence in the vicinity of thunderstorms obtained during a flight evaluation of an experimental C band (5.5 cm) airborne radar are summarized. The turbulence data were obtained with an NACA VGH recorder installed in a United Air Lines DC-3 airplane.

  12. Evaluation of SIR-A space radar for geologic interpretation: United States, Panama, Colombia, and New Guinea

    NASA Technical Reports Server (NTRS)

    Macdonald, H.; Waite, W. P.; Kaupp, V. H.; Bridges, L. C.; Storm, M.

    1983-01-01

    Comparisons between LANDSAT MSS imagery, and aircraft and space radar imagery from different geologic environments in the United States, Panama, Colombia, and New Guinea demonstrate the interdependence of radar system geometry and terrain configuration for optimum retrieval of geologic information. Illustrations suggest that in the case of space radars (SIR-A in particular), the ability to acquire multiple look-angle/look-direction radar images of a given area is more valuable for landform mapping than further improvements in spatial resolution. Radar look-angle is concluded to be one of the most important system parameters of a space radar designed to be used for geologic reconnaissance mapping. The optimum set of system parameters must be determined for imaging different classes of landform features and tailoring the look-angle to local topography.

  13. [Comparative evaluation of the circulatory reaction during work in weightlessness and in the mockup of the Saliut station].

    PubMed

    Doroshev, V G; Lapshina, N A; Kirillova, Z A; Kulikov, O B; Kaliberdin, A V

    1982-01-01

    Comparative evaluations of circulation responses of 22 operators and 13 cosmonauts to simulated and real flights onboard Salyut station revealed significant differences. By the end of flight cardiovascular responses of the operators showed signs of their increased conditioning, whereas the cosmonauts exhibited symptoms of circulation tension, which were particularly expressed during the first week and by the end of flight. Operators' activities in an orbital station mockup cannot be considered an adequate model for cardiovascular studies.

  14. Evaluation of available analytical techniques for monitoring the quality of space station potable water

    NASA Technical Reports Server (NTRS)

    Geer, Richard D.

    1989-01-01

    To assure the quality of potable water (PW) on the Space Station (SS) a number of chemical and physical tests must be conducted routinely. After reviewing the requirements for potable water, both direct and indirect analytical methods are evaluated that could make the required tests and improvements compatible with the Space Station operation. A variety of suggestions are made to improve the analytical techniques for SS operation. The most important recommendations are: (1) the silver/silver chloride electrode (SB) method of removing I sub 2/I (-) biocide from the water, since it may interfere with analytical procedures for PW and also its end uses; (2) the orbital reactor (OR) method of carrying out chemistry and electrochemistry in microgravity by using a disk shaped reactor on an orbital table to impart artificial G force to the contents, allowing solution mixing and separation of gases and liquids; and (3) a simple ultra low volume highly sensitive electrochemical/conductivity detector for use with a capillary zone electrophoresis apparatus. It is also recommended, since several different conductivity and resistance measurements are made during the analysis of PW, that the bipolar pulse measuring circuit be used in all these applications for maximum compatibility and redundancy of equipment.

  15. Spaceborne radar

    NASA Technical Reports Server (NTRS)

    Moore, R. K.; Eckerman, J.; Meneghini, R.; Atlas, D.; Boerner, W. M.; Cherry, S.; Clark, J. F.; Doviak, R. J.; Goldhirsh, J.; Lhermitte, R. M.

    1981-01-01

    The spaceborne radar panel considered how radar could be used to measure precipitation from satellites. The emphasis was on how radar could be used with radiometry (at microwave, visible (VIS), and infrared (IR) wavelengths) to reduce the uncertainties of measuring precipitation with radiometry alone. In addition, the fundamental electromagnetic interactions involved in the measurements were discussed to determine the key work areas for research and development to produce effective instruments. Various approaches to implementing radar systems on satellites were considered for both shared and dedicated instruments. Finally, a research and development strategy was proposed for establishing the parametric relations and retrieval algorithms required for extracting precipitation information from the radar and associated radiometric data.

  16. MER vistas: ground-truth for Earth-based radar

    NASA Technical Reports Server (NTRS)

    Haldemann, Albert F.; Larsen, Kristopher W.; Jurgens, Raymond F.; Golombek, Matthew P.; Slade, Martin A.

    2004-01-01

    Earth-based delay-Doppler radar observations of Mars with four receiving stations were carried out during the Mars oppositions of 2001 and 2003 in support of Mars Exploration Rover landing site selection. This interferometric planetary radar technique has demonstrated radar mapping of Mars with a 5 km spatial resolution.

  17. Evaluation of the soil moisture prediction accuracy of a space radar using simulation techniques. [Kansas

    NASA Technical Reports Server (NTRS)

    Ulaby, F. T. (Principal Investigator); Dobson, M. C.; Stiles, J. A.; Moore, R. K.; Holtzman, J. C.

    1981-01-01

    Image simulation techniques were employed to generate synthetic aperture radar images of a 17.7 km x 19.3 km test site located east of Lawrence, Kansas. The simulations were performed for a space SAR at an orbital altitude of 600 km, with the following sensor parameters: frequency = 4.75 GHz, polarization = HH, and angle of incidence range = 7 deg to 22 deg from nadir. Three sets of images were produced corresponding to three different spatial resolutions; 20 m x 20 m with 12 looks, 100 m x 100 m with 23 looks, and 1 km x 1 km with 1000 looks. Each set consisted of images for four different soil moisture distributions across the test site. Results indicate that, for the agricultural portion of the test site, the soil moisture in about 90% of the pixels can be predicted with an accuracy of = + or - 20% of field capacity. Among the three spatial resolutions, the 1 km x 1 km resolution gave the best results for most cases, however, for very dry soil conditions, the 100 m x 100 m resolution was slightly superior.

  18. Performance evaluation of integer to integer wavelet transform for synthetic aperture radar image compression

    NASA Astrophysics Data System (ADS)

    Xue, Wentong; Song, Jianshe; Yuan, Lihai; Shen, Tao

    2005-11-01

    An efficient and novel imagery compression system for Synthetic Aperture Radar (SAR) which uses integer to integer wavelet transform and Modified Set Partitioning Embedded Block Coder (M-SPECK) has been presented in this paper. The presence of speckle noise, detailed texture, high dynamic range in SAR images, and even its vast data volume show the great differences of SAR imagery. Integer to integer wavelet transform is invertible in finite precision arithmetic, it maps integers to integers, and approximates linear wavelet transforms from which they are derived. Considering in terms of computational load, compression ratio and subjective visual quality metrics, several filter banks are compared together and some factors affecting the compression performance of the integer to integer wavelet transform are discussed in details. Then the optimal filter banks which are more appropriate for the SAR images compression are given. Information of high frequency has relatively larger proportion in SAR images compared with those of nature images. Measures to modify the quantizing thresholds in traditional SPECK are taken, which could be suitable to the contents of SAR imagery for the purpose of compression. Both the integer to integer wavelet transform and modified SPECK have the desirable feature of low computational complexity. Experimental results show its superiority over the traditional approaches in the condition of tradeoffs between compression efficiency and computational complexity.

  19. Satellite-Based Investigation and Evaluation of the Observational Environment of Meteorological Stations in Anhui Province, China

    NASA Astrophysics Data System (ADS)

    Li, Yu-Bin; Shi, Tao; Yang, Yuan-Jian; Wu, Bi-Wen; Wang, La-Bao; Shi, Chun-E.; Guo, Jian-Xia; Ji, Cheng-Li; Wen, Hua-Yang

    2015-06-01

    In this paper, by using multi-temporal and high resolution Landsat data and geographic information system techniques, the land use/land cover (LULC) in the 2-km buffer zone of 52 meteorological stations in the Anhui province of China is retrieved and categorized into three types: vegetation (including farmland, forest and grass land), water (including lakes, rivers and pools), and construction (including buildings and roads). Besides, the land surface temperature (LST) in the buffer zone of these stations is also obtained from thermal infrared data. The normalized LST index (NLI) and the heat effect contribution index (HECI) of different LULC types are calculated. Via case studies and statistical analysis, the LULC and thermal environment's temporal-spatial variance in the 2-km buffer zone of these stations are surveyed, and their impacts on the observational environment are investigated. The study shows that the observational environments of the meteorological stations in Anhui province have been greatly influenced by rapid urbanization. The study proposes two new methods to classify the stations' observational environment into three types (urban, sub-urban, and rural). One uses the NLI and the other uses the HECI. The NLI method needs only LST information. The HECI method combines both LULC and LST information and, hence, is considered more reliable. The evaluation methods and criteria can be used conveniently, effectively, and quantitatively, and are especially useful when analyzing observational data from meteorological stations in weather and climate research and when choosing a location for a new meteorological station.

  20. Test and evaluation of the heat recovery incinerator system at Naval Station, Mayport, Florida

    NASA Astrophysics Data System (ADS)

    1981-05-01

    This report describes test and evaluation of the two-ton/hr heat recovery incinerator (HRI) facility located at Mayport Naval Station, Fla., carried out during November and December 1980. The tests included: (1) Solid Waste: characterization, heating value, and ultimate analysis, (2) Ash: moisture, combustibles, and heating values of both bottom and cyclone ashes; Extraction Procedure toxicity tests on leachates from both bottom and cyclone ashes; trace metals in cyclone particulates, (3) Stack Emissions: particulates (quantity and size distribution), chlorides, oxygen, carbon dioxide, carbon monoxide, and trace elements, and (4) Heat and Mass Balance: all measurements required to carry out complete heat and mass balance calculations over the test period. The overall thermal efficiency of the HRI facility while operating at approximately 1.0 ton/hr was found to be 49% when the primary Btu equivalent of the electrical energy consumed during the test program was included.

  1. Evaluation of a voice recognition system for the MOTAS pseudo pilot station function

    NASA Technical Reports Server (NTRS)

    Houck, J. A.

    1982-01-01

    The Langley Research Center has undertaken a technology development activity to provide a capability, the mission oriented terminal area simulation (MOTAS), wherein terminal area and aircraft systems studies can be performed. An experiment was conducted to evaluate state-of-the-art voice recognition technology and specifically, the Threshold 600 voice recognition system to serve as an aircraft control input device for the MOTAS pseudo pilot station function. The results of the experiment using ten subjects showed a recognition error of 3.67 percent for a 48-word vocabulary tested against a programmed vocabulary of 103 words. After the ten subjects retrained the Threshold 600 system for the words which were misrecognized or rejected, the recognition error decreased to 1.96 percent. The rejection rates for both cases were less than 0.70 percent. Based on the results of the experiment, voice recognition technology and specifically the Threshold 600 voice recognition system were chosen to fulfill this MOTAS function.

  2. Design and evaluation of FDDI fiber optics networkfor Ethernets, VAX's and Ingraph work stations

    NASA Technical Reports Server (NTRS)

    Wernicki, M. Chris

    1992-01-01

    The purpose of this project is to design and evaluate the FDDI Fiber Optics Network for Ethernets, VAX's, and Ingraph work stations. From the KSC Headquarters communication requirement, it would be necessary to develop the FDDI network based on IEEE Standards outlined in the ANSI X3T9.5, Standard 802.3 and 802.5 topology - direct link via intermediate concentrator and bridge/router access. This analysis should examine the major factors that influence the operating conditions of the Headquarters Fiber plant. These factors would include, but are not limited to the interconnecting devices such as repeaters, bridges, routers and many other relevant or significant FDDI characteristics. This analysis is needed to gain a better understanding of overall FDDI performance.

  3. Evaluation of speech recognizers for use in advanced combat helicopter crew station research and development

    NASA Technical Reports Server (NTRS)

    Simpson, Carol A.

    1990-01-01

    The U.S. Army Crew Station Research and Development Facility uses vintage 1984 speech recognizers. An evaluation was performed of newer off-the-shelf speech recognition devices to determine whether newer technology performance and capabilities are substantially better than that of the Army's current speech recognizers. The Phonetic Discrimination (PD-100) Test was used to compare recognizer performance in two ambient noise conditions: quiet office and helicopter noise. Test tokens were spoken by males and females and in isolated-word and connected-work mode. Better overall recognition accuracy was obtained from the newer recognizers. Recognizer capabilities needed to support the development of human factors design requirements for speech command systems in advanced combat helicopters are listed.

  4. Evaluation of Radar Vegetation Indices for Vegetation Water Content Estimation Using Data from a Ground-Based SMAP Simulator

    NASA Technical Reports Server (NTRS)

    Srivastava, Prashant K.; O'Neill, Peggy; Cosh, Michael; Lang, Roger; Joseph, Alicia

    2015-01-01

    Vegetation water content (VWC) is an important component of microwave soil moisture retrieval algorithms. This paper aims to estimate VWC using L band active and passive radar/radiometer datasets obtained from a NASA ground-based Soil Moisture Active Passive (SMAP) simulator known as ComRAD (Combined Radar/Radiometer). Several approaches to derive vegetation information from radar and radiometer data such as HH, HV, VV, Microwave Polarization Difference Index (MPDI), HH/VV ratio, HV/(HH+VV), HV/(HH+HV+VV) and Radar Vegetation Index (RVI) are tested for VWC estimation through a generalized linear model (GLM). The overall analysis indicates that HV radar backscattering could be used for VWC content estimation with highest performance followed by HH, VV, MPDI, RVI, and other ratios.

  5. Performance evaluation of high-resolution rainfall estimation by X-band dual-polarization radar for flash flood applications in mountainous basins

    NASA Astrophysics Data System (ADS)

    Anagnostou, Marios N.; Kalogiros, John; Anagnostou, Emmanouil N.; Tarolli, Michele; Papadopoulos, Anastasios; Borga, Marco

    2010-11-01

    SummaryDifferent relations between surface rainfall rate, R, and high-resolution polarimetric X-band radar observations were evaluated using a dense network of rain gauge measurements over complex terrain in Central Italian Alps. The specific differential phase shift, KDP, rainfall algorithm (RKDP) although associated with low systematic error it exhibits low sensitivity to the spatial variability of rainfall as compared to the standard algorithm (RSTD) that is based on the reflectivity-to-rainfall (Z-R) relationship. On the other hand, the dependence of the reflectivity measurement on the absolute radar calibration and the rain-path radar signal attenuation introduces significant systematic error on the RSTD rainfall estimates. The study shows that adjusting the Z-R relationship for mean-field bias determined using the RKDP estimates as reference is the best technique for acquiring unbiased radar-rainfall estimates at fine space-time scales. Overall, the bias of the RKDP-adjusted Z-R estimator is shown to be lower than 10% for both storm cases, while the relative root-mean-square error is shown to range from 0.6 (convective storm) to 0.9 (stratiform storm). A vertical rainfall profile correction (VPR) technique is tested in this study for the stratiform storm case. The method is based on a newly developed VPR algorithm that uses the X-band polarimetric information to identify the properties of the melting layer and devices a precipitation profile that varies for each radar volume scan to correct the radar-rainfall estimates. Overall, when accounting for the VPR effect there is up to 70% reduction in the systematic error of the 3° elevation estimates, while the reduction in terms of relative root-mean-square error is limited to within 10%.

  6. Evaluating space station applications of automation and robotics technologies from a human productivity point of view

    NASA Technical Reports Server (NTRS)

    Bard, J. F.

    1986-01-01

    The role that automation, robotics, and artificial intelligence will play in Space Station operations is now beginning to take shape. Although there is only limited data on the precise nature of the payoffs that these technologies are likely to afford there is a general consensus that, at a minimum, the following benefits will be realized: increased responsiveness to innovation, lower operating costs, and reduction of exposure to hazards. Nevertheless, the question arises as to how much automation can be justified with the technical and economic constraints of the program? The purpose of this paper is to present a methodology which can be used to evaluate and rank different approaches to automating the functions and tasks planned for the Space Station. Special attention is given to the impact of advanced automation on human productivity. The methodology employed is based on the Analytic Hierarchy Process. This permits the introduction of individual judgements to resolve the confict that normally arises when incomparable criteria underly the selection process. Because of the large number of factors involved in the model, the overall problem is decomposed into four subproblems individually focusing on human productivity, economics, design, and operations, respectively. The results from each are then combined to yield the final rankings. To demonstrate the methodology, an example is developed based on the selection of an on-orbit assembly system. Five alternatives for performing this task are identified, ranging from an astronaut working in space, to a dexterous manipulator with sensory feedback. Computational results are presented along with their implications. A final parametric analysis shows that the outcome is locally insensitive to all but complete reversals in preference.

  7. Evaluate the Application of TPH test kits to Identify the Potential Contaminants in Gas Stations

    NASA Astrophysics Data System (ADS)

    Liao, P. Y.; Liu, C. W.; Liu, W. Y.

    2012-04-01

    This study is focusing on the utility and applicability of the portable equipments such as, photo ionization detector (PID) and flame ionization detector (FID) for the determination of contaminants during the investigation of various gas stations. According to the onsite screening results, high contaminated soil samples were sent to analytical laboratory for the detection and quantification of the contaminants present therein. However, due to limitations, PID and FID cannot detect the low vapor pressure components. Hence, they cannot reflect the real situation of the contaminated soil samples and areas. This study summarizes the analytical results of total 37 soil samples, collecting from 17 gas stations. Soil samples were not only analyzed according to the standard method of Taiwan EPA in the laboratory, but also tested using the Total Petroleum Hydrocarbon (TPH) test kits, following the USEPA method 9074, to evaluate the TPH concentration in soil samples. With test kits, onsite, first the TPH was extracted from the soil samples using methanol and then mixed with emulsifier to produce turbidity, and finally then measured using the turbidity meter. The TPH test kits method is simple and rapid, and not time consuming like the laboratory method. A positive relationship has been observed (co-efficient of determination, R2 = 0.74) comparing between the results obtained from the laboratory test and kits test methods, especially for the high carbon content oil such as, diesel, but it does not show the obvious relationship with gasoline. Number of advantages has been considered in using the TPH test kits including, easily portable, simple and rapid testing, cost-effective, and onsite quantification. The technique can be applied for high carbon content oil contamination sites during soil sampling, to realize the actual situations and the promoting confirmation efficiency.

  8. Report by the International Space Station (ISS) Management and Cost Evaluation (IMCE) Task Force

    NASA Technical Reports Server (NTRS)

    Young, A. Thomas; Kellogg, Yvonne (Technical Monitor)

    2001-01-01

    The International Space Station (ISS) Management and Cost Evaluation Task Force (IMCE) was chartered to conduct an independent external review and assessment of the ISS cost, budget, and management. In addition, the Task Force was asked to provide recommendations that could provide maximum benefit to the U.S. taxpayers and the International Partners within the President's budget request. The Task Force has made the following principal findings: (1) The ISS Program's technical achievements to date, as represented by on-orbit capability, are extraordinary; (2) The Existing ISS Program Plan for executing the FY 02-06 budget is not credible; (3) The existing deficiencies in management structure, institutional culture, cost estimating, and program control must be acknowledged and corrected for the Program to move forward in a credible fashion; (4) Additional budget flexibility, from within the Office of Space Flight (OSF) must be provided for a credible core complete program; (5) The research support program is proceeding assuming the budget that was in place before the FY02 budget runout reduction of $1B; (6) There are opportunities to maximize research on the core station program with modest cost impact; (7) The U.S. Core Complete configuration (three person crew) as an end-state will not achieve the unique research potential of the ISS; (8) The cost estimates for the U.S.-funded enhancement options (e.g., permanent seven person crew) are not sufficiently developed to assess credibility. After these findings, the Task Force has formulated several primary recommendations which are published here and include: (1) Major changes must be made in how the ISS program is managed; (2) Additional cost reductions are required within the baseline program; (3) Additional funds must be identified and applied from the Human Space Flight budget; (4) A clearly defined program with a credible end-state, agreed to by all stakeholders, must be developed and implemented.

  9. Performance Evaluation of the Operational Air Quality Monitor for Water Testing Aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    Wallace, William T.; Limero, Thomas F.; Gazda, Daniel B.; Macatangay, Ariel V.; Dwivedi, Prabha; Fernandez, Facundo M.

    2014-01-01

    In the history of manned spaceflight, environmental monitoring has relied heavily on archival sampling. For short missions, this type of sample collection was sufficient; returned samples provided a snapshot of the presence of chemical and biological contaminants in the spacecraft air and water. However, with the construction of the International Space Station (ISS) and the subsequent extension of mission durations, soon to be up to one year, the need for enhanced, real-time environmental monitoring became more pressing. The past several years have seen the implementation of several real-time monitors aboard the ISS, complemented with reduced archival sampling. The station air is currently monitored for volatile organic compounds (VOCs) using gas chromatography-differential mobility spectrometry (Air Quality Monitor [AQM]). The water on ISS is analyzed to measure total organic carbon and biocide concentrations using the Total Organic Carbon Analyzer (TOCA) and the Colorimetric Water Quality Monitoring Kit (CWQMK), respectively. The current air and water monitors provide important data, but the number and size of the different instruments makes them impractical for future exploration missions. It is apparent that there is still a need for improvements in environmental monitoring capabilities. One such improvement could be realized by modifying a single instrument to analyze both air and water. As the AQM currently provides quantitative, compound-specific information for target compounds present in air samples, and many of the compounds are also targets for water quality monitoring, this instrument provides a logical starting point to evaluate the feasibility of this approach. In this presentation, we will discuss our recent studies aimed at determining an appropriate method for introducing VOCs from water samples into the gas phase and our current work, in which an electro-thermal vaporization unit has been interfaced with the AQM to analyze target analytes at the

  10. New weather radar coming

    NASA Astrophysics Data System (ADS)

    Maggs, William Ward

    What would you call the next generation of radar for severe weather prediction? NEXRAD, of course. A prototype for the new system was recently completed in Norman, Okla., and by the early 1990s up to 195 stations around the United States will be tracking dangerous weather and sending faster, more accurate, and more detailed warnings to the public.NEXRAD is being built for the Departments of Commerce, Transportation, and Defense by the Unisys Corporation under a $450 million contract signed in December 1987. Th e system will be used by the National Weather Service, the Federal Aviation Administration (FAA), and the U.S. Air Force and Navy. The NEXRAD radar tower in Norman is expected to be operational in October.

  11. Radar history

    NASA Astrophysics Data System (ADS)

    Putley, Ernest

    2008-07-01

    The invention of radar, as mentioned in Chris Lavers' article on warship stealth technology (March pp21-25), continues to be a subject of discussion. Here in Malvern we have just unveiled a blue plaque to commemorate the physicist Albert Percival Rowe, who arrived in 1942 as the head of the Telecommunications Research Establishment (TRE), which was the Air Ministry research facility responsible for the first British radar systems.

  12. Properties of inertia-gravity waves in the lowermost stratosphere as observed by the PANSY radar over Syowa Station in the Antarctic

    NASA Astrophysics Data System (ADS)

    Mihalikova, Maria; Sato, Kaoru; Tsutsumi, Masaki; Sato, Toru

    2016-05-01

    Inertia-gravity waves (IGWs) are an important component for the dynamics of the middle atmosphere. However, observational studies needed to constrain their forcing are still insufficient especially in the remote areas of the Antarctic region. One year of observational data (January to December 2013) by the PANSY radar of the wind components (vertical resolution of 150 m and temporal resolution of 30 min) are used to derive statistical analysis of the properties of IGWs with short vertical wavelengths ( ≤ 4 km) and ground-based periods longer than 4 h in the lowermost stratosphere (height range 10 to 12 km) with the help of the hodograph method. The annual change of the IGWs parameters are inspected but no pronounced year cycle is found. The year is divided into two seasons (summer and winter) based on the most prominent difference in the ratio of Coriolis parameter (f) to intrinsic frequency (ω^) distribution. Average of f/ω^ for the winter season is 0.40 and for the summer season 0.45 and the average horizontal wavelengths are 140 and 160 km respectively. Vertical wavelengths have an average of 1.85 km through the year. For both seasons the properties of IGWs with upward and downward propagation of the energy are also derived and compared. The percentage of downward propagating waves is 10.7 and 18.4 % in the summer and winter season respectively. This seasonal change is more than the one previously reported in the studies from mid-latitudes and model-based studies. It is in agreement with the findings of past radiosonde data-based studies from the Antarctic region. In addition, using the so-called dual-beam technique, vertical momentum flux and the variance of the horizontal perturbation velocities of IGWs are examined. Tropospheric disturbances of synoptic-scale are suggested as a

  13. Evaluation of station keeping systems for deepwater drilling semi-submersibles

    NASA Astrophysics Data System (ADS)

    Song, An-Ke; Sun, Li-Ping; Luo, Yong; Wang, Qiang

    2010-09-01

    This paper addresses the need for systematic evaluation of the station keeping systems of deepwater drilling semi-submersibles. Based on the selected drilling semi-submersible configuration, the mooring systems were analyzed and designed for a range of water depths using different mooring line materials. These were steel wire rope, polyester rope and HMPE (high modulus poly ethylene). The mooring analysis was carried out using the advanced fully coupled time domain analysis method in the computer software package HARP. Diffraction analysis was first applied to solve the hydrodynamic properties of the vessel and then the motion equations of the complete dynamic system including the drilling rig, the mooring lines and risers were developed and solved in the time domain. Applying the advanced analysis method, a matrix of mooring systems was developed for operating in water depths of 1 000 m, 1 500 m, and 2 000 m using various mooring materials. The development of mooring systems was conducted in accordance with the commonly adopted mooring design code, API RP 2SK and API RP 2SM. Fresh attempts were then made to comparatively evaluate the mooring system’s characteristics and global performance. Useful results have been obtained in terms of mooring materials, water depths, and key parameters of mooring configurations. The results provide in-depth insight for the design and operation of deepwater mooring systems in the South China Sea environment.

  14. Atomic oxygen durability evaluation of the flexible batten for the photovoltaic array mast on Space Station

    NASA Technical Reports Server (NTRS)

    Stidham, Curtis R.; Rutledge, Sharon K.; Sechkar, Edward A.; Flaherty, David S.; Roig, David M.; Edwards, Jonathan L.

    1994-01-01

    A test program was conducted at the National Aeronautics and Space Administration's Lewis Research Center (LeRC) to evaluate the long term low Earth orbital (LEO) atomic oxygen (AO) durability of a flexible (fiberglass-epoxy composite) batten. The flexible batten is a component used to provide structural rigidity in the photovoltaic array mast on Space Station. The mast is used to support and articulate the photovoltaic array, therefore, the flexible batten must be preloaded for the 15 year lifetime of an array blanket. Development hardware and composite materials were evaluated in ground testing facilities for AO durability and dynamic retraction-deployment cyclic loading representative of expected full life in-space application. The CV1144 silicone (AO protective) coating was determined to provide adequate protection against AO degradation of the composite material and provided fiber containment, thus the structural integrity of the flexible batten was maintained. Both silicone coated and uncoated flexible battens maintained load carrying capabilities. Results of the testing did indicate that the CV1144 silicone protective coating was oxidized by AO reactions to form a brittle glassy (SiO2) skin that formed cracking patterns on all sides of the coated samples. The cracking was observed in samples that were mechanically stressed as well as samples in non-stressed conditions. The oxidized silicon was observed to randomly spall in small localized areas, on the flexible battens that underwent retraction-deployment cycling. Some darkening of the silicon, attributed to vacuum ultraviolet (VUV) radiation, was observed.

  15. Evaluation of the present theoretical basis for determination of planetary surface properties by earth-based radar

    NASA Technical Reports Server (NTRS)

    Staton, L. D.

    1975-01-01

    Spaceflight programs such as the planned Viking landing on Mars require the determination of planetary surface slopes and surface dielectric constants by earth-based methods. Heavy reliance is often placed on radar backscattering data for estimation of these surface properties. An assessment is presented of the basic theory by which the raw radar data are interpreted, and it is shown that serious difficulties and internal inconsistencies are present in the available theoretical formulas. The discussion brings into question the reliability of the presently available results for these surface properties as obtained by earth-based radar methods.

  16. Shuttle radar topography mission accuracy assessment and evaluation for hydrologic modeling

    NASA Astrophysics Data System (ADS)

    Mercuri, Pablo Alberto

    Digital Elevation Models (DEMs) are increasingly used even in low relief landscapes for multiple mapping applications and modeling approaches such as surface hydrology, flood risk mapping, agricultural suitability, and generation of topographic attributes. The National Aeronautics and Space Administration (NASA) has produced a nearly global database of highly accurate elevation data, the Shuttle Radar Topography Mission (SRTM) DEM. The main goals of this thesis were to investigate quality issues of SRTM, provide measures of vertical accuracy with emphasis on low relief areas, and to analyze the performance for the generation of physical boundaries and streams for watershed modeling and characterization. The absolute and relative accuracy of the two SRTM resolutions, at 1 and 3 arc-seconds, were investigated to generate information that can be used as a reference in areas with similar characteristics in other regions of the world. The absolute accuracy was obtained from accurate point estimates using the best available federal geodetic network in Indiana. The SRTM root mean square error for this area of the Midwest US surpassed data specifications. It was on the order of 2 meters for the 1 arc-second resolution in flat areas of the Midwest US. Estimates of error were smaller for the global coverage 3 arc-second data with very similar results obtained in the flat plains in Argentina. In addition to calculating the vertical accuracy, the impacts of physiography and terrain attributes, like slope, on the error magnitude were studied. The assessment also included analysis of the effects of land cover on vertical accuracy. Measures of local variability were described to identify the adjacency effects produced by surface features in the SRTM DEM, like forests and manmade features near the geodetic point. Spatial relationships among the bare-earth National Elevation Data and SRTM were also analyzed to assess the relative accuracy that was 2.33 meters in terms of the total

  17. Terrestrial ecosystem recovery following removal of a PCB point source at a former pole vault line radar station in Northern Labrador.

    PubMed

    Ficko, Sarah A; Luttmer, Carol; Zeeb, Barbara A; Reimer, Kenneth

    2013-09-01

    Saglek Bay (LAB-2), located on the northeast coast of Labrador is a former Polevault station that was operated by the U.S. Air Force from 1953 to 1971 when it was abandoned. An environmental assessment carried out in 1996 determined that the site was contaminated with polychlorinated biphenyls (PCBs) with concentrations in soils far exceeding the Canadian Environmental Protection Agency (CEPA) regulation of 50 μg/g in three areas of the site (Beach, Site Summit, Antenna Hill). This led to remediation work carried out between 1999 and 2004 to remove and/or isolate all PCB-contaminated soil exceeding 50 μg/g and to further remediate parts of the site to <5 μg/g PCBs. In this study, spatial and temporal trends of PCB concentrations in soil, vegetation (Betula glandulosa and Salix spp.), and deer mice (Peromyscus maniculatus) were investigated over a period of fourteen (1997-2011) years in an effort to track ecosystem recovery following the removal of the PCB point sources. The data collected shows that PCB levels in vegetation samples are approximately four times lower in 2011 than pre-remediation in 1997. Similarly, PCB concentrations in deer mice in 2011 are approximately three times lower than those measured in 1997/98. Spatial trends in vegetation and deer mice continue to demonstrate that areas close to the former point sources of PCBs have higher PCB concentrations than those further away (and higher than background levels) and these residual PCB levels are not likely to decrease in the foreseeable future given the persistent nature of PCBs in general in the environment, and in particular in cold climates.

  18. Using Radar Charts with Qualitative Evaluation: Techniques to Assess Change in Blended Learning

    ERIC Educational Resources Information Center

    Kaczynski, Dan; Wood, Leigh; Harding, Ansie

    2008-01-01

    When university academics implement changes in learning, such as introducing blended learning, it is conventional practice to examine and evaluate the impact of the resulting curriculum reform. Judging the worth and impact of an educational development is a complex task involving subtle differences in learning. Qualitative methods to explore these…

  19. Invacuo tribological evaluation of coarse-pitch gears for use on the Space Station alpha joint

    NASA Technical Reports Server (NTRS)

    Allen, Scotty R.

    1992-01-01

    Existing invacuo or ambient test data of slow-speed (less than 30 meters/minute pitch line velocity), coarse-pitch gears could not be found suitable for use in evaluating gear materials and surface treatments for the gear-driven bearing race of the Solar Alpha Rotary Joint (SARJ) for Space Station Freedom (SSF). Gear testing was conducted by AEC-Able Engineering Company, Inc. to obtain design data for this critical SSF component. Some bull gear/pinion/lubrication combinations endured over 600,000 cycles (100 SSF years) without measurable wear, while other combinations experienced surface treatment degradation after only 40,000 cycles (seven SSF years). No catastrophic failures, such as seizing or tooth breakage, occurred during any test, all of which were run at least 201,000 cycles (34.5 SSF years). Specific results such as debris characteristics, mechanical efficiencies, effectiveness and degradation of lubrication, and wear data for the various gear combinations tested are described.

  20. An Evaluation of Technology to Remove Problematic Organic Compounds from the International Space Station Potable Water

    NASA Technical Reports Server (NTRS)

    Rector, Tony; Metselaar, Carol; Peyton, Barbara; Steele, John; Michalek, William; Bowman, Elizabeth; Wilson, Mark; Gazda, Daniel; Carter, Layne

    2014-01-01

    Since activation of the Water Processor Assembly (WPA) on the International Space Station (ISS) in November of 2008, there have been three events in which the TOC (Total Organic Carbon) in the product water has increased to approximately 3 mg/L and has subsequently recovered. Analysis of the product water in 2010 identified the primary component of the TOC as dimethylsilanediol (DMSD). An investigation into the fate of DMSD in the WPA ultimately determined that replacement of both Multifiltration (MF) Beds is the solution to recovering product water quality. The MF Beds were designed to ensure that ionic breakthrough occurs before organic breakthrough. However, DMSD saturated both MF Beds in the series, requiring removal and replacement of both MF Beds with significant life remaining. Analysis of the MF Beds determined that the adsorbent was not effectively removing DMSD, trimethylsilanol, various polydimethylsiloxanes, or dimethylsulfone. Coupled with the fact that the current adsorbent is now obsolete, the authors evaluated various media to identify a replacement adsorbent as well as media with greater capacity for these problematic organic contaminants. This paper provides the results and recommendations of this collaborative study.

  1. Findings of the Joint Workshop on Evaluation of Impacts of Space Station Freedom Ground Configurations

    NASA Technical Reports Server (NTRS)

    Ferguson, Dale C.; Snyder, David B.; Carruth, Ralph

    1991-01-01

    At the workshop, experts from the plasma interactions community evaluated the impacts of environmental interactions on the Space Station Freedom (SSF) under each of the proposed grounding schemes. The grounding scheme chosen for the SSF power system was found to have serious implications for SSF design. Interactions of the SSF power system and structure with the low Earth orbit (LEO) plasma differ significantly between different proposed grounding schemes. Environmental constraints will require modification of current SSF designs under any grounding scheme. Maintaining the present negative-grounding scheme compromises SSF safety, structural integrity, and electromagnetic compatibility. It also will increase contamination rates over alternative grounding schemes. One alternative, positive grounding of the array, requires redesign of the primary power system in work package four. Floating the array reduces the number of circuit changes to work package four but adds new hardware. Maintaining the current design will affect all work packages; however, no impacts were identified on work packages one, two, or three by positively grounding or floating the array, with the possible exception of extra corona protection in multi-wire connectors.

  2. Findings of the Joint Workshop on Evaluation of Impacts of Space Station Freedom Ground Configurations

    NASA Technical Reports Server (NTRS)

    Ferguson, Dale C.; Snyder, David B.; Carruth, Ralph

    1990-01-01

    A workshop to consider the effects of various proposed Space Station Freedom (SSF) grounding schemes was held. Expert from the plasma interactions community evaluated the impacts of environmental interactions on SSF under each of three proposed grounding schemes. The choice of the grounding scheme for the SSF power system was found to have important implications for SSF design. Interactions of the SSF power system and structure with the low earth orbit (LEO) plasma differ significantly between different grounding schemes. Environmental constraints will require modification of current SSF designs under any grounding scheme. Maintaining the present negative ground scheme may compromise SSF safety, structural integrity, and electromagnetic compatibility, and will increase contamination rates over alternate schemes. Positive grounding of the array requires redesign of the primary power system. Floating the array reduces the number of circuit changes in the primary power system but adds new hardware. Maintaining the present design will affect all parts of SSF. However, no impacts were identified on SSF systems outside of the electrical power system by positively grounding or floating the array.

  3. Evaluation of the Air Quality Monitor's Performance on the International Space Station

    NASA Technical Reports Server (NTRS)

    Limero, Thomas; Reese, Eric; Ballard, Ken; Durham, Tamara

    2010-01-01

    The Air Quality Monitor (AQM) was flown to the International Space Station (ISS) as an experiment to evaluate its potential to replace the aging Volatile Organic Analyzer (VOA), which ceased operations in August 2009. The AQM (Figure 1) is a small gas chromatography/differential mobility spectrometer (GC/DMS) manufactured by Sionex. Data was presented at last year s ISIMS conference that detailed the preparation of the AQM for flight, including instrument calibration. Furthermore, initial AQM data was compared to VOA results from simultaneous runs of the two instruments. Although comparison with VOA data provided a measure of confidence in the AQM performance, it is the comparison with results from simultaneously acquired air samples (grab sample containers-GSCs) that will define the success (or failure) of the AQM performance. This paper will update the progress in the AQM investigation by comparing AQM data to results from the analyses of GSC samples, returned from ISS. Additionally, a couple of example will illustrate the AQM s ability to detect disruptions in the spacecraft s air quality. Discussion will also focus upon a few unexpected issues that have arisen and how these will be a addressed in the final operational unit now being built.

  4. Structural evaluation of concepts for a solar energy concentrator for Space Station advanced development program

    NASA Technical Reports Server (NTRS)

    Kenner, Winfred S.; Rhodes, Marvin D.

