WorldWideScience

Sample records for surveillance radar techniques

  1. Airport Surveillance Radar : Model 8 -

    Data.gov (United States)

    Department of Transportation — The Airport Surveillance Radar Model 8 (ASR-8) is a short-range (60 nautical mile (nmi)), analog radar system used to detect and report the presence and location of...

  2. Airport Surveillance Radar : Model 7 -

    Data.gov (United States)

    Department of Transportation — The Airport Surveillance Radar Model 7 (ASR-7) is a short-range (60 nautical miles (nmi)) analog radar system used to detect and report the presence and location of...

  3. Performance indicators modern surveillance radar

    NARCIS (Netherlands)

    Nooij, P.N.C.; Theil, A.

    2014-01-01

    Blake chart computations are widely employed to rank detection coverage capabilities of competitive search radar systems. Developed for comparable 2D radar systems with a mechanically rotating reflector antenna, it was not necessary to regard update rate and plot quality in Blake's chart. To

  4. Performance indicators modern surveillance radar

    NARCIS (Netherlands)

    Nooij, P.N.C.; Theil, A.

    2014-01-01

    Blake chart computations are widely employed to rank detection coverage capabilities of competitive search radar systems. Developed for comparable 2D radar systems with a mechanically rotating reflector antenna, it was not necessary to regard update rate and plot quality in Blake's chart. To charact

  5. Polarization changing technique in macrocosm and it's application to radar

    Institute of Scientific and Technical Information of China (English)

    潘健; 毛二可

    2004-01-01

    A new model of air-surveillance radar (named polarization changing in macrocosm radar: PCM radar), which makes use of the polarization changing technique in macrocosm, is presented in this paper. On basis of careful selection of representative 98 states of polarization in macrocosm, PCM radar can not only perform transmitting and receiving polarization matching for various targets, consequently make full use of transmitting and receiving signals of radar, but also improve the capability against active interference and jamming. Experimental test in air defense early-warning radar system demonstrates that it can effectively enhance radar performance.

  6. Radar techniques using array antennas

    CERN Document Server

    Wirth, Wulf-Dieter

    2013-01-01

    Radar Techniques Using Array Antennas is a thorough introduction to the possibilities of radar technology based on electronic steerable and active array antennas. Topics covered include array signal processing, array calibration, adaptive digital beamforming, adaptive monopulse, superresolution, pulse compression, sequential detection, target detection with long pulse series, space-time adaptive processing (STAP), moving target detection using synthetic aperture radar (SAR), target imaging, energy management and system parameter relations. The discussed methods are confirmed by simulation stud

  7. Fusion of Radar and EO-sensors for Surveillance

    NARCIS (Netherlands)

    Kester, L.J.H.M.; Theil, A.

    2001-01-01

    Fusion of radar and EO-sensors is investigated for the purpose of surveillance in littoral waters is. All sensors are considered to be co-located with respect to the distance, typically 1 to 10 km, of the area under surveillance. The sensor suite is a coherent polarimetric radar in combination with

  8. Fusion of Radar and EO-sensors for Surveillance

    NARCIS (Netherlands)

    Kester, L.J.H.M.; Theil, A.

    2001-01-01

    Fusion of radar and EO-sensors is investigated for the purpose of surveillance in littoral waters is. All sensors are considered to be co-located with respect to the distance, typically 1 to 10 km, of the area under surveillance. The sensor suite is a coherent polarimetric radar in combination with

  9. Fusion of Radar and EO-sensors for Surveillance

    NARCIS (Netherlands)

    Kester, L.J.H.M.; Theil, A.

    2000-01-01

    Fusion of radar and EO-sensors for the purpose of surveillance is investigated. All sensors are considered to be co-located with respect to the distance of the area under surveillance. More specifically, the applicability for such multi-sensor systems is examined for surveillance in littoral

  10. Biometric identification using holographic radar imaging techniques

    Science.gov (United States)

    McMakin, Douglas L.; Sheen, David M.; Hall, Thomas E.; Kennedy, Mike O.; Foote, Harlen P.

    2007-04-01

    Pacific Northwest National Laboratory researchers have been at the forefront of developing innovative screening systems to enhance security and a novel imaging system to provide custom-fit clothing using holographic radar imaging techniques. First-of-a-kind cylindrical holographic imaging systems have been developed to screen people at security checkpoints for the detection of concealed, body worn, non-metallic threats such as plastic and liquid explosives, knifes and contraband. Another embodiment of this technology is capable of obtaining full sized body measurements in near real time without the person under surveillance removing their outer garments. Radar signals readily penetrate clothing and reflect off the water in skin. This full body measurement system is commercially available for best fitting ready to wear clothing, which was the first "biometric" application for this technology. One compelling feature of this technology for security biometric applications is that it can see effectively through disguises, appliances and body hair.

  11. Radar interferometry persistent scatterer technique

    CERN Document Server

    Kampes, Bert M

    2006-01-01

    Only book on Permanent Scatterer technique of radar interferometryExplains the Permanent Scatterer technique in detail, possible pitfalls, and details a newly developed stochastic model and estimator algorithm to cope with possible problems for the application of the PS techniqueThe use of Permanent Scatterer allows very precise measurements of the displacement of hundreds of points per square kilometerDescribes the only technique currently able to perform displacement measurements in the past, utilizing the ERS satellite data archive using data acquired from 1992-prese

  12. Principles of modern radar advanced techniques

    CERN Document Server

    Melvin, William

    2012-01-01

    Principles of Modern Radar: Advanced Techniques is a professional reference for practicing engineers that provides a stepping stone to advanced practice with in-depth discussions of the most commonly used advanced techniques for radar design. It will also serve advanced radar academic and training courses with a complete set of problems for students as well as solutions for instructors.

  13. Multiple frequency atmospheric radar techniques

    Science.gov (United States)

    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. Mapping wintering waterfowl distributions using weather surveillance radar.

    Science.gov (United States)

    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.

  15. Mapping wintering waterfowl distributions using weather surveillance radar

    Science.gov (United States)

    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.

  16. PENGGUNAAN SECONDARY SURVEILLANCE RADAR UNTUK PENENTUAN POSISI PESAWAT UDARA

    Directory of Open Access Journals (Sweden)

    Akhmad Hafidz Irfandi

    2015-02-01

    Full Text Available Republik Indonesia merupakan negara kepulauan terbesar di dunia yang memiliki lebih dari 17.000 pulau dengan pertumbuhan demografi yang sangat pesat, hal ini menjadikan Indonesia sebagai negara berpenduduk terbesar ke-empat di dunia. Pesawat udara merupakan alat transportasi yang paling efektif dalam mendukung mobilitas penduduk.Navigasi atau pandu arah adalah penentuan kedudukan (position dan arah perjalanan baik di medan sebenarnya atau di peta. Navigasi ini dilakukan pada pesawat udara yang dipandu dari darat melalui sinyal yang dipancarkan oleh instrumen terpasang pada menara (ground base maupun sinyal dari satelit (satellite base.Dalam navigasi ada beberapa macam radar yang umum digunakan yaitu Primary Surveillance Radar (PSR dan Secondary Surveillance Radar (SSR.Kedua jenis radar baik PSR maupun SSR mempunyai cara kerja berbeda. Pada PSR sifatnya aktif dan pesawat yang ditargetkan sifatnya pasif.Karena PSR hanya menerima pantulan gelombang radio dari refleksi pesawat tersebut (echo.Sedangkan pesawat itu sendiri tidak ikut aktif dengan pancaran sinyal radar di bawah. Pada SSR, baik radar maupun pesawat kedua-duanya aktif. Hal ini dapat dilakukan karena pesawat terbang telah dilengkapi dengan transponder. Pesawat-pesawat yang tidak dilengkapi transponder tidak akan dapat dilihat pada radar scope seperti identifikasi pesawat, ketinggiannya, dan lain-lain.SSR merupakan peralatan untuk mendeteksi dan mengetahui posisi dan data target yang ada di sekelilingnya secara aktif, dimana pesawat ikut aktif jika menerima pancaran sinyal Radio Frequency (RF radar sekunder. Pancaran radar ini berupa pulsa-pulsa mode, pesawat yang dipasangi transponder, akan menerima pulsa-pulsa tersebut dan akan menjawab berupa pulsa-pulsa code ke sistem penerima radar.

  17. Algorithms for Separation of Secondary Surveillance Radar Replies

    NARCIS (Netherlands)

    Petrochilos, N.L.R.

    2002-01-01

    Air Traffic Control (ATC) centers aim at ensuring safety of aircrafts cruising in their area. The information required to face this mission includes the data provided by primary and Secondary Surveillance Radar (SSR). The first one indicates the presence of an aircraft, whereas the second gives info

  18. Modern Air Situation Picture Display for Air Surveillance Radar Applications

    Directory of Open Access Journals (Sweden)

    M. Stamatović

    2013-06-01

    Full Text Available We have developed a modern air situation picture display applicable in air surveillance radars. The display is based on commercial of-the-shelf hardware and custom software. This paper is focused on the details of the development process. Comparison with a similar commercially available product is given too.

  19. Interval algebra: an effective means of scheduling surveillance radar networks

    CSIR Research Space (South Africa)

    Focke, RW

    2015-05-01

    Full Text Available Interval Algebra provides an effective means to schedule surveillance radar networks, as it is a temporal ordering constraint language. Thus it provides a solution to a part of resource management, which is included in the revised Data Fusion...

  20. Tracking Theory for Airborne Surveillance Radars

    Science.gov (United States)

    1983-02-01

    transformation is a geometric one: using the current AEW aircraft position, the maps are translated into radar-centered polar coor- dinates. The second...interference ratio. The resultant polar , AEW- relative measurements are translated into "absolute" coordinates for input to the tracker using the current...postulates any trajectory which begins in scan 2. During expansion of G5 or G6, however, this would not be the case. GI1. BDD : one target, observed in three

  1. A Polarization Technique for Mitigating Low Grazing Angle Radar Sea Clutter

    Science.gov (United States)

    2017-03-03

    A Polarization Technique for Mitigating Low-Grazing-Angle Radar Sea Clutter Molly K. Crane MIT Lincoln Laboratory Lexington, MA 02420 Email...MA 02420 Email: mabel.ramirez@ll.mit.edu Abstract—Traditional detection schemes in conventional mar- itime surveillance radars may suffer serious...effective means of enhancing target detection in sea clutter, MIT Lincoln Laboratory (MIT LL) collected a fully polarimetric X-band radar dataset on

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

    Science.gov (United States)

    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.

  3. Maritime target and sea clutter measurements with a coherent Doppler polarimetric surveillance radar

    NARCIS (Netherlands)

    Smith, A.J.E.; Gelsema, S.J.; Kester, L.J.H.M.; Melief, H.W.; Premel Cabic, G.; Theil, A.; Woudenberg, E.

    2002-01-01

    Doppler polarimetry in a surveillance radar for the maritime surface picture is considered. This radar must be able to detect low-RCS targets in littoral environments. Measurements on such targets have been conducted with a coherent polarimetric measurement radar in March 2001 and preliminary

  4. Maritime target and sea clutter measurements with a coherent Doppler polarimetric surveillance radar

    NARCIS (Netherlands)

    Smith, A.J.E.; Gelsema, S.J.; Kester, L.J.H.M.; Melief, H.W.; Premel Cabic, G.; Theil, A.; Woudenberg, E.

    2002-01-01

    Doppler polarimetry in a surveillance radar for the maritime surface picture is considered. This radar must be able to detect low-RCS targets in littoral environments. Measurements on such targets have been conducted with a coherent polarimetric measurement radar in March 2001 and preliminary result

  5. Tomographic Techniques for Radar Ice Sounding

    DEFF Research Database (Denmark)

    Nielsen, Ulrik

    AbstractLow frequency radars, also known as sounders, can be used for subsurfacemeasurements of Earth’s massive ice sheets. Radar data are essential toimproving ice sheet models for better prediction of the response of theseice sheets to global climate change. While airborne sounders are neededfor...... challenge. This dissertation deals with tomographic techniques based on multiphase-center radars that represent state-of-the-art technology within thefield of ice sounding. The use of advanced tomographic processing forclutter suppression is investigated, which up to this point has beenlargely unexplored...... acquired withthe POLarimetric Airborne Radar Ice Sounder (POLARIS), single-passtomographic surface clutter suppression capabilities are demonstratedfor the system. Using repeat-pass POLARIS data, a method based ondata-driven DOA estimation is used to show an along-track variation ofthe effective scattering...

  6. Battlespace surveillance using netted wireless random noise radar systems

    Science.gov (United States)

    Surender, Shrawan C.; Narayanan, Ram M.

    2005-05-01

    Network-Centric Warfare (NCW) technology is currently being investigated to enhance the military"s effectiveness in the battlespace by providing the warfighter the necessary information to take proper decisions and win wars. One of the main battlespace requirements is surveillance, especially in today"s guerilla warfare theaters, such as the littoral and urban zones. NCW requires warfighters to be networked, self-organizing, spectrally undetectable, and having precise information about hostile targets in their vicinity. Towards this end, we are developing the concept of Netted Wireless Random Noise Radars, which is presented in this paper. The low probability-of-detection (LPD) and low probability-of-intercept (LPI) properties of random noise radars are well-known. Such radar sensors form a self-organizing network-centric architecture, using a deterministically fragmented spectrum to avoid spectral fratricide. The central concept is to use notch filtering to fragment parts of the band-limited non-coherent random noise waveform spectrum, and use these intermediate bandwidths for network communication (target tracking and track fusion) among the wireless sensors. For target detection and ranging, these sensors transmit random noise waveforms combined with continuous signals carrying digital data. As seen by the hostile target, the transmitted waveform appears random and noise-like. However, for the friendly sensors of this system, the noise-like signal contains camouflaged information. The advantages being envisioned with such a system are lower probability of detection due to noise-like transmissions, mobility to sensors due to the self-organizing capability, spectral efficiency due to fragmentation of spectrum, and better immunity to coherent interference due to the use of non-coherent signal waveforms.

  7. Numerical simulation of radar surveillance for the ship target in oceanic clutters

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A fast iterative approach of generalized forward-backward method with the spectrum acceleration algorithm (GFBM/SAA) is developed for solving electromagnetic field integral equation and is applied to numerical simulation of radar surveillance of the ship target in oceanic clutters. Randomly rough surface is realized by the Monte Carlo method using the Pierson-Moskowitz spectrum. Numerical results of bistatic and back-scattering from the ship target and oceanic clutters demonstrate the functional dependencies upon the situation of radar surveillance such as the incidence and observation angles, radar altitude, ship RCS and other oceanic conditions.