    1994-01-01

    Solar dynamic power systems have a higher thermodynamic efficiency than conventional photovoltaic systems; therefore they are attractive for long-term space missions with high electrical power demands. In an investigation conducted in support of a preliminary concept for Space Station Freedom, an approach for a solar dynamic power system was developed and a number of the components for the solar concentrator were fabricated for experimental evaluation. The concentrator consists of hexagonal panels comprised of triangular reflective facets which are supported by a truss. Structural analyses of the solar concentrator and the support truss were conducted using finite-element models. A number of potential component failure scenarios were postulated and the resulting structural performance was assessed. The solar concentrator and support truss were found to be adequate to meet a 1.0-Hz structural dynamics design requirement in pristine condition. However, for some of the simulated component failure conditions, the fundamental frequency dropped below the 1.0-Hz design requirement. As a result, two alternative concepts were developed and assessed. One concept incorporated a tetrahedral ring truss support for the hexagonal panels: the second incorporated a full tetrahedral truss support for the panels. The results indicate that significant improvements in stiffness can be obtained by attaching the panels to a tetrahedral truss, and that this concentrator and support truss will meet the 1.0-Hz design requirement with any of the simulated failure conditions.

  5. Evaluation of the failure of the HP nozzle block at the Nebraska City Station

    SciTech Connect

    Karloff, J.A.; Weins, W.N.

    1995-12-31

    Since the start-up of the Nebraska City Station unit in 1978, the nozzle block section of the high pressure turbine has had to be replaced or repaired each time this section of the turbine was disassembled. In nearly all cases the damage was limited to the lower half of the nozzle block, where many airfoils had been chipped away. This damage not only dramatically increased maintenance costs, but also reduced the efficiency of the nozzle block. The objective of this report is to evaluate if corrosion-fatigue is part of the failure mechanism and what role if any solid particle erosion played in this process. Results and analysis show that both corrosion and SPE were shown to be minor contributors in the failure analysis process. Scanning Electron Microscope (SEM) photographs revealed that fatigue was the major contributor in the failure. It is speculated that the blade passing pressure disturbance caused the trailing edge of the nozzle to vacillate. As the metal reached its fatigue limit, minute fatigue cracks began to form parallel and in a direction opposite to the steam flow. When a crack grew large enough, part of the metal would be torn away leaving the ``chipped`` away appearance. SPE may have initially accelerated the crack growth by decreasing the thickness of the trailing edge. Intergranular corrosion; which was shown to be present, could have weakened the metal at its grain boundaries essentially reducing its fatigue strength.

  6. Evaluation of solid state nuclear track detector stacks exposed on the international space station.

    PubMed

    Pálfalvi, J K; Akatov, Yu; Szabó, J; Sajó-Bohus, L; Eördögh, I

    2004-01-01

    The aim of the study was to investigate the contribution of secondary neutrons to the total dose inside the International Space Station (ISS). For this purpose solid-state nuclear track detector (SSNTD) stacks were used. Each stack consisted of three CR-39 sheets. The first and second sheets were separated by a Ti plate, and the second and third sheets sandwiched a Lexan polycarbonate foil. The neutron and proton responses of each sheet were studied through MC calculations and experimentally, utilising monoenergetic protons. Seven stacks were exposed in 2001 for 249 days at different locations of the Russian segment 'Zvezda'. The total storage time before and after the exposure onboard was estimated to be seven months. Another eight stacks were exposed at the CERF high-energy neutron field for calibration purposes. The CR-39 detectors were evaluated in four steps: after 2, 6, 12 and 20 h etching in 6 N NaOH at 70 degrees C (VB = 1.34 microm h(-1)). All the individual tracks were investigated and recorded using an image analyser. The stacks provided the averaged neutron ambient dose equivalent (H*) between 200 keV and 20 MeV, and the values varied from 39 to 73 microSv d(-1), depending on the location. The Lexan detectors were used to detect the dose originating from high-charge and high-energy (HZE) particles. These results will be published elsewhere.

  7. Evaluation of shoulder integrity in space: first report of musculoskeletal US on the International Space Station

    NASA Technical Reports Server (NTRS)

    Fincke, E. Michael; Padalka, Gennady; Lee, Doohi; van Holsbeeck, Marnix; Sargsyan, Ashot E.; Hamilton, Douglas R.; Martin, David; Melton, Shannon L.; McFarlin, Kellie; Dulchavsky, Scott A.

    2005-01-01

    Investigative procedures were approved by Henry Ford Human Investigation Committee and NASA Johnson Space Center Committee for Protection of Human Subjects. Informed consent was obtained. Authors evaluated ability of nonphysician crewmember to obtain diagnostic-quality musculoskeletal ultrasonographic (US) data of the shoulder by following a just-in-time training algorithm and using real-time remote guidance aboard the International Space Station (ISS). ISS Expedition-9 crewmembers attended a 2.5-hour didactic and hands-on US training session 4 months before launch. Aboard the ISS, they completed a 1-hour computer-based Onboard Proficiency Enhancement program 7 days before examination. Crewmembers did not receive specific training in shoulder anatomy or shoulder US techniques. Evaluation of astronaut shoulder integrity was done by using a Human Research Facility US system. Crew used special positioning techniques for subject and operator to facilitate US in microgravity environment. Common anatomic reference points aided initial probe placement. Real-time US video of shoulder was transmitted to remote experienced sonologists in Telescience Center at Johnson Space Center. Probe manipulation and equipment adjustments were guided with verbal commands from remote sonologists to astronaut operators to complete rotator cuff evaluation. Comprehensive US of crewmember's shoulder included transverse and longitudinal images of biceps and supraspinatus tendons and articular cartilage surface. Total examination time required to guide astronaut operator to acquire necessary images was approximately 15 minutes. Multiple arm and probe positions were used to acquire dynamic video images that were of excellent quality to allow evaluation of shoulder integrity. Postsession download and analysis of high-fidelity US images collected onboard demonstrated additional anatomic detail that could be used to exclude subtle injury. Musculoskeletal US can be performed in space by minimally

  8. Evaluation of shoulder integrity in space: first report of musculoskeletal US on the International Space Station.

    PubMed

    Fincke, E Michael; Padalka, Gennady; Lee, Doohi; van Holsbeeck, Marnix; Sargsyan, Ashot E; Hamilton, Douglas R; Martin, David; Melton, Shannon L; McFarlin, Kellie; Dulchavsky, Scott A

    2005-02-01

    Investigative procedures were approved by Henry Ford Human Investigation Committee and NASA Johnson Space Center Committee for Protection of Human Subjects. Informed consent was obtained. Authors evaluated ability of nonphysician crewmember to obtain diagnostic-quality musculoskeletal ultrasonographic (US) data of the shoulder by following a just-in-time training algorithm and using real-time remote guidance aboard the International Space Station (ISS). ISS Expedition-9 crewmembers attended a 2.5-hour didactic and hands-on US training session 4 months before launch. Aboard the ISS, they completed a 1-hour computer-based Onboard Proficiency Enhancement program 7 days before examination. Crewmembers did not receive specific training in shoulder anatomy or shoulder US techniques. Evaluation of astronaut shoulder integrity was done by using a Human Research Facility US system. Crew used special positioning techniques for subject and operator to facilitate US in microgravity environment. Common anatomic reference points aided initial probe placement. Real-time US video of shoulder was transmitted to remote experienced sonologists in Telescience Center at Johnson Space Center. Probe manipulation and equipment adjustments were guided with verbal commands from remote sonologists to astronaut operators to complete rotator cuff evaluation. Comprehensive US of crewmember's shoulder included transverse and longitudinal images of biceps and supraspinatus tendons and articular cartilage surface. Total examination time required to guide astronaut operator to acquire necessary images was approximately 15 minutes. Multiple arm and probe positions were used to acquire dynamic video images that were of excellent quality to allow evaluation of shoulder integrity. Postsession download and analysis of high-fidelity US images collected onboard demonstrated additional anatomic detail that could be used to exclude subtle injury. Musculoskeletal US can be performed in space by minimally

  9. Improvement of radar quantitative precipitation estimation based on real-time adjustments to Z-R relationships and inverse distance weighting correction schemes

    NASA Astrophysics Data System (ADS)

    Wang, Gaili; Liu, Liping; Ding, Yuanyuan

    2012-05-01

    The errors in radar quantitative precipitation estimations consist not only of systematic biases caused by random noises but also spatially nonuniform biases in radar rainfall at individual rain-gauge stations. In this study, a real-time adjustment to the radar reflectivity-rainfall rates ( Z-R) relationship scheme and the gauge-corrected, radar-based, estimation scheme with inverse distance weighting interpolation was developed. Based on the characteristics of the two schemes, the two-step correction technique of radar quantitative precipitation estimation is proposed. To minimize the errors between radar quantitative precipitation estimations and rain gauge observations, a real-time adjustment to the Z-R relationship scheme is used to remove systematic bias on the time-domain. The gauge-corrected, radar-based, estimation scheme is then used to eliminate non-uniform errors in space. Based on radar data and rain gauge observations near the Huaihe River, the two-step correction technique was evaluated using two heavy-precipitation events. The results show that the proposed scheme improved not only in the underestimation of rainfall but also reduced the root-mean-square error and the mean relative error of radar-rain gauge pairs.

  10. Evaluating a Radar-Based, Non Contact Streamflow Measurement System in the San Joaquin River at Vernalis, California

    USGS Publications Warehouse

    Cheng, Ralph T.; Gartner, Jeffrey W.; Mason, Jr., Robert R.; Costa, John E.; Plant, William J.; Spicer, Kurt R.; Haeni, F. Peter; Melcher, Nick B.; Keller, William C.; Hayes, Ken

    2004-01-01

    Accurate measurement of flow in the San Joaquin River at Vernalis, California, is vital to a wide range of Federal and State agencies, environmental interests, and water contractors. The U.S. Geological Survey uses a conventional stage-discharge rating technique to determine flows at Vernalis. Since the flood of January 1997, the channel has scoured and filled as much as 20 feet in some sections near the measurement site resulting in an unstable stage-discharge rating. In response to recent advances in measurement techniques and the need for more accurate measurement methods, the Geological Survey has undertaken a technology demonstration project to develop and deploy a radar-based streamflow measuring system on the bank of the San Joaquin River at Vernalis, California. The proposed flow-measurement system consists of a ground-penetrating radar system for mapping channel geometries, a microwave radar system for measuring surface velocities, and other necessary infrastructure. Cross-section information derived from ground penetrating radar provided depths similar to those measured by other instruments during the study. Likewise, surface-velocity patterns and magnitudes measured by the pulsed Doppler radar system are consistent with near surface current measurements derived from acoustic velocity instruments. Since the ratio of surface velocity to mean velocity falls to within a small range of theoretical value, using surface velocity as an index velocity to compute river discharge is feasable. Ultimately, the non-contact radar system may be used to make continuous, near-real-time flow measurements during high and medium flows. This report documents the data collected between April 14, 2002 and May 17, 2002 for the purposes of testing this radar based system. Further analyses of the data collected during this field effort will lead to further development and improvement of the system.

  11. MARIA M4: clinical evaluation of a prototype ultrawideband radar scanner for breast cancer detection.

    PubMed

    Preece, Alan W; Craddock, Ian; Shere, Mike; Jones, Lyn; Winton, Helen L

    2016-07-01

    A microwave imaging system has been developed as a clinical diagnostic tool operating in the 3- to 8-GHz region using multistatic data collection. A total of 86 patients recruited from a symptomatic breast care clinic were scanned with a prototype design. The resultant three-dimensional images have been compared "blind" with available ultrasound and mammogram images to determine the detection rate. Images show the location of the strongest signal, and this corresponded in both older and younger women, with sensitivity of [Formula: see text], which was found to be maintained in dense breasts. The pathway from clinical prototype to clinical evaluation is outlined.

  12. MARIA M4: clinical evaluation of a prototype ultrawideband radar scanner for breast cancer detection.

    PubMed

    Preece, Alan W; Craddock, Ian; Shere, Mike; Jones, Lyn; Winton, Helen L

    2016-07-01

    A microwave imaging system has been developed as a clinical diagnostic tool operating in the 3- to 8-GHz region using multistatic data collection. A total of 86 patients recruited from a symptomatic breast care clinic were scanned with a prototype design. The resultant three-dimensional images have been compared "blind" with available ultrasound and mammogram images to determine the detection rate. Images show the location of the strongest signal, and this corresponded in both older and younger women, with sensitivity of [Formula: see text], which was found to be maintained in dense breasts. The pathway from clinical prototype to clinical evaluation is outlined. PMID:27446970

  13. Evaluating the surface circulation in the Ebro delta (northeastern Spain) with quality-controlled high-frequency radar measurements

    NASA Astrophysics Data System (ADS)

    Lorente, P.; Piedracoba, S.; Soto-Navarro, J.; Alvarez-Fanjul, E.

    2015-11-01

    The Ebro River delta is a relevant marine protected area in the western Mediterranean. In order to promote the conservation of its ecosystem and support operational decision making in this sensitive area, a three-site standard-range (13.5 MHz) CODAR SeaSonde high-frequency (HF) radar was deployed in December 2013. The main goal of this work is to explore basic features of the sea surface circulation in the Ebro deltaic region as derived from reliable HF radar surface current measurements. For this aim, a combined quality control methodology was applied: firstly, 1-year long (2014) real-time web monitoring of nonvelocity-based diagnostic parameters was conducted to infer both radar site status and HF radar system performance. The signal-to-noise ratio at the monopole exhibited a consistent monthly evolution, although some abrupt decreases (below 10 dB), occasionally detected in June for one of the radar sites, impacted negatively on the spatiotemporal coverage of total current vectors. It seemed to be sporadic episodes since radar site overall performance was found to be robust during 2014. Secondly, a validation of HF radar data with independent in situ observations from a moored current meter was attempted for May-October 2014. The accuracy assessment of radial and total vectors revealed a consistently high agreement. The directional accuracy of the HF radar was rated at better than 8°. The correlation coefficient and root mean square error (RMSE) values emerged in the ranges [0.58-0.83] and [4.02-18.31] cm s-1, respectively. The analysis of the monthly averaged current maps for 2014 showed that the HF radar properly represented basic oceanographic features previously reported, namely, the predominant southwestward flow, the coastal clockwise eddy confined south of the Ebro delta mouth, or the Ebro River impulsive-type freshwater discharge. The EOF analysis related the flow response to local wind forcing and confirmed that the surface current field evolved in

  14. Preliminary evaluation of polarimetric parameters from a new dual-polarization C-band weather radar in an alpine region

    NASA Astrophysics Data System (ADS)

    Paulitsch, H.; Teschl, F.; Randeu, W. L.

    2010-05-01

    The first operational weather radar with dual polarization capabilities was recently installed in Austria. The use of polarimetric radar variables rises several expectations: an increased accuracy of the rain rate estimation compared to standard Z-R relationships, a reliable use of attenuation correction methods, and finally hydrometeor classification. In this study the polarimetric variables of precipitation events are investigated and the operational quality of the parameters is discussed. For the new weather radar also several polarimetric rain rate estimators, which are based on the horizontal polarization radar reflectivity, ZH, the differential reflectivity, ZDR, and the specific differential propagation phase shift, KDP, have been tested. The rain rate estimators are further combined with an attenuation correction scheme. A comparison between radar and rain gauge indicates that ZDR based rain rate algorithms show an improvement over the traditional Z-R estimate. KDP based estimates do not provide reliable results, mainly due to the fact, that the observed KDP parameters are quite noisy. Furthermore the observed rain rates are moderate, where KDP is less significant than in heavy rain.

  15. Evaluation of precipitation chemistry siting criteria using paired stations from northern Maine and southeastern Texas

    SciTech Connect

    Artz, R.S.; Rolph, G.D. )

    1987-01-01

    During the early 1970's, the Environmental Protection Agency (EPA) and the National Oceanic and Atmospheric Administration (NOAA) began precipitation chemistry monitoring at ten National Weather Service (NWS) stations located across the United States. The goal was to design a network consisting of regionally representative precipitation stations to define the levels and gradients of concentration of the chemicals found in precipitation. The data were also useful for effects research and, over a period of decades, for the calculation of trends. A monthly wet-only sampling protocol was used and EPA analyzed the samples for pH, SO{sub 4}{sup =}, NO{sub 3}{sup -}, Cl{sup -}, Na{sup +}, NH{sub 4}{sup +}, Mg{sup ++}, K{sup +}, Ca{sup ++}, conductivity and precipitation depth. In an effort to test the representativeness of two of the sites, Victoria, and Caribou, colocated stations were established at Beeville, Texas and Presque Isle, Maine according to NADP protocol. Two-year data records are currently available for both of these new sites. It is the purpose of this paper to compare the data from the paired stations to determine whether or not the precipitation chemistry from the original stations is different from the new stations.

  16. Precise gravity-field modeling in the area of the Japanese Antarctic station Syowa and evaluation of recent EGMs

    NASA Astrophysics Data System (ADS)

    Fukuda, Yoichi; Nogi, Yoshifumi; Matsuzaki, Kazuya

    2016-03-01

    By combining a Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) Earth Gravity Model (EGM) and in situ gravity data obtained from the Japanese Antarctic Research Expedition (JARE) surveys, we estimated the regional gravity field in the area of Syowa Station, a Japanese research station located in Lützow-Holm Bay, East Antarctica. In situ data sets that were used consisted of land gravity data collected since 1967, shipborne data collected since 1985 and airborne gravity data collected in 2006. The GOCE direct (DIR) solution release 5 (R5) model was used as the long-wavelength reference of the gravity field. Using these data sets, we calculated gravity anomalies and geoid heights at 1-by-1‧ grid by means of least-squares collocation. The resulting geoid height at Syowa Station was compared with a local height based on GPS, spirit leveling and tide gauge data. The result suggests that the sea surface height at Syowa Station is -1.57 m, which is consistent with a dynamic ocean topography model. During this investigation, we also evaluated GOCE EGMs and other recent EGMs by comparing them with the airborne gravity data. The results indicate that the GOCE DIR R5 produced the smallest RMS (Root Mean Square) differences and that the newer models performed nearly as well. These comparisons demonstrate the importance of using reliable in situ data when evaluating satellite-only EGMs.

  17. 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.

  18. Evaluating the Impact of the Summit Station, Greenland Radiosonde Program on Science and Forecast Services

    NASA Astrophysics Data System (ADS)

    Martinez, C. J.; Starkweather, S.; Cox, C. J.; Solomon, A.; Shupe, M.

    2015-12-01

    Radiosondes are balloon-borne meteorological sensors used to acquire profiles of temperature and humidity. Radiosonde data are essential inputs for numerical weather prediction models and are used for climate research, particularly in the creation of reanalysis products. However, radiosonde programs are costly to maintain, in particular in the remote regions of the Arctic (e.g., $440,000/yr at Summit, Greenland), where only 40 of approximately 1000 routine global launches are made. The climate of this data-sparse region is poorly understood and forecast data assimilation procedures are designed for global applications. Thus, observations may be rejected from the data assimilation because they are too far from the model expectations. For the most cost-efficient deployment of resources and to improve forecasting methods, analyses of the effectiveness of individual radiosonde programs are necessary. Here, we evaluate how radiosondes launched twice daily (0 and 12 UTC) from Summit Station, Greenland, (72.58⁰N, 38.48⁰W, 3210 masl) influence the European Centre for Medium Range Weather Forecasting (ECMWF) operational forecasts from June 2013 through May of 2015. A statistical analysis is conducted to determine the impact of the observations on the forecast model and the meteorological regimes that the model fails to reproduce are identified. Assimilation rates in the inversion layer are lower than any other part of the troposphere. Above the inversion, assimilation rates range from 85%-100%, 60%-98%, and > 99% for temperature, humidity, and wind, respectively. The lowest assimilation rates are found near the surface, possibly associated with biases in the representation of the temperature inversion by the ECMWF model at Summit. Consequently, assimilation rates are lower near the surface during winter when strong temperature inversions are frequently observed. Our findings benefit the scientific community who uses this information for climatological analysis of the

  19. Evaluating the Impact of the Summit Station, Greenland Radiosonde Program on Data Modelers and Forecast Services

    NASA Astrophysics Data System (ADS)

    Martinez, C. J.; Starkweather, S.; Cox, C. J.; Solomon, A.; Shupe, M.

    2015-12-01

    Radiosondes are balloon-borne meteorological sensors used to acquire profiles of temperature and humidity. Radiosonde data are essential inputs for numerical weather prediction models and are used for climate research, particularly in the creation of reanalysis products. However, radiosonde programs are costly to maintain, in particular in the remote regions of the Arctic (e.g., $440,000/yr at Summit, Greenland), where only 40 of approximately 1000 routine global launches are made. The climate of this data-sparse region is poorly understood and forecast data assimilation procedures are designed for global applications. Thus, observations may be rejected from the data assimilation because they are too far from the model expectations. For the most cost-efficient deployment of resources and to improve forecasting methods, analyses of the effectiveness of individual radiosonde programs are necessary. Here, we evaluate how radiosondes launched twice daily (0 and 12 UTC) from Summit Station, Greenland, (72.58⁰N, 38.48⁰W, 3210 masl) influence the European Centre for Medium Range Weather Forecasting (ECMWF) operational forecasts from June 2013 through May of 2015. A statistical analysis is conducted to determine the impact of the observations on the forecast model and the meteorological regimes that the model fails to reproduce are identified. Assimilation rates in the inversion layer are lower than any other part of the troposphere. Above the inversion, assimilation rates range from 85%-100%, 60%-98%, and > 99% for temperature, humidity, and wind, respectively. The lowest assimilation rates are found near the surface, possibly associated with biases in the representation of the temperature inversion by the ECMWF model at Summit. Consequently, assimilation rates are lower near the surface during winter when strong temperature inversions are frequently observed. Our findings benefit the scientific community who uses this information for climatological analysis of the

  20. Planetary radar

    NASA Technical Reports Server (NTRS)

    Taylor, R. M.

    1980-01-01

    The radar astronomy activities supported by the Deep Space Network during June, July, and August 1980 are reported. The planetary bodies observed were Venus, Mercury, and the asteroid Toro. Data were obtained at both S and X band, and the observations were considered successful.

  1. Bistatic and Multistatic Radar: Surveillance, Countermeasures, and Radar Cross Sections. (Latest citations from the Aerospace Database)

    NASA Technical Reports Server (NTRS)

    1998-01-01

    The bibliography contains citations concerning the design, development, testing, and evaluation of bistatic and multistatic radar used in surveillance and countermeasure technology. Citations discuss radar cross sections, target recognition and characteristics, ghost recognition, motion image compensation, and wavelet analysis. Stealth aircraft design, stealth target tracking, synthetic aperture radar, and space applications are examined.

  2. Bistatic and Multistatic Radar: Surveillance, Countermeasures, and Radar Cross Sections. (Latest Citations from the Aerospace Database)

    NASA Technical Reports Server (NTRS)

    1997-01-01

    The bibliography contains citations concerning the design, development, testing, and evaluation of bistatic and multistatic radar used in surveillance and countermeasure technology. Citations discuss radar cross sections, target recognition and characteristics, ghost recognition, motion image compensation, and wavelet analysis. Stealth aircraft design, stealth target tracking, synthetic aperture radar, and space applications are examined.

  3. 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.

  4. Evaluation of the 29-km Eta Model. Part 1; Objective Verification at Three Selected Stations

    NASA Technical Reports Server (NTRS)

    Nutter, Paul A.; Manobianco, John; Merceret, Francis J. (Technical Monitor)

    1998-01-01

    This paper describes an objective verification of the National Centers for Environmental Prediction (NCEP) 29-km eta model from May 1996 through January 1998. The evaluation was designed to assess the model's surface and upper-air point forecast accuracy at three selected locations during separate warm (May - August) and cool (October - January) season periods. In order to enhance sample sizes available for statistical calculations, the objective verification includes two consecutive warm and cool season periods. Systematic model deficiencies comprise the larger portion of the total error in most of the surface forecast variables that were evaluated. The error characteristics for both surface and upper-air forecasts vary widely by parameter, season, and station location. At upper levels, a few characteristic biases are identified. Overall however, the upper-level errors are more nonsystematic in nature and could be explained partly by observational measurement uncertainty. With a few exceptions, the upper-air results also indicate that 24-h model error growth is not statistically significant. In February and August 1997, NCEP implemented upgrades to the eta model's physical parameterizations that were designed to change some of the model's error characteristics near the surface. The results shown in this paper indicate that these upgrades led to identifiable and statistically significant changes in forecast accuracy for selected surface parameters. While some of the changes were expected, others were not consistent with the intent of the model updates and further emphasize the need for ongoing sensitivity studies and localized statistical verification efforts. Objective verification of point forecasts is a stringent measure of model performance, but when used alone, is not enough to quantify the overall value that model guidance may add to the forecast process. Therefore, results from a subjective verification of the meso-eta model over the Florida peninsula are

  5. Construction and precision evaluation of the GPS virtual reference station network in North Taiwan

    NASA Astrophysics Data System (ADS)

    Yeh, T.; Lee, Z.; Chang, M.; Chen, C.

    2006-12-01

    The conventional single-reference station positioning is affected by systematic errors such as ionospheric and tropospheric delay, so that the rover must be located within 10 km from the reference station in order to acquire centimeter-level accuracy. The medium-range real-time kinematic has been proven feasible and can be used for high precision applications. However, the longer of the baseline, the more of the time for resolving the integer ambiguity. This is due to the fact that systematic errors can't be eliminated effectively by double- differencing. Recently, network approaches have been proposed to overcome the limitation of the single- reference station positioning. The real-time systematic error modeling can be achieved with the use of GPS network. For expanding the effective range and decreasing the density of the reference stations, Land Survey Bureau, Ministry of the Interior in Taiwan have set up a national GPS network. In order to obtain the high precision positioning and provide the multi-goals services, a GPS network including 27 stations already been constructed in North Taiwan. The users can download the corrections from the data center via the wireless internet and obtain the centimeter-level accuracy positioning. The service is very useful for surveyors and the high precision coordinates can be obtained real time.

  6. Evaluation of RTV coating for station insulators subjected to coastal contamination

    SciTech Connect

    Carberry, R.E.; Schneider, H.M.

    1989-01-01

    Measurements and analysis of contaminant samples from a nuclear power station which has suffered flashovers due to wind-swept salt spray are presented. The results of a program of laboratory tests on artificially contaminated porcelain station insulators, with and without a room temperature vulcanized (RTV) silicone rubber coating, are reported. Data from clean fog and salt mist tests are used to determine the improvement in flashover voltage level over a range of high contamination severity on RTV coated insulators. Visual observations and leakage current measurements made during surface discharge activity are utilized to demonstrate the influence of the RTV coating on discharge behavior. Switching impulse test results are also presented.

  7. 33. Site Plan: Custer Air Force Station, Battle Creek, Michigan, ...

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

    33. Site Plan: Custer Air Force Station, Battle Creek, Michigan, FD Radar Facilities-FPS-27, Electrical Plot Plan and Duet Details, USACOE, not date. - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

  8. TRMM radar

    NASA Technical Reports Server (NTRS)

    Okamoto, Kenichi

    1993-01-01

    The results of a conceptual design study and the performance of key components of the Bread Board Model (BBM) of the Tropical Rainfall Measuring Mission (TRMM) radar are presented. The radar, which operates at 13.8 GHz and is designed to meet TRMM mission objectives, has a minimum measurable rain rate of 0.5 mm/h with a range resolution of 250 m, a horizontal resolution of about 4 km, and a swath width of 220 km. A 128-element active phased array system is adopted to achieve contiguous scanning within the swath. The basic characteristics of BBM were confirmed by experiments. The development of EM started with the cooperation of NASDA and CRL.

  9. Evaluating the potential use of a high-resolution X-band polarimetric radar observations in Urban Hydrology

    NASA Astrophysics Data System (ADS)

    Anagnostou, Marios N.; Kalogiros, John; Marzano, Frank S.; Anagnostou, Emmanouil N.; Baldini, Luca; Nikolopoulos, EfThymios; Montopoli, Mario; Picciotti, Errico

    2014-05-01

    The Mediterranean area concentrates the major natural risks related to the water cycle, including heavy precipitation and flash-flooding during the fall season. Every year in central and south Europe we witness several fatal and economical disasters from severe storm rainfall triggering Flash Floods, and its impacts are increasing worldwide, but remain very difficult to manage. The spatial scale of flash flood occurrence is such that its vulnerability is often focused on dispersed urbanization, transportation and tourism infrastructures (De Marchi and Scolobig 2012). Urbanized and industrialized areas shows peculiar hydrodynamic and meteo-oceanographic features and they concentrate the highest rates of flash floods and fatal disasters. The main causes of disturbance being littoral urban development and harbor activities, the building of littoral rail- and highways, and the presence of several polluted discharges. All the above mentioned characteristics limit our ability to issue timely flood warnings. Precipitation estimates based on raingauge networks are usually associated with low coverage density, particularly at high altitudes. On the other hand, operational weather radar networks may provide valuable information of precipitation at these regimes but reliability of their estimates is often limited due to retrieval (e.g. variability in the reflectivity-to-rainfall relationship) and spatial extent constrains (e.g. blockage issues, overshooting effects). As a result, we currently lack accurate precipitation estimates over urban complex terrain areas, which essentially means that we lack accurate knowledge of the triggering factor for a number of hazards like flash floods and debris flows/landslides occurring in those areas. A potential solution to overcome sampling as well as retrieval uncertainty limitations of current observational networks might be the use of network of low-power dual-polarization X-band radars as complement to raingauges and gap-filling to

  10. Modelisation du Signal Radar EN Milieu Stratifie et Evaluation de Techniques de Mesure de L'humidite du Sol

    NASA Astrophysics Data System (ADS)

    Boisvert, Johanne

    La presente etude se penche sur des problemes relies a l'echantillonnage de l'humidite de sol et a l'estimation du signal radar sur sols nus. Le travail se divise en deux volets. Le volet 1 evalue trois techniques de mesure de l'humidite du sol (gravimetrie, reflectometrie temporelle et sonde dielectrique) et deux protocoles d'echantillonnage. Dans le volet 2, un modele de simulation du signal en milieu stratifie est developpe, et les estimes de signal obtenus sont compares aux estimes bases uniquement sur une valeur moyenne d'humidite du sol prise sur une profondeur fixe d'echantillonnage. Les differences entre les deux estimes dependent de la frequence et du choix judicieux de la profondeur d'echantillonnage; elles sont plus importantes aux faibles angles et en polarisation HV, puis VV. Le modele de simulation a aussi ete utilise pour etudier la profondeur de penetration du signal et en deduire la profondeur optimale d'echantillonnage en tenant compte des caracteristiques du signal. Une variation de 25 ^circ de l'angle d'incidence a peu d'effet sur la profondeur de penetration en bande Ku; l'ecart reste inferieur ou egal a 0,5 cm en bande C mais peut atteindre 1,3 cm en bande L. L'impact de la polarisation est nul en bande Ku mais croi t avec l'angle d'incidence en bande C et L. A 50^circ, il est, en moyenne de 1 cm en bande C et de 2 cm en bande L. En polarisation VV, la profondeur croi t avec une augmentation de l'angle alors que l'effet est inverse en polarisation HH. Deux methodes pour estimer la profondeur d'echantillonnage en conditions operationnelles sont presentees. Lorsqu'on inverse un modele pour estimer l'humidite du sol a partir du signal, ces methodes permettent aussi d'estimer l'epaisseur de sol representee par l'humidite ainsi estimee.

  11. 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.

  12. Post-Flight Back Pain Following International Space Station Missions: Evaluation of Spaceflight Risk Factors

    NASA Technical Reports Server (NTRS)

    Laughlin, M. S.; Murray, J. D.; Wear, M. L.; Van Baalen, M.

    2016-01-01

    INTRODUCTION Back pain during spaceflight has often been attributed to the lengthening of the spinal column due to the absence of gravity during both short and long-duration missions. Upon landing and re-adaptation to gravity, the spinal column reverts back to its original length thereby causing some individuals to experience pain and muscular spasms, while others experience no ill effects. With International Space Station (ISS) missions, cases of back pain and injury are more common post-flight, but little is known about the potential risk factors. Thus, the purpose of this project was to perform an initial evaluation of reported post-flight back pain and injury cases to relevant spaceflight risk factors in United States astronauts that have completed an ISS mission. METHODS All US astronauts who completed an ISS mission between Expeditions (EXP) 1 and 41 (2000-2015) were included in this evaluation. Forty-five astronauts (36 males and 9 females) completed 50 ISS missions during the study time period, as 5 astronauts completed 2 ISS missions. Researchers queried medical records of the 45 astronauts for occurrences of back pain and injury. A case was defined as any reported event of back pain or injury to the cervical, thoracic, lumbar, sacral, or coccyx spine regions. Data sources for the cases included the Flight Medicine Clinic's electronic medical record; Astronaut Strength, Conditioning and Rehabilitation electronic documentation; the Private Medical Conference tool; and the Space Medicine Operations Team records. Post-flight cases were classified as an early case if reported within 45 days of landing (R + 45) or a late case if reported from R + 46 to R + 365 days after landing (R + 1y). Risk factors in the astronaut population for back pain include age, sex, prior military service, and prior history of back pain. Additionally, spaceflight specific risk factors such as type of landing vehicle and onboard exercise countermeasures were included to evaluate their

  13. [Evaluating psychophysiologic adaptation state in operators of Bilibino nuclear power station].

    PubMed

    Isaeva, N A; Torubarov, F S; Denisova, E A; Zvereva, Z F; Koronotova, M A

    2014-01-01

    The study revealed that 60% operators of Bilibino nuclear power station suffer from psychosomatic diseases, 41.7% of them are assigned to occupational group of workers, and major part of the examinees with psychosomatic diseases (45.82%) are aged 41-50, high integral level ofpsychophysiologic adaptation is revealed in 5 examinees (12.5%), medium integral level--in 12 examinees (30%). Lower integral level of psychophysiologic adaptation manifested in decrease in psychophysiologic and physiologic levels. PMID:25845144

  14. [Evaluating psychophysiologic adaptation state in operators of Bilibino nuclear power station].

    PubMed

    Isaeva, N A; Torubarov, F S; Denisova, E A; Zvereva, Z F; Koronotova, M A

    2014-01-01

    The study revealed that 60% operators of Bilibino nuclear power station suffer from psychosomatic diseases, 41.7% of them are assigned to occupational group of workers, and major part of the examinees with psychosomatic diseases (45.82%) are aged 41-50, high integral level ofpsychophysiologic adaptation is revealed in 5 examinees (12.5%), medium integral level--in 12 examinees (30%). Lower integral level of psychophysiologic adaptation manifested in decrease in psychophysiologic and physiologic levels.

  15. Laboratory evaluation of the Design Analysis Associates DAA H-3613i radar water-level sensor—Results of temperature, distance, and SDI-12 tests

    USGS Publications Warehouse

    Carnley, Mark V.

    2016-09-30

    The Design Analysis Associates (DAA) DAA H-3613i radar water-level sensor (DAA H-3613i), manufactured by Xylem Incorporated, was evaluated by the U.S. Geological Survey (USGS) Hydrologic Instrumentation Facility (HIF) for conformance to manufacturer’s accuracy specifications for measuring a distance throughout the sensor’s operating temperature range, for measuring distances from 3 to 15 feet at ambient temperatures, and for compliance with the SDI-12 serial-to-digital interface at 1200-baud communication standard. The DAA H-3613i is a noncontact water-level sensor that uses pulsed radar to measure the distance between the radar and the water surface from 0.75 to 131 feet over a temperature range of −40 to 60 degrees Celsius (°C). Manufacturer accuracy specifications that were evaluated, the test procedures that followed, and the results obtained are described in this report. The sensor’s accuracy specification of ± 0.01 feet (± 3 millimeters) meets USGS requirements for a primary water-stage sensor used in the operation of a streamgage. The sensor met the manufacturer’s stated accuracy specifications for water-level measurements during temperature testing at a distance of 8 feet from the target over its temperature-compensated operating range of −40 to 60 °C, except at 60 °C. At 60 °C, about half the measurements exceeded the manufacturer’s accuracy specification by not more than 0.005 feet.The sensor met the manufacturer’s stated accuracy specifications for water-level measurements during distance-accuracy testing at the tested distances from 3 to 15 feet above the water surface at the HIF.

  16. Laboratory Evaluation of the Design Analysis Associates DAA H-3613i Radar Water-Level Sensor—Results of Temperature, Distance, and SDI-12 Tests

    USGS Publications Warehouse

    Carnley, Mark V.

    2016-09-30

    The Design Analysis Associates (DAA) DAA H-3613i radar water-level sensor (DAA H-3613i), manufactured by Xylem Incorporated, was evaluated by the U.S. Geological Survey (USGS) Hydrologic Instrumentation Facility (HIF) for conformance to manufacturer’s accuracy specifications for measuring a distance throughout the sensor’s operating temperature range, for measuring distances from 3 to 15 feet at ambient temperatures, and for compliance with the SDI-12 serial-to-digital interface at 1200-baud communication standard. The DAA H-3613i is a noncontact water-level sensor that uses pulsed radar to measure the distance between the radar and the water surface from 0.75 to 131 feet over a temperature range of −40 to 60 degrees Celsius (°C). Manufacturer accuracy specifications that were evaluated, the test procedures that followed, and the results obtained are described in this report. The sensor’s accuracy specification of ± 0.01 feet (± 3 millimeters) meets USGS requirements for a primary water-stage sensor used in the operation of a streamgage. The sensor met the manufacturer’s stated accuracy specifications for water-level measurements during temperature testing at a distance of 8 feet from the target over its temperature-compensated operating range of −40 to 60 °C, except at 60 °C. At 60 °C, about half the measurements exceeded the manufacturer’s accuracy specification by not more than 0.005 feet.The sensor met the manufacturer’s stated accuracy specifications for water-level measurements during distance-accuracy testing at the tested distances from 3 to 15 feet above the water surface at the HIF.

  17. 23. SITE BUILDING 002 SCANNER BUILDING RADAR CONTROL ...

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

    23. SITE BUILDING 002 - SCANNER BUILDING - RADAR CONTROL INTERFACE "RCL NO. 2" WITH COMPUTER CONTROL DISC DRIVE UNITS IN FOREGROUND. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

  18. 8. View of power plant and radar tower, looking southwest ...