  8. Comparison of Image Processing Techniques using Random Noise Radar

    Science.gov (United States)

    2014-03-27

    pseudo - random noise . The noise waveforms employed by the radar systems 9 are generally white and Gaussian, that is, the waveform’s power...2010. [5] Hardin, Joshua A. “Information Encoding on a Pseudo Random Noise Radar Waveform”, 2013. [6] Jackson, Julie A. “EENG 668/714 Advanced Radar ...COMPARISON OF IMAGE PROCESSING TECHNIQUES USING RANDOM NOISE RADAR THESIS Jesse Robert B. Cruz, Capt, USAF AFIT-ENG-14-M-22 DEPARTMENT OF THE

  9. Through Wall Surveillance Using Ultrawideband Random Noise Radar

    Science.gov (United States)

    2006-11-01

    confound detection. A non-coherent polarimetric random noise radar architecture is being developed based on ultrawideband (UWB) technology and software...defined radio, which has great promise in its ability to covertly detect obscured targets. The main advantages of the random noise radar lie in two

  10. Digital signal processing techniques and applications in radar image processing

    CERN Document Server

    Wang, Bu-Chin

    2008-01-01

    A self-contained approach to DSP techniques and applications in radar imagingThe processing of radar images, in general, consists of three major fields: Digital Signal Processing (DSP); antenna and radar operation; and algorithms used to process the radar images. This book brings together material from these different areas to allow readers to gain a thorough understanding of how radar images are processed.The book is divided into three main parts and covers:* DSP principles and signal characteristics in both analog and digital domains, advanced signal sampling, and

  11. Status and Prospects of Radar Polarimetry Techniques

    Directory of Open Access Journals (Sweden)

    Wang Xuesong

    2016-04-01

    Full Text Available Radar polarimetry is an applied fundamental science field that is focused on understanding interaction processes between radar waves and targets and disclosing their mechanisms. Radar polarimetry has significant application prospects in the fields of microwave remote sensing, earth observation, meteorological measurement, battlefield reconnaissance, anti-interference, target recognition, and so on. This study briefly reviews the development history of radar polarization theory and technology. Next, the state of the art of several key technologies within radar polarimetry, including the precise acquisition of radar polarization information, polarization-sensitive array signal processing, target polarization characteristics, polarization antiinterference, and target polarization classification and recognition, is summarized. Finally, the future developments of radar polarization technology are considered.

  12. External calibration technique of millimeter-wave cloud radar

    Science.gov (United States)

    Wen, Tao; Zhao, Zeng-Liang; Yao, Zhi-Gang; Han, Zhi-Gang; Guo, Lin-Da

    2016-10-01

    The millimeter-wave cloud radar can provide a large number of fine and reliable information for the inversion of cloud macro and micro parameters. A key link of using the millimeter-wave cloud radar to detect the cloud is that the radar must be calibrated. Due to the precision components and severe environment of millimeter-wave cloud radar, subtle changes may take place in the operation process of cloud radar, unless the cloud radar is calibrated regularly. Although the calibration system inside the cloud radar can track and monitor the main working parameters and correct the detection results, it fails to consider the characteristics of the antenna and the mutual influence among different components of cloud radar. Therefore, the external calibration for cloud radar system is very important. Combined with the actual situation of cloud radar under domestic onboard platform, this paper builds a complete external calibration technique process of cloud radar based on the calm sea, providing the theoretical support for the external calibration experiments of the airborne and even satellite-borne millimeter-wave cloud radar developed by our country.

  13. A Fast Method for Embattling Optimization of Ground-Based Radar Surveillance Network

    Science.gov (United States)

    Jiang, H.; Cheng, H.; Zhang, Y.; Liu, J.

    A growing number of space activities have created an orbital debris environment that poses increasing impact risks to existing space systems and human space flight. For the safety of in-orbit spacecraft, a lot of observation facilities are needed to catalog space objects, especially in low earth orbit. Surveillance of Low earth orbit objects are mainly rely on ground-based radar, due to the ability limitation of exist radar facilities, a large number of ground-based radar need to build in the next few years in order to meet the current space surveillance demands. How to optimize the embattling of ground-based radar surveillance network is a problem to need to be solved. The traditional method for embattling optimization of ground-based radar surveillance network is mainly through to the detection simulation of all possible stations with cataloged data, and makes a comprehensive comparative analysis of various simulation results with the combinational method, and then selects an optimal result as station layout scheme. This method is time consuming for single simulation and high computational complexity for the combinational analysis, when the number of stations increases, the complexity of optimization problem will be increased exponentially, and cannot be solved with traditional method. There is no better way to solve this problem till now. In this paper, target detection procedure was simplified. Firstly, the space coverage of ground-based radar was simplified, a space coverage projection model of radar facilities in different orbit altitudes was built; then a simplified objects cross the radar coverage model was established according to the characteristics of space objects orbit motion; after two steps simplification, the computational complexity of the target detection was greatly simplified, and simulation results shown the correctness of the simplified results. In addition, the detection areas of ground-based radar network can be easily computed with the

  14. Detection, Deterrence, Docility: Techniques of Control by Surveillance Cameras

    NARCIS (Netherlands)

    Balamir, S.

    2013-01-01

    In spite of the growing omnipresence of surveillance cameras, not much is known by the general public about their background. While many disciplines have scrutinised the techniques and effects of surveillance, the object itself remains somewhat of a mystery. A design typology of surveillance cameras

  15. GIS Based Stereoscopic Visualization Technique for Weather Radar Data

    Science.gov (United States)

    Lim, S.; Jang, B. J.; Lee, K. H.; Lee, C.; Kim, W.

    2014-12-01

    As rainfall characteristic is more quixotic and localized, it is important to provide a prompt and accurate warning for public. To monitor localized heavy rainfall, a reliable disaster monitoring system with advanced remote observation technology and high-precision display system is needed. To advance even more accurate weather monitoring using weather radar, there have been growing concerns regarding the real-time changes of mapping radar observations on geographical coordinate systems along with the visualization and display methods of radar data based on spatial interpolation techniques and geographical information system (GIS). Currently, the method of simultaneously displaying GIS and radar data is widely used to synchronize the radar and ground systems accurately, and the method of displaying radar data in the 2D GIS coordinate system has been extensively used as the display method for providing weather information from weather radar. This paper proposes a realistic 3D weather radar data display technique with higher spatiotemporal resolution, which is based on the integration of 3D image processing and GIS interaction. This method is focused on stereoscopic visualization, while conventional radar image display works are based on flat or two-dimensional interpretation. Furthermore, using the proposed technique, the atmospheric change at each moment can be observed three-dimensionally at various geological locations simultaneously. Simulation results indicate that 3D display of weather radar data can be performed in real time. One merit of the proposed technique is that it can provide intuitive understanding of the influence of beam blockage by topography. Through an exact matching each 3D modeled radar beam with 3D GIS map, we can find out the terrain masked areas and accordingly it facilitates the precipitation correction from QPE underestimation caused by ground clutter filtering. It can also be expected that more accurate short-term forecasting will be

  16. Interval algebra - an effective means of scheduling surveillance radar networks

    CSIR Research Space (South Africa)

    Focke, RW

    2015-05-01

    Full Text Available constraints. The target selection function S(k) is then simply: S(k) =    1 if k ∈ K, 0 otherwise (2) Given an arbitrary reference line and radar positioner rotation, C(m,n, r) returns constraints as follows: C(m,n, r) =    θr (m) ≺ θr (n) if m < n... straight arrows. Thus the minimum time that will pass is the angular difference between the two targets divided by the maximum scan rate. This value will be largest for the radar which has the greatest angular difference to rotate. During this time, all...