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

    8. View of power plant and radar tower, looking southwest - Naval Air Station Fallon, Power Plant, 800 Complex, off Carson Road near intersection of Pasture & Berney Roads, Fallon, Churchill County, NV

  19. 1. View of east elevation of power plant, radar tower ...

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

    1. View of east elevation of power plant, radar tower in background, looking west - Naval Air Station Fallon, Power Plant, 800 Complex, off Carson Road near intersection of Pasture & Berney Roads, Fallon, Churchill County, NV

  20. 9. View southeast corner of perimeter acquisition radar power plant ...

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

    9. View southeast corner of perimeter acquisition radar power plant room #214, control room; showing central monitoring station console in foreground. Well and booster control panel in left background and electric power management panel on far right - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Power Plant, In Limited Access Area, Southwest of PARB at end of Service Road B, Nekoma, Cavalier County, ND

  1. 50. View of waveguides beginning to move toward two radar ...

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

    50. View of waveguides beginning to move toward two radar scanner switches (two per radar scanner building) by vertical bends; also tuning devices are located here. - 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

  2. Technical evaluation of the adequacy of station electric distribution system voltages for the Rancho Seco Nuclear Generating Station, Unit No. 1: selected issues program (Docket No. 50-312)

    SciTech Connect

    White, R. L.

    1981-11-10

    This report documents the technical evaluation of the adequacy of the station electric distribution system voltages for the Rancho Seco Nuclear Generation Station, Unit No. 1. The evaluation is to determine if the onsite distribution system, in conjunction with the offsite power sources, has sufficient capacity to automatically start and operate all Class 1E loads within the equipment voltage ratings under certain conditions established by the Nuclear Regulatory Commission. The licensee demonstrates with the analysis that with certain modifications the guidelines and requirements of the NRC will be met.

  3. Agricultural and hydrological applications of radar

    NASA Technical Reports Server (NTRS)

    Ulaby, F. T.

    1976-01-01

    Program objectives, covering a wide range of disciplines and activities in radar remote sensing, include radar systems development and analysis, data processing and display, and data interpretation in geology, geography and oceanography. Research was focused on the evaluation of radar remote sensing applications in hydrology and agriculture based on data acquired with the Microwave Active Spectrometer (MAS) system. The title, author(s) and abstract of each of the 62 technical reports generated under this contract are appended.

  4. Post-Flight Back Pain Following International Space Station Missions: Evaluation of Spaceflight Risk Factors

    NASA Technical Reports Server (NTRS)

    Laughlin, Mitzi S.; Murray, Jocelyn D.; Wear, Mary L.; Van Baalen, Mary

    2016-01-01

    Back pain during spaceflight has often been attributed to the lengthening of the spinal column due to the absence of gravity during both short and long-duration missions. Upon landing and re-adaptation to gravity, the spinal column reverts back to its original length thereby causing some individuals to experience pain and muscular spasms, while others experience no ill effects. With International Space Station (ISS) missions, cases of back pain and injury are more common post-flight, but little is known about the potential risk factors.

  5. State of subsoil in a former petrol station: physicochemical characterization and hydrocarbon contamination evaluation

    NASA Astrophysics Data System (ADS)

    María Rosales, Rosa; Martinez-Pagán, Pedro; Faz, Ángel; Bech, Jaume

    2013-04-01

    Former petrol stations are, possibly, potential hydrocarbon contaminated soil areas due to leakage in Underground Storage Tanks and fuel dispensing activities. Volatile Organic Compounds (VOCs) in gasoline, like benzene and semi-volatile organics in diesel, are carcinogenic and very toxic substances which can involve a serious risk for ecosystem and human health. Based on Electrical Resistivity Tomography 2D results from a previous work, there have been selected three potentially contaminated goal areas in a former petrol station located in SE Spain in order to obtain soil samples by drilling and to assess the gasoline and diesel contamination. A special sampling design was carried out and soil samples for VOCs were preserved at field with a KCl solution to minimize volatilization losses. It had been chosen Headspace-GC-MS as the better technique to quantify individual VOCs and GC-FID to get a Total Petroleum Hydrocarbon (TPH) assessment after a solid/fluid pressurized extraction. The physicochemical characterization of the subsoil was performed to know how humidity, clay content or pH data could be related to the presence of hydrocarbons in the soil samples. Results show that VOCs concentrations in subsoil samples of the petrol station are around ppb levels. TPH ranged between 17 mg/kg soil and 93 mg/kg soil (ppm levels) what involves diesel and gasoline leaks due to these detected residual concentrations in the subsoil. The maximum value was found at 6 m deep in an intermediate zone between Underground Storage Tanks positions (located at 4 m deep). Therefore, these results confirm that organic compounds transference with strong vertical component has taken place. It has been observed that humidity minimum values in the subsoil are related to TPH maximum values that could be explained because of the vapour phase and the retention of hydrocarbon in soil increases when humidity goes down. Adsorption of hydrocarbons in the subsoil tend to be pH-dependent and clay

  6. Evaluation of atmospheric turbulence, energy exchanges and structure of convective cores during the occurrence of mesoscale convective systems using MST radar facility at Gadanki

    NASA Astrophysics Data System (ADS)

    Satyanarayana, A. N. V.; Sultana, Sabiha; Narayana Rao, T.; Satheesh Kumar, S.

    2014-06-01

    Mesoscale convective systems (MCSs) wreak lots of havoc and severe damage to life and property due to associated strong gusty winds, rainfall and hailstorms even though they last for an hour or so. Planetary boundary layer (PBL) plays an important role in the transportation of energy such as momentum, heat and moisture through turbulence into the upper layers of the atmosphere and acts as a feedback mechanism in the generation and sustenance of MCS. In the present study, three severe thunderstorms that occurred over mesosphere-stratosphere-troposphere (MST) radar facility at National Atmospheric Research Laboratory (NARL), Gadanki, India, have been considered to understand turbulence, energy exchanges and wind structure during the different epochs such as pre-, during and after the occurrence of these convective episodes. Significant changes in the turbulence structure are noticed in the upper layers of the atmosphere during the thunderstorm activity. Identified strong convective cores with varying magnitudes of intensity in terms of vertical velocity at different heights in the atmosphere discern the presence of shallow as well as deep convection during initial, mature and dissipative stages of the thunderstorm. Qualitative assessments of these convective cores are verified using available Doppler Weather Radar imageries in terms of reflectivity. The MST radar derived horizontal wind profiles are in good comparison with observed radiosonde winds. Significant variations in the surface meteorological parameters, sensible heat flux and turbulent kinetic energy as well as horizontal wind profiles are noticed during the different epochs of the convective activity. This work is useful in evaluating the performance of PBL schemes of mesoscale models in simulating MCS.

  7. A methodology for automation and robotics evaluation applied to the space station telerobotic servicer

    NASA Technical Reports Server (NTRS)

    Smith, Jeffrey H.; Gyanfi, Max; Volkmer, Kent; Zimmerman, Wayne

    1988-01-01

    The efforts of a recent study aimed at identifying key issues and trade-offs associated with using a Flight Telerobotic Servicer (FTS) to aid in Space Station assembly-phase tasks is described. The use of automation and robotic (A and R) technologies for large space systems would involve a substitution of automation capabilities for human extravehicular or intravehicular activities (EVA, IVA). A methodology is presented that incorporates assessment of candidate assembly-phase tasks, telerobotic performance capabilities, development costs, and effect of operational constraints (space transportation system (STS), attached payload, and proximity operations). Changes in the region of cost-effectiveness are examined under a variety of systems design assumptions. A discussion of issues is presented with focus on three roles the FTS might serve: (1) as a research-oriented testbed to learn more about space usage of telerobotics; (2) as a research based testbed having an experimental demonstration orientation with limited assembly and servicing applications; or (3) as an operational system to augment EVA and to aid the construction of the Space Station and to reduce the programmatic (schedule) risk by increasing the flexibility of mission operations.

  8. Lunar radar mapping: Correlation between radar reflectivity and stratigraphy in north-western mare imbrium

    USGS Publications Warehouse

    Schaber, G.G.; Eggleton, R.E.; Thompson, T.W.

    1970-01-01

    DELAY-DOPPLER radar maps of the Moon obtained with the 430 MHz (70 cm wavelength) radar of the Arecibo Ionospheric Observatory in Puerto Rico (Thompson, unpublished) are at present being studied to correlate geological information with the radar reflexion characteristics of the lunar surface. Preliminary evaluation of the radar data for the Sinus Iridum quadrangle (32??-48?? N; 14??-38?? W) has revealed that the lowest values of radar reflectivity are closely correlated with the mare materials of lowest albedo mapped by Schaber1 as of most recent volcanic origin. These radar data were obtained with a surface resolution of 50 to 100 km2 on January 24 and April 17, 1967. A detailed account of the delay-doppler radar mapping technique can be found in unpublished reports by Thompson. ?? 1970 Nature Publishing Group.

  9. GEOS-3 C-Band radar investigations

    NASA Technical Reports Server (NTRS)

    Dempsey, D. J.

    1978-01-01

    The absolute accuracy of instrumentation radar systems, refined methods of calibrating these systems, and the techniques employed in processing the associated data. A world-wide network of C-Band instrumentation radars augmented by lasers and other tracking instrumentation systems were used. The NASA WFC AN/FPQ-6 instrumentation radar and the AN/FPS-16 instrumentation radar also located at NASA WFC were the primary instruments used in the accuracy and calibration evaluations. The results achieved at WFC were then disseminated to other Ranges where they were verified, augmented and used as part of routine operations.

  10. Radar and Lidar Radar DEM

    NASA Technical Reports Server (NTRS)

    Liskovich, Diana; Simard, Marc

    2011-01-01

    Using radar and lidar data, the aim is to improve 3D rendering of terrain, including digital elevation models (DEM) and estimates of vegetation height and biomass in a variety of forest types and terrains. The 3D mapping of vegetation structure and the analysis are useful to determine the role of forest in climate change (carbon cycle), in providing habitat and as a provider of socio-economic services. This in turn will lead to potential for development of more effective land-use management. The first part of the project was to characterize the Shuttle Radar Topography Mission DEM error with respect to ICESat/GLAS point estimates of elevation. We investigated potential trends with latitude, canopy height, signal to noise ratio (SNR), number of LiDAR waveform peaks, and maximum peak width. Scatter plots were produced for each variable and were fitted with 1st and 2nd degree polynomials. Higher order trends were visually inspected through filtering with a mean and median filter. We also assessed trends in the DEM error variance. Finally, a map showing how DEM error was geographically distributed globally was created.

  11. Detail view of northwest side of Signal Corps Radar (S.C.R.) ...

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

    Detail view of northwest side of Signal Corps Radar (S.C.R.) 296 Station 5 Transmitter Building foundation, showing portion of concrete gutter drainage system and asphalt floor tiles, camera facing north - Fort Barry, Signal Corps Radar 296, Station 5, Transmitter Building Foundation, Point Bonita, Marin Headlands, Sausalito, Marin County, CA

  12. Analysis of Borehole-Radar Reflection Data from Machiasport, Maine, December 2003

    USGS Publications Warehouse

    Johnson, Carole D.; Joesten, Peter K.

    2005-01-01

    In December 2003, the U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, collected borehole-radar reflection logs in two boreholes in Machiasport, Maine. These bedrock boreholes were drilled as part of a hydrogeologic investigation of the area surrounding the former Air Force Radar Tracking Station site on Howard Mountain near Bucks Harbor. The boreholes, MW09 and MW10, are located approximately 50 meters (m) from, and at the site of, respectively, the locations of former buildings where trichloroethylene was used as part of defense-site operations. These areas are thought to be potential source areas for contamination that has been detected in downgradient bedrock wells. This investigation focused on testing borehole-radar methods at this site. Single-hole radar-reflection surveys were used to identify the depth, orientation, and spatial continuity of reflectors that intersect and surround the boreholes. In addition, the methods were used to (1) identify the radial depth of penetration of the radar waves in the electrically resistive bimodal volcanic formation at the site, (2) provide information for locating additional boreholes at the site, and (3) test the potential applications of borehole-radar methods for further aquifer characterization and (or) evaluation of source-area remediation efforts. Borehole-radar reflection logging uses a pair of downhole transmitting and receiving antennas to record the reflected wave amplitude and transit time of high-frequency electromagnetic waves. For this investigation, 60- and 100-megahertz antennas were used. The electromagnetic waves emitted by the transmitter penetrate into the formation surrounding the borehole and are reflected off of a material with different electromagnetic properties, such as a fracture or change in rock type. Single-hole directional radar surveys indicate the bedrock surrounding these boreholes is highly fractured, because several reflectors were identified in the radar

  13. Shuttle orbiter Ku-band radar/communications system design evaluation: High gain antenna/widebeam horn

    NASA Technical Reports Server (NTRS)

    Iwasaki, R.; Dodds, J. G.; Broad, P.

    1979-01-01

    The physical characteristics of the high gain antenna reflector and feed elements are described. Deficiencies in the sum feed are discussed, and lack of atmospheric venting is posed as a potential problem area. The measured RF performance of the high gain antenna is examined and the high sidelobe levels measured are related to the physical characteristics of the antenna. An examination of the attributes of the feed which might be influenced by temperature extremes shows that the antenna should be insensitive to temperature variations. Because the feed support bipod structure is considered a significant contributor to the high sidelobe levels measured in the azimuth plane, pod relocation, material changes, and shaping are suggested as improvements. Alternate feed designs are presented to further improve system performance. The widebeam horn and potential temperature effects due to the polarizer are discussed as well as in the effects of linear polarization on TDRS acquisition, and the effects of circular polarization on radar sidelobe avoidance. The radar detection probability is analyzed as a function of scan overlap and target range.

  14. Evaluation of Pactruss design characteristics critical to space station primary structure

    NASA Technical Reports Server (NTRS)

    Hedgepeth, John M.

    1987-01-01

    Several aspects of the possible application of the Pactruss concept to the primary truss structure of the space station are investigated. Estimates are made of the loads and hinge moments in deploying diagonal members as full deployment is approached. Included are the effects of beam columning and compliance of the surrounding structure. Requirements for joint design are suggested and a two-stage mid-diagonal latching hinge concept is described or analyzed. The problems with providing the experimental and theoretical tools needed for assuring reliable synchronous deployment are discussed and a first attempt at high-fidelity analytical simulation with NASTRAN is described. An alternative construction scenario in which the entire dual-keel truss structure is deployed as a single Shuttle payload is suggested.

  15. Evaluation of the Biolog MicroStation system for yeast identification

    NASA Technical Reports Server (NTRS)

    McGinnis, M. R.; Molina, T. C.; Pierson, D. L.; Mishra, S. K.

    1996-01-01

    One hundred and fifty-nine isolates representing 16 genera and 53 species of yeasts were processed with the Biolog MicroStation System for yeast identification. Thirteen genera and 38 species were included in the Biolog database. For these 129 isolates, correct identifications to the species level were 13.2, 39.5 and 48.8% after 24, 48 and 72 hours incubation at 30 degrees C, respectively. Three genera and 15 species which were not included in the Biolog database were also tested. Of the 30 isolates studied, 16.7, 53.3 and 56.7% of the isolates were given incorrect names from the system's database after 24,48 and 72 h incubation at 30 degrees C, respectively. The remaining isolates of this group were not identified.

  16. Application of the Doppler weather radar in real-time quality control of hourly gauge precipitation in eastern China

    NASA Astrophysics Data System (ADS)

    Zhong, Lingzhi; Zhang, Zhiqiang; Chen, Lin; Yang, Jinhong; Zou, Fengling

    2016-05-01

    The current real-time operational quality control method for hourly rain gauge records at meteorological stations of China is primarily based on a comparison with historical extreme records, and the spatial and temporal consistencies of rain records. However, this method might make erroneous judgments for heavy precipitation because of its remarkable inhomogeneous features. In this study, we develop a Radar Supported Operational Real-time Quality Control (RS_ORQC) method to improve hourly gauge precipitation records in eastern China by using Doppler weather radar data and national automatic rain-gauge network in JJA (i.e., June, July and August) between 2010 and 2011. According to the probability density function (PDF) and cumulative probability density function (CDF), we establish the statistic relationships between NSN precipitation records under 7 radar coverage and radar quantitative precipitation estimation (QPE). The other NSN records under 5 radar coverage are used for the verification. The results show that the correct rate of this radar-supported new method in judging gauge precipitation is close to 99.95% when the hourly rainfall rate is below 10 mm h- 1 and is 96.21% when the rainfall intensity is above 10 mm h- 1. Moreover, the improved quality control method is also applied to evaluate the quality of provincial station network (PSN) precipitation records over eastern China. The correct rate of PSN precipitation records is 99.92% when the hourly rainfall rate is below 10 mm h- 1, and it is 93.33% when the hourly rainfall rate is above 10 mm h- 1. Case studies also exhibit that the radar-supported method can make correct judgments for extreme heavy rainfall.

  17. Evaluation of the MICAST #2-12 AI-7wt%Si Sample Directionally Solidified Aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    Tewari, Surendra N.; Ghods, Masoud; Angart, Samuel G.; Lauer, Mark; Grugel, Richard N.; Poirier, David R.

    2016-01-01

    The US team of the European led "MIcrostructure Formation in CASTing of Technical Alloys under Diffusive and Magnetically Controlled Convective Conditions" (MICAST) program recently received a third Aluminum - 7wt% silicon alloy that was processed in the microgravity environment aboard the International Space Station. The sample, designated MICAST#2-12, was directionally solidified in the Solidification with Quench Furnace (SQF) at a constant rate of 40micometers/s through an imposed temperature gradient of 31K/cm. Procedures taken to evaluate the state of the sample prior to sectioning for metallographic analysis are reviewed and rational for measuring the microstructural constituents, in particular the primary dendrite arm spacing (Lambda (sub1)), is given. The data are presented, put in context with the earlier samples, and evaluated in view of a relevant theoretical model.

  18. Performance and evaluation of gas-engine-driven split-system cooling equipment at the Willow Grove Naval Air Station

    SciTech Connect

    Armstrong, P.R.; Schmelzer, J.R.

    1997-01-01

    DOE`s Federal Energy Management Program supports efforts to reduce energy use and associated expenditures within the federal sector; one such effort, the New Technology Demonstration Program (NTDP)(formerly the Test Bed Demonstration program), seeks to evaluate new energy saving US technologies and secure their more timely adoption by the federal government. This report describes the field evaluation conducted to examine the performance of a 15-ton natural-gas-engine- driven, split-system, air-conditioning unit. The unit was installed at a multiple-use building at Willow Grove Naval Air Station, a regular and reserve training facility north of Philadelphia, and its performance was monitored under the NTDP.

  19. An application of multiattribute decision analysis to the Space Station Freedom program. Case study: Automation and robotics technology evaluation

    NASA Technical Reports Server (NTRS)

    Smith, Jeffrey H.; Levin, Richard R.; Carpenter, Elisabeth J.

    1990-01-01

    The results are described of an application of multiattribute analysis to the evaluation of high leverage prototyping technologies in the automation and robotics (A and R) areas that might contribute to the Space Station (SS) Freedom baseline design. An implication is that high leverage prototyping is beneficial to the SS Freedom Program as a means for transferring technology from the advanced development program to the baseline program. The process also highlights the tradeoffs to be made between subsidizing high value, low risk technology development versus high value, high risk technology developments. Twenty one A and R Technology tasks spanning a diverse array of technical concepts were evaluated using multiattribute decision analysis. Because of large uncertainties associated with characterizing the technologies, the methodology was modified to incorporate uncertainty. Eight attributes affected the rankings: initial cost, operation cost, crew productivity, safety, resource requirements, growth potential, and spinoff potential. The four attributes of initial cost, operations cost, crew productivity, and safety affected the rankings the most.

  20. Observation of the Earth by radar

    NASA Technical Reports Server (NTRS)

    Elachi, C.

    1982-01-01

    Techniques and applications of radar observation from Earth satellites are discussed. Images processing and analysis of these images are discussed. Also discussed is radar imaging from aircraft. Uses of this data include ocean wave analysis, surface water evaluation, and topographic analysis.

  1. Using Radar Interferometry (DinSAR) to Evaluate Land Subsidence Caused by Excessive Groundwater Withdrawal in Morocco

    NASA Astrophysics Data System (ADS)

    Durham, M. C.; Milewski, A.; El Kadiri, R.

    2013-12-01

    The combination of natural, anthropogenic, and climate change impacts on the water resources of the Middle East and North Africa (MENA) region has devastated its water resources well beyond its current and projected populations. The increased exploitation of groundwater resources in the past half-century coupled with successive droughts has resulted in the acceleration of subsidence rates in the Souss and Massa basins in Morocco. We have completed a preliminary investigation of these impacts on the Souss and Massa basins (~27,000 km2) in the southwestern part of Morocco. This area is characterized by a semi-arid climate (annual precipitation 70-250 mm/year) with agriculture, tourism, and commercial fishing as the primary economic activities, all of which require availability of adequate freshwater resources. Additionally the primary groundwater aquifer (Plio-Quaternary Plain Aquifer), an unconfined aquifer formed mostly of sand and gravel, is being harvested by >20,000 wells at a rate of 650 MCM/yr., exceeding the rate of recharge by 260 MCM/year. Intense development over the past 50 years has exposed the aquifer to a serious risk of groundwater table drawdown (0.5m-2.5m/yr.), land subsidence, loss of artesian pressure, salinization, salt water intrusions along the coast, and deterioration of water quality across the watershed. Differential Interferometry Synthetique Aperture Radar (DInSAR) was utilized to measure ground subsidence induced by groundwater withdrawal. Land subsidence caused by excessive groundwater extraction was determined using a threefold methodology: (1) extraction of subsidence and land deformation patterns using radar interferometry, (2) correlation of the high subsidence areas within the basins to possible natural and anthropogenic factors (e.g. sea level rise, unconsolidated lithological formations distribution, urbanization, excessive groundwater extraction), and (3) forecasting the future of the Souss and Massa basins over the next century

  2. Analysis of long term trends of precipitation estimates acquired using radar network in Turkey

    NASA Astrophysics Data System (ADS)

    Tugrul Yilmaz, M.; Yucel, Ismail; Kamil Yilmaz, Koray

    2016-04-01

    Precipitation estimates, a vital input in many hydrological and agricultural studies, can be obtained using many different platforms (ground station-, radar-, model-, satellite-based). Satellite- and model-based estimates are spatially continuous datasets, however they lack the high resolution information many applications often require. Station-based values are actual precipitation observations, however they suffer from their nature that they are point data. These datasets may be interpolated however such end-products may have large errors over remote locations with different climate/topography/etc than the areas stations are installed. Radars have the particular advantage of having high spatial resolution information over land even though accuracy of radar-based precipitation estimates depends on the Z-R relationship, mountain blockage, target distance from the radar, spurious echoes resulting from anomalous propagation of the radar beam, bright band contamination and ground clutter. A viable method to obtain spatially and temporally high resolution consistent precipitation information is merging radar and station data to take advantage of each retrieval platform. An optimally merged product is particularly important in Turkey where complex topography exerts strong controls on the precipitation regime and in turn hampers observation efforts. There are currently 10 (additional 7 are planned) weather radars over Turkey obtaining precipitation information since 2007. This study aims to optimally merge radar precipitation data with station based observations to introduce a station-radar blended precipitation product. This study was supported by TUBITAK fund # 114Y676.

  3. Evaluation of Maximal Oxygen Uptake and Submaximal Estimates of VO2max Before, During, and After Long Duration International Space Station Missions

    NASA Technical Reports Server (NTRS)

    2008-01-01

    Evaluation of Maximal Oxygen Uptake and Submaximal Estimates of VO2max Before, During, and After Long Duration International Space Station Missions (VO2max) will document changes in maximum oxygen uptake for crewmembers onboard the International Space Station (ISS) on long-duration missions, greater than 90 days. This investigation will establish the characteristics of VO2max during flight and assess the validity of the current methods of tracking aerobic capacity change during and following the ISS missions.

  4. Evaluation of Electrochemically Generated Potable Water Disinfectants for Use on the International Space Station

    NASA Technical Reports Server (NTRS)

    Rodriquez, Branelle; Anderson, Molly; Anderson, Molly; Adam, Niklas; Vega, Leticia; Modica, Catherine; Bodkin, Douglas

    2012-01-01

    Microbial contamination and subsequent growth in spacecraft water systems are constant concerns for missions involving human crews. The current potable water disinfectant for the International Space Station (ISS) is iodine; however, with the end of the Space Shuttle program, there is a need to develop redundant biocide systems that do not require regular up ]mass dependencies. Throughout the course of a year, four different electrochemical systems were investigated as a possible biocide for potable water on the ISS. Research has indicated that there is a wide variability with regards to efficacy in both concentration and exposure time of these disinfectants, therefore baseline efficacy values were established. This paper describes a series of tests performed in order to establish optimal concentrations and exposure times for four disinfectants against single and mixed species planktonic and biofilm bacteria. Results of the testing determined whether these electrochemical disinfection systems are able to produce a sufficient amount of chemical in both concentration and volume to act as a biocide for potable water on ISS.

  5. Evaluation of Electrochemically Generated Potable Water Disinfectants for Use on the International Space Station

    NASA Technical Reports Server (NTRS)

    Vega, Leticia; Aber, Gregory; Adam, Niklas; Clements, Anna; Modica, Catherine; Younker, Diane

    2011-01-01

    Microbial contamination and subsequent growth in spacecraft water systems are constant concerns for missions involving human crews. The current potable water disinfectant is iodine; however, with the end of the Space Shuttle program, there is a need to develop redundant biocide systems which are less dependent on hardware that would need to be launched on a regular basis. Three systems for electrochemical production of potable water disinfectants are being assessed for use on the International Space Station (ISS). Since there is a wide variability in the literature with regards to efficacy in both concentration and exposure time of these disinfectants, there is a need to establish baseline efficacy values. This paper describes a series of tests performed in order to establish optimal concentrations and exposure times for four disinfectants against single and mixed species planktonic and biofilm bacteria and to determine whether these electrochemical disinfection devices are able to produce a sufficient amount of chemical in both concentration and volume to act as a biocide for potable water on ISS.

  6. Electrochemical Disinfection Feasibility Assessment Materials Evaluation for the International Space Station

    NASA Technical Reports Server (NTRS)

    Rodriquez, Branelle; Shindo, David; Montgomery, Eliza

    2013-01-01

    The International Space Station (ISS) Program recognizes the risk of microbial contamination in their potable and non-potable water sources. The end of the Space Shuttle Program limited the ability to send up shock kits of biocides in the event of an outbreak. Currently, the United States Orbital Segment water system relies primarily on iodine to mitigate contamination concerns, which has been successful in remediating the small cases of contamination documented. However, a secondary method of disinfection is a necessary investment for future space flight. Over the past year, NASA Johnson Space Center has investigated the development of electrochemically generated systems for use on the ISS. These systems include: hydrogen peroxide, ozone, sodium hypochlorite, and peracetic acid. To use these biocides on deployed water systems, NASA must understand of the effect these biocides have on current ISS materials prior to proceeding forward with possible on-orbit applications. This paper will discuss the material testing that was conducted to assess the effects of the biocides on current ISS materials.

  7. Microstructural Evaluation and Comparison of Solder Samples Processed Aboard the International Space Station

    NASA Technical Reports Server (NTRS)

    Grugel, R. N.; Hua, F.; Anilkumar, A. V.

    2008-01-01

    Samples from the In-Space Soldering Investigation (ISSI), conducted aboard the International Space Station (ISS), are being examined for post-solidification microstructural development and porosity distribution. In this preliminary study, the internal structures of two ISSI processed samples are compared. In one case 10cm of rosin-core solder was wrapped around a coupon wire and melted by conduction, whereas, in the other a comparable length of solder was melted directly onto the hot wire; in both cases the molten solder formed ellipsoidal blobs, a shape that was maintained during subsequent solidification. In the former case, there is clear evidence of porosity throughout the sample, and an accumulation of larger pores near the hot end that implies thermocapillary induced migration and eventual coalescence of the flux vapor bubbles. In the second context, when solder was fed onto the wire. a part of the flux constituting the solder core is introduced into and remains within the liquid solder ball, becoming entombed upon solidification. In both cases the consequential porosity, particularly at a solder/contact interface, is very undesirable. In addition to compromising the desired electrical and thermal conductivity, it promotes mechanical failure.

  8. Evaluation of Electrochemically Generated Potable Water Disinfectants for Use on the International Space Station

    NASA Technical Reports Server (NTRS)

    Rodriquez, Branelle; Anderson, Molly; Adams, Niklas; Vega, Leticia; Botkin, Douglas

    2013-01-01

    Microbial contamination and subsequent growth in spacecraft water systems are constant concerns for missions involving human crews. The current potable water disinfectant for the International Space Station (ISS) is iodine; however, with the end of the Space Shuttle Program, there is a need to develop redundant biocide systems that do not require regular up-mass dependencies. Throughout the course of a year, four different electrochemical systems were investigated as a possible biocide for potable water on the ISS. Research has indicated that a wide variability exists with regards to efficacy in both concentration and exposure time of these disinfectants; therefore, baseline efficacy values were established. This paper describes a series of tests performed to establish optimal concentrations and exposure times for four disinfectants against single and mixed species planktonic and biofilm bacteria. Results of the testing determined whether these electrochemical disinfection systems are able to produce a sufficient amount of chemical in both concentration and volume to act as a biocide for potable water on the ISS.

  9. Evaluation of Low Earth Orbit Environmental Effects on International Space Station Thermal Control Materials

    NASA Technical Reports Server (NTRS)

    Dever, Joyce A.; Rutledge, Sharon K.; Hasegawa, Mark M.; Reed, Charles K.

    1998-01-01

    Samples of International Space Station (ISS) thermal control coatings were exposed to simulated low Earth orbit (LEO) environmental conditions to determine effects on optical properties. In one test, samples of the white paint coating Z-93P were coated with outgassed products from Tefzel(R) (ethylene tetrafluoroethylene copolymer) power cable insulation as-may occur on ISS. These samples were then exposed, along with an uncontaminated Z-93P witness sample, to vacuum ultraviolet (VUV) radiation to determine solar absorptance degradation. The Z-93P samples coated with Tefzel(R) outgassing products experienced greater increases in solar absorptance than witness samples not coated with Tefzel(R) outgassing products. In another test, samples of second surface silvered Teflon(R) FEP (fluorinated ethylene propylene), SiO. (where x=2)-coated silvered Teflon(R) FEP, and Z-93P witness samples were exposed to the combined environments of atomic oxygen and VLTV radiation to determine optical properties changes due to these simulated ISS environmental effects. This test verified the durability of these materials in the absence of contaminants.

  10. [Study on pollution evaluation of heavy metal in surface soil of the original site of Qingdao North Station].

    PubMed

    Zhu, Lei; Jia, Yong-gang; Pan, Yu-ying

    2013-09-01

    The determination of pollution extent and health risk assessment are the premise of heavy metal contaminated site remediation. The content of Cu, Cr, Pb, Cd, Zn, Ni in Qingdao North Station was detected, and the correlation of the 6 kinds of heavy metal content was analyzed. The pollution extent in excess of background values was characterized by anthropogenic influence multiple, and the pollution of heavy metal in soil was evaluated using geoaccumulation index and a new method which connects geoaccumulation index with Nemero index. Finally, human health risk assessment was carried out with health risk assessment model for heavy metal content. The results showed that Qingdao North Station soil were polluted by heavy metals. Six heavy metal pollution levels were: Cd > Cu > Ni > Pb > Cr > Zn, and Cd had reached the severity pollution level, Cu and Ni followed by, Cr, Pb and Zn were in minor pollution level. The order of coefficient variation in all heavy metals was: Cd > Ni > Cr > Zn > Pb > Cu. Within the study area soil heavy metal distribution was different, but overall discrepancy was small. The order of non-cancer hazards of heavy metals in soil was Cr > Pb > Cu > Ni > Cd > Zn, and the order of carcinogen risks of heavy metals was Ni > Cd. The non-cancer hazard and carcinogen risks values of metals were both lower than that their threshold values. They were not the direct threats to human health.

  11. [Study on pollution evaluation of heavy metal in surface soil of the original site of Qingdao North Station].

    PubMed

    Zhu, Lei; Jia, Yong-gang; Pan, Yu-ying

    2013-09-01

    The determination of pollution extent and health risk assessment are the premise of heavy metal contaminated site remediation. The content of Cu, Cr, Pb, Cd, Zn, Ni in Qingdao North Station was detected, and the correlation of the 6 kinds of heavy metal content was analyzed. The pollution extent in excess of background values was characterized by anthropogenic influence multiple, and the pollution of heavy metal in soil was evaluated using geoaccumulation index and a new method which connects geoaccumulation index with Nemero index. Finally, human health risk assessment was carried out with health risk assessment model for heavy metal content. The results showed that Qingdao North Station soil were polluted by heavy metals. Six heavy metal pollution levels were: Cd > Cu > Ni > Pb > Cr > Zn, and Cd had reached the severity pollution level, Cu and Ni followed by, Cr, Pb and Zn were in minor pollution level. The order of coefficient variation in all heavy metals was: Cd > Ni > Cr > Zn > Pb > Cu. Within the study area soil heavy metal distribution was different, but overall discrepancy was small. The order of non-cancer hazards of heavy metals in soil was Cr > Pb > Cu > Ni > Cd > Zn, and the order of carcinogen risks of heavy metals was Ni > Cd. The non-cancer hazard and carcinogen risks values of metals were both lower than that their threshold values. They were not the direct threats to human health. PMID:24289020

  12. Multiparameter radar analysis using wavelets

    NASA Astrophysics Data System (ADS)

    Tawfik, Ben Bella Sayed

    was observed namely, R( KDP) has reduced the spatial variability due to smoothing of KDP estimates. The convective and stratiform separation was studied using multiresolution analysis. The June 22, 1995 data collected by CSU-CHILL radar were used to evaluate the technique. Another set of data collected on August 23, 1991 representing stratiform conditions were also studied.

  13. Evaluation of the prompt alerting systems at four nuclear power stations

    SciTech Connect

    Towers, D.A.; Anderson, G.S.; Keast, D.N.; Kenoyer, J.L.; Desrosiers, A.E.

    1982-09-01

    This report presents evaluations of the prompt notification siren systems at the following four US nuclear power facilities: Trojan, Three Mile Island, Indian Point, and Zion. The objective of these evaluations was to provide examples of an analytical procedure for predicting siren-system effectiveness under specific conditions in the 10-mile emergency planning zone (EPZ) surrounding nuclear power plants. This analytical procedure is discussed in report No. PNL-4227.

  14. Initial Evaluation of Dual Frequency Radar (DPR) on Global Precipitation Measurement (GPM) Core Observatory and Global Precipitation Map (GSMaP)

    NASA Astrophysics Data System (ADS)

    Oki, R.; Kachi, M.; Kubota, T.; Masaki, T.; Kaneko, Y.; Takayabu, Y. N.; Iguchi, T.; Nakamura, K.

    2014-12-01

    The Global Precipitation Measurement (GPM) Core Observatory was successfully launched on February 28, 2014 (JST) from the JAXA Tanegashima Space Center by the H-IIA F23 rocket. The GPM mission is a satellite program led by Japan and the U.S. to measure the global distribution of precipitation accurately in a sufficient frequency. The GPM Core Observatory carries the Dual-frequency Precipitation Radar (DPR) developed by the Japan Aerospace Exploration Agency (JAXA) and the National Institute of Information and Communications Technology (NICT), and GPM Microwave Imager (GMI) developed by the National Aeronautics and Space Administration (NASA). The frequent precipitation measurement about every three hours will be achieved by constellation satellites with microwave radiometers or microwave sounders, which are provided by international partners. JAXA also provides the Global Change Observation Mission (GCOM) - Water (GCOM-W) named "SHIZUKU," as one of the constellation satellites. The Japanese GPM research project conducts scientific activities on algorithm development, ground validation, application research. JAXA develops the DPR Level 1 algorithm, and the NASA-JAXA Joint Algorithm Team develops the DPR Level 2 and DPR-GMI combined Level 2 algorithms. JAXA also develops the new version of Global Satellite Mapping of Precipitation (GSMaP) algorithm, which is hourly and 0.1-degree spatial resolution rain map, as one of the national products.After the 2-months initial checkout of the satellite and the sensors, calibration and validation of DPR and other products have been implemented toward the public release. For DPR evaluation includes: (1) sensitivity, observation range, etc., (2) consistency with TRMM, (3) comparison with ground rain gauge data, (4) ground based Ka radar validation and others. Initial results of quick data evaluation, validation and status of data processing will be presented.

  15. Evaluation of geophysical logs, Phase I, at Willow Grove Naval Air Station, Montgomery County, Pennsylvania

    USGS Publications Warehouse

    Conger, R.W.

    1997-01-01

    Between April and June 1997, the U.S. Navy contracted Brown and Root Environmental, Inc., to drill 20 monitor wells at the Willow Grove Naval Air Station in Horsham Township, Montgomery County, Pa. The wells were installed to monitor water levels and allow collection of water samples from shallow, intermediate, and deep water-bearing zones. Analysis of the samples will determine the horizontal and vertical distribution of any contaminated ground water migrating from known contaminant sources. Eight wells were drilled near the Fire Training Area (Site 5), five wells near the 9th Street Landfill (Site 3), four wells at the Antenna Field Landfill (Site 2), and three wells near Privet Road Compound (Site 1). Depths range from 73 to 167 feet below land surface. The U.S. Geological Survey conducted borehole-geophysical and borehole-video logging to identify water-bearing zones so that appropriate intervals could be screened in each monitor well. Geophysical logs were run on the 20 monitor wells and 1 existing well. Video logs were run on 16 wells. Caliper and video logs were used to locate fractures, inflections on fluid-temperature and fluid-resistivity logs were used to locate possible water-bearing fractures, and flowmeter measurements verified these locations. Single-point-resistance and natural-gamma logs provided information on stratigraphy. After interpretation of geophysical logs, video logs, and driller's notes, all wells were screened such that water-level fluctuations could be monitored and discrete water samples collected from one or more shallow and intermediate water-bearing zones in each borehole.