  17. Test and Evaluation of the Airport Surveillance Radar Performance Monitor.

    Science.gov (United States)

    1978-09-01

    u r i n g a por t ion of the data run. Wi th the front—panel calibrate switch set to a nomina l or mi nim~m error as indicated on Results showed that...alarms remained appeared to be due to ambient temperature wi thin .1 dB of nomina l for normal and Nil. In changes occurring in the radar equipment th

  18. Modern Radar Techniques for Geophysical Applications: Two Examples

    Science.gov (United States)

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

    2005-01-01

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

  19. Radar Range Sidelobe Reduction Using Adaptive Pulse Compression Technique

    Science.gov (United States)

    Li, Lihua; Coon, Michael; McLinden, Matthew

    2013-01-01

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

  20. Discussion on Application of Polarimetric Synthetic Aperture Radar in Marine Surveillance

    Directory of Open Access Journals (Sweden)

    Zhang Jie

    2016-12-01

    Full Text Available Synthetic Aperture Radar (SAR, an important earth observation sensor, has been used in a wide range of applications for land and marine surveillance. Polarimetric SAR (PolSAR can obtain abundant scattering information of a target to improve the ability of target detection, classification, and quantitative inversion. In this paper, the important role of PolSAR in ocean monitoring is discussed with factors such as sea ice, ships, oil spill, waves, internal waves, and seabed topography. Moreover, the future development direction of PolSAR is put forward to get an inspiration for further research of PolSAR in marine surveillance applications.

  1. FMCW Radar Jamming Techniques and Analysis

    Science.gov (United States)

    2013-09-01

    Hz (2.19) The beat frequency for the 1st and 2nd section is then f 𔃻b = 2R!F ’ cto " 2V # (2.20) and f 𔃼b = 2R!F ’ cto + 2V " (2.21) with...both beat frequencies calculated, the target range can be computed as 16 R = cto 4!F ’ ( f 𔃻b+ f 𔃼b ) m (2.22) and the target’s range rate is...Australia, 2004, pp. 167–172. [9] Lab-Volt (Quebec) Ltd., Principles of Radar Systems Student Manual . Telecommunications Radar, 2006. [10] O. C

  2. Bistatic weak target detection method using non-cooperative air surveillance radar

    Institute of Scientific and Technical Information of China (English)

    Zengping Chen

    2015-01-01

    At present, most of the passive radar system re-searches utilize FM radios, TV broadcasts, navigation satel ites, etc. as il uminators. The transmitted signals are not specifical y de-signed radar waveforms. In this work, the frequency agile, phased array air surveil ance radar (ASR) is used as the il uminator of opportunity to detect the weak target. The phased array tech-nology can help realize beam agility to track targets from diffe-rent aspects simultaneously. The frequency agility technology is widely employed in radar system design to increase the ability of anti-jamming and increase the detection probability. While the fre-quency bandwidth of radar signals is usual y wide and the range resolution is high, the range cel migration effect is obvious during the long time integration of non-cooperative bistatic radar. In this context, coherent integration methods are not applicable. In this work, a parametric non-coherent integration algorithm based on task de-interweaving is proposed. Numerical experiments verify that this is effective in weak target detection.

  3. Validation of vertical refractivity profiles as required for performance prediction of coastal surveillance radars

    CSIR Research Space (South Africa)

    Naicker, K

    2011-04-01

    Full Text Available for modeling the detection performance of coastal surveillance radars. Validation is provided through meteorological and radio wave propagation measurements undertaken in False Bay, South Africa. Keywords-vertical refractive profiles, evaporation ducts.... An atmospheric duct is a horizontal layer in troposphere, where the refractive conditions are such that an EM wave will be channeled or guided as discussed above. This results in EM wave propagation over great ranges. In a littoral environment, evaporation...

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

    Science.gov (United States)

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

    2012-01-01

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

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

    Directory of Open Access Journals (Sweden)

    R. Murat Demirer

    2012-01-01

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

  6. Radar Cross-section Measurement Techniques

    Directory of Open Access Journals (Sweden)

    V.G. Borkar

    2010-03-01

    Full Text Available Radar cross-section (RCS is an important study parameter for defence applications specially dealing with airborne weapon system. The RCS parameter guides the detection range for a target and is therefore studied to understand the effectiveness of a weapon system. It is not only important to understand the RCS characteristics of a target but also to look into the diagnostic mode of study where factors contributing to a particular RCS values are studied. This further opens up subject like RCS suppression and stealth. The paper discusses the RCS principle, control, and need of measurements. Classification of RCS in terms of popular usage is explained with detailed theory of RF imaging and inverse synthetic aperture radar (ISAR. The various types of RCS measurement ranges are explained with brief discussion on outdoor RCS measurement range. The RCS calibration plays a critical role in referencing the measurement to absolute values and has been described.The RCS facility at Reseach Centre Imarat, Hyderabad, is explained with some details of different activities that are carried out including RAM evaluation, scale model testing, and diagnostic imaging.Defence Science Journal, 2010, 60(2, pp.204-212, DOI:http://dx.doi.org/10.14429/dsj.60.341

  7. Signal processing technique for randomly discontinuous spectra HF radar waveforms

    Institute of Scientific and Technical Information of China (English)

    张东坡; 刘兴钊

    2004-01-01

    A major problem with all high frequency (HF) radars is a relatively poor range resolution available due to many interference sources. To avoid the interferences in frequency domain and operate with wideband, the randomly discontinuous spectra (RDS) signal is employed. However, it results in high range sidelobes when matching the reflected echo, which is much more difficult for target detection. A new signal processing technique that is radically different from the conventional technique to lower range sidelobes is introduced. This method is based on suppressing the selfclutter of the radar range ambiguity function (AF) by mismatched filtering. An effective algorithm is adopted to solve the filter coefficients. Simulation results show that the peak sidelobe level can be reduced to -30dB and the achievable system bandwidth is about 400KHz. The technique is adaptable to practical radar systems and applicable for other realtime signal processing.

  8. Extended radar observations with the frequency radar domain interferometric imaging (FII) technique

    Science.gov (United States)

    Luce, H.; Yamamoto, M.; Fukao, S.; Crochet, M.

    2001-07-01

    In this paper, we present high-resolution observations obtained with the Middle and Upper Atmosphere (MU) radar (Shigaraki, Japan, /34.85°N, /136.10°E) using the frequency radar domain interferometric imaging (FII) technique. This technique has recently been introduced for improving the range resolution capabilities of the mesosphere-stratosphere-troposphere (MST) radars which are limited by their minimum pulse length. The Fourier-based imaging, the Capon method have been performed with 5 equally spaced frequencies between 46.25 and 46.75MHz and with an initial range resolution of 300m. These results have been compared firstly to results obtained using the frequency domain interferometry (FDI) technique with Δf=0.5MHz and, secondly, to results from a classical Doppler beam swinging (DBS) mode applied with a range resolution of 150m. Thin echoing structures could be tracked owing to the improved radar range resolution and some complex structures possibly related to Kelvin Helmholtz instabilities have been detected. Indeed, these structures appeared within the core of a wind shear and were associated with intense vertical wind fluctuations. Moreover, a well-defined thin echo layer was found in an altitude range located below the height of the wind shear. The radar observations have not been fully interpreted yet because the radar configuration was not adapted for this kind of study and because of the lack of complementary information provided by other techniques when the interesting echoing phenomena occurred. However, the results confirm the high potentialities of the FII technique for the study of atmospheric dynamics at small scales.

  9. Improved Space Surveillance Network (SSN) Scheduling using Artificial Intelligence Techniques

    Science.gov (United States)

    Stottler, D.