  16. Evaluating the Medical Kit System for the International Space Station(ISS) - A Paradigm Revisited

    NASA Technical Reports Server (NTRS)

    Hailey, Melinda J.; Urbina, Michelle C.; Hughlett, Jessica L.; Gilmore, Stevan; Locke, James; Reyna, Baraquiel; Smith, Gwyn E.

    2010-01-01

    Medical capabilities aboard the International Space Station (ISS) have been packaged to help astronaut crew medical officers (CMO) mitigate both urgent and non-urgent medical issues during their 6-month expeditions. Two ISS crewmembers are designated as CMOs for each 3-crewmember mission and are typically not physicians. In addition, the ISS may have communication gaps of up to 45 minutes during each orbit, necessitating medical equipment that can be reliably operated autonomously during flight. The retirement of the space shuttle combined with ten years of manned ISS expeditions led the Space Medicine Division at the NASA Johnson Space Center to reassess the current ISS Medical Kit System. This reassessment led to the system being streamlined to meet future logistical considerations with current Russian space vehicles and future NASA/commercial space vehicle systems. Methods The JSC Space Medicine Division coordinated the development of requirements, fabrication of prototypes, and conducted usability testing for the new ISS Medical Kit System in concert with implementing updated versions of the ISS Medical Check List and associated in-flight software applications. The teams constructed a medical kit system with the flexibility for use on the ISS, and resupply on the Russian Progress space vehicle and future NASA/commercial space vehicles. Results Prototype systems were developed, reviewed, and tested for implementation. Completion of Preliminary and Critical Design Reviews resulted in a streamlined ISS Medical Kit System that is being used for training by ISS crews starting with Expedition 27 (June 2011). Conclusions The team will present the process for designing, developing, , implementing, and training with this new ISS Medical Kit System.

  17. Study to investigate and evaluate means of optimizing the Ku-band combined radar/communication functions for the space shuttle

    NASA Technical Reports Server (NTRS)

    Weber, C. L.; Udalov, S.; Alem, W.

    1977-01-01

    The performance of the space shuttle orbiter's Ku-Band integrated radar and communications equipment is analyzed for the radar mode of operation. The block diagram of the rendezvous radar subsystem is described. Power budgets for passive target detection are calculated, based on the estimated values of system losses. Requirements for processing of radar signals in the search and track modes are examined. Time multiplexed, single-channel, angle tracking of passive scintillating targets is analyzed. Radar performance in the presence of main lobe ground clutter is considered and candidate techniques for clutter suppression are discussed. Principal system parameter drivers are examined for the case of stationkeeping at ranges comparable to target dimension. Candidate ranging waveforms for short range operation are analyzed and compared. The logarithmic error discriminant utilized for range, range rate and angle tracking is formulated and applied to the quantitative analysis of radar subsystem tracking loops.

  18. Test and evaluation of the heat recovery incinerator system at Naval Station, Mayport, Florida. Final report, June 1980-April 1981

    SciTech Connect

    Not Available

    1981-05-01

    This report describes test and evaluation of the two-ton/hr heat recovery incinerator (HRI) facility located at Mayport Naval Station, FL, carried out during November and December 1980. The tests included: (1) Solid Waste: characterization, heating value, and ultimate analysis, (2) Ash: moisture, combustibles, and heating values of both bottom and cyclone ashes; Extraction Procedure toxicity tests on leachates from both bottom and cyclone ashes; trace metals in cyclone particulates, (3) Stack Emissions: particulates (quantity and size distribution), chlorides, oxygen, carbon dioxide, carbon monoxide, and trace elements, and (4) Heat and Mass Balance: all measurements required to carry out complete heat and mass balance calculations over the test period. The overall thermal efficiency of the HRI facility while operating at approximately 1.0 ton/hr was found to be 49% when the primary Btu equivalent of the electrical energy consumed during the test program was included.

  19. Evaluation of a Treadmill with Vibration Isolation and Stabilization (TVIS) for Use on the International Space Station

    NASA Technical Reports Server (NTRS)

    McCrory, Jean L.; Lemmon, David R.; Sommer, H. Joseph; Prout, Brian; Smith, Damon; Korth, Deborah W.; Lucero, Javier; Greenisen, Michael; Moore, Jim

    1999-01-01

    A treadmill with vibration isolation and stabilization designed for the International Space Station (ISS) was evaluated during Shuttle mission STS-81. Three crew members ran and walked on the device, which floats freely in zero gravity. For the majority of the more than 2 hours of locomotion studied, the treadmill showed peak to peak linear and angular displacements of less than 2.5 cm and 2.5 deg, respectively. Vibration transmitted to the vehicle was within the microgravity allocation limits that are defined for the ISS. Refinements to the treadmill and harness system are discussed. This approach to treadmill design offers the possibility of generating 1G-like loads on the lower extremities while preserving the microgravity environment of the ISS for structural safety and vibration free experimental conditions.

  20. XOQDOQ: computer program for the meteorological evaluation of routine effluent releases at nuclear power stations. Final report

    SciTech Connect

    Sagendorf, J.F.; Goll, J.T.; Sandusky, W.F.

    1982-09-01

    Provided is a user's guide for the US Nuclear Regulatory Commission's (NRC) computer program X0QDOQ which implements Regulatory Guide 1.111. This NUREG supercedes NUREG-0324 which was published as a draft in September 1977. This program is used by the NRC meteorology staff in their independent meteorological evaluation of routine or anticipated intermittent releases at nuclear power stations. It operates in a batch input mode and has various options a user may select. Relative atmospheric dispersion and deposition factors are computed for 22 specific distances out to 50 miles from the site for each directional sector. From these results, values for 10 distance segments are computed. The user may also select other locations for which atmospheric dispersion deposition factors are computed. Program features, including required input data and output results, are described. A program listing and test case data input and resulting output are provided.

  1. Evaluation of a Treadmill with Vibration Isolation and Stabilization (TVIS) for use on the International Space Station.

    PubMed

    McCrory, J L; Lemmon, D R; Sommer, H J; Prout, B; Smith, D; Korth, D W; Lucero, J; Greenisen, M; Moore, J; Kozlovskaya, I; Pestov, I; Stepansov, V; Miyakinchenko, Y; Cavanagh, P R

    1999-08-01

    A treadmill with vibration isolation and stabilization designed for the International Space Station (ISS) was evaluated during Shuttle mission STS-81. Three crew members ran and walked on the device, which floats freely in zero gravity. For the majority of the more than 2 hours of locomotion studied, the treadmill showed peak to peak linear and angular displacements of less than 2.5 cm and 2.5 degrees, respectively. Vibration transmitted to the vehicle was within the microgravity allocation limits that are defined for the ISS. Refinements to the treadmill and harness system are discussed. This approach to treadmill design offers the possibility of generating 1G-like loads on the lower extremities while preserving the microgravity environment of the ISS for structural safety and vibration free experimental conditions.

  2. Evaluation of Two Ionic Liquid-Based Epoxies from the MISSE-8 (Materials International Space Station Experiment-8) Sample Carrier

    NASA Technical Reports Server (NTRS)

    Rabenberg, Ellen; Kaukler, William; Grugel, Richard

    2015-01-01

    Two sets of epoxy mixtures, both containing the same ionic liquid (IL) based resin but utilizing two different curing agents, were evaluated after spending more than two years of continual space exposure outside of the International Space Station on the MISSE-8 sample rack. During this period the samples, positioned on nadir side, also experienced some 12,500 thermal cycles between approximately -40?C and +40 C. Initial examination showed some color change, a miniscule weight variance, and no cracks or de-bonding from the sample substrate. Microscopic examination of the surface reveled some slight deformities and pitting. These observations, and others, are discussed in view of the ground-based control samples. Finally, the impetus of this study in terms of space applications is presented.

  3. Evaluation on the environmental radioactivity in Shanghai city during the normal operational condition of Qinshan nuclear power station.

    PubMed

    Lu, Heqing; Wang, Qiang

    2013-08-01

    The objective of this work was to evaluate the impact of environmental radioactivity in Shanghai from the operation of Qinshan Nuclear Power Station (QNPS). The levels of terrestrial gamma radiation and radioactivities in the drinking water, main food and soils in the Jinshan area where is only 38 km far away from the QNPS were continuously measured in the past 19 y. Both the levels of terrestrial gamma radiation and the radioactivities in the samples were on the normal background levels. No significant changes were found before and after the running of QNPS. The annual public exposure to the terrestrial gamma radiation was estimated to be ∼0.1 mSv, and the annual exposure from intakes of (90)Sr and (137)Cs in food was ∼0.5 μSv. In the past 19 y, no significant impact on the environmental radioactivity in Shanghai was observed due to the operation of QNPS.

  4. The proposed flatland radar

    NASA Technical Reports Server (NTRS)

    Green, J. L.; Gage, K. S.; Vanzandt, T. E.; Nastrom, G. D.

    1986-01-01

    A flexible very high frequency (VHF) stratosphere-troposphere (ST) radar configured for meteorological research is to be constructed near Urbana, Illinois. Measurement of small vertical velocities associated with synoptic-scale meteorology can be performed. A large Doppler microwave radar (CHILL) is located a few km from the site of the proposed ST radar. Since the microwave radar can measure the location and velocity of hydrometeors and the VHF ST radar can measure clear (or cloudy) air velocities, simultaneous observations by these two radars of stratiform or convective weather systems would provide valuable meteorological information.

  5. Real-Time Risk and Fault Management in the Mission Evaluation Room for the International Space Station

    SciTech Connect

    Nelson, W.R.; Novack, S.D.

    2003-05-30

    Effective anomaly resolution in the Mission Evaluation Room (MER) of the International Space Station (ISS) requires consideration of risk in the process of identifying faults and developing corrective actions. Risk models such as fault trees from the ISS Probabilistic Risk Assessment (PRA) can be used to support anomaly resolution, but the functionality required goes significantly beyond what the PRA could provide. Methods and tools are needed that can systematically guide the identification of root causes for on-orbit anomalies, and to develop effective corrective actions that address the event and its consequences without undue risk to the crew or the mission. In addition, an overall information management framework is needed so that risk can be systematically incorporated in the process, and effectively communicated across all the disciplines and levels of management within the space station program. The commercial nuclear power industry developed such a decision making framework, known as the critical safety function approach, to guide emergency response following the accident at Three Mile Island in 1979. This report identifies new methods, tools, and decision processes that can be used to enhance anomaly resolution in the ISS Mission Evaluation Room. Current anomaly resolution processes were reviewed to identify requirements for effective real-time risk and fault management. Experience gained in other domains, especially the commercial nuclear power industry, was reviewed to identify applicable methods and tools. Recommendations were developed for next-generation tools to support MER anomaly resolution, and a plan for implementing the recommendations was formulated. The foundation of the proposed tool set will be a ''Mission Success Framework'' designed to integrate and guide the anomaly resolution process, and to facilitate consistent communication across disciplines while focusing on the overriding importance of mission success.

  6. Real-Time Risk and Fault Management in the Mission Evaluation Room of the International Space Station

    SciTech Connect

    William R. Nelson; Steven D. Novack

    2003-05-01

    Effective anomaly resolution in the Mission Evaluation Room (MER) of the International Space Station (ISS) requires consideration of risk in the process of identifying faults and developing corrective actions. Risk models such as fault trees from the ISS Probablistic Risk Assessment (PRA) can be used to support anomaly resolution, but the functionality required goes significantly beyond what the PRA could provide. Methods and tools are needed that can systematically guide the identification of root causes for on-orbit anomalies, and to develop effective corrective actions that address the event and its consequences without undue risk to the crew or the mission. In addition, an overall information management framework is needed so that risk can be systematically incorporated in the process, and effectively communicated across all the disciplines and levels of management within the space station program. The commercial nuclear power industry developed such a decision making framework, known as the critical safety function approach, to guide emergency response following the accident at Three Mile Island in 1979. This report identifies new methods, tools, and decision processes that can be used to enhance anomaly resolution in the ISS Mission Evaluation Room. Current anomaly resolution processes were reviewed to identify requirements for effective real-time risk and fault management. Experience gained in other domains, especially the commercial nuclear power industry, was reviewed to identify applicable methods and tools. Recommendations were developed for next-generation tools to support MER anomaly resolution, and a plan for implementing the recommendations was formulated. The foundation of the proposed toolset will be a "Mission Success Framework" designed to integrate and guide the anomaly resolution process, and to facilitate consistent communication across disciplines while focusing on the overriding importance of mission success.

  7. Computing Real-time Streamflow Using Emerging Technologies: Non-contact Radars and the Probability Concept

    NASA Astrophysics Data System (ADS)

    Fulton, J. W.; Bjerklie, D. M.; Jones, J. W.; Minear, J. T.

    2015-12-01

    Measuring streamflow, developing, and maintaining rating curves at new streamgaging stations is both time-consuming and problematic. Hydro 21 was an initiative by the U.S. Geological Survey to provide vision and leadership to identify and evaluate new technologies and methods that had the potential to change the way in which streamgaging is conducted. Since 2014, additional trials have been conducted to evaluate some of the methods promoted by the Hydro 21 Committee. Emerging technologies such as continuous-wave radars and computationally-efficient methods such as the Probability Concept require significantly less field time, promote real-time velocity and streamflow measurements, and apply to unsteady flow conditions such as looped ratings and unsteady-flood flows. Portable and fixed-mount radars have advanced beyond the development phase, are cost effective, and readily available in the marketplace. The Probability Concept is based on an alternative velocity-distribution equation developed by C.-L. Chiu, who pioneered the concept. By measuring the surface-water velocity and correcting for environmental influences such as wind drift, radars offer a reliable alternative for measuring and computing real-time streamflow for a variety of hydraulic conditions. If successful, these tools may allow us to establish ratings more efficiently, assess unsteady flow conditions, and report real-time streamflow at new streamgaging stations.

  8. An Evaluation of a Welding Fumes Exhaust System. Agricultural Experiment Station Research Report 284.

    ERIC Educational Resources Information Center

    Jacobs, C. O.

    A study evaluated the feasibility of introducing unheated outside air into the airstream of a cross-flow welding exhaust system to reduce heating energy costs of a school welding laboratory. The physical facility used was the agricultural mechanics laboratory at the University of Arizona, which is similar to facilities in which instruction in…

  9. Radiological Assessment Code System - Meteorological Evaluation of Routine Effluent Releases at Nuclear Power Stations.

    1989-07-31

    Version 00 XOQDOQ-82 evaluates the transport, dispersion, and deposition of effluents released to the atmosphere. Since the program uses meteorological data averaged over long periods of time, it is appropriate for use in environmental impact studies rather than in the analyses of accidental releases.

  10. 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.

  11. Airborne derivation of microburst alerts from ground-based Terminal Doppler Weather Radar information: A flight evaluation

    NASA Technical Reports Server (NTRS)

    Hinton, David A.

    1993-01-01

    An element of the NASA/FAA windshear program is the integration of ground-based microburst information on the flight deck, to support airborne windshear alerting and microburst avoidance. NASA conducted a windshear flight test program in the summer of 1991 during which airborne processing of Terminal Doppler Weather Radar (TDWR) data was used to derive microburst alerts. Microburst information was extracted from TDWR, transmitted to a NASA Boeing 737 in flight via data link, and processed to estimate the windshear hazard level (F-factor) that would be experienced by the aircraft in each microburst. The microburst location and F-factor were used to derive a situation display and alerts. The situation display was successfully used to maneuver the aircraft for microburst penetrations, during which atmospheric 'truth' measurements were made. A total of 19 penetrations were made of TDWR-reported microburst locations, resulting in 18 airborne microburst alerts from the TDWR data and two microburst alerts from the airborne reactive windshear detection system. The primary factors affecting alerting performance were spatial offset of the flight path from the region of strongest shear, differences in TDWR measurement altitude and airplane penetration altitude, and variations in microburst outflow profiles. Predicted and measured F-factors agreed well in penetrations near microburst cores. Although improvements in airborne and ground processing of the TDWR measurements would be required to support an airborne executive-level alerting protocol, the practicality of airborne utilization of TDWR data link data has been demonstrated.

  12. Aging of nuclear station diesel generators: Evaluation of operating and expert experience: Phase 1, Study

    SciTech Connect

    Hoopingarner, K.R.; Vause, J.W.; Dingee, D.A.; Nesbitt, J.F.

    1987-08-01

    Pacific Northwest Laboratory evaluated operational and expert experience pertaining to the aging degradation of diesel generators in nuclear service. The research, sponsored by the US Nuclear Regulatory Commission (NRC), identified and characterized the contribution of aging to emergency diesel generator failures. This report, Volume I, reviews diesel-generator experience to identify the systems and components most subject to aging degradation and isolates the major causes of failure that may affect future operational readiness. Evaluations show that as plants age, the percent of aging-related failures increases and failure modes change. A compilation is presented of recommended corrective actions for the failures identified. This study also includes a review of current, relevant industry programs, research, and standards. Volume II reports the results of an industry-wide workshop held on May 28 and 29, 1986 to discuss the technical issues associated with aging of nuclear service emergency diesel generators.

  13. Evaluation of 3% hydrogen peroxide for use as an environmental disenfectant aboard the Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Lucia, Helen L.; Mishra, S. K.; Gunter, Emelie G.; Pierson, Duane L.

    1993-01-01

    We evaluate the ability of a 3% (8800 micromolar) solution of hydogen peroxide to kill 12 strains of bacteria and 12 strains of fungi. A 1:4 dilution of 3% H2O2 equivalent to 1100 micromolar, was lethal to all the tested strains. If the situation calls for a nonagressive disinfectant without residue or toxic aftereffects, 3% H2O2 seems an ideal choice.

  14. Evaluation of 25 y of environmental monitoring data around Madras Atomic Power Station (MAPS), Kalpakkam, India.

    PubMed

    Rajaram, S; Brindha, J Thulasi; Sreedevi, K R; Manu, Anitha; Thilakavathi, A; Ramkumar, S; Santhanakrishnan, V; Balagurunathan, M R; Jesan, T; Kannan, V; Hegde, A G

    2010-12-01

    The Environmental Survey Laboratory at Kalpakkam, India carries out elaborate monitoring programme involving atmospheric, terrestrial and aquatic samples for radioactivity to evaluate the impact of operating two pressurised heavy water reactors. This paper presents the evaluation of 25 y (1983-2008) data. Statistical analysis of the environmental data for different radionuclides showed that the data best fits log-normal distribution. The data analysed showed that fission products such as (137)Cs, (90)Sr and (131)I were due to global fallout only. A ratio of 0.2 was obtained for (90)Sr to (137)Cs in air filter samples, only during Chernobyl accident period. The transfer factor of (137)Cs and (90)Sr for rice was computed to be 0.23 and 0.03 and vegetables 0.25 and 0.10, respectively. Activation products (3)H and (41)Ar are the only radionuclides that are related to MAPS operation. A strong correlation (r = 0.9) was observed between (3)H activity in air and (3)H discharged to the atmosphere. A similar correlation (r = 0.8) was observed in (3)H concentration in seawater and (3)H discharged in the liquid waste. The annual internal dose due to (3)H and annual external dose due to (41)Ar evaluated in the last 25 y show that the members of the public received less than 2 % of the dose limit (1 mSv y(-1)) set by ICRP 72.

  15. Global radar units on Venus derived from statistical analysis of Pioneer Venus Orbiter radar data

    NASA Technical Reports Server (NTRS)

    Davis, P. A.; Kozak, R. C.; Schaber, G. G.

    1986-01-01

    The classification of surface radar units on Venus using an unsupervised cluster analysis of Pioneer Venus radar reflectivity and root-mean-square (rms)-slope data is described. The advantages of the unsupervised analysis are discussed. F tests are utilized to evaluate the numerical significance of the clusters. The derived rms-slope data and reflectivity for 15 radar units are presented. The relations between radar data bases and elevation are studied. The lowlands, rolling plains, highlands, and mountainous surface of Venus are examined. The geology of Venus landing sites and radar properties, and the surface radar reflectivity images and earth-based images are compared. The spatial relations between classification units are calculated. It is concluded that the unsupervised analysis data correlate well with Head et al. (1985b) data and produce more detailed classification images.

  16. The MST Radar Technique

    NASA Technical Reports Server (NTRS)

    Roettger, J.

    1984-01-01

    The coherent radar technique is reviewed with special emphasis to mesosphere-stratosphere-troposphere (MST) radars operating in the VHF band. Some basic introduction to Doppler radar measurements and the radar equation is followed by an outline of the characteristics of atmospheric turbulence, viewed from the scattering and reflection processes of radar signals. Radar signal acquisition and preprocessing, namely coherent detection, digital sampling, pre-integration and coding, is briefly discussed. The data analysis is represented in terms of the correlation and spectrum analysis, yielding the essential parameters: power, signal-to-noise ratio, average and fluctuating velocity and persistency. The techniques to measure wind velocities, viz. the different modes of the Doppler method as well as the space antenna method are surveyed and the feasibilities of the MST radar interferometer technique are elucidated. A general view on the criteria to design phased array antennas is given. An outline of the hardware of a typical MST radar system is presented.

  17. Past-time Radar Rainfall Estimates using Radar AWS Rainrate system with Local Gauge Correction method

    NASA Astrophysics Data System (ADS)

    Choi, D.; Lee, M. H.; Suk, M. K.; Nam, K. Y.; Hwang, J.; Ko, J. S.

    2015-12-01

    The Weather Radar Center at Korea Meteorological Administration (KMA) has radar network for warnings for heavy rainfall and severe storms. We have been operating an operational real-time adjusted the Radar-Automatic Weather Station (AWS) Rainrate (RAR) system developed by KMA in 2006 for providing radar-based quantitative precipitation estimation (QPE) to meteorologists. This system has several uncertainty in estimating precipitation by radar reflectivity (Z) and rainfall intensity (R) relationship. To overcome uncertainty of the RAR system and improve the accuracy of QPE, we are applied the Local Gauge Correction (LGC) method which uses geo-statistical effective radius of errors of the QPE to RAR system in 2012. According to the results of previous study in 2014 (Lee et al., 2014), the accuracy of the RAR system with LGC method improved about 7.69% than before in the summer season of 2012 (from June to August). It has also improved the accuracy of hydrograph when we examined the accuracy of flood simulation using hydrologic model and data derived by the RAR system with LGC method. We confirmed to have its effectiveness through these results after the application of LGC method. It is required for high quality data of long term to utilize in hydrology field. To provide QPE data more precisely and collect past-time data, we produce that calculated by the RAR system with LGC method in the summer season from 2006 to 2009 and investigate whether the accuracy of past-time radar rainfall estimation enhance or not. Keywords : Radar-AWS Rainrate system, Local gauge correction, past-time Radar rainfall estimation Acknowledgements : This research is supported by "Development and application of Cross governmental dual-pol radar harmonization (WRC-2013-A-1)" project of the Weather Radar Center, Korea Meteorological Administration in 2015.

  18. Doppler radar results

    NASA Technical Reports Server (NTRS)

    Bracalente, Emedio M.

    1992-01-01

    The topics are covered in viewgraph form and include the following: (1) a summary of radar flight data collected; (2) a video of combined aft cockpit, nose camera, and radar hazard displays; (3) a comparison of airborne radar F-factor measurements with in situ and Terminal Doppler Weather Radar (TDWR) F-factors for some sample events; and (4) a summary of wind shear detection performance.

  19. Radar measurement instruments

    NASA Astrophysics Data System (ADS)

    Hartl, P.

    1983-02-01

    The radar techniques used for Earth observation are reviewed. Range, direction and speed measuring techniques, and the principles of scatterometers, side-looking radar, altimeters and SAR are discussed. The ERS-1 radar package including the active microwave instrumentation and the radar altimeter are described. The analysis of the calibration problems leads to the conclusion that only the test of the system loop as a whole, besides the individual part tests, can provide a calibration in the absolute sense.

  20. Rain-Mapping Radar

    NASA Technical Reports Server (NTRS)

    Im, K. E.; Li, F. K.; Wilson, W. J.; Rosing, D.

    1988-01-01

    Orbiting radar system measures rates of rainfall from 0.5 to 60 mm/h. Radar waves scattered and absorbed by rainfall to extents depending on wavelength, polarization, rate of rainfall, and distribution of sizes and shapes of raindrops. Backscattered radar signal as function of length of path through rain used to infer detailed information about rain. Accumulated radar return signals processed into global maps of monthly average rainfall for use in climatological studies.

  1. Aging of nuclear station diesel generators: Evaluation of operating and expert experience: Workshop

    SciTech Connect

    Hoopingarner, K.R.; Vause, J.W.

    1987-08-01

    Pacific Northwest Laboratory (PNL) evaluated operational and expert experience pertaining to the aging degradation of diesel generators in nuclear service. The research, sponsored by the US Nuclear Regulatory Commission (NRC), identified and characterized the contribution of aging to emergency diesel generator failures. This report, Volume II, reports the results of an industry-wide workshop held on May 28 and 29, 1986, to discuss the technical issues associated with aging of nuclear service emergency diesel generators. The technical issues discussed most extensively were: man/machine interfaces, component interfaces, thermal gradients of startup and cooldown and the need for an accurate industry database for trend analysis of the diesel generator system.

  2. Comparison and evaluation of nuclear power plant options for geosynchronous power stations

    NASA Technical Reports Server (NTRS)

    Williams, J. R.

    1975-01-01

    The suitability of eleven types of nuclear fission reactors in combination with five potential energy conversion systems for use in geosynchronous power plants is evaluated. Gas turbine, potassium Rankine liquid metal MHD, and thermionic energy conversion systems are considered. The existing technology of reactors in near-term, intermediate-term, and long-term classes is discussed, together with modifications for use in large-scale power production in space. Unless the temperature is high enough for MHD, reactors which heat gases are generally more suitable for use with gas turbines. Those which heat liquid metals will be more useful for potassium Rankine or liquid metal MHD conversion systems.

  3. Imaging radar observations of Askja Caldera, Iceland

    NASA Technical Reports Server (NTRS)

    Malin, M. C.; Evans, D.; Elachi, C.

    1978-01-01

    A 'blind' test involving interpretation of computer-enhanced like- and cross-polarized radar images is used to evaluate the surface roughness of Askja Caldera, a large volcanic complex in central Iceland. The 'blind' test differs from earlier analyses of radar observations in that computer-processes images and both qualitative and quantitative analyses are used. Attention is given to photogeologic examination and subsequent survey-type field observations, along with aerial photography during the field trip. The results indicate that the 'blind' test of radar interpretation of the Askja volcanic area can be considered suitable within the framework of limitations of radar data considered explicitly from the onset. The limitations of the radar techniques can be eliminated by using oblique-viewing conditions to remove geometric distortions and slope effects.

  4. Fractal characteristics for binary noise radar waveform

    NASA Astrophysics Data System (ADS)

    Li, Bing C.

    2016-05-01

    Noise radars have many advantages over conventional radars and receive great attentions recently. The performance of a noise radar is determined by its waveforms. Investigating characteristics of noise radar waveforms has significant value for evaluating noise radar performance. In this paper, we use binomial distribution theory to analyze general characteristics of binary phase coded (BPC) noise waveforms. Focusing on aperiodic autocorrelation function, we demonstrate that the probability distributions of sidelobes for a BPC noise waveform depend on the distances of these sidelobes to the mainlobe. The closer a sidelobe to the mainlobe, the higher the probability for this sidelobe to be a maximum sidelobe. We also develop Monte Carlo framework to explore the characteristics that are difficult to investigate analytically. Through Monte Carlo experiments, we reveal the Fractal relationship between the code length and the maximum sidelobe value for BPC waveforms, and propose using fractal dimension to measure noise waveform performance.

  5. Health hazard evaluation report HETA 82-093-1453, Southwest Power Station City Utilities, Springfield, Missouri

    SciTech Connect

    Zey, J.N.; Aw, T.C.

    1984-04-01

    In response to a request from the Safety Department of City Utilities to evaluate employee exposures to coal and other dusts and fumes at the Southwest Power Facility (SIC-4911), Springfield, Missouri a visit was made to the site. All personal coal dust, fly ash, crystalline silica (14808607), nitrogen-dioxide (10102440), nitric-oxide (10102439), and sulfuric-acid (7664939) samples were below the lowest current criterion level. Four of eight personal sulfur-dioxide (7446095) samples exceeded the NIOSH recommended criterion of 1.3mg/cu m. Medical evaluation resulted in the identification of three workers with chronic bronchitis each of whom smoked cigarettes, eight workers with pulmonary function test abnormalities indicating obstructive airways disease, and two workers with features of restrictive lung disease. One chest X-ray was consistent with pneumoconiosis. The authors conclude that a health hazard existed for employees exposed to sulfur-dioxide and noise. A potential hazard also existed for employee exposure to heat stress in certain locations in the facility. The authors recommend improvements in the respiratory protection program, use of personal protective equipment, and initiation of an employee training program and environmental monitoring by management.

  6. Evaluation of a Gas Chromatograph-Differential Mobility Spectrometer for Potential Water Monitoring on the International Space Station

    NASA Technical Reports Server (NTRS)

    Wallace, William T.; Limero, Thomas F.; Gazda, Daniel B.; Macatangay, Ariel V.; Dwivedi, Prabha; Fernandez, Facundo M.

    2015-01-01

    Environmental monitoring for manned spaceflight has long depended on archival sampling, which was sufficient for short missions. However, the longer mission durations aboard the International Space Station (ISS) have shown that enhanced, real-time monitoring capabilities are necessary in order to protect both the crewmembers and the spacecraft systems. Over the past several years, a number of real-time environmental monitors have been deployed on the ISS. Currently, volatile organic compounds (VOCs) in the station air are monitored by the Air Quality Monitor (AQM), a small, lightweight gas chromatograph-differential mobility spectrometer. For water monitoring, real-time monitors are used for total organic carbon (TOC) and biocide analysis. No information on the actual makeup of the TOC is provided presently, however. An improvement to the current state of environmental monitoring could be realized by modifying a single instrument to analyze both air and water. As the AQM currently provides quantitative, compound-specific information for VOCs in air samples, this instrument provides a logical starting point to evaluate the feasibility of this approach. The major hurdle for this effort lies in the liberation of the target analytes from the water matrix. In this presentation, we will discuss our recent studies, in which an electro-thermal vaporization unit has been interfaced with the AQM to analyze target VOCs at the concentrations at which they are routinely detected in archival water samples from the ISS. We will compare the results of these studies with those obtained from the instrumentation routinely used to analyze archival water samples.

  7. The Provence ST radar

    NASA Technical Reports Server (NTRS)

    Crochet, M.

    1986-01-01

    Since the Alpex Campaign, when 3 Stratosphere-Troposphere (ST) radar operated in Camarque as a cooperative effort of the Aeronomy Laboratory of NOAA, CO, and LSEET from Toulon, a 50 MHz Very High Frequency (VHF) ST radar was developed, improved, and tested. The operating characteristics, main objectives, preliminary results, and future experiment costs of the VHF ST radar are discussed.

  8. 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…

  9. Controlling radar signature

    SciTech Connect

    Foulke, K.W. )

    1992-08-01

    Low observable technologies for military and tactical aircraft are reviewed including signature-reduction techniques and signal detection/jamming. Among the applications considered are low-signature sensors and the reduction of radar cross section in conjunction with radar-absorbing structures and materials. Technologies for reducing radar cross section are shown to present significant technological challenges, although they afford enhanced aircraft survivability.

  10. A Critical Evaluation of Ground-Penetrating Radar Methodology on the Kalavasos and Maroni Built Environments (KAMBE) Project, Cyprus (Invited)

    NASA Astrophysics Data System (ADS)

    Leon, J.; Urban, T.; Gerard-Little, P.; Kearns, C.; Manning, S. W.; Fisher, K.; Rogers, M.

    2013-12-01

    at these settlements. Having just completed this first phase of the project, we report on the results of large-scale geophysical survey, including the identification of at least two previously unknown building complexes (one at each site). Here we focus particularly on ground-penetrating radar (GPR) data and survey methodology, in an effort to critically examine the range of approaches applied throughout the project (e.g. various antennae frequencies, data-collection densities, soil moisture/seasonality of survey, and post-collection data processing [2]), and to identify the most effective parameters for archaeological geophysical survey in the region. This paper also advocates for the role of geophysical survey within a multi-component archaeological project, not simply as a prospection tool but as an archaeological data collection method in its own right. 1]Fisher, K. D., J. Leon, S. Manning, M. Rogers, and D. Sewell. In Press. 2011-2012. 'The Kalavasos and Maroni Built Environments Project: Introduction and preliminary report on the 2008 and 2010 seasons. Report of the Department of Antiquities, Cyprus. 2] e.g. Rogers, M., J. F. Leon, K. D. Fisher, S. W. Manning and D. Sewell. 2012. 'Comparing similar ground-penetrating radar surveys under different soil moisture conditions at Kalavasos-Ayios Dhimitrios, Cyprus.' Archaeological Prospection 19 (4): 297-305.

  11. Using three-parameter models to evaluate the Good Cents(TM) program in College Station, Texas

    NASA Astrophysics Data System (ADS)

    Ellingson, Lee Allen

    Integrated Resource Planning (IRP) refers to a comprehensive strategy adopted by many utility companies that addresses both the supply and demand of energy. Activities that focus on the demand for energy are called Demand Side Management (DSM). This study is an evaluation of a DSM program sponsored by College Station, Texas, called the Good CentsspTM Program. The Good Cents Program is designed to encourage builders to build more energy-efficient homes. One difficulty with evaluating this type of program is that energy use not related to outdoor air temperature introduces a large amount of unexplained variability into total energy use. This study uses a statistical method that separates energy related to outdoor temperature from energy not related to outdoor temperature. Three-parameter models have proven to be very useful in modeling residential energy use. This study uses parameter estimates of three-parameter models to compare a treatment group of Good Cents houses to a control group of non-Good Cents houses. Parameters used are cooling slope, heating slope, and Normalized Annual Consumption (NAC). In addition, independent variables are regressed against the cooling and heating slopes to determine which variables correlate to energy efficiency.

  12. Redetermination of the precise gravity fields around the Japanese Antarctic Station, Syowa, and evaluation of GOCE EGMs

    NASA Astrophysics Data System (ADS)

    Fukuda, Y.; Nogi, Y.; Matsuzaki, K.

    2014-12-01

    We have been conducting the precise gravity field determination around the Japanese Antarctic Station, Syowa in Lützow-Holm Bay, East Antarctica. So far, we employed GOCE (Gravity field and steady-state Ocean Circulation Explorer) RL-4 and earlier versions of the EGMs and the in-situ gravity data obtained by the Japanese Antarctic Research Expedition (JARE), i.e., land gravity data since 1967, surface ship data since 1985 and airborne gravity data in 2006. Using these data sets, we calculated the precise gravity fields by means of Least Squares Colocations (LSC) and evaluated the GOCE EGMs by comparing with the in-situ gravity data. Recently, new GOCE EGMs, TIM RL-5 and DIR RL-5 have been released. In addition, JARE ship borne gravity data have been reprocessed following a more unified procedure and some land gravity data have been added. Accordingly, we have recalculated the gravity fields using all the data combined. Practically, using those data sets, we estimated gravity anomalies and geoid heights in the area of 60-80S and 20-60E by means of LSC using a GOCE EGM as the long wave-length gravity fields and an empirical covariance function estimated from the airborne gravity data. In this procedure as well as using the obtained gravity field data, we also evaluated GOCE EGMs and other recent EGMs.

  13. Structural review of the San Onofre Nuclear Generation Station Unit 1 containment structure under combined loads. Systematic Evaluation Program

    SciTech Connect

    Lo, T.Y.

    1982-05-01

    This report is a structural assessment of the containment structure of the San Onofre Nuclear Generation Station Unit 1, performed for the Nuclear Regulatory Commission as part of the Systematic Evaluation Program (SEP). The San Onofre assessment focused on the overall structural integrity of the containment structure under a safe shutdown earthquake an a postulated design basis accident. The safe shutdown earthquake was represented by the Housner Spectra, scaled to 0.67 g peak ground acceleration. The postulated design basis accident was either a loss of coolant accident or a main steam line break. Several combined stresses were evaluated for their adherence to the 1980 edition of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code allowables. All the calculated stress intensities were found to be acceptable according to this code except the general primary membrane stress due to combined dead and pressure loads under level A service limits. Because the containment structure was previously tested under combined dead and pressure loads for a higher peak pressure than the one used here, this study concluded that it was acceptable.

  14. Space Station operations

    NASA Technical Reports Server (NTRS)

    Gray, R. H.

    1985-01-01

    An evaluation of the success of the Space Station will be based on the service provided to the customers by the Station crew, the productivity of the crew, and the costs of operation. Attention is given to details regarding Space Station operations, a summary of operational philosophies and requirements, logistics and resupply operations, prelaunch processing and launch operations, on-orbit operations, aspects of maintainability and maintenance, habitability, and questions of medical care. A logistics module concept is considered along with a logistics module processing timeline, a habitability module concept, and a Space Station rescue mission.

  15. Pattern recognition applied to seismic signals of Llaima volcano (Chile): An evaluation of station-dependent classifiers

    NASA Astrophysics Data System (ADS)

    Curilem, Millaray; Huenupan, Fernando; Beltrán, Daniel; San Martin, Cesar; Fuentealba, Gustavo; Franco, Luis; Cardona, Carlos; Acuña, Gonzalo; Chacón, Max; Khan, M. Salman; Becerra Yoma, Nestor

    2016-04-01

    Automatic pattern recognition applied to seismic signals from volcanoes may assist seismic monitoring by reducing the workload of analysts, allowing them to focus on more challenging activities, such as producing reports, implementing models, and understanding volcanic behaviour. In a previous work, we proposed a structure for automatic classification of seismic events in Llaima volcano, one of the most active volcanoes in the Southern Andes, located in the Araucanía Region of Chile. A database of events taken from three monitoring stations on the volcano was used to create a classification structure, independent of which station provided the signal. The database included three types of volcanic events: tremor, long period, and volcano-tectonic and a contrast group which contains other types of seismic signals. In the present work, we maintain the same classification scheme, but we consider separately the stations information in order to assess whether the complementary information provided by different stations improves the performance of the classifier in recognising seismic patterns. This paper proposes two strategies for combining the information from the stations: i) combining the features extracted from the signals from each station and ii) combining the classifiers of each station. In the first case, the features extracted from the signals from each station are combined forming the input for a single classification structure. In the second, a decision stage combines the results of the classifiers for each station to give a unique output. The results confirm that the station-dependent strategies that combine the features and the classifiers from several stations improves the classification performance, and that the combination of the features provides the best performance. The results show an average improvement of 9% in the classification accuracy when compared with the station-independent method.