    There are close to 20,000 cataloged manmade objects in space, the large majority of which are not active, functioning satellites. These are tracked by phased array and mechanical radars and ground and space-based optical telescopes, collectively known as the Space Surveillance Network (SSN). A better SSN schedule of observations could, using exactly the same legacy sensor resources, improve space catalog accuracy through more complementary tracking, provide better responsiveness to real-time changes, better track small debris in low earth orbit (LEO) through efficient use of applicable sensors, efficiently track deep space (DS) frequent revisit objects, handle increased numbers of objects and new types of sensors, and take advantage of future improved communication and control to globally optimize the SSN schedule. We have developed a scheduling algorithm that takes as input the space catalog and the associated covariance matrices and produces a globally optimized schedule for each sensor site as to what objects to observe and when. This algorithm is able to schedule more observations with the same sensor resources and have those observations be more complementary, in terms of the precision with which each orbit metric is known, to produce a satellite observation schedule that, when executed, minimizes the covariances across the entire space object catalog. If used operationally, the results would be significantly increased accuracy of the space catalog with fewer lost objects with the same set of sensor resources. This approach inherently can also trade-off fewer high priority tasks against more lower-priority tasks, when there is benefit in doing so. Currently the project has completed a prototyping and feasibility study, using open source data on the SSN's sensors, that showed significant reduction in orbit metric covariances. The algorithm techniques and results will be discussed along with future directions for the research.

  10. Chirp Signals and Noisy Waveforms for Solid-State Surveillance Radars

    Directory of Open Access Journals (Sweden)

    Gaspare Galati

    2017-03-01

    Full Text Available Since the advent of “pulse compression” radar, the “chirp” signal (Linear Frequency Modulation, LFM has been one of the most widely used radar waveforms. It is well known that, by changing its modulation into a Non-Linear Frequency Modulation (NLFM, better performance in terms of Peak-to-Sidelobes Ratio (PSLR can be achieved to mitigate the masking effect of nearby targets and to increase the useful dynamic range. Adding an appropriate amplitude modulation, as occurs in Hybrid-NLFM (HNLFM, the PSLR can reach very low values (e.g., PSLR < −60 dB, comparable to the two-way antenna sidelobes in azimuth. On the other hand, modern solid-state power amplifier technology, using low-power modules, requires them to be combined at the Radio Frequency (RF stage in order to achieve the desired transmitted power. Noise Radar Technology (NRT represents a valid alternative to deterministic waveforms. It makes use of pseudo-random waveforms—realizations of a noise process. The higher its time-bandwidth (or BT product, the higher the (statistical PSLR. With practical BT values, the achievable PSLR using pure random noise is generally not sufficient. Therefore, the generated pseudorandom waveforms can be “tailored” (TPW: Tailored Pseudorandom Waveforms at will through suitable algorithms in order to achieve the desired sidelobe level, even only in a limited range interval, as shown in this work. Moreover, the needed high BT, i.e., the higher time duration T having fixed the bandwidth B, matches well with the low power solid-state amplifiers of Noise Radar. Focusing the interest on (civil surveillance radar applications, such as ATC (Air Traffic Control and marine radar, this paper proposes a general review of the two classes of waveforms, i.e., HNLFM and TPW.

  11. Skin artifact removal technique for breast cancer radar detection

    Science.gov (United States)

    Caorsi, S.; Lenzi, C.

    2016-06-01

    In this paper we propose a new model-based skin artifact cleaning technique with the aim to remove skin reflections with good effectiveness, without introducing significant signal distortions, and without assuming a priori information on the real structure of the breast. The reference cleaning model, constituted by a two-layer geometry skin-adipose tissue, is oriented to all the ultrawideband radar methods able to detect the tumor starting by the knowledge of each trace recorded around the breast. All the radar signal measurements were simulated by using realistic breast models derived from the University of Wisconsin computational electromagnetic laboratory database and the finite difference time domain (FDTD)-based open source software GprMax. First, we have searched for the best configuration for the reference cleaning model with the aim to minimize the distortions introduced on the radar signal. Second, the performance of the proposed cleaning technique has been assessed by using a breast cancer radar detection technique based on the use of artificial neural network (ANN). In order to minimize the signal distortions, we found that it was necessary to use the real skin thickness and the static Debye parameters of both skin and adipose tissue. In such a case the ANN-based radar approach was able to detect the tumor with an accuracy of 87%. By extending the performance assessment also to the case when only average standard values are used to characterize the reference cleaning model, the detection accuracy was of 84%.

  12. Multi-Frequency Target Detection Techniques for DVB-T Based Passive Radar Sensors

    Directory of Open Access Journals (Sweden)

    Tatiana Martelli

    2016-09-01

    Full Text Available This paper investigates the possibility to improve target detection capability in a DVB-T- based passive radar sensor by jointly exploiting multiple digital television channels broadcast by the same transmitter of opportunity. Based on the remarkable results obtained by such a multi-frequency approach using other signals of opportunity (i.e., FM radio broadcast transmissions, we propose appropriate modifications to the previously devised signal processing techniques for them to be effective in the newly considered scenarios. The resulting processing schemes are extensively applied against experimental DVB-T-based passive radar data pertaining to different surveillance applications. The obtained results clearly show the effectiveness of the proposed multi-frequency approaches and demonstrate their suitability for application in the considered scenarios.

  13. A Processing Technique for OFDM-Modulated Wideband Radar Signals

    NARCIS (Netherlands)

    Tigrek, R.F.

    2010-01-01

    The orthogonal frequency division multiplexing (OFDM) is a multicarrier spread-spectrum technique which finds wide-spread use in communications. The OFDM pulse compression method that utilizes an OFDM communication signal for radar tasks has been developed and reported in this dissertation. Using th

  14. Review of the homodyne technique for coherent radar

    DEFF Research Database (Denmark)

    Christensen, Erik Lintz; Madsen, Søren Nørvang; Skou, Niels

    1990-01-01

    The merits of using homodyne techniques for coherent radar are examined. The influence of various component deficiencies is discussed with relation to the choice between homodyne and heterodyne. The use of digital IQ signal generation and processing to correct for some of the problems of modulator...... and demodulator design by predistortion, offset correction, etc. is briefly addressed. A 5.3 GHz synthetic aperture radar designed for strip mapping at high resolution is then considered to illustrate the use of the homodyne approach. Measurement results on quadrature modulators and demodulators at 300 MHz and 5...

  15. Surveillance Unattended Foliage Penetrating Radar for Border Control and Homeland Protection

    Directory of Open Access Journals (Sweden)

    Felicia Amato

    2013-06-01

    Full Text Available The increasing request for safety, security and environment protection at local and national level reveal the deficiency of the traditional surveillance and control centers to satisfy the needs and requirements of modern border control systems for homeland protection where land border is expected to be monitored as well as the maritime one. This is, for instance, the case of any land border affected by hidden immigration and/or illegal traffics as well as any small areas such as critical infrastructures or military/ civilian posts in forest or jungle environment characterized by vegetation. In such challenging environment, logistics constraints strongly recommend to have very low power devices able to operate months or years without maintenance. A such scenario should be the perfect place for implementing an Unattended Ground Sensors (UGS network making use FOliage PENetration (FOPEN radar for border control. The paper aims to present the basic characteristics and preliminary results of a Surveillance Unattended FOPEN (SUF radar suitable for detecting moving targets, people or vehicles, in dense forest environment.

  16. Surveillance Radar Design Options as a Function of Cataloguing Performance Requirements

    Science.gov (United States)

    Krag, H.; Klinkrad, H.

    2009-03-01

    Europe is preparing for the development of an autonomous space surveillance and situational awareness system. First concept and capability analysis studies have led to a draft proposal for the surveillance and tracking part of the system. This foresees, in a first deployment step, ground-based surveillance and tracking radar systems, a network of optical telescopes and a data centre. In a second step the system is planned to be extended by adding space-based assets and the associated ground-segment. The terrestrial part of the system will be responsible for the build-up and maintenance of a catalogue of space objects. Studies showed that one large phased array radar alone could act as the single means for the generation of a catalogue of LEO objects (apogee altitudes radar search window for a minimum time span to enable orbit determination of sufficient accuracy. Catalogue maintenance requires objects to be re-observable after limited time spans so that they can be clearly correlated. Today, the user requirements on the performance of the system are under definition. Different options to specify the desired system performance in terms of the resulting object catalogue have been proposed. One of them is to specify a certain coverage level of the existing NORAD catalogue. A second one is to request full coverage of all objects above a certain diameter threshold. Both approaches have certain advantages (e.g. the first one being verifiable by tests and the second one leading to an unbiased/independent catalogue). However, these requirements might impose different system designs in terms of the sensor location, and the dimensions and the orientation of the search field. This paper outlines the consequences of the cataloguing performance requirements on the high-level system design. Simulation tools are used to investigate key parameters such as the optimum radar wavelength, the viewing direction and search field dimensions as a function of these specifications. First

  17. Lightning Initiation Forecasting: An Operational Dual-Polarimetric Radar Technique

    Science.gov (United States)

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

    2011-01-01

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

  18. Review of Ship Surveillance Technologies Based on High-Resolution Wide-Swath Synthetic Aperture Radar Imaging

    Directory of Open Access Journals (Sweden)

    Xing Xiang-wei

    2015-02-01

    Full Text Available Synthetic Aperture Radar (SAR is widely used in ship surveillance. High-Resolution Wide-Swath (HRWS SAR data are simultaneously collected, which introduces challenges and offers new research opportunities. SAR-based ship-surveillance technologies and the performance requirements of SAR systems are reviewed and summarized. Furthermore, the characteristics of HRWS SAR imaging and ship surveillance technologies are considered in tandem, and preliminary research results on ship detection, feature extraction, and classification are discussed. Finally, we point out issues to be addressed in future work.

  19. A novel data association scheme for LEO space debris surveillance based on a double fence radar system

    Science.gov (United States)

    Huang, Jian; Hu, Weidong; Xin, Qin; Guo, Weiwei

    2012-12-01

    The increasing amount of space debris threatens to seriously deteriorate and damage space-based instruments in Low Earth Orbit (LEO) environments. Therefore, LEO space debris surveillance systems must be developed to provide situational awareness in space and issue warnings of collisions with LEO space debris. In this paper, a double fence radar system is proposed as an emerging paradigm for LEO space debris surveillance. This system exhibits several unique and promising characteristics compared with existing surveillance systems. In this paper, we also investigate the data association scheme for LEO space debris surveillance based on a double fence radar system. We also perform a theoretical analysis of the performance of our proposed scheme. The superiority and the effectiveness of our novel data association scheme is demonstrated by experimental results. The data used in our experiments is the LEO space debris catalog produced by the North American Air Defense Command (NORAD) up to 2009, especially for scenarios with high densities of LEO space debris, which were primarily produced by the collisions between Iridium 33 and Cosmos 2251. We hope that our work will stimulate and benefit future work on LEO space debris surveillance approaches and enable construction of the double fence radar system.

  20. Millimeter-wave/THz FMCW radar techniques for sensing applications

    Science.gov (United States)

    Mirando, D. Amal; Higgins, Michael D.; Wang, Fenggui; Petkie, Douglas T.

    2016-10-01

    Millimeter-wave and terahertz continuous-wave radar systems have been used to measure physiological signatures for biometric applications and for a variety of non-destructive evaluation applications, such as the detection of defects in materials. Sensing strategies for the simplest homodyne systems, such as a Michelson Interferometer, can be enhanced by using Frequency Modulated Continuous Wave (FMCW) techniques. This allows multiple objects or surfaces to be range resolved while monitoring the phase of the signal in a particular range bin. We will discuss the latest developments in several studies aimed at demonstrating how FMCW techniques can enhance mmW/THz sensing applications.

  1. Modification of polarization filtering technique in HF ground wave radar

    Institute of Scientific and Technical Information of China (English)

    Zhang Guoyi; Tan Zhongji; Wang Jiantao

    2006-01-01

    The polarization filter using three orthogonal linear polarization antennas can suppress more disturbances than the polarization filter using two orthogonal linear polarization antennas in HF ground wave radar. But the algorithm of the threedimension filter is relatively complicated and not suitable for real-time processing. It can't use linear and nonlinear polarization vector translation technique directly. A modified polarization filter which is simple and has same suppressing ability as the three-dimension polarization filter is given. It only has half parameters of the primary one. Some problems about estimation of polarization parameters and selection of disturbances are discussed. A method of holding the phase of radar backscatter signal constantly is put forward so that unstationary disturbance signal can be processed.

  2. Real-time windowing in imaging radar using FPGA technique

    Science.gov (United States)

    Ponomaryov, Volodymyr I.; Escamilla-Hernandez, Enrique

    2005-02-01

    The imaging radar uses the high frequency electromagnetic waves reflected from different objects for estimating of its parameters. Pulse compression is a standard signal processing technique used to minimize the peak transmission power and to maximize SNR, and to get a better resolution. Usually the pulse compression can be achieved using a matched filter. The level of the side-lobes in the imaging radar can be reduced using the special weighting function processing. There are very known different weighting functions: Hamming, Hanning, Blackman, Chebyshev, Blackman-Harris, Kaiser-Bessel, etc., widely used in the signal processing applications. Field Programmable Gate Arrays (FPGAs) offers great benefits like instantaneous implementation, dynamic reconfiguration, design, and field programmability. This reconfiguration makes FPGAs a better solution over custom-made integrated circuits. This work aims at demonstrating a reasonably flexible implementation of FM-linear signal and pulse compression using Matlab, Simulink, and System Generator. Employing FPGA and mentioned software we have proposed the pulse compression design on FPGA using classical and novel windows technique to reduce the side-lobes level. This permits increasing the detection ability of the small or nearly placed targets in imaging radar. The advantage of FPGA that can do parallelism in real time processing permits to realize the proposed algorithms. The paper also presents the experimental results of proposed windowing procedure in the marine radar with such the parameters: signal is linear FM (Chirp); frequency deviation DF is 9.375MHz; the pulse width T is 3.2μs taps number in the matched filter is 800 taps; sampling frequency 253.125*106 MHz. It has been realized the reducing of side-lobes levels in real time permitting better resolution of the small targets.

  3. Design and development of correlation techniques to maintain a space surveillance system catalogue

    Science.gov (United States)

    Olmedo, E.; Sánchez Ortiz, Noelia; Lerate, Mercedes; Belló-Mora, Miguel; Klinkrad, H.