  16. The Southern Argentine Agile Meteor Radar (SAAMER)

    NASA Astrophysics Data System (ADS)

    Janches, Diego

    2014-11-01

    The Southern Argentina Agile Meteor Radar (SAAMER) is a new generation system deployed in Rio Grande, Tierra del Fuego, Argentina (53 S) in May 2008. SAAMER transmits 10 times more power than regular meteor radars, and uses a newly developed transmitting array, which focuses power upward instead of the traditional single-antenna-all-sky configuration. The system is configured such that the transmitter array can also be utilized as a receiver. The new design greatly increases the sensitivity of the radar enabling the detection of large number of particles at low zenith angles. The more concentrated transmitted power enables additional meteor studies besides those typical of these systems based on the detection of specular reflections, such as routine detections of head echoes and non-specular trails, previously only possible with High Power and Large Aperture radars. In August 2010, SAAMER was upgraded to a system capable to determine meteoroid orbital parameters. This was achieved by adding two remote receiving stations approximately 10 km away from the main site in near perpendicular directions. The upgrade significantly expands the science that is achieved with this new radar enabling us to study the orbital properties of the interplanetary dust environment. Because of the unique geographical location, SAAMER allows for additional inter-hemispheric comparison with measurements from Canadian Meteor Orbit Radar, which is geographically conjugate. Initial surveys show, for example, that SAAMER observes a very strong contribution of the South Toroidal Sporadic meteor source, of which limited observational data is available. In addition, SAAMER offers similar unique capabilities for meteor showers and streams studies given the range of ecliptic latitudes that the system enables detailed study of showers at high southern latitudes (e.g July Phoenicids or Puppids complex). Finally, SAAMER is ideal for the deployment of complementary instrumentation in both, permanent

  17. Preliminary Results of the Third Test Series of Nonmetal Material Flammability Evaluation In SKOROST Apparatus on the Space Station Mir

    NASA Technical Reports Server (NTRS)

    Ivanov, A. V.; Alymov, V. F.; Smirnov, A. B.; Shalayev, S. P.; Ye.Belov, D.; Balashov, Ye.V.; Andreeva, T. V.; Semenov, A. V.; Melikhov, A. S.; Bolodyan, I. A.; Potyakin, V. I.

    1999-01-01

    The work has been done according to the US/Russian Joint Project "Experimental Evaluation of the Material Flammability in Microgravity" a continued combustion study in the SKOROST test apparatus on the OS Mir. The objective of the project was to evaluate the flammability and flame-spread rate for the selected polymer materials in low velocity flow in microgravity. Lately, the issue of nonmetal material combustion in microgravity has become of great importance, based on the necessity to develop the fire safety system for the new International Space Station (ISS). Lack of buoyant flow in microgravity reduces oxygen transfer into the combustion zone, which leads to flame extinction when the flow velocity is less than the limiting flow velocity V(sub lim) for the material. The ISS FGB fire-safety system was developed based on this phenomenon. The existence of minimum flow velocity V(sub lim) to sustain fire for the selected materials was determined both theoretically and experimentally. In the latter, it is shown that, even for thermally thin nonmetal materials with a very low oxygen index C(sub lim) of 12.5% (paper sheets with the thickness of 0.1 mm), a limiting flow velocity V(sub lim) exists at oxygen concentration Co(sub OX) = 17-21%, and is about 1.0 - 0.1 cm/sec. This might be explained by the relative increase in thermal losses due to radiation from the surface and from the gaseous phase. In the second series of experiments in Skorost apparatus on Orbital Station Mir the existence of the limiting flow velocity V(sub lim) for combustion was confirmed for PMMA and glass-epoxy composite strip samples 2 mm thick at oxygen concentration C(sub OX) = 21.5%. It was concluded that V(sub lim) depends on C(sub OX) for the PMMA sample with a low oxygen index of 15.5%, the limiting flow velocity V(sub lim) was less than 0.5 cm/sec, and for the glass-epoxy composite sample with a high oxygen index of 19%, the limiting flow velocity V(sub lim) was higher than 15 cm/sec. As of

  18. Cloud and Precipitation Radar

    NASA Astrophysics Data System (ADS)

    Hagen, Martin; Höller, Hartmut; Schmidt, Kersten

    Precipitation or weather radar is an essential tool for research, diagnosis, and nowcasting of precipitation events like fronts or thunderstorms. Only with weather radar is it possible to gain insights into the three-dimensional structure of thunderstorms and to investigate processes like hail formation or tornado genesis. A number of different radar products are available to analyze the structure, dynamics and microphysics of precipitation systems. Cloud radars use short wavelengths to enable detection of small ice particles or cloud droplets. Their applications differ from weather radar as they are mostly orientated vertically, where different retrieval techniques can be applied.

  19. Airborne rain mapping radar

    NASA Technical Reports Server (NTRS)

    Wilson, W. J.; Parks, G. S.; Li, F. K.; Im, K. E.; Howard, R. J.

    1988-01-01

    An airborne scanning radar system for remote rain mapping is described. The airborne rain mapping radar is composed of two radar frequency channels at 13.8 and 24.1 GHz. The radar is proposed to scan its antenna beam over + or - 20 deg from the antenna boresight; have a swath width of 7 km; a horizontal spatial resolution at nadir of about 500 m; and a range resolution of 120 m. The radar is designed to be applicable for retrieving rainfall rates from 0.1-60 mm/hr at the earth's surface, and for measuring linear polarization signatures and raindrop's fall velocity.

  20. The effects of speed enforcement with mobile radar on speed and accidents. An evaluation study on rural roads in the Dutch province Friesland.

    PubMed

    Goldenbeld, Charles; van Schagen, Ingrid

    2005-11-01

    In an evaluation study, the effects of targeted speed enforcement on speed and road accidents were assessed. Enforcement was predominantly carried out by means of mobile radar and focused on rural non-motorway roads. Information and publicity supported the enforcement activities. The evaluation covered a period of 5 years of enforcement. The speed data of these 5 years and the year preceding the enforcement project showed a significant decrease in mean speed and the percentage speed limit violators over time. The largest decrease was found in the first year of the enforcement project and in the fourth year of the project, when the enforcement effort was further intensified. There were similar decreases in speeding at both the enforced roads and at the nearby comparison roads that were not subjected to the targeted speed enforcement project, which may be explained by spillover effects. The best estimate for the safety effect of the enforcement project is a reduction of 21% in both the number of injury accidents and the number of serious casualties. This was based on comparison between the number of accidents/casualties during the enforcement project (5 years) and and the 8 preceding years on the enforced roads and at all other roads outside urban areas in the same region.

  1. Multidimensional radar picture

    NASA Astrophysics Data System (ADS)

    Waz, Mariusz

    2010-05-01

    In marine navigation systems, the three-dimensional (3D) visualization is often and often used. Echosonders and sonars working in hydroacustic systems can present pictures in three dimensions. Currently, vector maps also offer 3D presentation. This presentation is used in aviation and underwater navigation. In the nearest future three-dimensional presentation may be obligatory presentation in displays of navigation systems. A part of these systems work with radar and communicates with it transmitting data in a digital form. 3D presentation of radar picture require a new technology to develop. In the first step it is necessary to compile digital form of radar signal. The modern navigation radar do not present data in three-dimensional form. Progress in technology of digital signal processing make it possible to create multidimensional radar pictures. For instance, the RSC (Radar Scan Converter) - digital radar picture recording and transforming tool can be used to create new picture online. Using RSC and techniques of modern computer graphics multidimensional radar pictures can be generated. The radar pictures mentioned should be readable for ECDIS. The paper presents a method for generating multidimensional radar picture from original signal coming from radar receiver.

  2. Planetary radar astronomy

    NASA Technical Reports Server (NTRS)

    Ostro, Steven J.

    1987-01-01

    The scientific aims, theoretical principles, techniques and instrumentation, and future potential of radar observations of solar-system objects are discussed in a general overview. Topics examined include the history of radar technology, echo detectability, the Arecibo and Goldstone radar observatories, echo time delay and Doppler shift, radar waveforms, albedo and polarization ratio, measurement of dynamical properties, and the dispersion of echo power. Consideration is given to angular scattering laws; the radar signatures of the moon and inner planets, Mars, and asteroids; topographic relief; delay-Doppler radar maps and their physical interpretation; and radar observations of the icy Galilean satellites of Jupiter, comets, and the rings of Saturn. Diagrams, drawings, photographs, and sample maps and images are provided.

  3. 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.

  4. The evaluation of 3cm-wavelength radar for mapping surface deposits in the Bristol Lake/Granite Mountain area, Mojave Desert, California

    NASA Technical Reports Server (NTRS)

    Sugiura, R.; Sabins, F. F., Jr.

    1980-01-01

    Surface deposits in the Bristol Lake/Granite Mountains area, Mojave Desert, California were mapped using high resolution 3 cm wavelength radar images. The surface deposits range from silt to boulders in size and were separated into six radar-rock units on the basis of radar return signatures (brightness and texture) and geomorphic expression. Field reconnaissance of the six units showed that the brightness of the radar signatures on the images correlates with the surface roughness of each unit. Two major radar signatures anomalies were noted during the study. A dark radar signature for the large sand ridges in the Kelso Dunes area and a distinct northwest trending contrast boundary between bright and dark radar signatures in the Bristol Dry Lake area. Field reconnaissance of the two areas indicated that near surface moisture may be the cause of dark signatures. Dune areas with little to no vegetation produce a dark signature, whereas areas with sparse to moderate vegetation produce an intermediate to dark signature.

  5. Locating narrow bipolar events with single-station measurement of low-frequency magnetic fields

    NASA Astrophysics Data System (ADS)

    Zhang, Hongbo; Lu, Gaopeng; Qie, Xiushu; Jiang, Rubin; Fan, Yanfeng; Tian, Ye; Sun, Zhuling; Liu, Mingyuan; Wang, Zhichao; Liu, Dongxia; Feng, Guili

    2016-06-01

    We developed a method to locate the narrow bipolar events (NBEs) based on the single-station measurement of low-frequency (LF, 40-500 kHz) magnetic fields. The direction finding of a two-axis magnetic sensor provides the azimuth of NBEs relative to the measurement site; the ionospheric reflection pairs in the lightning sferics are used to determine the range and height. We applied this method to determine the three-dimensional (3D) locations of 1475 NBEs with magnetic signals recorded during the SHandong Artificially Triggered Lightning Experiment (SHATLE) in summer of 2013. The NBE detections are evaluated on a storm basis by comparing with radar observations of reflectivity and lightning data from the World Wide Lightning Location Network (WWLLN) for two mesoscale convective systems (MCSs) of different sizes. As revealed by previous studies, NBEs are predominately produced in the convective regions with relatively strong radar echo (with composite reflectivity ≥30 dBZ), although not all the convections with high reflectivity and active lightning production are in favor of NBE production. The NBEs located by the single-station magnetic method also exhibit the distinct segregation in altitude for positive and negative NBEs, namely positive NBEs are mainly produced between 7 km and 15 km, while negative NBEs are predominantly produced above 14 km. In summary, the results of comparison generally show that the single-station magnetic method can locate NBEs with good reliability, although the accuracy of 3D location remains to be evaluated with the traditional multi-station method based on the time-of-arrival technique. This method can be applied to track the motion of storm convection within 800 km, especially when they move out to ocean beyond the detection range (typically <400 km) of meteorological radars, making it possible to study NBEs in oceanic thunderstorms for which the location with multiple ground-based stations is usually not feasible.

  6. 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.

  7. High resolution images of Venus from ground-based radar

    NASA Technical Reports Server (NTRS)

    Jurgens, R. F.; Slade, M. A.; Robinett, L.; Brokl, S.; Downs, G. S.

    1988-01-01

    The Goldstone Deep Space Station ground-based synthetic aperture radar system has been used to obtain radar images of Venus with resolutions of close to 1.3 km. Observations were made at 12.5 cm wavelength using circular polarization. From 12 days of observations during the 1986 inferior conjunction, three images have been selected for initial processing. The images show remarkable surface features including craters, ridges, and regions of high Fresnel reflectivity in the plains region.

  8. A Potential Integrated Multiwavelength Radar System at the Medicina Radiotelescopes

    NASA Astrophysics Data System (ADS)

    Montebugnoli, S.; Salerno, E.; Pupillo, G.; Pluchino, S.

    2009-03-01

    Ground-based radars provide a powerful tool for detection, tracking and identification of the space debris fragments orbiting around Earth at different altitudes. The Medicina Radioastronomical Station is an Italian radio observation facility that is here proposed as receiving part of a bistatic radar system for detecting and tracking space debris at different orbital regions (from Low Earth Orbits up to Geostationary Earth Orbits).

  9. 52. View from ground level showing lower radar scanner switch ...

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

    52. View from ground level showing lower radar scanner switch with open port door in radar scanner building 105 showing emanating waveguides from lower switch in vertical run; photograph also shows catwalk to upper scanner switch in upper left side of photograph and structural supports. - 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

  10. Performance and evaluation of gas engine driven rooftop air conditioning equipment at the Willow Grove (PA) Naval Air Station

    SciTech Connect

    Armstrong, P.R.; Conover, D.R.

    1993-05-01

    In a field evaluation conducted for the US Department of Energy (DOE) Office of Federal Energy Management Program (FEMP), the Pacific Northwest Laboratory (PNL) examined the performance of a new US energy-related technology under the FEMP Test Bed Demonstration Program. The technology was a 15-ton natural gas engine driven roof top air conditioning unit. Two such units were installed on a naval retail building to provide space conditioning to the building. Under the Test Bed Demonstration Program, private and public sector interests are focused to support the installation and evaluation of new US technologies in the federal sector. Participating in this effort under a Cooperative Research and Development Agreement (CRADA) with DOE were the American Gas Cooling Center, Philadelphia Electric Company, Thermo King Corporation, and the US Naval Air Station at Willow Grove, Pennsylvania. Equipment operating and service data as well as building interior and exterior conditions were secured for the 1992 cooling season. Based on a computer assessment of the building using standard weather data, a comparison was made with the energy and operating costs associated with the previous space conditioning system. Based on performance during the 1992 cooling season and adjusted to a normal weather year, the technology will save the site $6,000/yr in purchased energy costs. An additional $9,000 in savings due to electricity demand ratchet charge reductions will also be realized. Detailed information on the technology, the installation, and the results of the technology test are provided to illustrate the advantages to the federal sector of using this technology. A history of the CRADA development process is also reported.

  11. Ground penetrating radar evaluation of the internal structure of fluvial tufa deposits (Dévanos-Añavieja system, NE Spain): an approach to different scales of heterogeneity

    NASA Astrophysics Data System (ADS)

    Pueyo Anchuela, Ó.; Luzón, A.; Pérez, A.; Muñoz, A.; Mayayo, M. J.; Gil Garbi, H.

    2016-07-01

    The Quaternary Añavieja-Dévanos tufa system is located in the northern sector of the Iberian Chain. It has been previously tackled by means sedimentological studies focused on the available outcrops and some boreholes. They have permitted the proposal of a sedimentary scenario that fits with a pool-barrage fluvial tufa model. However a better knowledge of the characteristics and internal distribution of the usually non-outcropping pool deposits as well as of its relationship with barrage deposits has not been evaluated in detail yet. Palaeoenvironmental studies on tufas are usually biased because tufas are commonly delicate facies exposed to intense erosion during water level fall stages; for this reason outcrops are usually scarce and very often coincide with the most cemented barrage deposits. In order to analyse the internal characteristics of the tufa deposits under study, but also the lateral correlation among different facies, ground penetrating radar (GPR) has been employed both for the evaluation of its applicability in such kind of environments and to improve, if possible, the sedimentary model using geophysical data in sectors without outcrops. A GPR survey including different antennas ranging from 50 to 500 MHz along different sectors and its comparison with natural outcrops has been carried out. GPR results have permitted to deduce clear differences between pool and barrage deposits and to recognise its internal structure and geometrical relationships. The survey also permitted an approach to different scales of heterogeneities in the radarfacies evaluation by using distinct antennas and therefore, reaching different resolutions and penetrations. The resulting integration from different antennas allows three different attenuant and eight reflective radarfacies to be defined permitting a better approach to the real extension of the pool areas. These results have permitted to decipher the horizontal and vertical facies changes and the identification of

  12. Rendezvous radar for the orbital maneuvering vehicle

    NASA Technical Reports Server (NTRS)

    Locke, John W.; Olds, Keith; Parks, Howard

    1991-01-01

    This paper describes the development of the Rendezvous Radar Set (RRS) for the Orbital Maneuvering Vehicle (OMV) for the National Aeronautics and Space Administration (NASA). The RRS was to be used to locate, and then provide vectoring information to, target satellites (or Shuttle or Space Station) to aid the OMV in making a minimum-fuel-consumption approach and rendezvous. The RRS design is that of an X-Band, all solid-state, monopulse tracking, frequency hopping, pulse-Doppler radar system. The development of the radar was terminated when the OMV prime contract to TRW was terminated by NASA. At the time of the termination, the development was in the circuit design stage. The system design was virtually completed, the PDR had been held. The RRS design was based on Motorola's experiences, both in the design and production of radar systems for the US Army and in the design and production of hi-rel communications systems for NASA space programs. Experience in these fields was combined with the latest digital signal processor and micro-processor technology to design a light-weight, low-power, spaceborne radar. The antenna and antenna positioner (gimbals) technology developed for the RRS is now being used in the satellite-to-satellite communication link design for Motorola's Iridium telecommunications system.

  13. Superresolution in a jammed radar signal environment

    NASA Astrophysics Data System (ADS)

    Carlstedt, O.

    1993-12-01

    For radar surveillance of air targets flying close together super resolution with array antennas can be a possible method to separate targets within the main antenna lobe. A system based on an algorithm of type Parametric Target Model fitting has been simulated and evaluated for some cases of electronic jamming and target configuration. A target configuration can include both radar quiet but illuminated targets and active jammers.

  14. Laser radar in robotics

    SciTech Connect

    Carmer, D.C.; Peterson, L.M.

    1996-02-01

    In this paper the authors describe the basic operating principles of laser radar sensors and the typical algorithms used to process laser radar imagery for robotic applications. The authors review 12 laser radar sensors to illustrate the variety of systems that have been applied to robotic applications wherein information extracted from the laser radar data is used to automatically control a mechanism or process. Next, they describe selected robotic applications in seven areas: autonomous vehicle navigation, walking machine foot placement, automated service vehicles, manufacturing and inspection, automotive, military, and agriculture. They conclude with a discussion of the status of laser radar technology and suggest trends seen in the application of laser radar sensors to robotics. Many new applications are expected as the maturity level progresses and system costs are reduced.

  15. 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.

  16. 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

  17. Space Station

    NASA Technical Reports Server (NTRS)

    Anderton, D. A.

    1985-01-01

    The official start of a bold new space program, essential to maintain the United States' leadership in space was signaled by a Presidential directive to move aggressively again into space by proceeding with the development of a space station. Development concepts for a permanently manned space station are discussed. Reasons for establishing an inhabited space station are given. Cost estimates and timetables are also cited.

  18. Performance Evaluation of UHF RFID Technologies for Real-Time Bus Recognition in the Taipei Bus Station

    PubMed Central

    Own, Chung-Ming; Lee, Da-Sheng; Wang, Ti-Ho; Wang, De-Jun; Ting, Yu-Lun

    2013-01-01

    Transport stations such as airports, ports, and railways have adopted blocked-type pathway management to process and control travel systems in a one-directional manner. However, this excludes highway transportation where large buses have great variability and mobility; thus, an instant influx of numerous buses increases risks and complicates station management. Focusing on Taipei Bus Station, this study employed RFID technology to develop a system platform integrated with modern information technology that has numerous characteristics. This modern information technology comprised the following systems: ultra-high frequency (UHF) radio-frequency identification (RFID), ultrasound and license number identification, and backstage graphic controls. In conclusion, the system enabled management, bus companies, and passengers to experience the national bus station's new generation technology, which provides diverse information and synchronization functions. Furthermore, this technology reached a new milestone in the energy-saving and efficiency-increasing performance of Taiwan's buses. PMID:23778192

  19. Performance evaluation of UHF RFID technologies for real-time bus recognition in the Taipei Bus Station.

    PubMed

    Own, Chung-Ming; Lee, Da-Sheng; Wang, Ti-Ho; Wang, De-Jun; Ting, Yu-Lun

    2013-06-18

    Transport stations such as airports, ports, and railways have adopted blocked-type pathway management to process and control travel systems in a one-directional manner. However, this excludes highway transportation where large buses have great variability and mobility; thus, an instant influx of numerous buses increases risks and complicates station management. Focusing on Taipei Bus Station, this study employed RFID technology to develop a system platform integrated with modern information technology that has numerous characteristics. This modern information technology comprised the following systems: ultra-high frequency (UHF) radio-frequency identification (RFID), ultrasound and license number identification, and backstage graphic controls. In conclusion, the system enabled management, bus companies, and passengers to experience the national bus station's new generation technology, which provides diverse information and synchronization functions. Furthermore, this technology reached a new milestone in the energy-saving and efficiency-increasing performance of Taiwan's buses.

  20. The Goldstone solar system radar: A science instrument for planetary research

    NASA Technical Reports Server (NTRS)

    Dvorsky, J. D.; Renzetti, N. A.; Fulton, D. E.

    1992-01-01

    The Goldstone Solar System Radar (GSSR) station at NASA's Deep Space Communications Complex in California's Mojave Desert is described. A short chronological account of the GSSR's technical development and scientific discoveries is given. This is followed by a basic discussion of how information is derived from the radar echo and how the raw information can be used to increase understanding of the solar system. A moderately detailed description of the radar system is given, and the engineering performance of the radar is discussed. The operating characteristics of the Arcibo Observatory in Puerto Rico are briefly described and compared with those of the GSSR. Planned and in-process improvements to the existing radar, as well as the performance of a hypothetical 128-m diameter antenna radar station, are described. A comprehensive bibliography of referred scientific and engineering articles presenting results that depended on data gathered by the instrument is provided.

  1. Use of a combined personal computer and Rock-Eval in an integrated petroleum evaluation work station to estimate volumes of hydrocarbons generated and migrated in sedimentary basins

    SciTech Connect

    Espitalie, J.; Lafargue, E.; Drouet, S.

    1989-09-01

    A petroleum evaluation work station consisting in a modified Rock-Eval apparatus connected to an IBM personal computer has been designed at Institut Francais du petrole to estimate the amount of hydrocarbon generated and migrated in sedimentary basins. The work-station is provided with specific software for Rock-Eval data analysis, quick determination of kinetic parameters (Optim model), and quantitative hydrocarbon generation (Matoil model). Along with the classical Rock-Eval parameters (S{sub 0}, S{sub 1}, S{sub 2}, TOC, and T{sub max}), new parameters concerning the source rocks, such as the transformation efficiency ratio (TER), the migration efficiency ration (MER), and the initial generation capacity (IGC), are defined. These new parameters combined with geological data give access to a rapid volumetric estimation (in 10{sup 6}MT/km{sup 2}) of hydrocarbon generation and migration in the studied area. These data can be displayed on different specific maps for rapid visualization. This work station has been successfully used in the Paris and Aquitaine basins, making possible a better assessment of their petroleum potential. The petroleum evaluation work station appears to be a very valuable tool that can be used in the different phases of exploration in a sedimentary basin.

  2. Monitoring by holographic radar systems

    NASA Astrophysics Data System (ADS)

    Catapano, Ilaria; Crocco, Lorenzo; Affinito, Antonio; Gennarelli, Gianluca; Soldovieri, Francesco

    2013-04-01

    Nowadays, radar technology represents a significant opportunity to collect useful information for the monitoring and conservation of critical infrastructures. Radar systems exploit the non-invasive interaction between the matter and the electromagnetic waves at microwave frequencies. Such an interaction allows obtaining images of the region under test from which one can infer the presence of potential anomalies such as deformations, cracks, water infiltrations, etc. This information turns out to be of primary importance in practical scenarios where the probed structure is in a poor state of preservation and renovation works must be planned. In this framework, the aim of this contribution is to describe the potentialities of the holographic radar Rascan 4/4000, a holographic radar developed by Remote Sensing Laboratory of Bauman Moscow State Technical University, as a non-destructive diagnostic tool capable to provide, in real-time, high resolution subsurface images of the sounded structure [1]. This radar provides holograms of hidden anomalies from the amplitude of the interference signal arising between the backscattered signal and a reference signal. The performance of the holographic radar is appraised by means of several experiments. Preliminary tests concerning the imaging below the floor and inside wood structures are carried out in controlled conditions at the Electromagnetic Diagnostic Laboratory of IREA-CNR. After, with reference to bridge monitoring for security aim, the results of a measurement campaign performed on the Musmeci bridge are presented [2]. Acknowledgments This research has been performed in the framework of the "Active and Passive Microwaves for Security and Subsurface imaging (AMISS)" EU 7th Framework Marie Curie Actions IRSES project (PIRSES-GA-2010-269157). REFERENCES [1] S. Ivashov, V. Razevig, I. Vasilyev, A. Zhuravlev, T. Bechtel, L. Capineri, The holographic principle in subsurface radar technology, International Symposium to

  3. Radar Scattering Properties of Terra Meridiani, Mars

    NASA Astrophysics Data System (ADS)

    Larsen, K. W.; Haldemann, A. F.; Jurgens, R. F.; Slade, M. A.; Arvidson, R. E.

    2002-12-01

    A series of fourteen radar observations of Mars were made during the 2001 opposition. Four of these observation tracks passed over Terra Meridiani, a prime candidate landing site for one of the 2003 Mars Exploration Rover missions. Observations were conducted using X-band (3.5 centimeter wavelength) radar transmitted with a pseudo-random binary phase encoding which, combined with the frequency resolution of the processing FFT, yields a maximum spatial resolution of approximately five kilometers. Actual spatial resolution is coarser than this (between five and twenty kilometers) due to signal-to-noise considerations that predicated longer integration times as well as greater planetary ranges for the off-opposition observations. We have processed the Terra Meridiani data in stages, beginning with one-dimensional sub-radar track profiles and culminating with four-station interferometry. Not all observations were amendable to the full four-station interferometry, due to technical issues, but were processed with a minimum of two stations to remove the spatial ambiguities inherent to radar observations. Our processing yields one- and two-dimensional maps of the surface reflectivity along the radar track. We extract scattering data for points along the sub-radar track, where the angle in incidence varies most, and model the scattering function. The multi-station reflectivity data is also modeled according to the Hagfors scattering model to extract two-dimensional maps of RMS roughness and dielectric constant. The RMS roughness data for the Terra Meridiani landing sites shows the local surface slopes to be less than 3 degrees, on the scale of tens of wavelengths. An enhanced dielectric constant is apparent over Terra Meridiani that is spatially correlated with the MGS detected hematite deposits. The level of the enhancement is consistent with the inclusion of 10-15 percent hematite, according to a weighted dielectric or PVL model. Integral to our processing, and new to

  4. Intercomparison of snowfall estimates derived from the CloudSat Cloud Profiling Radar and the ground based weather radar network over Sweden

    NASA Astrophysics Data System (ADS)

    Norin, L.; Devasthale, A.; L'Ecuyer, T. S.; Wood, N. B.; Smalley, M.

    2015-08-01

    To be able to estimate snowfall accurately is important for both weather and climate applications. Ground-based weather radars and space-based satellite sensors are often used as viable alternatives to rain-gauges to estimate precipitation in this context. The Cloud Profiling Radar (CPR) onboard CloudSat is especially proving to be a useful tool to map snowfall globally, in part due to its high sensitivity to light precipitation and ability to provide near-global vertical structure. The importance of having snowfall estimates from CloudSat/CPR further increases in the high latitude regions as other ground-based observations become sparse and passive satellite sensors suffer from inherent limitations. Here we intercompared snowfall estimates from two observing systems, CloudSat and Swerad, the Swedish national weather radar network. Swerad offers one of the best calibrated data sets of precipitation amount at very high latitudes that are anchored to rain-gauges and that can be exploited to evaluate usefulness of CloudSat/CPR snowfall estimates in the polar regions. In total 7.2×105 matchups of CloudSat and Swerad over Sweden were inter-compared covering all but summer months (October to May) from 2008 to 2010. The intercomparison shows encouraging agreement between these two observing systems despite their different sensitivities and user applications. The best agreement is observed when CloudSat passes close to a Swerad station (46-82 km), when the observational conditions for both systems are comparable. Larger disagreements outside this range suggest that both platforms have difficulty with shallow snow but for different reasons. The correlation between Swerad and CloudSat degrades with increasing distance from the nearest Swerad station as Swerad's sensitivity decreases as a function of distance and Swerad also tends to overshoots low level precipitating systems further away from the station, leading to underestimation of snowfall rate and occasionally missing

  5. An evaluation of water-quality data obtained at four streamflow daily-record stations in Idaho

    USGS Publications Warehouse

    Dyer, Kenneth L.

    1973-01-01

    Chemical data for four stream-gaging stations in Idaho, each having 6 to 22 years of available records, were analyzed to determine functional relations between concentrations of the major inorganic constituents, specific conductance, and stream discharge. Three of the four stations had sufficient available record for assessing changes in constituent relations with time. The records for each long-term station were subdivided into segments of approximately 5 years each. Plots and regression equations were derived for each record segment to show the relations of each major constituent value to levels of specific conductance and stream discharge. At only one stations, Boise River at Notus, was there was an apparent significant change in chemical characteristics with time. Between 1940 and 1951, the percentages of chloride and sulfate in solution at this station declined appreciably and were largely replaced by bicarbonate. In general, there were highly significant correlations between the major inorganic ions and specific conductance, although those observed at Bear River at Border were distinctly poorer than those observed for the other stations. Corresponding correlations between the major ions and discharge were almost always less significant than those observed between the same ions and specific conductance. The common ion-discharge relations observed on the Snake River near Heise were more highly correlated before 1957 than thereafter--probably because of changes induced by the construction of Palisades Dam. A similar decline in correlation of common ion-discharge relations was observed at the Snake River at King Hill station after 1957, and this also might be attributable to changes in water regulation at various upstream impoundments.

  6. 46 CFR 28.875 - Radar, depth sounding, and auto-pilot.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... screen mounted at the operating station, and facilities on the bridge for plotting radar readings. (b) Each vessel must be fitted with a suitable echo depth sounding device. (c) Except as provided in 33...

  7. 46 CFR 28.875 - Radar, depth sounding, and auto-pilot.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... screen mounted at the operating station, and facilities on the bridge for plotting radar readings. (b) Each vessel must be fitted with a suitable echo depth sounding device. (c) Except as provided in 33...

  8. 46 CFR 28.875 - Radar, depth sounding, and auto-pilot.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... screen mounted at the operating station, and facilities on the bridge for plotting radar readings. (b) Each vessel must be fitted with a suitable echo depth sounding device. (c) Except as provided in 33...

  9. An analysis of simulated stereo radar imagery

    NASA Technical Reports Server (NTRS)

    Pisaruck, M. A.; Kaupp, V. H.; Macdonald, H. C.; Waite, W. P.

    1983-01-01

    Simulated stereo radar imagery is used to investigate parameters for a spaceborne imaging radar. Incidence angles ranging from small to intermediate to large are used with three digital terrain model areas which are representative of relatively flat, moderately rough, and mountainous terrain. The simulated radar imagery was evaluated by interpreters for ease of stereo perception and information content, and rank order within each class of terrain. The interpreter's results are analyzed for trends between the height of a feature and either parallax or vertical exaggeration for a stereo pair. A model is developed which predicts the amount of parallax (or vertical exaggeration) an interpreter would desire for best stereo perception of a feature of a specific height. Results indicate the selection of angle of incidence and stereo intersection angle depend upon the relative relief of the terrain. Examples of the simulated stereo imagery are presented for a candidate spaceborne imaging radar having four selectable angles of incidence.

  10. Dynamic gauge adjustment of high-resolution X-band radar data for convective rain storms: Model-based evaluation against measured combined sewer overflow

    NASA Astrophysics Data System (ADS)

    Borup, Morten; Grum, Morten; Linde, Jens Jørgen; Mikkelsen, Peter Steen

    2016-08-01

    Numerous studies have shown that radar rainfall estimates need to be adjusted against rain gauge measurements in order to be useful for hydrological modelling. In the current study we investigate if adjustment can improve radar rainfall estimates to the point where they can be used for modelling overflows from urban drainage systems, and we furthermore investigate the importance of the aggregation period of the adjustment scheme. This is done by continuously adjusting X-band radar data based on the previous 5-30 min of rain data recorded by multiple rain gauges and propagating the rainfall estimates through a hydraulic urban drainage model. The model is built entirely from physical data, without any calibration, to avoid bias towards any specific type of rainfall estimate. The performance is assessed by comparing measured and modelled water levels at a weir downstream of a highly impermeable, well defined, 64 ha urban catchment, for nine overflow generating rain events. The dynamically adjusted radar data perform best when the aggregation period is as small as 10-20 min, in which case it performs much better than static adjusted radar data and data from rain gauges situated 2-3 km away.

  11. Evaluation of local versus remote areas of CH4 sources at IC3 stations using a combined analysis of 222Rn tracer and Atmospheric Particles Transport Model (APTM) results. Application at the Gredos and Iruelas station (GIC3), Spain.

    NASA Astrophysics Data System (ADS)

    Grossi, Claudia; Morguí, Josep Anton; Curcoll, Roger; Àgueda, Alba; Arnold, Delia; Batet, Oscar; Cañas, Lidia; Nofuentes, Manel; Occhipinti, Paola; Vogel, Felix; Vargas, Arturo; Rodó, Xavier

    2014-05-01

    The Gredos and Iruelas station (GIC3) is part of the IC3 (Institut Català de Ciències del Clima) atmospheric monitoring network. This station is located in the Gredos Natural Park (40.22º N; -5.14º E) in the Spanish central plateau. The IC3 network consists of 8 stations distributed across Spain. It has been developed with the aim of studying climatic processes and the responses of impacted systems at different temporal and spatial scales. Since 2012, CO2, CH4, 222Rn (a natural radioactive gas) and meteorological variables are continuously measured at GIC3 at 20 m a.g.l. (1100 m a.s.l.). Furthermore, 4-days backward simulations are run daily for each IC3 station using the FLEXPART model. Simulations use ECMWF meteorological data as input and a horizontal spatial resolution of 0.2 degrees. The Laboratory of the Atmosphere and the Oceans (LAO) of the IC3 has elaborated a new approach to evaluate the local or remote greenhouse gases emissions using the radon gas as tracer and the atmospheric particles transport model FLEXPART under nocturnal and winter conditions. The ratios between the normalized and rescaled measured concentrations of CH4 and 222Rn during nocturnal hours (21h, 00h, 03h and 06h) and in the winter season, in order to reduce local radon flux and methane source due to seasonal livestock migration and to get stable atmospheric conditions, have been analyzed in relation to the influence of the local area (set to an initial dimension of 20x20 km2). The influence area (IA) has been defined as the percentage of the ratio between the residence time of the fictitious particles released in FLEXPART simulations over the area of interest (TLocal Area) and the residence time of these fictitious particles over the total area included in the simulation (TTotal Area ), i.e. IA = (TLocal Area/TTotal Area * 100). First results considering an area of interest of 20x20 km2 show a linear increase of the radon concentration with IA until reaching a maximum when IA is

  12. 31. Construction Drawing: Fort Custer Air Force Station, Battle Creek, ...

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

    31. Construction Drawing: Fort Custer Air Force Station, Battle Creek, Michigan, Emergency Power Building, Floor Plans and Details, USACOE, no date. - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

  13. 30. Construction Drawing: Fort Custer Air Force Station, Battle Creek, ...

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

    30. Construction Drawing: Fort Custer Air Force Station, Battle Creek, Michigan, Emergency Power Building, Sections and Elevations, USACOE, no date. - Fort Custer Military Reservation, P-67 Radar Station, .25 mile north of Dickman Road, east of Clark Road, Battle Creek, Calhoun County, MI

  14. 17. CAPE COD AIR STATION PAVE PAWS FACILITY AERIAL VIEW ...

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

    17. CAPE COD AIR STATION PAVE PAWS FACILITY AERIAL VIEW WITH PROJECT NEARING COMPLETION. VIEW SHOWS "A" FACE (LEFT) AND "B" FACE OF RADAR ARRAY SYSTEM. NOTE THAT NORTH IS GENERALLY TO RIGHT OF VIEW. - Cape Cod Air Station, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

  15. Evaluation of ground-penetrating radar to detect free-phase hydrocarbons in fractured rocks - Results of numerical modeling and physical experiments

    USGS Publications Warehouse

    Lane, J.W.; Buursink, M.L.; Haeni, F.P.; Versteeg, R.J.

    2000-01-01

    The suitability of common-offset ground-penetrating radar (GPR) to detect free-phase hydrocarbons in bedrock fractures was evaluated using numerical modeling and physical experiments. The results of one- and two-dimensional numerical modeling at 100 megahertz indicate that GPR reflection amplitudes are relatively insensitive to fracture apertures ranging from 1 to 4 mm. The numerical modeling and physical experiments indicate that differences in the fluids that fill fractures significantly affect the amplitude and the polarity of electromagnetic waves reflected by subhorizontal fractures. Air-filled and hydrocarbon-filled fractures generate low-amplitude reflections that are in-phase with the transmitted pulse. Water-filled fractures create reflections with greater amplitude and opposite polarity than those reflections created by air-filled or hydrocarbon-filled fractures. The results from the numerical modeling and physical experiments demonstrate it is possible to distinguish water-filled fracture reflections from air- or hydrocarbon-filled fracture reflections, nevertheless subsurface heterogeneity, antenna coupling changes, and other sources of noise will likely make it difficult to observe these changes in GPR field data. This indicates that the routine application of common-offset GPR reflection methods for detection of hydrocarbon-filled fractures will be problematic. Ideal cases will require appropriately processed, high-quality GPR data, ground-truth information, and detailed knowledge of subsurface physical properties. Conversely, the sensitivity of GPR methods to changes in subsurface physical properties as demonstrated by the numerical and experimental results suggests the potential of using GPR methods as a monitoring tool. GPR methods may be suited for monitoring pumping and tracer tests, changes in site hydrologic conditions, and remediation activities.The suitability of common-offset ground-penetrating radar (GPR) to detect free-phase hydrocarbons

  16. Evaluation of station blackout accidents at nuclear power plants: Technical findings related to unresolved safety issue A-44: Final report

    SciTech Connect

    Not Available

    1988-06-01

    ''Station Blackout,'' which is the complete loss of alternating current (AC) electrical power in a nuclear power plant, has been designated as Unresolved Safety Issue A-44. Because many safety systems required for reactor core decay heat removal and containment heat removal depend on AC power, the consequences of a station blackout could be severe. This report documents the findings of technical studies performed as part of the program to resolve this issue. The important factors analyzed include: the fequency of loss of offsite power; the probability that emergency or onsite AC power supplies would be unavailable; the capability and reliability of decay heat removal systems independent of AC power; and the likelihood that offsite power would be restored before systems that cannot operate for extended periods without AC power fail, thus resulting in core damage. This report also addresses effects of different designs, locations, and operational features on the estimated frequency of core damage resulting from station blackout events.

  17. 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.

  18. Decoders for MST radars

    NASA Technical Reports Server (NTRS)

    Woodman, R. F.

    1983-01-01

    Decoding techniques and equipment used by MST radars are described and some recommendations for new systems are presented. Decoding can be done either by software in special-purpose (array processors, etc.) or general-purpose computers or in specially designed digital decoders. Both software and hardware decoders are discussed and the special case of decoding for bistatic radars is examined.

  19. Determination of radar MTF

    SciTech Connect

    Chambers, D.

    1994-11-15

    The ultimate goal of the Current Meter Array (CMA) is to be able to compare the current patterns detected with the array with radar images of the water surface. The internal wave current patterns modulate the waves on the water surface giving a detectable modulation of the radar cross-section (RCS). The function relating the RCS modulations to the current patterns is the Modulation Transfer Function (MTF). By comparing radar images directly with co-located CMA measurements the MTF can be determined. In this talk radar images and CMA measurements from a recent experiment at Loch Linnhe, Scotland, will be used to make the first direct determination of MTF for an X and S band radar at low grazing angles. The technical problems associated with comparing radar images to CMA data will be explained and the solution method discussed. The results suggest the both current and strain rate contribute equally to the radar modulation for X band. For S band, the strain rate contributes more than the current. The magnitude of the MTF and the RCS modulations are consistent with previous estimates when the wind is blowing perpendicular to the radar look direction.

  20. 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.

  1. Alpine radar conversion for LAWR

    NASA Astrophysics Data System (ADS)

    Savina, M.; Burlando, P.

    2012-04-01

    class of radars, because it accounts for the large variability of hydrometeors reflectivity and vertical hydrometeors positioning (echo-top), which is strongly influenced by the high location of the radar. The ARCOM procedure is in addition embedded in a multistep quality control framework, which also includes the calibration on raingauge observations, and can be summarized as follow: 1) correction of both LAWR and raingauge observations for known errors (e.g. magnetron decay and heated-related water loss) 2) evaluation of the local Pearson's correlation coefficient (PCC) as estimator of the linear correlation between raingauge and LAWR observations (logarithmic receiver); 3) computation of the local ACF in the form of the local linear regression coefficient between raingauge and LAWR observations; 4) calibration of the ARCOM, i.e. definition of the parametrization able to reproduce the spatial variability of ACF as function of the local sP, being the PCCs used as weight in the calibration procedure. The resulting calibrated ARCOM finally allows, in any ungauged mountain spot, to convert LAWR observations into precipitation rate. The temporal and the spatial transferability of the ARCOM are evaluated via split-sample and a take-one-out cross validation. The results revealed good spatial transferability and a seasonal bias within 7%, thus opening new opportunities for local range distributed measurements of precipitation in mountain regions.

  2. SU-E-T-162: Evaluation of Dose Calculation of RayStation Planning System in Heterogeneous Media

    SciTech Connect

    Xu, H; Yi, B; Chung, H; Prado, K; Chen, S

    2014-06-01

    Purpose: To investigate the clinical reliability of heterogeneity-based dose algorithm using RayStation treatment planning system v.4.0. Methods: The collapsed cone dose calculations in RayStation (RaySearch, Sweden) were compared with the measurements (ion chamber and EBT2 film) and with an in-house Monte Carlo algorithm. A heterogeneous multi-layer phantom and CT images of 4 lung cancer patients were used here. The phantom, composed of multiple solid water slabs and Styrofoams, was irradiated with 6MV beams perpendicular to the layers. The MLC-defined field sizes were 5×5, 10×10, 15×15 and 20×20cm{sup 2}. The chamber was positioned at center of central solid water layer, and the films were placed at interfaces of solid water and Styrofoam. The RayStation dose and Monte Carlo dose were compared by performing absolute gamma analysis (3mm/3%): 1D gamma for PDD in the phantom and 3D gamma for patient volumes receiving dose above 10% of maximum dose. Results: The point dose differences between RayStation and ion chamber measurement were smaller than 1% for all of the field sizes. Between RayStation and film measurement, 5×5cm2 field had the maximum differences : <4mm for the penumbra and <0.3mm for the field width at all Styrofoam-and-solid-water interfaces. The absolute gamma analysis showed good agreement between RayStation and Monte Carlo. For PDD along beam axis in the phantom, the 1D gamma was 95.4, 98.6, 99.6 and 99.3% for field size 5×5, 10×10, 15×15 and 20×202 respectively. For dose comparison using patient CT images, 3D gamma was > 95% for all the patients. Conclusion: With respect to ion chamber/film measurement and Monte Carlo calculation, the collapsed cone algorithm in RayStation computed reasonable dose in both phantom and patient cases. Heterogeneity-based dose calculation of RayStation is clinically acceptable in heterogeneous media.

  3. Micropower impulse radar imaging

    SciTech Connect

    Hall, M.S.

    1995-11-01

    From designs developed at the Lawrence Livermore National Laboratory (LLNL) in radar and imaging technologies, there exists the potential for a variety of applications in both public and private sectors. Presently tests are being conducted for the detection of buried mines and the analysis of civil structures. These new systems use a patented ultra-wide band (impulse) radar technology known as Micropower Impulse Radar (GPR) imaging systems. LLNL has also developed signal processing software capable of producing 2-D and 3-D images of objects embedded in materials such as soil, wood and concrete. My assignment while at LLNL has focused on the testing of different radar configurations and applications, as well as assisting in the creation of computer algorithms which enable the radar to scan target areas of different geometeries.

  4. Spaceborne weather radar

    NASA Technical Reports Server (NTRS)

    Meneghini, Robert; Kozu, Toshiaki

    1990-01-01

    The present work on the development status of spaceborne weather radar systems and services discusses radar instrument complementarities, the current forms of equations for the characterization of such aspects of weather radar performance as surface and mirror-image returns, polarimetry, and Doppler considerations, and such essential factors in spaceborne weather radar design as frequency selection, scanning modes, and the application of SAR to rain detection. Attention is then given to radar signal absorption by the various atmospheric gases, rain drop size distribution and wind velocity determinations, and the characteristics of clouds, as well as the range of available estimation methods for backscattering, single- and dual-wavelength attenuation, and polarimetric and climatological characteristics.

  5. Radar sensors for automotive collision warning and avoidance

    NASA Astrophysics Data System (ADS)

    Grosch, Theodore O.

    1995-06-01

    Many different sensors and systems, from sonar to machine vision, have been installed on ground vehicles and automobiles. This paper describes the use of radar to improve driving safety and convenience. Radars are valuable sensors for all weather operation and experiments with automotive radar sensors have been conducted for over 40 years. This paper shows the advantages and disadvantages of applying microwave and millimeter wave radar to obstacle detection and collision avoidance in a roadway environment. The performance differences between avoidance and warning sensors are discussed and a problem set is devised for a typical forward-looking collision warning application. Various radar systems have been applied to this problem that include pulse and continuous wave transceivers. These system types are evaluated as to their suitability as a collision warning sensor. The various possible solutions are reduced to a small number of candidate radar types, and one such radar was chosen for full scale development. A low cost frequency modulated/continuous wave radar system was developed for automotive collision warning. The radar is attached to the sun visor inside the vehicle, and has been in operation for over four years. The radar monitors the range and range-rate of other vehicles and obstacles, and warns the driver when it perceives that a dangerous situation is developing. A system description and measured data is presented that shows how the 24.075 to 24.175 GHz band can be used for an adequate early warning system.

  6. [MODERN INSTRUMENTS FOR EAR, NOSE AND THROAT RENDERING AND EVALUATION IN RESEARCHES ON RUSSIAN SEGMENT OF THE INTERNATIONAL SPACE STATION].

    PubMed

    Popova, I I; Orlov, O I; Matsnev, E I; Revyakin, Yu G

    2016-01-01

    The paper reports the results of testing some diagnostic video systems enabling digital rendering of TNT teeth and jaws. The authors substantiate the criteria of choosing and integration of imaging systems in future on Russian segment of the International space station kit LOR developed for examination and download of high-quality images of cosmonauts' TNT, parodentium and teeth. PMID:27344858

  7. [MODERN INSTRUMENTS FOR EAR, NOSE AND THROAT RENDERING AND EVALUATION IN RESEARCHES ON RUSSIAN SEGMENT OF THE INTERNATIONAL SPACE STATION].

    PubMed

    Popova, I I; Orlov, O I; Matsnev, E I; Revyakin, Yu G

    2016-01-01

    The paper reports the results of testing some diagnostic video systems enabling digital rendering of TNT teeth and jaws. The authors substantiate the criteria of choosing and integration of imaging systems in future on Russian segment of the International space station kit LOR developed for examination and download of high-quality images of cosmonauts' TNT, parodentium and teeth.

  8. An Evaluation of the General Dynamics 20 Khz 5 Kw Breadboard for Space Station Electrical Power at MSFC

    NASA Technical Reports Server (NTRS)

    Hall, David K.; Kapustka, Robert E.

    1989-01-01

    The results and observations are discussed of tests made on the General Dynamics 20 kHz Breadboard for Space Station Electrical Power. The General Dynamics 20 kHz system only is considered, and not the issue of the use of 20 kHz ac Power for Spacecraft Applications.

  9. An Evaluation of the Observational Capabilities of A Scanning 95-GHz Radar in Studying the 3D Structures of Marine Stratocumulus Clouds

    NASA Astrophysics Data System (ADS)

    Bowley, Kevin

    Marine stratocumulus clouds play a critical role in Earth's radiative balance primarily due to the role of their high albedo reflecting incoming solar radiation, causing a cooling effect, while weakly reflecting outgoing infrared radiation. Characterization of the 3-Dimensional (3D) structure of these cloud systems over scales of 20-40 km is required to accurately account for the role of cloud inhomogeneity and structure on their shortwave forcing and lifetime, which has important applications for Global Climate Models. For first time, such 3D measurements in clouds were made available from a scanning cloud radar during the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) program's Clouds, Aerosol, and Precipitation in the Marine Boundary Layer (CAP-MBL) field campaign in the Azores Islands. The scanning radar observations were complemented by a suite of zenith-pointing active and passive remote sensors that were deployed to provide a detailed description of marine stratus over a long-term observation period in the ideal marine environment commonly found at the Azores. The scanning cloud radar observations present a shift from a multi-instrument, vertically pointing 'soda-straw' observation technique to a radar-only, 'radar-centric' observation technique. The scanning radar observations were gridded using a nearest-neighbor type scheme devised to take the natural variability of the observed field into account. The ability of the scheme to capture primary cloud properties (cloud fraction, cloud boundaries, drizzle detection) was assessed using measurements from the vertically pointing sensors. Despite the great sensitivity of the scanning cloud radar (-42.5 dBZ at 1 km range), the drop in sensitivity with range resulted in an artificial thinning of clouds with range from the radar. Drizzle-free cloud structures were undetectable beyond 5 km from the radar. Cloud fields containing drizzle were generally detectable to ranges exceeding 10 km from

  10. Meteorological and dynamical requirements for MST radar networks: Waves

    NASA Technical Reports Server (NTRS)

    Avery, S. K.

    1983-01-01

    Studies of wave motions using the MST radar have concentrated on single station time series analyses of gravity waves and tides. Since these radars collect high time resolution data they have the potential to become a significant tool for mesoscale research. In addition, radars are operated almost continuously unattended and, consequently, data sets are available for analyzing longer period wave motions such as tides and planetary scale waves. Although there is much to learn from single station data, the possibilities of new knowledge from a network of radars is exciting. The scales of wave motions in the atmosphere cover a broad range. Consequently the choice of a radar network depends to a large extent on the types of wave motions that are studied. There are many outstanding research problems that would benefit from observations from a MST radar network. In particular, there is a strong need for measurements of gravity wave parameters and equatorial wave motions. Some of the current problems in wave dynamics are discussed.

  11. Synoptic Analysis of Heavy Rainfall and Flood Observed in Izmir on 20 May 2015 Using Radar and Satellite Images

    NASA Astrophysics Data System (ADS)

    Avsar, Ercument

    2016-07-01

    In this study, a meteorological analysis is conducted on the sudden and heavy rainfall that occurred in Izmir on May 20, 2015. The barotropic model that is observed in upper carts is shown in detail. We can access the data of and analyze the type, severity and amount of many meteorological parameters using the meteorological radars that form a remote sensing system. The one field that uses the radars most intensively is rainfall. Images from the satellite and radar systems are used in the meteorological analysis of the heavy rainfall that occurred in Izmir on 20 May 2015, and the development of the system that led to this rainfall is shown. In this study, data received from Bornova Automatic Meteorological Observation Station (OMGI), which is under the management of Meteorology General Directorate (MGM), Izmir 2. Regional Directorate; satellite images; Radar PPI (Plan Position Indicator) and Radar MAX (Maximum Display) images are evaluated. In addition, synoptic situation, outputs of numerical estimation models, indices calculated from Skew T Log-P diagram are shown. All these results are mapped and analyzed. At the end of these analyses, it is found that this sudden rainfall had developed according to the frontal system motion. A barotropic model occurred on the day of the rainfall over the Aegean Region. As a result of the rainfall that happened in Izmir at 12.00 UTC (Universal Coordinated Time), the May month rainfall record for the last 64 years is achieved with a rainfall amount of 67.7 mm per meter square. Keywords: Izmir, barotropic model, heavy rainfall, radar, synoptic analysis

  12. Evaluation of prototype Advanced Life Support (ALS) pack for use by the Health Maintenance Facility (HMF) on Space Station Freedom (SSF)

    NASA Technical Reports Server (NTRS)

    Krupa, Debra T.; Gosbee, John; Murphy, Linda; Kizzee, Victor D.

    1991-01-01

    The purpose is to evaluate the prototype Advanced Life Support (ALS) Pack which was developed for the Health Maintenance Facility (HMF). This pack will enable the Crew Medical Officer (CMO) to have ready access to advanced life support supplies and equipment for time critical responses to any situation within the Space Station Freedom. The objectives are: (1) to evaluate the design of the pack; and (2) to collect comments for revision to the design of the pack. The in-flight test procedures and other aspects of the KC-135 parabolic test flight to simulate weightlessness are presented.

  13. Multiple frequency atmospheric radar techniques

    NASA Astrophysics Data System (ADS)

    Stitt, Gary Richard

    The use of multiple frequency coding to improve the vertical resolution of pulsed-Doppler very high frequency atmospheric radars, especially with regards to the two-frequency techniques known as frequency domain interferometry (FDI), is presented. This technique consists of transmitting alternate pulses on two distinct carrier frequencies. The two resulting time series are used to evaluate the normalized cross-correlation function, whose magnitude and phase are related to the thickness and position of a scattering layer. These same time series are also used to evaluate cross-spectra, which yield magnitude and phase values for each Doppler frequency component of the return signal.

  14. Radar Based Quantitative Precipitation Estimation in Taiwan

    NASA Astrophysics Data System (ADS)

    Wang, Y.; Zhang, J.; Chang, P.

    2012-12-01

    Accurate high-resolution radar quantitative precipitation estimation (QPE) has shown increasing values in hydrological predictions in the last decade. Such QPEs are especially valuable in complex terrain where rain gauge network is sparse and hard to maintain while flash floods and mudslides are common hazards. Taiwan Central Weather Bureau has deployed four S-band radars to support their flood warning operations in recent years, and a real-time multi-radar QPE system was developed. Evaluations of the real-time system over one-year revealed some underestimation issues in the radar QPE. The current work investigates these issues and develops a series of refinements to the system. The refinements include replacing the general R-Z relationships used in the old system with the local ones, mitigating non-standard beam blockage artifacts based on long-term accumulations, and applying vertical profile of reflectivity (VPR) corrections. The local R-Z relationships were derived from 2D video disdrometer observations of winter stratiform precipitation, meiyu fronts, local convective storms, and typhoons. The VPR correction was applied to reduce radar QPE errors in severely blocked area near the Central Mountain Range (CMR). The new radar QPE system was tested using different precipitation events and showed significant improvements over the old system especially along the CMR.

  15. Radar Location Equipment Development Program: Phase I

    SciTech Connect

    Sandness, G.A.; Davis, K.C.

    1985-06-01

    The work described in this report represents the first phase of a planned three-phase project designed to develop a radar system for monitoring waste canisters stored in a thick layer of bedded salt at the Waste Isolation Pilot Plant near Carlsbad, New Mexico. The canisters will be contained in holes drilled into the floor of the underground waste storage facility. It is hoped that these measurements can be made to accuracies of +-5 cm and +-2/sup 0/, respectively. The initial phase of this project was primarily a feasibility study. Its principal objective was to evaluate the potential effectiveness of the radar method in the planned canister monitoring application. Its scope included an investigation of the characteristics of radar signals backscattered from waste canisters, a test of preliminary data analysis methods, an assessment of the effects of salt and bentonite (a proposed backfill material) on the propagation of the radar signals, and a review of current ground-penetrating radar technology. A laboratory experiment was performed in which radar signals were backscattered from simulated waste canisters. The radar data were recorded by a digital data acquisition system and were subsequently analyzed by three different computer-based methods to extract estimates of canister location and tilt. Each of these methods yielded results that were accurate within a few centimeters in canister location and within 1/sup 0/ in canister tilt. Measurements were also made to determine the signal propagation velocities in salt and bentonite (actually a bentonite/sand mixture) and to estimate the signal attenuation rate in the bentonite. Finally, a product survey and a literature search were made to identify available ground-penetrating radar systems and alternative antenna designs that may be particularly suitable for this unique application. 10 refs., 21 figs., 4 tabs.

  16. Moving target detection for frequency agility radar by sparse reconstruction

    NASA Astrophysics Data System (ADS)

    Quan, Yinghui; Li, YaChao; Wu, Yaojun; Ran, Lei; Xing, Mengdao; Liu, Mengqi

    2016-09-01

    Frequency agility radar, with randomly varied carrier frequency from pulse to pulse, exhibits superior performance compared to the conventional fixed carrier frequency pulse-Doppler radar against the electromagnetic interference. A novel moving target detection (MTD) method is proposed for the estimation of the target's velocity of frequency agility radar based on pulses within a coherent processing interval by using sparse reconstruction. Hardware implementation of orthogonal matching pursuit algorithm is executed on Xilinx Virtex-7 Field Programmable Gata Array (FPGA) to perform sparse optimization. Finally, a series of experiments are performed to evaluate the performance of proposed MTD method for frequency agility radar systems.

  17. Radar target classification studies: Software development and documentation

    NASA Astrophysics Data System (ADS)

    Kamis, A.; Garber, F.; Walton, E.

    1985-09-01

    Three computer programs were developed to process and analyze calibrated radar returns. The first program, called DATABASE, was developed to create and manage a random accessed data base. The second program, called FTRAN DB, was developed to process horizontal and vertical polarizations radar returns into different formats (i.e., time domain, circular polarizations and polarization parameters). The third program, called RSSE, was developed to simulate a variety of radar systems and to evaluate their ability to identify radar returns. Complete computer listings are included in the appendix volumes.

  18. Goldstone solar system radar

    NASA Technical Reports Server (NTRS)

    Jurgens, Raymond F.

    1988-01-01

    Planning, direction, experimental design, and coordination of data-acquisition and engineering activities in support of all Goldstone planetary radar astronomy were performed. This work demands familiarity with the various components of a planetary radar telescope (transmitter, receiver, antenna, computer hardware and software) as well as knowledge of how the entire system must function as a cohesive unit to meet the particular scientific objectives at hand in a given observation. Support radar data-processing facilities, currently being used for virtually all Goldstone data reduction includes: a VAX 11/780 computer system, an FPS 5210 array processor, terminals, tape drives, and image-display devices, as well as a large body of data-reduction software to accommodate the variety of data-acquisition formats and strategems. Successful 113-cm radar observation of Callisto and the near-Earth asteroid 1981 Midas and Goldstone/VLA radar observations of Saturn's rings were obtained. Quick-look verification programs from data taken with phase-coded cw (i.e., ranging) waveforms, applicable to Venus, the Moon, and small bodies were completed. Definition of scientific and engineering requirements on instrument performance, radar system configuration, and personnel, for all 1988 Goldstone radar investigations was accomplished.

  19. Hazard Evaluation for the Mars Pathfinder Prime Landing Site from Synthesis of Radar Ranging and Continuous Wave Observations during the 1995 Mars Opposition

    NASA Technical Reports Server (NTRS)

    Slade, M. A.; Jurgens, R. F.; Haldemann, A. F. C.; Mitchell, D. L.

    1995-01-01

    During the 1995 Mars opposition, Earth-based radars had a favorable angle for viewing many of the possible landing sites for Mars Pathfinder. The Goldstone 70-m antenna was used at X-band (3.5 cm) to get a measure of roughness to nearly that size.

  20. Study to investigate and evaluate means of optimizing the Ku-band combined radar/communication functions for the space shuttle

    NASA Technical Reports Server (NTRS)

    Weber, C. L.; Alem, W. K.; Simon, M. K.

    1977-01-01

    The Ku band radar system on the shuttle orbiter operates in both a search and a tracking mode, and its transmitter and antennas share time with the communication mode in the integrated system. The power allocation properties and the Costa subloop subcarrier tracking performance associated with the baseline digital phase shift implementation of the three channel orbiter Ku band modulator are discussed.

  1. The design and implementation of a multi-waveform radar echo simulator.

    PubMed

    Quan, Yinghui; Gao, Xiaoxiao; Li, Yachao; Xing, Mengdao

    2015-10-01

    Radar simulator is an effective tool for performance assessment of radar systems by accurately reproducing echo signals from complicated environment. This paper presents a design of fast multi-waveform radar echo generation based on deconvolution method. First, scene information is retrieved from outfield data based on improved conjugate gradient algorithm. Then, the new radar echoes are generated through convolution of new transmitted signal and restored scene information. A fast and area-efficient field programmable gate array realization is provided to meet the real-time requirement of radar echo simulation. Finally, a series of experiments are performed to evaluate the effectiveness of proposed radar simulation instrument.

  2. The design and implementation of a multi-waveform radar echo simulator

    NASA Astrophysics Data System (ADS)

    Quan, Yinghui; Gao, Xiaoxiao; Li, Yachao; Xing, Mengdao

    2015-10-01

    Radar simulator is an effective tool for performance assessment of radar systems by accurately reproducing echo signals from complicated environment. This paper presents a design of fast multi-waveform radar echo generation based on deconvolution method. First, scene information is retrieved from outfield data based on improved conjugate gradient algorithm. Then, the new radar echoes are generated through convolution of new transmitted signal and restored scene information. A fast and area-efficient field programmable gate array realization is provided to meet the real-time requirement of radar echo simulation. Finally, a series of experiments are performed to evaluate the effectiveness of proposed radar simulation instrument.

  3. 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.

  4. 9. View of back side of radar scanner building no. ...

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

    9. View of back side of radar scanner building no. 106 showing passageway links to other buildings east and west, and DR 3 antenna in background. - 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

  5. 10. View of back side of radar scanner building no. ...

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

    10. View of back side of radar scanner building no. 104 showing passageway links to other building to east and DR 1 antenna in background. - 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

  6. 74. Transmitter building no. 102, view of radar digital test ...

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

    74. Transmitter building no. 102, view of radar digital test and maintenance cabinet area control panel and date storage system showing ampex tape storage devices. - 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

  7. 37. View of detection radar environmental display (DRED) console for ...

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

    37. View of detection radar environmental display (DRED) console for middle DR 2 (structure no. 736) antenna, located in MWOC facility. - 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

  8. 23. View of junction of passageway link with radar transmitter ...

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

    23. View of junction of passageway link with radar transmitter building 102 (view looking south) showing main personnel entrance door. - 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

  9. Comparison of Ambient Noise From Two Station Designs, Evaluating USArray's Transportable and Flexible Arrays in the Pacific Northwest

    NASA Astrophysics Data System (ADS)

    Pfeifer, M.; Alvarez, M.; Woodward, R.; Yang, Z.

    2009-12-01

    The USArray program within the National Science Foundation-funded Earthscope program is comprised of two portable broadband seismic projects; the Transportable Array (TA), and the Flexible Array (FA). The TA consists of 400 stations occupy locations within the United States on a nominal 70 km spacing for a period of approximately 24 months. As a network, these TA stations roll from west to east so that within 10 years the entire lower 48 states will have been occupied by the TA network. As a complementary component of USArray, the FA pool of instruments is comprised of 1200 active-source, 120 short-period and 326 broadband portable stations. These instruments are used by Principal Investigator-driven studies which focus on geologic targets within the TA footprint. Currently the TA network is transitioning from the Rocky Mountains into the Great Plains. The FA currently has four experiments installed. In this study we quantify the overall performance of these two tandem networks using a controlled set of continuous recordings in Western Washington. We compare the background noise levels between the standard deep TA and shallow FA broadband sensor vault system. We use McNamara’s probability density function (PDF) analysis as the basis of the comparison. We combine the network wide PDF’s of each network for a period of over 600 days of contemporaneous recordings. Preliminary analysis using data from 28 TA stations in western Washington and 47 nearby FA stations from the CAFE experiment (Abers, et al. Eos Trans. AGU 88(52), Fall Meet. Suppl. S43D-07), show that the TA stations are quieter at periods below 20 seconds by about 12 dB on the horizontal components. The vertical components for both the TA and FA are equivalent for periods below 5 seconds. At higher frequencies (> 2 Hz), however, the FA shallower vault is quieter by approximately 10 dB on both the vertical and horizontal components. The question addressed is, what is contributing to the difference in

  10. Health hazard evaluation report HETA 93-1062-2558, Texas Utilities Electric Company, Martin Lake Steam Electric Station, Tatum, Texas

    SciTech Connect

    Malkin, R.; Moss, C.E.; Reh, C.M.; Ragab, M.

    1996-01-01

    In response to a request from workers at the Texas Utilities Electric Company (SIC-4911), Martin Lake Steam Electric Station in Tatum, Texas, the incidence of neurologic symptoms and exposure to electromagnetic fields and organophosphates were investigated. Workers reported neurological symptoms, including memory loss, dizziness and fatigue. A site visit to the station revealed electromagnetic field levels below the current occupational standard of 10 gauss. The use of an organophosphate containing fire resistant hydraulic fluid, Fyrquel-EH (1330785), was reported by employees. A significant correlation was identified between memory of past symptoms indicative of acute organophosphate exposure after working with Fyrquel-EH and current symptoms; however, blood cholinesterase levels were all within the normal range and no relevant neurologic abnormalities were noted on neurological examinations. The authors conclude that a hazard existed from the use of Fyrquel-EH. The authors recommend measures for the safe handling of organophosphate compounds.

  11. Cassini radar : system concept and simulation results

    NASA Astrophysics Data System (ADS)

    Melacci, P. T.; Orosei, R.; Picardi, G.; Seu, R.

    1998-10-01

    The Cassini mission is an international venture, involving NASA, the European Space Agency (ESA) and the Italian Space Agency (ASI), for the investigation of the Saturn system and, in particular, Titan. The Cassini radar will be able to see through Titan's thick, optically opaque atmosphere, allowing us to better understand the composition and the morphology of its surface, but the interpretation of the results, due to the complex interplay of many different factors determining the radar echo, will not be possible without an extensive modellization of the radar system functioning and of the surface reflectivity. In this paper, a simulator of the multimode Cassini radar will be described, after a brief review of our current knowledge of Titan and a discussion of the contribution of the Cassini radar in answering to currently open questions. Finally, the results of the simulator will be discussed. The simulator has been implemented on a RISC 6000 computer by considering only the active modes of operation, that is altimeter and synthetic aperture radar. In the instrument simulation, strict reference has been made to the present planned sequence of observations and to the radar settings, including burst and single pulse duration, pulse bandwidth, pulse repetition frequency and all other parameters which may be changed, and possibly optimized, according to the operative mode. The observed surfaces are simulated by a facet model, allowing the generation of surfaces with Gaussian or non-Gaussian roughness statistic, together with the possibility of assigning to the surface an average behaviour which can represent, for instance, a flat surface or a crater. The results of the simulation will be discussed, in order to check the analytical evaluations of the models of the average received echoes and of the attainable performances. In conclusion, the simulation results should allow the validation of the theoretical evaluations of the capabilities of microwave instruments, when

  12. Aircraft radar antennas

    NASA Astrophysics Data System (ADS)

    Schrank, Helmut E.

    1987-04-01

    Many changes have taken place in airborne radar antennas since their beginnings over forty years ago. A brief historical review of the advances in technology is presented, from mechanically scanned reflectors to modern multiple function phased arrays. However, emphasis is not on history but on the state-of-the-art technology and trends for future airborne radar systems. The status of rotating surveillance antennas is illustrated by the AN/APY-1 Airborne Warning and Control System (AWACS) slotted waveguide array, which achieved a significant breakthrough in sidelobe suppression. Gimballed flat plate arrays in nose radomes are typified by the AN/APG-66 (F-16) antenna. Multifunction phased arrays are presented by the Electronically Agile Radar (EAR) antenna, which has achieved significant advances in performance versatility and reliability. Trends toward active aperture, adaptive, and digital beamforming arrays are briefly discussed. Antennas for future aircraft radar systems must provide multiple functions in less aperture space, and must perform more reliably.

  13. Laser Radar Animation

    NASA Video Gallery

    Laser and radar instruments aboard NASA aircraft provide measurements of the snow and ice surface and down to the bedrock under the ice. Lasers, with a shorter wavelength, measure the surface eleva...

  14. Multispectral imaging radar

    NASA Technical Reports Server (NTRS)

    Porcello, L. J.; Rendleman, R. A.

    1972-01-01

    A side-looking radar, installed in a C-46 aircraft, was modified to provide it with an initial multispectral imaging capability. The radar is capable of radiating at either of two wavelengths, these being approximately 3 cm and 30 cm, with either horizontal or vertical polarization on each wavelength. Both the horizontally- and vertically-polarized components of the reflected signal can be observed for each wavelength/polarization transmitter configuration. At present, two-wavelength observation of a terrain region can be accomplished within the same day, but not with truly simultaneous observation on both wavelengths. A multiplex circuit to permit this simultaneous observation has been designed. A brief description of the modified radar system and its operating parameters is presented. Emphasis is then placed on initial flight test data and preliminary interpretation. Some considerations pertinent to the calibration of such radars are presented in passing.

  15. Air Shower Detection by Bistatic Radar

    NASA Astrophysics Data System (ADS)

    Othman, M. Abou Bakr; Allen, C.; Belz, J.; Besson, D.; Farhang-Boroujeny, B.; Ikeda, D.; Kunwar, S.; Lundquist, J. P.; Kravchenko, I.; Myers, I.; Nakamura, T.; Sagawa, H.; Sokolsky, P.; Takai, H.; Terasawa, T.; Thomson, G. B.

    2011-09-01

    Progress in the field of high-energy cosmic rays is currently limited by the rarity of the most interesting rays striking the Earth. Indeed, the continuation of the field beyond the current generation of observatories may become financially and practically impossible if new ways are not found to achieve remote coverage over large portions of the Earth's surface. We describe the development of an observatory based on such a new technique: the remote sensing via bistatic radar technology of cosmic ray induced extensive air showers. We build on pilot studies performed by MARIACHI which have demonstrated that air shower radar echoes are detectable, the opportunity afforded by the location of the Northern Hemisphere's largest ``conventional'' cosmic ray observatory (The Telescope Array) in radio-quiet western Utah, and the donation of analog television transmission equipment to this effort by a local television station.

  16. Rendezvous radar for the orbital maneuvering vehicle

    NASA Technical Reports Server (NTRS)

    Locke, John W.; Olds, Keith A.; Quaid, Thomas

    1991-01-01

    The Rendezvous Radar Set (RRS) was designed at Motorola's Strategic Electronics Division in Chandler, Arizona, to be a key subsystem aboard NASA's Orbital Maneuvering Vehicle (OMV). The unmanned OMV, which was under development at TRW's Federal Systems Division in Redondo Beach, California, was designed to supplement the Shuttle's satellite delivery, retrieval, and maneuvering activities. The RRS was to be used to locate and then provide the OMV with vectoring information to the target satellite (or Shuttle or Space Station) to aid the OMV in making a minimum fuel consumption approach and rendezvous. The OMV development program was halted by NASA in 1990 just as parts were being ordered for the RRS engineering model. The paper presented describes the RRS design and then discusses new technologies, either under development or planned for development at Motorola, that can be applied to radar or alternative sensor solutions for the Automated Rendezvous and Capture problem.

  17. Downhole pulse radar

    DOEpatents

    Chang, Hsi-Tien

    1989-01-01

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

  18. Downhole pulse radar

    DOEpatents

    Chang, Hsi-Tien

    1987-09-28

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

  19. Phased-array radars

    NASA Astrophysics Data System (ADS)

    Brookner, E.

    1985-02-01

    The operating principles, technology, and applications of phased-array radars are reviewed and illustrated with diagrams and photographs. Consideration is given to the antenna elements, circuitry for time delays, phase shifters, pulse coding and compression, and hybrid radars combining phased arrays with lenses to alter the beam characteristics. The capabilities and typical hardware of phased arrays are shown using the US military systems COBRA DANE and PAVE PAWS as examples.

  20. Earth resources shuttle imaging radar. [systems analysis and design analysis of pulse radar for earth resources information system

    NASA Technical Reports Server (NTRS)

    1975-01-01

    A report is presented on a preliminary design of a Synthetic Array Radar (SAR) intended for experimental use with the space shuttle program. The radar is called Earth Resources Shuttle Imaging Radar (ERSIR). Its primary purpose is to determine the usefulness of SAR in monitoring and managing earth resources. The design of the ERSIR, along with tradeoffs made during its evolution is discussed. The ERSIR consists of a flight sensor for collecting the raw radar data and a ground sensor used both for reducing these radar data to images and for extracting earth resources information from the data. The flight sensor consists of two high powered coherent, pulse radars, one that operates at L and the other at X-band. Radar data, recorded on tape can be either transmitted via a digital data link to a ground terminal or the tape can be delivered to the ground station after the shuttle lands. A description of data processing equipment and display devices is given.

  1. On wave radar measurement

    NASA Astrophysics Data System (ADS)

    Ewans, Kevin; Feld, Graham; Jonathan, Philip

    2014-09-01

    The SAAB REX WaveRadar sensor is widely used for platform-based wave measurement systems by the offshore oil and gas industry. It offers in situ surface elevation wave measurements at relatively low operational costs. Furthermore, there is adequate flexibility in sampling rates, allowing in principle sampling frequencies from 1 to 10 Hz, but with an angular microwave beam width of 10° and an implied ocean surface footprint in the order of metres, significant limitations on the spatial and temporal resolution might be expected. Indeed there are reports that the accuracy of the measurements from wave radars may not be as good as expected. We review the functionality of a WaveRadar using numerical simulations to better understand how WaveRadar estimates compare with known surface elevations. In addition, we review recent field measurements made with a WaveRadar set at the maximum sampling frequency, in the light of the expected functionality and the numerical simulations, and we include inter-comparisons between SAAB radars and buoy measurements for locations in the North Sea.

  2. Seasonal evaluation and spatial variability of suspended particulate matter in the vicinity of a large coal-fired power station in India--a case study.

    PubMed

    Sharma, Rajnikant; Pervez, Yasmeen; Pervez, Shamsh

    2005-03-01

    Coal combustion in the power sector gives rise to the emission of primary and secondary particulate pollutants. Since the emission of pollutants depends on coal quality and combustion technology, and given that transport, transformation and deposition of contaminants depend on regional climatic conditions, specific studies for the power stations is needed to evaluate their environmental impacts. Monitoring of ambient respirable suspended particulate matter (RSPM) and suspended particulate matter (SPM) levels around a large coal-fired power station in India was carried out. The specific objectives were the determination of spatial and seasonal variability in RSPM and SPM levels, and their relationship with meteorological parameters such as wind velocity and relative humidity. The results have shown a marked seasonal trend and spatial variability in RSPM and SPM levels in the study area. Higher concentrations of ambient RSPM and SPM were found in downwind monitoring stations compared to upwind direction. Ratios of RSPM to SPM and correlation coefficient values between RSPM and SPM along with meteorological parameters were also worked out. Relative humidity and wind velocity have shown an inverse relation with particulate deposition pattern.