    2009-10-01

    A growing interest exists in a future, autonomous European Space Surveillance System (ESSS). Currently, most of the knowledge about Earth-orbiting space objects is based on information provided by the USASPACECOM. This paper presents the required initial orbit determination (IOD) and correlation techniques to process optical measurements. Former studies were focused on the handling of radar measurements, which are summarised with the aim of describing a global procedure for processing hybrid measurement types (combination of radar and optic data for catalogue maintenance). The introduction of manoeuvres are presented due to their importance in the space object catalogue maintenance. The detection of uncatalogued objects and the successful correlation of already catalogued objects involve two different tasks for telescopes: survey and tasking. Assumptions for both strategies are developed on the basis of the previous work developed at the University of Berne (see [T. Flohrer, T. Schildknecht, R. Musci, E. Stöveken, Performance estimation for GEO space surveillance, Advances in Space Research 35 (2005). [1]; T. Flohrer, T. Schildknecht, R. Musci, Proposed strategies for optical observations in a future European Space Surveillance Network, presented in the 36th COSPAR Scientific Assembly (2006). [2]; R. Musci, T. Schildknecht, M. Ploner, Orbit improvement for GEO objects using follow-up observations, Advances in Space Research 34 (2004). [3]; R. Musci, T. Schildknecht, M. Ploner, G. Beutler, Orbit improvement for GTO objects using follow-up observations, Advances in Space Research 35 (2005). [4]; R. Musci, T. Schildknecht, T. Flohrer, G. Beutler, Concept for a catalogue of space debris in GEO, Proceedings of the Fourth European Conference on Space Debris, (ESA SP-587, 2005). [5

  4. Sensors for Desert Surveillance

    Directory of Open Access Journals (Sweden)

    B. S. Chauhan

    2005-10-01

    Full Text Available Various types of sensors-visible, passive night vision, infrared, synthetic aperture radar, etc can be used for desert surveillance. The surveillance capability of these sensors depends to a large extent, on various atmospheric effects, viz., absorption, scattering, aerosol, turbulence, and optical mirage. In this paper, effects of various atmospheric phenomena on the transmission of signals, merits and demerits of different means of surveillance under desert environmental conditions are discussed. Advanced surveillance techniques, ie, multisensor fusion, multi and hyperspectral imaging, having special significance for desert surveillance, have also been discussed.

  5. radR: an open-source platform for acquiring and analysing data on biological targets observed by surveillance radar.

    Science.gov (United States)

    Taylor, Philip D; Brzustowski, John M; Matkovich, Carolyn; Peckford, Michael L; Wilson, Dave

    2010-10-26

    Radar has been used for decades to study movement of insects, birds and bats. In spite of this, there are few readily available software tools for the acquisition, storage and processing of such data. Program radR was developed to solve this problem. Program radR is an open source software tool for the acquisition, storage and analysis of data from marine radars operating in surveillance mode. radR takes time series data with a two-dimensional spatial component as input from some source (typically a radar digitizing card) and extracts and retains information of biological relevance (i.e. moving targets). Low-level data processing is implemented in "C" code, but user-defined functions written in the "R" statistical programming language can be called at pre-defined steps in the calculations. Output data formats are designed to allow for future inclusion of additional data items without requiring change to C code. Two brands of radar digitizing card are currently supported as data sources. We also provide an overview of the basic considerations of setting up and running a biological radar study. Program radR provides a convenient, open source platform for the acquisition and analysis of radar data of biological targets.

  6. A novel signal processing approach for LEO space debris based on a fence-type space surveillance radar system

    Science.gov (United States)

    Huang, Jian; Hu, Weidong; Ghogho, Mounir; Xin, Qin; Du, Xiaoyong; Guo, Weiwei

    2012-12-01

    The increase in space debris can seriously threaten regular activities in the Low Earth Orbit (LEO) environment. Therefore, it is necessary to develop robust, efficient and reliable techniques to understand the potential motions of the LEO debris. In this paper, we propose a novel signal processing approach to detect and estimate the motions of LEO space debris that is based on a fence-type space surveillance radar system. Because of the sparse distribution of the orbiting debris through the fence in our observations, we formulate the signal detection and the motion parameter estimation as a sparse signal reconstruction problem with respect to an over-complete dictionary. Moreover, we propose a new scheme to reduce the size of the original over-complete dictionary without the loss of the important information. This new scheme is based on a careful analysis of the relations between the acceleration and the directions of arrival for the corresponding LEO space debris. Our simulation results show that the proposed approach can achieve extremely good performance in terms of the accuracy for detection and estimation. Furthermore, our simulation results demonstrate the robustness of the approach in scenarios with a low Signal-to-Noise Ratio (SNR) and the super-resolution properties. We hope our signal processing approach can stimulate further work on monitoring LEO space debris.

  7. Integrating radar and laser-based remote sensing techniques for monitoring structural deformation of archaeological monuments

    OpenAIRE

    Tapete D.; Casagli N.; Luzi G.; Fanti R.; Gigli G.; Leva D.

    2013-01-01

    Ground-Based Synthetic Aperture Radar Interferometry (GBInSAR) and Terrestrial Laser Scanning (TLS) were purposely integrated to obtain 3D interferometric radar point clouds to facilitate the spatial interpretation of displacements affecting archaeological monuments. The paper describes the procedure to implement this integrated approach in the real-world situations of surveillance of archaeological and built heritage. Targeted tests were carried out on the case study of the Domus Tiberiana s...

  8. Techniques for Radar Imaging Based on MUSIC Algorithm

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    At first, the radar target scattering centers model and MUSIC algorithm are analyzed in this paper. How to efficiently set the parameters of the MUSIC algorithms is given by a great deal of simulated radar data in experiments. After that, according to measured data from two kinds of plane targets on fully polarized and high range resolution radar system, the author mainly investigated particular utilization of MUSIC algorithm in radar imaging. And two-dimensional radar images are generated for two targets measured in compact range. In the end, a conclusion is drew about the relation of radar target scattering properties and imaging results.

  9. Characterization of Adolescent Prescription Drug Abuse and Misuse Using the Researched Abuse Diversion and Addiction-Related Surveillance (RADARS[R]) System

    Science.gov (United States)

    Zosel, Amy; Bartelson, Becki Bucher; Bailey, Elise; Lowenstein, Steven; Dart, Rick

    2013-01-01

    Objective: To describe the characteristics and health effects of adolescent (age 13-19 years) prescription drug abuse and misuse using the Researched Abuse Diversion and Addiction-Related Surveillance (RADARS[R])) System. Method: Secondary analysis of data collected from RADARS System participating poison centers was performed. Data for all…

  10. New endoscopic imaging techniques in surveillance ofinflammatory bowel disease

    Institute of Scientific and Technical Information of China (English)

    Tommaso Gabbani; Natalia Manetti; Andrea Giovanni Bonanomi; Antonio Luca Annese; Vito Annese

    2015-01-01

    Endoscopy plays a crucial role in the managementof inflammatory bowel disease (IBD). Advancesimaging techniques allow visualization of mucosaldetails, tissue characteristics and cellular alteration. Inparticular chromoendoscopy, magnification endoscopy,confocal laser endomicroscopy and endocytoscopyseem to have the possibility to radically modify theapproach to surveillance and decision making. Dyebasedchromoendoscopy (DBC) and magnificationchromoendoscopy improve detection of dysplasia,and evaluation of inflammatory activity and extensionof ulcerative colitis and are thus considered thestandard of care. Dye-less chromoendoscopy couldprobably replace conventional DBC for surveillance.Narrow band imaging and i-scan have shown toimprove activity and extent assessment in comparisonto white-light endoscopy. Confocal laser endomicroscopy(CLE) can detect more dysplastic lesions insurveillance colonoscopy and predict neoplastic andinflammatory changes with high accuracy comparedto histology. This technology is best used in conjunctionwith chromoendoscopy, narrow-band imaging, orautofluorescence because of its minute scanning area.This combination is useful for appropriate tissueclassification of mucosal lesions already detectedby standard or optically enhanced endoscopy. Thebest combination for IBD surveillance appear tobe chromoendoscopy for identification of areas ofsuspicion, with further examination with CLE to detectintraepithelial neoplasia. However cost, availability, andexperience are still an issue.