  3. Inversion and assessment of swell waveheights from HF radar spectra in the Iroise Sea

    NASA Astrophysics Data System (ADS)

    Wang, Weili; Forget, Philippe; Guan, Changlong

    2016-04-01

    As an extension of previous work in Wang et al. (Ocean Dyn 64:1447-1456, 2014), this article presents significant waveheights of swell inverted from a 13 month dataset of two high-frequency (HF) phased array radars. As an important intermediate variable in the calculation of significant waveheights, relative swell directions obtained by two different methods from a single radar station are also presented. The impact of the inaccuracy of relative swell direction on the calculation of waveheight is investigated and an alternative way of using constant swell direction is proposed. Radar-inverted swell significant waveheights using different ranges of relative swell directions are investigated. Results are assessed by WAVEWATCH III model hind casts. Analysis of the complete database shows that radar-inverted swell significant waveheights agree reasonably well with model estimates with large scatter. Standard deviation of the difference between the two estimations increases with waveheight, whereas the relative standard deviation, normalized by waveheight, keeps nearly constant. The constant direction scheme of waveheight inversion gives good estimations except for energetic swell exceeding the small perturbation assumption. Statistical analysis suggests that radar measurement uncertainty explains a considerable part of the difference between radar and model estimates. Swell estimates from both radar stations are consistent. This enables combined use of both radar spectra at common radar cells. Use of double spectra solves the ambiguity of relative swell direction, i.e., absolute swell direction is obtained, and effectively improves the accuracy of swell direction by the least-squares method.

  4. Optimal frequency range for medical radar measurements of human heartbeats using body-contact radar.

    PubMed

    Brovoll, Sverre; Aardal, Øyvind; Paichard, Yoann; Berger, Tor; Lande, Tor Sverre; Hamran, Svein-Erik

    2013-01-01

    In this paper the optimal frequency range for heartbeat measurements using body-contact radar is experimentally evaluated. A Body-contact radar senses electromagnetic waves that have penetrated the human body, but the range of frequencies that can be used are limited by the electric properties of the human tissue. The optimal frequency range is an important property needed for the design of body-contact radar systems for heartbeat measurements. In this study heartbeats are measured using three different antennas at discrete frequencies from 0.1 - 10 GHz, and the strength of the received heartbeat signal is calculated. To characterize the antennas, when in contact with the body, two port S-parameters(†) are measured for the antennas using a pork rib as a phantom for the human body. The results shows that frequencies up to 2.5 GHz can be used for heartbeat measurements with body-contact radar.

  5. Evaluation of Cloud Microphysics in JMA-NHM Simulations Using Bin or Bulk Microphysical Schemes through Comparison with Cloud Radar Observations

    NASA Technical Reports Server (NTRS)

    Iguchi, Takamichi; Nakajima, Teruyuki; Khain, Alexander P.; Saito, Kazuo; Takemura, Toshihiko; Okamoto, Hajime; Nishizawa, Tomoaki; Tao, Wei-Kuo

    2012-01-01

    Numerical weather prediction (NWP) simulations using the Japan Meteorological Agency NonhydrostaticModel (JMA-NHM) are conducted for three precipitation events observed by shipborne or spaceborneW-band cloud radars. Spectral bin and single-moment bulk cloud microphysics schemes are employed separatelyfor an intercomparative study. A radar product simulator that is compatible with both microphysicsschemes is developed to enable a direct comparison between simulation and observation with respect to theequivalent radar reflectivity factor Ze, Doppler velocity (DV), and path-integrated attenuation (PIA). Ingeneral, the bin model simulation shows better agreement with the observed data than the bulk modelsimulation. The correction of the terminal fall velocities of snowflakes using those of hail further improves theresult of the bin model simulation. The results indicate that there are substantial uncertainties in the masssizeand sizeterminal fall velocity relations of snowflakes or in the calculation of terminal fall velocity of snowaloft. For the bulk microphysics, the overestimation of Ze is observed as a result of a significant predominanceof snow over cloud ice due to substantial deposition growth directly to snow. The DV comparison shows thata correction for the fall velocity of hydrometeors considering a change of particle size should be introducedeven in single-moment bulk cloud microphysics.

  6. Observation Station

    ERIC Educational Resources Information Center

    Rutherford, Heather

    2011-01-01

    This article describes how a teacher integrates science observations into the writing center. At the observation station, students explore new items with a science theme and use their notes and questions for class writings every day. Students are exposed to a variety of different topics and motivated to write in different styles all while…

  7. Intercontinental Bistatic Radar Test Observation of Asteroid 1998 WT24

    NASA Technical Reports Server (NTRS)

    Righini, S.; Poppi, S.; Montebugnoli, S.; DiMartino, M.; Saba, L.; Delbo, M.; Ostro, S.; Monari, J.; Poloni, M.; Orlati, A.

    2002-01-01

    thanks to the collaboration undertaken with the Evpatoria radar station, and consisted in the observation of the ETALON-1 low orbit satellite

  8. Wave parameters comparisons between High Frequency (HF) radar system and an in situ buoy: a case study

    NASA Astrophysics Data System (ADS)

    Fernandes, Maria; Alonso-Martirena, Andrés; Agostinho, Pedro; Sanchez, Jorge; Ferrer, Macu; Fernandes, Carlos

    2015-04-01

    The coastal zone is an important area for the development of maritime countries, either in terms of recreation, energy exploitation, weather forecasting or national security. Field measurements are in the basis of understanding how coastal and oceanic processes occur. Most processes occur over long timescales and over large spatial ranges, like the variation of mean sea level. These processes also involve a variety of factors such as waves, winds, tides, storm surges, currents, etc., that cause huge interference on such phenomena. Measurement of waves have been carried out using different techniques. The instruments used to measure wave parameters can be very different, i.e. buoys, ship base equipment like sonar and satellites. Each equipment has its own advantage and disadvantage depending on the study subject. The purpose of this study is to evaluate the behaviour of a different technology available and presently adopted in wave measurement. In the past few years the measurement of waves using High Frequency (HF) Radars has had several developments. Such a method is already established as a powerful tool for measuring the pattern of surface current, but its use in wave measurements, especially in the dual arrangement is recent. Measurement of the backscatter of HF radar wave provides the raw dataset which is analyzed to give directional data of surface elevation at each range cell. Buoys and radars have advantages, disadvantages and its accuracy is discussed in this presentation. A major advantage with HF radar systems is that they are unaffected by weather, clouds or changing ocean conditions. The HF radar system is a very useful tool for the measurement of waves over a wide area with real-time observation, but it still lacks a method to check its accuracy. The primary goal of this study was to show how the HF radar system responds to high energetic variations when compared to wave buoy data. The bulk wave parameters used (significant wave height, period and

  9. Stage measurement at gaging stations

    USGS Publications Warehouse

    Sauer, Vernon B.; Turnipseed, D. Phil

    2010-01-01

    Stream and reservoir stage are critical parameters in the computation of stream discharge and reservoir volume, respectively. In addition, a record of stream stage is useful in the design of structures that may be affected by stream elevation, as well as for the planning for various uses of flood plains. This report describes equipment and methodology for the observation, sensing, and recording of stage in streams and reservoirs. Although the U.S. Geological Survey (USGS) still uses the traditional, basic stilling-well float system as a predominant gaging station, modern electronic stage sensors and water-level recorders are now commonly used. Bubble gages coupled with nonsubmersible pressure transducers eliminate the need for stilling wells. Submersible pressure transducers have become common in use for the measurement of stage in both rivers and lakes. Furthermore, noncontact methods, such as radar, acoustic, and laser methods of sensing water levels, are being developed and tested, and in the case of radar, are commonly used for the measurement of stage. This report describes commonly used gaging-station structures, as well as the design and operation of gaging stations. Almost all of the equipment and instruments described in this report will meet the accuracy standard set by the USGS Office of Surface Water (OSW) for the measurement of stage for most applications, which is ?0.01 foot (ft) or 0.2 percent of the effective stage. Several telemetry systems are used to transmit stage data from the gaging station to the office, although satellite telemetry has become the standard. These telemetry systems provide near real-time stage data, as well as other information that alerts the hydrographer to extreme or abnormal events, and instrument malfunctions.

  10. Inversion of swell frequency from a 1-year HF radar dataset collected in Brittany (France)

    NASA Astrophysics Data System (ADS)

    Wang, Weili; Forget, Philippe; Guan, Changlong

    2014-10-01

    This article presents long period ocean wave (swell) frequencies inverted from a 13-month dataset of high-frequency (HF) phased array radars and an assessment of these estimates by comparison with WAVEWATCH III model data. The method of swell frequency inversion from high-frequency radar sea echo Doppler spectra is described. Radar data were collected from a two-site HF Wellen Radar (WERA) radar system on the west coast of Brittany (France) operating at 12 MHz. A standard beam-forming processing technique has been used to obtain Doppler spectra of processed radar cells. Swell frequencies are obtained from the frequencies of particular spectral peaks of the second-order continuum in hourly averaged Doppler spectra. The data coverage of effective Doppler spectra considered for swell frequency estimates shows the influence of islands and shallow water effects. Swell estimates from both radar stations are in good agreement. The comparison of radar-derived results to WAVEWATCH III (WW3) estimates shows that radar measurements agree quite well with model results. The bias and standard deviation between two estimates are very small for swells with frequency less than 0.09 Hz (period >11 s), whereas radar estimates are generally lower than model estimates for shorter swells, along with higher standard deviation. Statistical analysis suggests that radar measurement uncertainty explains most of the difference between radar and model estimates. For each swell event, time series of frequency exhibits a quasi-linear frequency increase which is associated with the dispersive property of wave phase velocity. The use of swell frequency estimates from both radars on common radar cells only slightly increases the accuracy of swell frequency measurement.

  11. Solving radar detection problems using simulation

    NASA Astrophysics Data System (ADS)

    Curtis Schleher, D.

    1995-04-01

    Simulation is a well-known but often misunderstood method for predicting the detection range of radars. Recent advances in computer software and hardware have made simulation easier to apply and use. Users are putting increased reliance on computer simulation in lieu of more expensive test and evaluation. In this paper, a simulation example is given of a complex radar detection problem which is not solvable using conventional procedures. It is shown how this problem is easily solved using a MATLAB simulation on a personal computer (PC).

  12. Evaluation of Plant- Compost -Microorganisms Synergy for the Remediation of Diesel contaminated Soil: Success Stories from the Field Station

    NASA Astrophysics Data System (ADS)

    Hussain, Imran; Wimmer, Bernhard; Soja, Gerhard; Sessitsch, Angela; Reichenauer, Thomas G.

    2016-04-01

    Total petroleum hydrocarbons (TPH) contain a mixture of crude oil, gasoline, creosote and diesel is one of the most common groups of persistent organic pollutants. TPH enters into the ecosystem (soil, water and air) through leakage of underground storage tanks (LUST), accidental oil spills, transportation losses and industrial processes. Pollution associated with diesel oil and its refined products is of great concern worldwide due to its threats/damages for human and ecosystem health, soil structure and ground water quality. Extensive soils pollution with petroleum hydrocarbons results in extreme harsh surroundings, produce hydrophobic conditions and infertile soils that ultimately lead towards less plant and microorganisms growth. Among biological methods, bioremediation and phytoremediation are promising technologies that have both technical and ecological benefits as compared to convention methods. Within phytoremediation, rhizoremediation based on stimulation of degrading microorganism's population influenced by plant rhizospheric effect is known as main mechanism for phytoremediation of petroleum polluted soils. Composting along with rhizodegradtion was used to remediate freshly spilled soils at Lysimeter station Siebersdof, Austria. Experiment was started in July 2013 and will be monitored up to September 2016. Field station has 12 Lysimeter in total; each has length, width and depth of 100 cm respectively. Each Lysimeter was filled with normal agricultural soil from Siebersdof (0-70 cm), sand (70-85 cm) and stones (85-100cm). Sand and stones were added to support the normal leaching and percolation of water as we collected leachate samples after regular intervals. After filling, commercial diesel oil (2% w/w of 0-70 cm soil) was spilled on top of each Lysimeter as accidental spill occurs in filed. Compost was added at 0-15 cm layer (5% w/w of soil) to stimulate plant as well as microorganisms growth. Whole Lysimeter station was divided into three treatments

  13. Radar detection during scintillation. Technical report

    SciTech Connect

    Knepp, D.L.; Reinking, J.T.

    1990-04-01

    Electromagnetic signals that propagate through a disturbed region of the ionosphere can experience scattering which can cause fluctuations in the received amplitude, phase, and angle-of-arrival. This report considers the performance of a radar that must operate through a disturbed propagation environment such as might occur during strong equatorial scintillation, during a barium release experiment or after a high altitude nuclear detonation. The severity of the channel disturbance is taken to range from weak scattering where the signal quadrature components are uncorrelated Gaussian variates. The detection performance of noncoherent combining is compared to that of double threshold (M out of N) combining under various levels of scintillation disturbance. Results are given for detection sensitivity as a function of the scintillation index and the ratio of the radar hopping bandwidth to the channel bandwidth. It is shown that both types of combining can provide mitigation of fading, and that noncoherent combining generally enjoys an advantage in detection sensitivity of about 2 dB. This work serves as a quantitative guideline to the advantages and disadvantages of certain types of detection strategies during scintillation and is, therefore, useful in the radar design process. However, a detailed simulation of the radar detection algorithms is necessary to evaluate a radar design strategy to predict performance under scintillation conditions.

  14. Ocean topography experiment (TOPEX) radar altimeter

    NASA Astrophysics Data System (ADS)

    Rossi, L. C.; Hancock, D. W.; Hayne, G. S.

    A spaceflight qualified Radar Altimeter capable of achieving the TOPEX Mission measurement precision requirement of 2-centimeters, is provided and its performance (Engineering Assessment) will be evaluated after launch and continuously during its 3-year mission operational period. Information will be provided to JPL about the calibration of the TOPEX Radar Altimeter. The specifications for the required data processing algorithms which will be necessary to convert the Radar Altimeter mission telemetry data into the geophysical data will also be provided. The stringent 2 cm precision requirement for ocean topography determination from space necessitated examining existing Radar Altimeter designs for their applicability towards TOPEX. As a result, a system configuration evolved using some flight proven designs in conjunction with needed improvements which include: (1) a second frequency or channel to remove the range delay or apparent height bias caused by the electron content of the ionosphere; (2) higher transmit pulse repetition frequencies for correlation benefits at higher sea states to maintain precision; and (3) a faster microprocessor to accommodate two channels of altimetry data. Additionally, examination of past altimeter programs associated data processing algorithms was accomplished to establish the TOPEX-class Radar Altimeter data processing algorithms, and the necessary direction was outlined to begin to generate these for the TOPEX Mission.

  15. Urban Flood Warning Systems using Radar Technologies

    NASA Astrophysics Data System (ADS)

    Fang, N.; Bedient, P. B.

    2013-12-01

    There have been an increasing number of urban areas that rely on weather radars to provide accurate precipitation information for flood warning purposes. As non-structural tools, radar-based flood warning systems can provide accurate and timely warnings to the public and private entities in urban areas that are prone to flash floods. The wider spatial and temporal coverage from radar increases flood warning lead-time when compared to rain and stream gages alone. The Third Generation Rice and Texas Medical Center (TMC) Flood Alert System (FAS3) has been delivering warning information with 2 to 3 hours of lead time and a R2 value of 93% to facility personnel in a readily understood format for more than 50 events in the past 15 years. The current FAS utilizes NEXRAD Level II radar rainfall data coupled with a real-time hydrologic model (RTHEC-1) to deliver warning information. The system has a user-friendly dashboard to provide rainfall maps, Google Maps based inundation maps, hydrologic predictions, and real-time monitoring at the bayou. This paper will evaluate its reliable performance during the recent events occurring in 2012 and 2013 and the development of a similar radar-based flood warning system for the City of Sugar Land, Texas. Having a significant role in the communication of flood information, FAS marks an important step towards the establishment of an operational and reliable flood warning system for flood-prone urban areas.

  16. Space station structures development

    NASA Technical Reports Server (NTRS)

    Teller, V. B.

    1986-01-01

    A study of three interrelated tasks focusing on deployable Space Station truss structures is discussed. Task 1, the development of an alternate deployment system for linear truss, resulted in the preliminary design of an in-space reloadable linear motor deployer. Task 2, advanced composites deployable truss development, resulted in the testing and evaluation of composite materials for struts used in a deployable linear truss. Task 3, assembly of structures in space/erectable structures, resulted in the preliminary design of Space Station pressurized module support structures. An independent, redundant support system was developed for the common United States modules.

  17. Program of the Antarctic Syowa MST/IS radar (PANSY)

    NASA Astrophysics Data System (ADS)

    Sato, K.; Tsutsumi, M.; Sato, T.; Saito, A.; Tomikawa, Y.; Aso, T.; Yamanouchi, T.; Ejiri, M.

    We have been promoting a project to introduce the first MST Mesosphere-Stratosphere-Troposphere IS Incoherent Scatter radar which is a VHF pulse Doppler radar in the Antarctic to Syowa Station 39E 69S Program of the Antarctic Syowa MST IS Radar PANSY as an important station observing the earth s environment with the aim to catch the climate change signals that the Antarctic atmosphere shows This radar consists of about 1000 crossed Yagi antennas having a peak power of 500kW which allows us to observe the Antarctic atmosphere with fine resolution and good accuracy in a wide height range of 1-500 km The interaction of the neutral atmosphere with the ionosphere and magnetosphere as well as the global-scale atmospheric circulation including the low and middle latitude regions are also targets of PANSY The observation data with high resolution and good accuracy obtained by the PANSY radar are also valuable from the viewpoint of certification of the reality of phenomena simulated by high-resolution numerical models The scientific importance of PANSY is discussed and resolved by international research organizations of IUGG URSI SCAR SCOSTEP and SPARC and documented in a report by Council of Science and Technology Policy in Japan One major issue for the operation of the MST IS radar at an isolated place such as Syowa Station is the reduction of power consumption We have developed a new power-efficient transmitter class-E amplifier and successfully reduced the needed power consumption to an acceptable

  18. Noise calibration and the development of remote receiver stations for TARA

    NASA Astrophysics Data System (ADS)

    Kunwar, Samridha

    2013-04-01

    The Telescope Array RAdar (TARA) detector is based on a remote sensing technique known as bi-static radar that aims to achieve remote coverage over large portions of the Earth's surface in search of cosmic ray induced radio echoes. In conjunction with North America's largest cosmic ray observatory (The Telescope Array) in radio quiet western Utah, the radar project's pilot receiver and transmitter stations have been functional for just over a year and a half, giving insight into the detect-ability of air shower radar echoes. Currently the receiver stations comprise an array of Log Periodic Dipole Antennas with an oscilloscope-based data acquisition system implemented for noise calibration including tracking galactic noise as the galactic plane migrates through the sky. Our experiences thus far have given impetus for upgrades, including the deployment of additional remote receiver stations. We discuss some of the results of this oscilloscope-based DAQ system and the development of these remote stations.

  19. An evaluation of the accuracy of geomagnetic data obtained from an unattended, automated, quasi-absolute station

    USGS Publications Warehouse

    Herzog, D.C.

    1990-01-01

    A comparison is made of geomagnetic calibration data obtained from a high-sensitivity proton magnetometer enclosed within an orthogonal bias coil system, with data obtained from standard procedures at a mid-latitude U.S. Geological Survey magnetic observatory using a quartz horizontal magnetometer, a Ruska magnetometer, and a total field magnetometer. The orthogonal coil arrangement is used with the proton magnetometer to provide Deflected-Inclination-Deflected-Declination (DIDD) data from which quasi-absolute values of declination, horizontal intensity, and vertical intensity can be derived. Vector magnetometers provide the ordinate values to yield baseline calibrations for both the DIDD and standard observatory processes. Results obtained from a prototype system over a period of several months indicate that the DIDD unit can furnish adequate absolute field values for maintaining observatory calibration data, thus providing baseline control for unattended, remote stations. ?? 1990.

  20. Evaluation of Manual Ultrasonic Examinations Applied to Detect Flaws in Primary System Dissimilar Metal Welds at North Anna Power Station

    SciTech Connect

    Anderson, Michael T.; Diaz, Aaron A.; Doctor, Steven R.

    2012-06-01

    During a recent inservice inspection (ISI) of a dissimilar metal weld (DMW) in an inlet (hot leg) steam generator nozzle at North Anna Power Station Unit 1, several axially oriented flaws went undetected by the licensee's manual ultrasonic testing (UT) technique. The flaws were subsequently detected as a result of outside diameter (OD) surface machining in preparation for a full structural weld overlay. The machining operation uncovered the existence of two through-wall flaws, based on the observance of primary water leaking from the DMW. Further ultrasonic tests were then performed, and a total of five axially oriented flaws, classified as primary water stress corrosion cracking (PWSCC), were detected in varied locations around the weld circumference.

  1. Test and evaluation of load converter topologies used in the Space Station Freedom Power Management and distribution DC test bed

    NASA Technical Reports Server (NTRS)

    Lebron, Ramon C.; Oliver, Angela C.; Bodi, Robert F.

    1991-01-01

    Power components hardware in support of the Space Station Freedom dc Electrical Power System were tested. One type of breadboard hardware tested is the dc Load Converter Unit, which constitutes the power interface between the electric power system and the actual load. These units are dc to dc converters that provide the final system regulation before power is delivered to the load. Three load converters were tested: a series resonant converter, a series inductor switchmode converter, and a switching full-bridge forward converter. The topology, operation principles, and tests results are described, in general. A comparative analysis of the three units is given with respect to efficiency, regulation, short circuit behavior (protection), and transient characteristics.

  2. Test and evaluation of load converter topologies used in the Space Station Freedom power management and distribution dc test bed

    NASA Technical Reports Server (NTRS)

    Lebron, Ramon C.; Oliver, Angela C.; Bodi, Robert F.

    1991-01-01

    Power components hardware in support of the Space Station freedom dc Electric Power System were tested. One type of breadboard hardware tested is the dc Load Converter Unit, which constitutes the power interface between the electric power system and the actual load. These units are dc to dc converters that provide the final system regulation before power is delivered to the load. Three load converters were tested: a series resonant converter, a series inductor switch-mode converter, and a switching full-bridge forward converter. The topology, operation principles, and test results are described, in general. A comparative analysis of the three units is given with respect to efficiency, regulation, short circuit behavior (protection), and transient characteristics.

  3. 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

  4. Developing Lightning Prediction Tools for the CCAFS Dual-Polarimetric Radar

    NASA Technical Reports Server (NTRS)

    Petersen, W. A.; Carey, L. D.; Deierling, W.; Johnson, E.; Bateman, M.

    2009-01-01

    NASA Marshall Space Flight Center and the University of Alabama Huntsville are collaborating with the 45th Weather Squadron (45WS) to develop improved lightning prediction capabilities for the new C-band dual-polarimetric weather radar being acquired for use by 45WS and launch weather forecasters at Cape Canaveral Air Force Station (CCAFS). In particular, these algorithms will focus on lightning onset, cessation and combined lightning-radar applications for convective winds assessment. Research using radar reflectivity (Z) data for prediction of lightning onset has been extensively discussed in the literature and subsequently applied by launch weather forecasters as it pertains to lightning nowcasting. Currently the forecasters apply a relatively straight forward but effective temperature-Z threshold algorithm for assessing the likelihood of lightning onset in a given storm. In addition, a layered VIL above the freezing level product is used as automated guidance for the onset of lightning. Only limited research and field work has been conducted on lightning cessation using Z and vertically-integrated Z for determining cessation. Though not used operationally vertically-integrated Z (basis for VIL) has recently shown promise as a tool for use in nowcasting lightning cessation. The work discussed herein leverages and expands upon these and similar reflectivity-threshold approaches via the application/addition of over two decades of polarimetric radar research focused on distinct multi-parameter radar signatures of ice/mixed-phase initiation and ice-crystal orientation in highly electrified convective clouds. Specifically, our approach is based on numerous previous studies that have observed repeatable patterns in the behavior of the vertical hydrometeor column as it relates to the temporal evolution of differential reflectivity and depolarization (manifested in either LDR or p(sub hv)), development of in-situ mixed and ice phase microphysics, electric fields, and

  5. Phase modulating the Urbana radar

    NASA Technical Reports Server (NTRS)

    Herrington, L. J., Jr.; Bowhill, S. A.

    1983-01-01

    The design and operation of a switched phase modulation system for the Urbana Radar System are discussed. The system is implemented and demonstrated using a simple procedure. The radar system and circuits are described and analyzed.

  6. 1. View of three detection radar (DR) antennas. DR 1 ...

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

    1. View of three detection radar (DR) antennas. DR 1 (structure no. 735) on left, DR 2 (structure no. 736) in center, and DR 3 (structure no. 737) looking north 30 degrees west, with tracking radar (large radome) and satcom (satellite communication) system in small radome in view between DR 2 and DR 3 antennae. - 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

  7. Characteristics of Sunset radar

    NASA Technical Reports Server (NTRS)

    Green, J. L.

    1983-01-01

    Located in a narrow canyon 15 km west of Boulder, Colorado, the Sunset pulsed Doppler radar was the first radar designed and constructed specifically as a VHF ST radar. The antenna system is a phased array of coaxial-colinear dopoles with computer-controlled phase shifters for each line of dipoles. It operates at a frequency of 40.475 MHz and a wavelength of 7.41M. Peak transmitter power is 100 kW. Aperture efficiency is 0.58 and resistive loss is 0.30 for its 3600 sq m area. The practical steering rate is 1 record/minute/position to any arbitrary antenna beam position. The first clear-air turbulence echoes and wind velocity measurements were obtained in 1974. Significant accomplishments are listed.

  8. Mercury radar speckle dynamics

    NASA Astrophysics Data System (ADS)

    Holin, Igor V.

    2010-06-01

    Current data reveal that Mercury is a dynamic system with a core which has not yet solidified completely and is at least partially decoupled from the mantle. Radar speckle displacement experiments have demonstrated that the accuracy in spin-dynamics determination for Earth-like planets can approach 10 -5. The extended analysis of space-time correlation properties of radar echoes shows that the behavior of speckles does not prevent estimation of Mercury's instantaneous spin-vector components to accuracy of a few parts in 10 7. This limit can be reached with more powerful radar facilities and leads to constraining the interior in more detail from effects of spin dynamics, e.g., from observation of the core-mantle interplay through high precision monitoring of the 88-day spin-variation of Mercury's crust.

  9. The MST Radar Technique

    NASA Technical Reports Server (NTRS)

    Balsley, B. B.

    1985-01-01

    The past ten year have witnessed the development of a new radar technique to examine the structure and dynamics of the atmosphere between roughly 1 to 100 km on a continuous basis. The technique is known as the MST (for Mesosphere-Stratosphere-Troposphere) technique and is usable in all weather conditions, being unaffected by precipitation or cloud cover. MST radars make use of scattering from small scale structure in the atmospheric refractive index, with scales of the order of one-half the radar wavelength. Pertinent scale sizes for middle atmospheric studies typically range between a fraction of a meter and a few meters. The structure itself arises primarily from atmospheric turbulence. The technique is briefly described along with the meteorological parameters it measures.

  10. Estimation of soil moisture with radar remote sensing

    NASA Technical Reports Server (NTRS)

    Batlivala, P. P.; Ulaby, F. T.

    1977-01-01

    The radar response to soil moisture content was investigated using a truck-mounted 1-18 GHz (30-1.67 cm wavelength, respectively) active microwave spectrometer (MAS) system. The sensitivity to soil moisture content and the accuracy with which it could be estimated were evaluated for both bare and vegetation-covered fields. Bare field experiments were conducted to determine the optimum radar parameters (frequency, angle of incidence range, and polarization configuration) for minimizing the response to surface roughness while retaining strong sensitivity to moisture content. In the vegetation-covered case, the effects of crop type, crop height and row direction relative to the radar look direct were evaluated.

  11. Bats Avoid Radar Installations: Could Electromagnetic Fields Deter Bats from Colliding with Wind Turbines?

    PubMed Central

    Nicholls, Barry; Racey, Paul A.

    2007-01-01

    Large numbers of bats are killed by collisions with wind turbines, and there is at present no direct method of reducing or preventing this mortality. We therefore determine whether the electromagnetic radiation associated with radar installations can elicit an aversive behavioural response in foraging bats. Four civil air traffic control (ATC) radar stations, three military ATC radars and three weather radars were selected, each surrounded by heterogeneous habitat. Three sampling points matched for habitat type and structure, dominant vegetation species, altitude and surrounding land class were located at increasing distances from each station. A portable electromagnetic field meter measured the field strength of the radar at three distances from the source: in close proximity (<200 m) with a high electromagnetic field (EMF) strength >2 volts/metre, an intermediate point within line of sight of the radar (200–400 m) and with an EMF strength <2 v/m, and a control site out of sight of the radar (>400 m) and registering an EMF of zero v/m. At each radar station bat activity was recorded three times with three independent sampling points monitored on each occasion, resulting in a total of 90 samples, 30 of which were obtained within each field strength category. At these sampling points, bat activity was recorded using an automatic bat recording station, operated from sunset to sunrise. Bat activity was significantly reduced in habitats exposed to an EMF strength of greater than 2 v/m when compared to matched sites registering EMF levels of zero. The reduction in bat activity was not significantly different at lower levels of EMF strength within 400 m of the radar. We predict that the reduction in bat activity within habitats exposed to electromagnetic radiation may be a result of thermal induction and an increased risk of hyperthermia. PMID:17372629

  12. Bats avoid radar installations: could electromagnetic fields deter bats from colliding with wind turbines?

    PubMed

    Nicholls, Barry; Racey, Paul A

    2007-03-14

    Large numbers of bats are killed by collisions with wind turbines, and there is at present no direct method of reducing or preventing this mortality. We therefore determine whether the electromagnetic radiation associated with radar installations can elicit an aversive behavioural response in foraging bats. Four civil air traffic control (ATC) radar stations, three military ATC radars and three weather radars were selected, each surrounded by heterogeneous habitat. Three sampling points matched for habitat type and structure, dominant vegetation species, altitude and surrounding land class were located at increasing distances from each station. A portable electromagnetic field meter measured the field strength of the radar at three distances from the source: in close proximity (<200 m) with a high electromagnetic field (EMF) strength >2 volts/metre, an intermediate point within line of sight of the radar (200-400 m) and with an EMF strength <2 v/m, and a control site out of sight of the radar (>400 m) and registering an EMF of zero v/m. At each radar station bat activity was recorded three times with three independent sampling points monitored on each occasion, resulting in a total of 90 samples, 30 of which were obtained within each field strength category. At these sampling points, bat activity was recorded using an automatic bat recording station, operated from sunset to sunrise. Bat activity was significantly reduced in habitats exposed to an EMF strength of greater than 2 v/m when compared to matched sites registering EMF levels of zero. The reduction in bat activity was not significantly different at lower levels of EMF strength within 400 m of the radar. We predict that the reduction in bat activity within habitats exposed to electromagnetic radiation may be a result of thermal induction and an increased risk of hyperthermia.

  13. 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.

  14. The Capabilities of Space Stations

    NASA Technical Reports Server (NTRS)

    1995-01-01

    Over the past two years the U.S. space station program has evolved to a three-phased international program, with the first phase consisting of the use of the U.S. Space Shuttle and the upgrading and use of the Russian Mir Space Station, and the second and third phases consisting of the assembly and use of the new International Space Station. Projected capabilities for research, and plans for utilization, have also evolved and it has been difficult for those not directly involved in the design and engineering of these space stations to learn and understand their technical details. The Committee on the Space Station of the National Research Council, with the concurrence of NASA, undertook to write this short report in order to provide concise and objective information on space stations and platforms -- with emphasis on the Mir Space Station and International Space Station -- and to supply a summary of the capabilities of previous, existing, and planned space stations. In keeping with the committee charter and with the task statement for this report, the committee has summarized the research capabilities of five major space platforms: the International Space Station, the Mir Space Station, the Space Shuttle (with a Spacelab or Spacehab module in its cargo bay), the Space Station Freedom (which was redesigned to become the International Space Station in 1993 and 1994), and Skylab. By providing the summary, together with brief descriptions of the platforms, the committee hopes to assist interested readers, including scientists and engineers, government officials, and the general public, in evaluating the utility of each system to meet perceived user needs.

  15. Imaging Radar Polarimeter

    NASA Technical Reports Server (NTRS)

    Zebker, Howard A.; Held, Daniel N.; Brown, Walter E.

    1987-01-01

    Radar measures full polarization tensor of each element in scene in one sweep. New system comprises dual-polarized antenna, single transmitter, and four-channel receiver and digital recorder installed in aircraft, plus digital processor on ground. Produces radar-backscatter images corresponding to 10- by 10-km regions on ground. Signals recorded from orthogonal linearly polarized antennas combined in computer after flight to synthesize any desired combination of transmitted and received polarizations. Data recorded on single flight processed to provide multiple images.

  16. Microwave radar oceanographic investigations

    NASA Technical Reports Server (NTRS)

    Jackson, F. C.

    1988-01-01

    The Radar Ocean Wave Spectrometer (ROWS) technique was developed and demonstrated for measuring ocean wave directional spectra from air and space platforms. The measurement technique was well demonstrated with data collected in a number of flight experiments involving wave spectral comparisons with wave buoys and the Surface Contour Radar (SCR). Recent missions include the SIR-B underflight experiment (1984), FASINEX (1986), and LEWEX (1987). ROWS related activity is presently concentrating on using the aircraft instrument for wave-processes investigations and obtaining the necessary support (consensus) for a satellite instrument development program. Prospective platforms include EOS and the Canadian RADARSAT.

  17. Spaceborne Imaging Radar Symposium

    NASA Technical Reports Server (NTRS)

    Elachi, C.

    1983-01-01

    An overview of the present state of the art in the different scientific and technological fields related to spaceborne imaging radars was presented. The data acquired with the SEASAT SAR (1978) and Shuttle Imaging Radar, SIR-A (1981) clearly demonstrated the important emphasis in the 80's is going to be on in-depth research investigations conducted with the more flexible and sophisticated SIR series instruments and on long term monitoring of geophysical phenomena conducted from free-flying platforms such as ERS-1 and RADARSAT.

  18. Survey of radar ADT

    NASA Astrophysics Data System (ADS)

    Trunk, G. V.

    1983-07-01

    The most recent advances in automatic detection and tracking are surveyed. The discussion deals with various noncoherent integrators that provide target enhancement, thresholding techniques for reducing false alarms and target suppression, and algorithms for estimating target position and resolving targets. Attention is also given to track-while-scan systems, and the entire tracking system is surveyed. This is followed by a discussion of the various components of the system, such as the tracking filter, maneuver-following logic, track initiation, and correlation logic. The survey concludes with a discussion of radar netting. It is emphasized that the automatic detector should be considered an integral part of the radar system.

  19. Small scale thematic mapping - A case for radar imagery

    NASA Technical Reports Server (NTRS)

    Henderson, F. M.

    1974-01-01

    Small scale thematic maps (1:250,000 and smaller) of physical and cultural phenomena manifested on the landscape are a major concern to scientists and investigators in diverse disciplines. A strip of K-band radar imagery consisting of a traverse from eastern Minnesota to northern Utah was employed to evaluate the potential of radar imagery for small scale land use mapping. In the course of this investigation, it was discovered that certain borders derived from radar imagery were compatible with borders found on the nonland use thematic maps used for comparison. Specifically, numerous borders and regions of small scale maps of landforms, soils, vegetation, and geology are found to be similar to the radar land use regions. Although far from conclusive it appears that radar imagery can be employed in the small scale mapping of landforms and possibly for mapping physiognomic or economic vegetation.

  20. Mapping diverse forest cover with multipolarization airborne radar

    NASA Technical Reports Server (NTRS)

    Ford, J. P.; Wickland, D. E.; Sharitz, R. R.

    1985-01-01

    Imaging radar backscatter in continuously forested areas contains information about the forest canopy; it also contains data about topography, landforms, and terrain texture. For purposes of radar image interpretation and geologic mapping researchers were interested in identifying and separating forest canopy effects from geologic or geomorphic effects on radar images. The objectives of this investigation was to evaluate forest canopy variables in multipolarization radar images under conditions where geologic and topographic variables are at a minimum. A subsidiary objective was to compare the discriminatory capabilities of the radar images with corresponding optical images of similar spatial resolution. It appears that the multipolarization images discriminate variation in tree density, but no evidence was found for discrimination between evergreen and deciduous forest types.

  1. The Implementation and Evaluation of the Emergency Response Dose Assessment System (ERDAS) at Cape Canaveral Air Station/Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Evans, Randolph J.; Tremback, Craig J.; Lyons, Walter A.

    1996-01-01

    The Emergency Response Dose Assessment System (ERDAS) is a system which combines the mesoscale meteorological prediction model RAMS with the diffusion models REEDM and HYPACT. Operators use a graphical user interface to run the models for emergency response and toxic hazard planning at CCAS/KCS. The Applied Meteorology Unit has been evaluating the ERDAS meteorological and diffusion models and obtained the following results: (1) RAMS adequately predicts the occurrence of the daily sea breeze during non-cloudy conditions for several cases. (2) RAMS shows a tendency to predict the sea breeze to occur slightly earlier and to move it further inland than observed. The sea breeze predictions could most likely be improved by better parameterizing the soil moisture and/or sea surface temperatures. (3) The HYPACT/REEDM/RAMS models accurately predict launch plume locations when RAMS winds are accurate and when the correct plume layer is modeled. (4) HYPACT does not adequately handle plume buoyancy for heated plumes since all plumes are presently treated as passive tracers. Enhancements should be incorporated into the ERDAS as it moves toward being a fully operational system and as computer workstations continue to increase in power and decrease in cost. These enhancements include the following: activate RAMS moisture physics; use finer RAMS grid resolution; add RAMS input parameters (e.g. soil moisture, radar, and/or satellite data); automate data quality control; implement four-dimensional data assimilation; modify HYPACT plume rise and deposition physics; and add cumulative dosage calculations in HYPACT.

  2. 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.

  3. Development of Ku-band rendezvous radar tracking and acquisition simulation programs

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The fidelity of the Space Shuttle Radar tracking simulation model was improved. The data from the Shuttle Orbiter Radar Test and Evaluation (SORTE) program experiments performed at the White Sands Missile Range (WSMR) were reviewed and analyzed. The selected flight rendezvous radar data was evaluated. Problems with the Inertial Line-of-Sight (ILOS) angle rate tracker were evaluated using the improved fidelity angle rate tracker simulation model.

  4. SEASAT Synthetic Aperture Radar Data

    NASA Technical Reports Server (NTRS)

    Henderson, F. M.

    1981-01-01

    The potential of radar imagery from space altitudes is discussed and the advantages of radar over passive sensor systems are outlined. Specific reference is made to the SEASAT synthetic aperture radar. Possible applications include oil spill monitoring, snow and ice reconnaissance, mineral exploration, and monitoring phenomena in the urban environment.

  5. 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.

  6. Nonlinear synthetic aperture radar imaging using a harmonic radar

    NASA Astrophysics Data System (ADS)

    Gallagher, Kyle A.; Mazzaro, Gregory J.; Ranney, Kenneth I.; Nguyen, Lam H.; Martone, Anthony F.; Sherbondy, Kelly D.; Narayanan, Ram M.

    2015-05-01

    This paper presents synthetic aperture radar (SAR) images of linear and nonlinear targets. Data are collected using a linear/nonlinear step frequency radar. We show that it is indeed possible to produce SAR images using a nonlinear radar. Furthermore, it is shown that the nonlinear radar is able to reduce linear clutter by at least 80 dB compared to a linear radar. The nonlinear SAR images also show the system's ability to detect small electronic devices in the presence of large linear clutter. The system presented here has the ability to completely ignore a 20-inch trihedral corner reflector while detecting a RF mixer with a dipole antenna attached.

  7. Radar image San Francisco Bay Area, California

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The San Francisco Bay Area in California and its surroundings are shown in this radar image from the Shuttle Radar Topography Mission (SRTM). On this image, smooth areas, such as the bay, lakes, roads and airport runways appear dark, while areas with buildings and trees appear bright. Downtown San Francisco is at the center and the city of Oakland is at the right across the San Francisco Bay. Some city areas, such as the South of Market district in San Francisco, appear bright due to the alignment of streets and buildings with respect to the incoming radar beam. Three of the bridges spanning the Bay are seen in this image. The Bay Bridge is in the center and extends from the city of San Francisco to Yerba Buena and Treasure Islands, and from there to Oakland. The Golden Gate Bridge is to the left and extends from San Francisco to Sausalito. The Richmond-San Rafael Bridge is in the upper right and extends from San Rafael to Richmond. Angel Island is the large island east of the Golden Gate Bridge, and lies north of the much smaller Alcatraz Island. The Alameda Naval Air Station is seen just below the Bay Bridge at the center of the image. Two major faults bounding the San Francisco-Oakland urban areas are visible on this image. The San Andreas fault, on the San Francisco peninsula, is seen on the left side of the image. The fault trace is the straight feature filled with linear reservoirs, which appear dark. The Hayward fault is the straight feature on the right side of the image between the urban areas and the hillier terrain to the east.

    This radar image was acquired by just one of SRTM's two antennas and, consequently, does not show topographic data, but only the strength of the radar signal reflected from the ground. This signal, known as radar backscatter, provides insight into the nature of the surface, including its roughness, vegetation cover and urbanization. The overall faint striping pattern in the images is a data processing artifact due to the

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

    SciTech Connect

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

    2012-03-05

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

  9. 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.

  10. The Southern Argentina Agile Meteor Radar (SAAMER): Platform for comprehensive meteor radar observations and studies

    NASA Astrophysics Data System (ADS)

    Janches, D.; Hormaechea, J.; Pifko, S.; Hocking, W.; Fritts, D.; Brunini, C.; Close, S.; Michell, R.; Samara, M.

    2014-07-01

    The Southern Argentina Agile Meteor Radar (SAAMER) is a new generation system deployed in Rio Grande, Tierra del Fuego, Argentina (53^oS) in May 2008 (Janches et al., 2013,2014). SAAMER transmits 10 times more power than regular meteor radars, and uses a newly developed transmitting array, which focuses power upward instead of the traditional single-antenna-all-sky configuration. The system is configured such that the transmitter array can also be utilized as a receiver. The new design greatly increases the sensitivity of the radar enabling the detection of large numbers of particles at low zenith angles. The more concentrated transmitted power enables additional meteor studies besides those typical of these systems based on the detection of specular reflections, such as routine detections of head echoes and non-specular trails, previously only possible with High Power and Large Aperture radars (Janches et al., 2014). In August 2010, SAAMER was upgraded to a system capable to determine meteoroid orbital parameters. This was achieved by adding two remote receiving stations approximately 10 km away from the main site in near perpendicular directions (Pifko et al., 2014). The upgrade significantly expands the science that is achieved with this new radar enabling us to study the orbital properties of the interplanetary dust environment. Because of the unique geographical location, the SAAMER allows for additional inter-hemispheric comparison with measurements from Canadian Meteor Orbit Radar, which is geographically conjugate. Initial surveys show, for example, that SAAMER observes a very strong contribution of the South Toroidal Sporadic meteor source (Pifko et al., 2014), of which limited observational data is available. In addition, SAAMER offers similar unique capabilities for meteor showers and streams studies given the range of ecliptic latitudes that the system enables to survey (Janches et al., 2013). It can effectively observe radiants from the ecliptic south

  11. Mapping wintering waterfowl distributions using weather surveillance radar.

    PubMed

    Buler, Jeffrey J; Randall, Lori A; Fleskes, Joseph P; Barrow, Wylie C; Bogart, Tianna; Kluver, Daria

    2012-01-01

    The current network of weather surveillance radars within the United States readily detects flying birds and has proven to be a useful remote-sensing tool for ornithological study. Radar reflectivity measures serve as an index to bird density and have been used to quantitatively map landbird distributions during migratory stopover by sampling birds aloft at the onset of nocturnal migratory flights. Our objective was to further develop and validate a similar approach for mapping wintering waterfowl distributions using weather surveillance radar observations at the onset of evening flights. We evaluated data from the Sacramento, CA radar (KDAX) during winters 1998-1999 and 1999-2000. We determined an optimal sampling time by evaluating the accuracy and precision of radar observations at different times during the onset of evening flight relative to observed diurnal distributions of radio-marked birds on the ground. The mean time of evening flight initiation occurred 23 min after sunset with the strongest correlations between reflectivity and waterfowl density on the ground occurring almost immediately after flight initiation. Radar measures became more spatially homogeneous as evening flight progressed because birds dispersed from their departure locations. Radars effectively detected birds to a mean maximum range of 83 km during the first 20 min of evening flight. Using a sun elevation angle of -5° (28 min after sunset) as our optimal sampling time, we validated our approach using KDAX data and additional data from the Beale Air Force Base, CA (KBBX) radar during winter 1998-1999. Bias-adjusted radar reflectivity of waterfowl aloft was positively related to the observed diurnal density of radio-marked waterfowl locations on the ground. Thus, weather radars provide accurate measures of relative wintering waterfowl density that can be used to comprehensively map their distributions over large spatial extents.

  12. Mapping wintering waterfowl distributions using weather surveillance radar

    USGS Publications Warehouse

    Buler, Jeffrey J.; Randall, Lori A.; Fleskes, Joseph P.; Barrow, Wylie C.; Bogart, Tianna; Kluver, Daria

    2012-01-01

    The current network of weather surveillance radars within the United States readily detects flying birds and has proven to be a useful remote-sensing tool for ornithological study. Radar reflectivity measures serve as an index to bird density and have been used to quantitatively map landbird distributions during migratory stopover by sampling birds aloft at the onset of nocturnal migratory flights. Our objective was to further develop and validate a similar approach for mapping wintering waterfowl distributions using weather surveillance radar observations at the onset of evening flights. We evaluated data from the Sacramento, CA radar (KDAX) during winters 1998–1999 and 1999–2000. We determined an optimal sampling time by evaluating the accuracy and precision of radar observations at different times during the onset of evening flight relative to observed diurnal distributions of radio-marked birds on the ground. The mean time of evening flight initiation occurred 23 min after sunset with the strongest correlations between reflectivity and waterfowl density on the ground occurring almost immediately after flight initiation. Radar measures became more spatially homogeneous as evening flight progressed because birds dispersed from their departure locations. Radars effectively detected birds to a mean maximum range of 83 km during the first 20 min of evening flight. Using a sun elevation angle of -5° (28 min after sunset) as our optimal sampling time, we validated our approach using KDAX data and additional data from the Beale Air Force Base, CA (KBBX) radar during winter 1998–1999. Bias-adjusted radar reflectivity of waterfowl aloft was positively related to the observed diurnal density of radio-marked waterfowl locations on the ground. Thus, weather radars provide accurate measures of relative wintering waterfowl density that can be used to comprehensively map their distributions over large spatial extents.

  13. Venus Radar Mapper (VRM): Multimode radar system design

    NASA Technical Reports Server (NTRS)

    Johnson, William T. K.; Edgerton, Alvin T.

    1986-01-01

    The surface of Venus has remained a relative mystery because of the very dense atmosphere that is opaque to visible radiation and, thus, normal photographic techniques used to explore the other terrestrial objects in the solar system are useless. The atmosphere is, however, almost transparent to radar waves and images of the surface have been produced via Earth-based and orbital radars. The technique of obtaining radar images of a surface is variously called side looking radar, imaging radar, or synthetic aperture radar (SAR). The radar requires a moving platform in which the antenna is side looking. High resolution is obtained in the cross-track or range direction by conventional radar pulse encoding. In the along-track or azimuth direction, the resolution would normally be the antenna beam width, but for the SAR case, a much longer antenna (or much sharper beam) is obtained by moving past a surface target as shown, and then combining the echoes from many pulses, by using the Doppler data, to obtain the images. The radar design of the Venus Radar Mapper (VRM) is discussed. It will acquire global radar imagery and altimetry data of the surface of Venus.

  14. Simulation of radar rainfall errors and their propagation into rainfall-runoff processes

    NASA Astrophysics Data System (ADS)

    Aghakouchak, A.; Habib, E.

    2008-05-01

    Radar rainfall data compared with rain gauge measurements provide higher spatial and temporal resolution. However, radar data obtained form reflectivity patterns are subject to various errors such as errors in Z-R relationship, vertical profile of reflectivity, spatial and temporal sampling, etc. Characterization of such uncertainties in radar data and their effects on hydrologic simulations (e.g., streamflow estimation) is a challenging issue. This study aims to analyze radar rainfall error characteristics empirically to gain information on prosperities of random error representativeness and its temporal and spatial dependency. To empirically analyze error characteristics, high resolution and accurate rain gauge measurements are required. The Goodwin Creek watershed located in the north part of Mississippi is selected for this study due to availability of a dense rain gauge network. A total of 30 rain gauge measurement stations within Goodwin Creak watershed and the NWS Level II radar reflectivity data obtained from the WSR-88dD Memphis radar station with temporal resolution of 5min and spatial resolution of 1 km2 are used in this study. Radar data and rain gauge measurements comparisons are used to estimate overall bias, and statistical characteristics and spatio-temporal dependency of radar rainfall error fields. This information is then used to simulate realizations of radar error patterns with multiple correlated variables using Monte Calro method and the Cholesky decomposition. The generated error fields are then imposed on radar rainfall fields to obtain statistical realizations of input rainfall fields. Each simulated realization is then fed as input to a distributed physically based hydrological model resulting in an ensemble of predicted runoff hydrographs. The study analyzes the propagation of radar errors on the simulation of different rainfall-runoff processes such as streamflow, soil moisture, infiltration, and over-land flooding.

  15. Impulse radar studfinder

    DOEpatents

    McEwan, Thomas E.

    1995-01-01

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

  16. Impulse radar studfinder

    DOEpatents

    McEwan, T.E.

    1995-10-10

    An impulse radar studfinder propagates electromagnetic pulses and detects reflected pulses from a fixed range. Unmodulated pulses, about 200 ps wide, are emitted. A large number of reflected pulses are sampled and averaged. Background reflections are subtracted. Reflections from wall studs or other hidden objects are detected and displayed using light emitting diodes. 9 figs.

  17. Passive bistatic radar analysis

    NASA Astrophysics Data System (ADS)

    O'Hagan, Daniel W.; Kuschel, H.; Schiller, Joachim

    2009-06-01

    Passive Bistatic Radar (PBR) research is at its zenith with several notable PBR systems currently operational, or available for deployment. Such PBRs include the Manastash Ridge Radar (MRR) developed for and by academia; Silent Sentry developed as a commercial concern by Lockheed Martin; and Homeland Alerter (HA100) also a commercial system developed by Thales. However at present, despite the existence of numerous PBR prototypes, take up of commercial passive radar technology remains slow. This is due in part to technology immaturity, in part to politics, and particularly due to the fact that monostatic radars perform so well. If PBRs are to enjoy longevity as a viable technology then it is imperative that they address certain niche application areas, with the aforementioned MRR being one prime example of this. The focus of this paper will be an analysis of a PBR system that utilised FM radio signals of opportunity to detect aircraft targets with an RCS generally not lower than 20 m2. The paper will demonstrate the theoretical detection coverage of an FM based PBR operating in a severe interference environment.

  18. Multiline radar scan

    NASA Technical Reports Server (NTRS)

    Levinson, S.

    1977-01-01

    Scanning scheme is more efficient than conventional scanning. Originally designed for optical radar in space vehicles, scheme may also find uses in site-surveillance security systems and in other industrial applications. It should be particularly useful when system must run on battery energy, as would be case in power outages.

  19. Rain radar instrument definition

    NASA Astrophysics Data System (ADS)

    Vincent, Nicolas; Chenebault, J.; Suinot, Noel; Mancini, Paolo L.

    1996-12-01

    As a result of a pre-phase a study, founded by ESA, this paper presents the definition of a spaceborne Rain Radar, candidate instrument for earth explorer precipitation mission. Based upon the description of user requirements for such a dedicated mission, a mission analysis defines the most suitable space segment. At system level, a parametric analysis compares pros and cons of instrument concepts associated with rain rate retrieval algorithms in order to select the most performing one. Several trade-off analysis at subsystem level leads then to the definition of the proposed design. In particular, as pulse compression is implemented in order to increase the radar sensitivity, the selected method to achieve a pulse response with a side-lobe level below--60 dB is presented. Antenna is another critical rain radar subsystem and several designs are com pared: direct radiating array, single or dual reflector illuminated by single or dual feed arrays. At least, feasibility of centralized amplification using TWTA is compared with criticality of Tx/Rx modules for distributed amplification. Mass and power budgets of the designed instrument are summarized as well as standard deviations and bias of simulated rain rate retrieval profiles. The feasibility of a compliant rain radar instrument is therefore demonstrated.

  20. Synthetic Aperture Radar Interferometry

    NASA Technical Reports Server (NTRS)

    Rosen, P. A.; Hensley, S.; Joughin, I. R.; Li, F.; Madsen, S. N.; Rodriguez, E.; Goldstein, R. M.

    1998-01-01

    Synthetic aperture radar interferometry is an imaging technique for measuring the topography of a surface, its changes over time, and other changes in the detailed characteristics of the surface. This paper reviews the techniques of interferometry, systems and limitations, and applications in a rapidly growing area of science and engineering.

  1. Radar environment simulator

    NASA Astrophysics Data System (ADS)

    Utteridge, E. J.

    A radar environment simulator (RES) is described which combines a high degree of signal realism with flexible real-time control. The RES features interactive simulation of IF and RF, aircraft echo simulation, active jamming (including simultaneous jamming, passive jamming, and simulator control. The general design and principal components of the RES are briefly described, and its detailed performance characteristics are presented.

  2. Radar studies related to the earth resources program. [remote sensing programs

    NASA Technical Reports Server (NTRS)

    Holtzman, J.

    1972-01-01

    The radar systems research discussed is directed toward achieving successful application of radar to remote sensing problems in such areas as geology, hydrology, agriculture, geography, forestry, and oceanography. Topics discussed include imaging radar and evaluation of its modification, study of digital processing for synthetic aperture system, digital simulation of synthetic aperture system, averaging techniques studies, ultrasonic modeling of panchromatic system, panchromatic radar/radar spectrometer development, measuring octave-bandwidth response of selected targets, scatterometer system analysis, and a model Fresnel-zone processor for synthetic aperture imagery.

  3. Evaluation of geophysical logs, Phase II, at Willow Grove Naval Air Station Joint Reserve Base, Montgomery County, Pennsylvania

    USGS Publications Warehouse

    Conger, Randall W.

    1999-01-01

    Between March and April 1998, the U.S. Navy contracted Tetra Tech NUS Inc., to drill two monitor wells in the Stockton Formation at the Willow Grove Naval Air Station Joint Reserve Base, Horsham Township, Montgomery County, Pa. The wells MG-1634 and MG-1635 were installed to monitor water levels and sample contaminants in the shallow, intermediate, and deep water-producing zones of the fractured bedrock. Chemical analyses of the samples will help determine the horizontal and vertical distribution of any contaminated ground water migrating from known contaminant sources. Wells were drilled near the Fire Training Area (Site 5). Depths of all boreholes range from 69 to 149 feet below land surface. The U.S. Geological Survey conducted borehole geophysical logging and video surveys to identify water-producing zones in newly drilled monitor wells MG-1634 and MG-1635 and in wells MG-1675 and MG-1676. The logging was conducted from March 5, 1998, to April 16, 1998. This work is a continuation of the Phase I work. Caliper logs and video surveys were used to locate fractures; inflections on fluid-temperature and fluid-resistivity logs were used to locate possible water-producing fractures. Heatpulse-flowmeter measurements were used to verify the locations of water-producing or water-receiving zones and to measure rates of flow between water-bearing fractures. Single-point-resistance and natural-gamma logs provided information on stratigraphy. After interpretation of geophysical logs, video surveys, and driller's notes, wells MG-1634 and MG-1635 were screened such that water-levels fluctuations could be monitored and discrete water samples collected from one or more water-producing zones in each borehole.

  4. Evaluation of Error Correcting Code performances of a free space optical communication system between LEO satellite and Ground Station

    NASA Astrophysics Data System (ADS)

    Chochol, M.; Rissons, A.; Lacan, J.; Vedrenne, N.; Artaud, G.

    2015-10-01

    The use of optical communication to transfer data between LEO satellite and optical ground station is being studied. It creates the opportunities to highly increase a transmitted data rate across a free space. The optical propagation channel has specificities that imply the potential use of error correcting code (ECC) and interleaving at physical and higher layer. The study aims to assess the performance of a combination of ECC and interleaving in presence of various channel scenarios and receiver architectures. As a result of these studies, a functional physical layer simulator is provided. The simulator emulates a signal generation and applies time series representing the propagation channel with an effect of receiver front-ends. It also features various detection methods and computes mutual information (MI) in order to approximate ECC performances. A number of receiver architectures and channel scenarios were studied. The channel scenarios combine a direct coupling of the received signal into the photo-detector (PD) and among other assume the use of pre-amplified receiver implying the signal coupling into a standard single mode fiber (SSMF) prior to the detection. Time series were generated and represent the power received at PD input depending on the chosen scenarios (without adaptive optics (AO), with tip-tilt correction, with no dynamical coupling losses or with higher order AO correction). Two modulations of OOK and DBPSK along with various detection methods were examined. The tuning of ECC parameters was studied through the computation of mutual information. Additionally two cases of physical and higher layer interleaving were implemented providing an excellent diversity to the channel seen by the codeword of ECC.

  5. Radar Observations of Asteroids

    NASA Astrophysics Data System (ADS)

    Ostro, S. J.

    2003-05-01

    During the past 25 years, radar investigations have provided otherwise unavailable information about the physical and dynamical properties of more than 200 asteroids. Measurements of the distribution of echo power in time delay and Doppler frequency provide two-dimensional images with spatial resolution as fine as a decameter. Sequences of delay-Doppler images can be used to produce geologically detailed three-dimensional models, to define the rotation state precisely, to constrain the internal density distribution, and to estimate the trajectory of the object's center of mass. Radar wavelengths (4 to 13 cm) and the observer's control of transmitted and received polarizations make the observations sensitive to near-surface bulk density and macroscopic structure. Since delay-Doppler positional measurements are orthogonal to optical angle measurements and typically have much finer fractional precision, they are powerful for refining orbits and prediction ephemerides. Radar astrometry can add decades or centuries to the interval over which an asteroid's close Earth approaches can accurately be predicted and can significantly refine collision probability estimates based on optical astrometry alone. In the highly unlikely case that a small body is on course for an Earth collision in this century, radar reconnaissance would almost immediately distinguish between an impact trajectory and a near miss and would dramatically reduce the difficulty and cost of any effort to prevent the collision. The sizes and rotation periods of radar-detected asteroids span more than four orders of magnitude. These observations have revealed both stony and metallic objects, elongated and nonconvex shapes as well as nearly featureless spheroids, small-scale morphology ranging from smoother than the lunar regolith to rougher than the rockiest terrain on Mars, craters and diverse linear structures, non-principal-axis spin states, contact binaries, and binary systems.

  6. Space Radar Image of Florence, Italy

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This radar image shows land use patterns in and around the city of Florence, Italy, shown here in the center of the image. Florence is situated on a plain in the Chianti Hill region of Central Italy. The Arno River flows through town and is visible as the dark line running from the upper right to the bottom center of the image. The city is home to some of the world's most famous art museums. The bridges seen crossing the Arno, shown as faint red lines in the upper right portion of the image, were all sacked during World War II with the exception of the Ponte Vecchio, which remains as Florence's only covered bridge. The large, black V-shaped feature near the center of the image is the Florence Railroad Station. This image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the Space Shuttle Endeavour on April 14, 1994. SIR-C/X-SAR, a joint mission of the German, Italian, and United States space agencies, is part of NASA's Mission to Planet Earth. This image is centered at 43.7 degrees north latitude and 11.15 degrees east longitude with North toward the upper left of the image. The area shown measures 20 kilometers by 17 kilometers (12.4 miles by 10.6 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; green is L-band horizontally transmitted, vertically received; blue is C-band horizontally transmitted, vertically received.

  7. An Independent Human Factors Analysis and Evaluation of the Emergency Medical Protocol Checklist for the International Space Station

    NASA Technical Reports Server (NTRS)

    Marshburn, Thomas; Whitmore, Mihriban; Ortiz, Rosie; Segal, Michele; Smart, Kieran; Hughes, Catherine

    2003-01-01

    Emergency medical capabilities aboard the ISS include a Crew Medical Officer (CMO) (not necessarily a physician), and back-up, resuscitation equipment, and a medical checklist. It is essential that CMOs have reliable, usable and informative medical protocols that can be carried out independently in flight. The study evaluates the existing ISS Medical Checklist layout against a checklist updated to reflect a human factors approach to structure and organization. Method: The ISS Medical checklist was divided into non-emergency and emergency sections, and re-organized based on alphabetical and a body systems approach. A desk-top evaluation examined the ability of subjects to navigate to specific medical problems identified as representative of likely non-emergency events. A second evaluation aims to focus on the emergency section of the Medical Checklist, based on the preliminary findings of the first. The final evaluation will use Astronaut CMOs as subjects comparing the original checklist against the updated layout in the task of caring for a "downed crewmember" using a Human Patient Simulator [Medical Education Technologies, Inc.]. Results: Initial results have demonstrated a clear improvement of the re-organized sections to determine the solution to the medical problems. There was no distinct advantage for either alternative, although subjects stated having a preference for the body systems approach. In the second evaluation, subjects will be asked to identify emergency medical conditions, with measures including correct diagnosis, time to completion and solution strategy. The third evaluation will compare the original and fully updated checklists in clinical situations. Conclusions: Initial findings indicate that the ISS Medical Checklist will benefit from a reorganization. The present structure of the checklist has evolved over recent years without systematic testing of crewmember ability to diagnose medical problems. The improvements are expected to enable ISS

  8. Bird migration flight altitudes studied by a network of operational weather radars.

    PubMed

    Dokter, Adriaan M; Liechti, Felix; Stark, Herbert; Delobbe, Laurent; Tabary, Pierre; Holleman, Iwan

    2011-01-01

    A fully automated method for the detection and quantification of bird migration was developed for operational C-band weather radar, measuring bird density, speed and direction as a function of altitude. These weather radar bird observations have been validated with data from a high-accuracy dedicated bird radar, which was stationed in the measurement volume of weather radar sites in The Netherlands, Belgium and France for a full migration season during autumn 2007 and spring 2008. We show that weather radar can extract near real-time bird density altitude profiles that closely correspond to the density profiles measured by dedicated bird radar. Doppler weather radar can thus be used as a reliable sensor for quantifying bird densities aloft in an operational setting, which--when extended to multiple radars--enables the mapping and continuous monitoring of bird migration flyways. By applying the automated method to a network of weather radars, we observed how mesoscale variability in weather conditions structured the timing and altitude profile of bird migration within single nights. Bird density altitude profiles were observed that consisted of multiple layers, which could be explained from the distinct wind conditions at different take-off sites. Consistently lower bird densities are recorded in The Netherlands compared with sites in France and eastern Belgium, which reveals some of the spatial extent of the dominant Scandinavian flyway over continental Europe.

  9. DOAS evaluation of volcanic SO2 using a modeled background spectrum: Examples from the NOVAC stations at Nevado del Ruiz (Colombia) and Tungurahua (Ecuador)

    NASA Astrophysics Data System (ADS)

    Lübcke, Peter; Lampel, Johannes; Bobrowski, Nicole; Arellano, Santiago; Galle, Bo; Garzón, Gustavo; Hidalgo, Silvana; Vogel, Leif; Warnach, Simon; Platt, Ulrich

    2015-04-01

    SO2 emission rates are monitored using Differential Optical Absorption Spectroscopy (DOAS) in the UV at an increasing number of volcano observatories. The Network for Observation of Volcanic and Atmospheric Change (NOVAC) has currently installed 80 scanning DOAS instruments at 30 volcanoes world-wide. One important question for the evaluation of spectra using DOAS is the availability of background spectra that are not influenced by volcanic gas emissions. An SO2 contaminated background spectrum would lead to a negative offset of the retrieved SO2 column densities, and thus to an underestimation of the volcanic SO2 emission rate. In NOVAC this problem is approached by performing a scan, e.g. through a plane from one horizon to the other horizon, and defining the average of the 20% spectra with the lowest SO2 content as the zero-baseline value, which is assumed to be gas free. To verify this assumption we revisit the idea of evaluating spectra using the DOAS method with a modeled background spectrum based on a high-resolution solar atlas. One challenge when evaluating spectra with a modeled background spectrum is properly accounting for instrumental effects that are usually removed when calculating the measured optical density relative to a measured background spectrum. We present our approach to handle these instrumental effects, showing that we gain a similar fit quality to the method using a measured reference spectrum. For example, wavelength dependent structures in the spectrum due to the spectrometer (e.g., quantum efficiency of the detector and grating efficiency) were identified with help of a principal component analysis of an SO2 free subset of the residual spectra. These structures were included in a second iteration of the fit in order to improve the evaluation. We further discuss influences like strong ozone absorption and the instrument temperature on the quality of the SO2 fit using a modeled background spectrum. The new evaluation scheme was applied

  10. EduCable. Evaluation of Station KUON-TV, Lincoln, Nebraska. Cable Television Research Program Demonstration. CPB Technical Report #8006.

    ERIC Educational Resources Information Center

    Corporation for Public Broadcasting, Washington, DC.

    Documentation of the status of the University of Nebraska-Lincoln Television Department's Cable Television Communications Research Project is provided, along with a report of an evaluation which was undertaken both to determine the impact and effectiveness of the EduCable program service to cable system subscribers and to assess the viability of…

  11. Space Radar Image of Orange County, California (annotated version)

    NASA Technical Reports Server (NTRS)

    1994-01-01

    This spaceborne radar image of Orange County, Calif., shows the massive urbanization of this rapidly growing region located just south of Los Angeles. Orange County, sandwiched between rugged mountains and the Pacific Ocean, includes the communities of Anaheim, Santa Ana and Huntington Beach. Anaheim Stadium can be seen in the upper center of the image, as a small white ring to the right of a major freeway intersection. The large dark blue rectangular area in the upper left is the Seal Beach Naval Weapons Station and adjacent wildlife refuge. Runways of the El Toro Marine Air Station appear as a black 'x' near the center of the image. The large purple area to the left of the the Air Station and extending to the coast is the scar left by the Laguna wildfire of October 1993. The sparse vegetation left in the wake of the fire provides a weak source of radar echoes, making the burn areas distinctively dark in the image. Another large burn area, from the Ortega fire of 1993, is seen in the mountains in the lower right of the image. The image was acquired by the Spaceborne Imaging Radar-C/X-band Synthetic Aperture Radar (SIR-C/X-SAR) onboard the space shuttle Endeavour on October 3, 1994. The image is centered at 33.7 degrees north latitude and 117.7 degrees west longitude. North is toward the upper right. The image shows an area 66.2 kilometers by 44.2 kilometers (41.0 miles by 27.4 miles). The colors are assigned todifferent frequencies and polarizations of the radar as follows: red is L-band, horizontally transmitted, horizontally received; green is L-band, horizontally transmitted, vertically received; blue is C-band, horizontally transmitted, vertically received. SIR-C/X-SAR, a joint mission of the German, Italian and United States space agencies, is part of NASA's Mission to Planet Earth program.

  12. Integrated mobile radar-camera system in airport perimeter security

    NASA Astrophysics Data System (ADS)

    Zyczkowski, M.; Szustakowski, M.; Ciurapinski, W.; Dulski, R.; Kastek, M.; Trzaskawka, P.

    2011-11-01

    The paper presents the test results of a mobile system for the protection of large-area objects, which consists of a radar and thermal and visual cameras. Radar is used for early detection and localization of an intruder and the cameras with narrow field of view are used for identification and tracking of a moving object. The range evaluation of an integrated system are presented as well as the probability of human detection as a function of the distance from radar-camera unit.

  13. Integrated radar-camera security system: range test

    NASA Astrophysics Data System (ADS)

    Zyczkowski, M.; Szustakowski, M.; Ciurapinski, W.; Karol, M.; Markowski, P.

    2012-06-01

    The paper presents the test results of a mobile system for the protection of large-area objects, which consists of a radar and thermal and visual cameras. Radar is used for early detection and localization of an intruder and the cameras with narrow field of view are used for identification and tracking of a moving object. The range evaluation of an integrated system is presented as well as the probability of human detection as a function of the distance from radar-camera unit.

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

    SciTech Connect

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

    2010-09-01

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

  15. An MSK Radar Waveform

    NASA Technical Reports Server (NTRS)

    Quirk, Kevin J.; Srinivasan, Meera

    2012-01-01

    The minimum-shift-keying (MSK) radar waveform is formed by periodically extending a waveform that separately modulates the in-phase and quadrature- phase components of the carrier with offset pulse-shaped pseudo noise (PN) sequences. To generate this waveform, a pair of periodic PN sequences is each passed through a pulse-shaping filter with a half sinusoid impulse response. These shaped PN waveforms are then offset by half a chip time and are separately modulated on the in-phase and quadrature phase components of an RF carrier. This new radar waveform allows an increase in radar resolution without the need for additional spectrum. In addition, it provides self-interference suppression and configurable peak sidelobes. Compared strictly on the basis of the expressions for delay resolution, main-lobe bandwidth, effective Doppler bandwidth, and peak ambiguity sidelobe, it appears that bi-phase coded (BPC) outperforms the new MSK waveform. However, a radar waveform must meet certain constraints imposed by the transmission and reception of the modulation, as well as criteria dictated by the observation. In particular, the phase discontinuity of the BPC waveform presents a significant impediment to the achievement of finer resolutions in radar measurements a limitation that is overcome by using the continuous phase MSK waveform. The phase continuity, and the lower fractional out-of-band power of MSK, increases the allowable bandwidth compared with BPC, resulting in a factor of two increase in the range resolution of the radar. The MSK waveform also has been demonstrated to have an ambiguity sidelobe structure very similar to BPC, where the sidelobe levels can be decreased by increasing the length of the m-sequence used in its generation. This ability to set the peak sidelobe level is advantageous as it allows the system to be configured to a variety of targets, including those with a larger dynamic range. Other conventionally used waveforms that possess an even greater

  16. Kiowa Creek Switching Station

    SciTech Connect

    Not Available

    1990-03-01

    The Western Area Power Administration (Western) proposes to construct, operate, and maintain a new Kiowa Creek Switching Station near Orchard in Morgan County, Colorado. Kiowa Creek Switching Station would consist of a fenced area of approximately 300 by 300 feet and contain various electrical equipment typical for a switching station. As part of this new construction, approximately one mile of an existing 115-kilovolt (kV) transmission line will be removed and replaced with a double circuit overhead line. The project will also include a short (one-third mile) realignment of an existing line to permit connection with the new switching station. In accordance with the Council on Environmental Quality (CEQ) regulations for implementing the procedural provisions of the National Environmental Policy Act of 1969 (NEPA), 40 CFR Parts 1500--1508, the Department of Energy (DOE) has determined that an environmental impact statement (EIS) is not required for the proposed project. This determination is based on the information contained in this environmental assessment (EA) prepared by Western. The EA identifies and evaluates the environmental and socioeconomic effects of the proposed action, and concludes that the advance impacts on the human environment resulting from the proposed project would not be significant. 8 refs., 3 figs., 1 tab.

  17. Evaluating the use of different precipitation datasets in flood modelling

    NASA Astrophysics Data System (ADS)

    Akyurek, Zuhal; Soytekin, Arzu

    2016-04-01

    Satellite based precipitation products, numerical weather prediction model precipitation forecasts and weather radar precipitation estimates can be a remedy for gauge sparse regions especially in flood forecasting studies. However, there is a strong need for evaluation of the performance and limitations of these estimates in hydrology. This study compares the Hydro-Estimator precipitation product, Weather Research and Forecasting (WRF) model precipitation and weather radar values with gauge data in Samsun-Terme region located in the eastern Black Sea region of Turkey, which generally receives high rainfall from north-facing slopes of mountains. Using different statistical factors, performance of the precipitation estimates are compared in point and areal based manner. In point based comparisons, three matching methods; direct matching method (DM), probability matching method (PMM) and window correlation matching method (WCMM) are used to make comparisons for the flood event (22.11.2014) lasted 40 hours. Hourly rainfall data from 13 ground observation stations were used in the analyses. This flood event created 541 m3/sec peak discharge at the 22-45 discharge observation station and flooding at the downstream of the basin. It is seen that, general trend of the rainfall is captured by the radar rainfall estimation well but radar underestimates the peaks. Moreover, it is observed that the assessment factor (gauge rainfall/ radar rainfall estimation) does not depend on the distance between radar and gauge station. In WCMM calculation it is found out that change of space window from 1x1 type to 5x5 type does not improve the results dramatically. In areal based comparisons, it is found out that the distribution of the HE product in time series does not show similarity for other datasets. Furthermore, the geometry of the subbasins, size of the area in 2D and 3D and average elevation do not have an impact on the mean statistics, RMSE, r and bias calculation for both radar

  18. Evaluation of severe accident risks and the potential for risk reduction: Surry Power Station, Unit 1: Draft report for comment

    SciTech Connect

    Benjamin, A.S.; Boyd, G.J.; Kunsman, D.M.; Murfin, W.B.; Williams, D.C.

    1987-02-01

    The Severe Accident Risk Reduction Program (SARRP) has completed a rebaselining of the risks to the public from a particular pressurized water reactor with a subatmospheric containment (Surry, Unit 1). Emphasis was placed on determining the magnitude and character of the uncertainties, rather than focusing on a point estimate. The risk-reduction potential of a set of proposed safety option backfits was also studied, and their costs and benefits were also evaluated. It was found that the risks from internal events are generally lower than previously evaluated in the Reactor Safety Study (RSS). However, certain unresolved issues (such as direct containment heating) caused the top of the uncertainty band to appear at a level that is comparable with the RSS point estimate. None of the postulated safety options appears to be cost effective for the Surry power plant. This work supports the Nuclear Regulatory Commission's assessment of severe accidents in NUREG-1150.

  19. Mathematical analysis study for radar data processing and enhancement. Part 1: Radar data analysis

    NASA Technical Reports Server (NTRS)

    James, R.; Brownlow, J. D.

    1985-01-01

    A study is performed under NASA contract to evaluate data from an AN/FPS-16 radar installed for support of flight programs at Dryden Flight Research Facility of NASA Ames Research Center. The purpose of this study is to provide information necessary for improving post-flight data reduction and knowledge of accuracy of derived radar quantities. Tracking data from six flights are analyzed. Noise and bias errors in raw tracking data are determined for each of the flights. A discussion of an altiude bias error during all of the tracking missions is included. This bias error is defined by utilizing pressure altitude measurements made during survey flights. Four separate filtering methods, representative of the most widely used optimal estimation techniques for enhancement of radar tracking data, are analyzed for suitability in processing both real-time and post-mission data. Additional information regarding the radar and its measurements, including typical noise and bias errors in the range and angle measurements, is also presented. This is in two parts. This is part 1, an analysis of radar data.

  20. RADAR Reveals Titan Topography

    NASA Technical Reports Server (NTRS)

    Kirk, R. L.; Callahan, P.; Seu, R.; Lorenz, R. D.; Paganelli, F.; Lopes, R.; Elachi, C.

    2005-01-01

    The Cassini Titan RADAR Mapper is a K(sub u)-band (13.78 GHz, lambda = 2.17 cm) linear polarized RADAR instrument capable of operating in synthetic aperture (SAR), scatterometer, altimeter and radiometer modes. During the first targeted flyby of Titan on 26 October, 2004 (referred to as Ta) observations were made in all modes. Evidence for topographic relief based on the Ta altimetry and SAR data are presented here. Additional SAR and altimetry observations are planned for the T3 encounter on 15 February, 2005, but have not been carried out at this writing. Results from the T3 encounter relevant to topography will be included in our presentation. Data obtained in the Ta encounter include a SAR image swath