  11. Advanced Doppler radar physiological sensing technique for drone detection

    Science.gov (United States)

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

    2017-05-01

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

  12. Three-dimensional radar imaging techniques and systems for near-field applications

    Energy Technology Data Exchange (ETDEWEB)

    Sheen, David M.; Hall, Thomas E.; McMakin, Douglas L.; Jones, Anthony M.; Tedeschi, Jonathan R.

    2016-05-12

    The Pacific Northwest National Laboratory has developed three-dimensional holographic (synthetic aperture) radar imaging techniques and systems for a wide variety of near-field applications. These applications include radar cross-section (RCS) imaging, personnel screening, standoff concealed weapon detection, concealed threat detection, through-barrier imaging, ground penetrating radar (GPR), and non-destructive evaluation (NDE). Sequentially-switched linear arrays are used for many of these systems to enable high-speed data acquisition and 3-D imaging. In this paper, the techniques and systems will be described along with imaging results that demonstrate the utility of near-field 3-D radar imaging for these compelling applications.

  13. Monitoring of Refractory wall recession using radar technique

    Energy Technology Data Exchange (ETDEWEB)

    University of missouri

    2003-12-30

    Furnaces are the most crucial components in the glass and metallurgical industry. Like any other components in an industry, furnaces require periodic maintenance and repair. Today, furnaces are being operated at higher temperatures and for longer periods of time thus increasing the rate of wear and tear on the furnace refractory lining. As a result of the competitive market facing these industries, longer furnace lifetime with shorter maintenance downtime are increasingly required. Higher fuel consumption, low production and safety are issues that accompany delayed maintenance. Consequently, there is a need to know the state of a refractory wall to prevent premature or unnecessary maintenance shutdowns. For many years the observation skills of an experienced operator has been the primary source of evaluating the wear associated with a refractory wall. The rate of regression of a refractory lining depends on the type of the refractory lining, the materials Monitoring of Refractory Wall Recession Using Frequency-Modulated Continuous-Wave (FM-CW) Radar Techniques: A Proof-of-Concept Study, Final Report, Submitted to the Department of Energy (DOE), September 2003. being melted, seepage, mechanical stresses, and temperature. Moreover, the regression of a refractory lining is also not uniform throughout a furnace and it is more prominent at the metal line along the sidewalls as this region is exposed to hot gaseous byproducts and flowing molten material. Hence, more accurate measurement techniques are required to determine the local residual thickness of a refractory lining so as to utilize the refractory lining to the maximum extent possible. The use of isotope radiators, thermocouples and endoscopes has also been investigated for monitoring regression. These techniques are capable of providing scanned thermal images showing the profile of the refractory wall. However, these techniques can only provide relative profile information and cannot provide absolute thickness

  14. Modelling a C-Band Space Surveillance Radar using Systems Tool Kit

    Science.gov (United States)

    2013-02-01

    Orbit LOS Line of Sight PRF Pulse Repetition Frequency PSD Power Spectral Density RCS Radar Cross Section RF Radio Frequency SAR Synthetic...Simulation of both monostatic and bistatic radar systems.  Modelling of system characteristics (e.g. transmitter power, frequency, antenna size) and...system definition, search/track modes, refraction and constraints. Synthetic aperture radar ( SAR ) and jammers can be modelled but are not applicable in

  15. Salient Feature Identification and Analysis using Kernel-Based Classification Techniques for Synthetic Aperture Radar Automatic Target Recognition

    Science.gov (United States)

    2014-03-27

    SALIENT FEATURE IDENTIFICATION AND ANALYSIS USING KERNEL-BASED CLASSIFICATION TECHNIQUES FOR SYNTHETIC APERTURE RADAR AUTOMATIC TARGET RECOGNITION...FEATURE IDENTIFICATION AND ANALYSIS USING KERNEL-BASED CLASSIFICATION TECHNIQUES FOR SYNTHETIC APERTURE RADAR AUTOMATIC TARGET RECOGNITION THESIS Presented...SALIENT FEATURE IDENTIFICATION AND ANALYSIS USING KERNEL-BASED CLASSIFICATION TECHNIQUES FOR SYNTHETIC APERTURE RADAR AUTOMATIC TARGET RECOGNITION

  16. A Novel Monopulse Technique for Adaptive Phased Array Radar

    Directory of Open Access Journals (Sweden)

    Xinyu Zhang

    2017-01-01

    Full Text Available The monopulse angle measuring technique is widely adopted in radar systems due to its simplicity and speed in accurately acquiring a target’s angle. However, in a spatial adaptive array, beam distortion, due to adaptive beamforming, can result in serious deterioration of monopulse performance. In this paper, a novel constrained monopulse angle measuring algorithm is proposed for spatial adaptive arrays. This algorithm maintains the ability to suppress the unwanted signals without suffering from beam distortion. Compared with conventional adaptive monopulse methods, the proposed algorithm adopts a new form of constraint in forming the difference beam with the merit that it is more robust in most practical situations. At the same time, it also exhibits the simplicity of one-dimension monopulse, helping to make this algorithm even more appealing to use in adaptive planar arrays. The theoretical mean and variance of the proposed monopulse estimator is derived for theoretical analysis. Mathematical simulations are formulated to demonstrate the effectiveness and advantages of the proposed algorithm. Both theoretical analysis and simulation results show that the proposed algorithm can outperform the conventional adaptive monopulse methods in the presence of severe interference near the mainlobe.

  17. Detection of space debris with VLBI radar technique

    Science.gov (United States)

    Molotov, I.; Konovalenko, A.; Agapov, V.; Sochilina, A.; Lipatov, B.; Molotov, E.; Gorshenkov, Y.

    The possibility of Evpatoria RT-70 planetary radar application for space debris research was tested in two trial experiments for targets at geostationary (GEO) and high-elliptic (HEO) orbits in 2001. The RT-70 has the 200 kW continuous power transmitter at 6-cm wavelength, which was used for radio location of planets. Therefore the bistatic radar system only may be realized for orbital object measurements. The receiving antennas (Bear Lakes RT-64, Svetloe RT-32, Noto RT- 32, Torun RT-32 and Urumqi RT-25) used the standard VLBI equipment for recording of echo-signals, because they have not specialized radar apparatus. Such multi-antennas configuration allows to add the classic radar data with VLBI measurements: radar has the resolution for range and radial velocity, VLBI provides the angle and angular rate. Moreover the VLBI radar may be a tool for 3D- measurements: combination of radar map and VLBI image can result the "radio holography" picture of investigated object. Seven GEO objects were detected in May session and four GEO + two HEO objects - in December session. The uncontrolled axial rotation with 5 - 20 s period was fixed for GEO targets. The first results of processing that carry out at Russia and Canada are presented. It is planned to finally adjust the VLBI radar method and t o start the regular observations under the international program of optical and radar monitoring of the near-Earth space environment that will be partially supported by INTAS-01-0669, RFBR-02-02- 17568 and RFBR-02-02-3108.

  18. Spectrum sharing between a surveillance radar and secondary Wi-Fi networks

    Science.gov (United States)

    Hessar, Farzad; Roy, Sumit

    2016-06-01

    Co-existence between unlicensed networks that share spectrum spatio-temporally with terrestrial (e.g. Air Traffic Control) and shipborne radars in 3-GHz band is attracting significant interest. Similar to every primary-secondary coexistence scenario, interference from unlicensed devices to a primary receiver must be within acceptable bounds. In this work, we formulate the spectrum sharing problem between a pulsed, search radar (primary) and 802.11 WLAN as the secondary. We compute the protection region for such a search radar for a) a single secondary user (initially) as well as b) a random spatial distribution of multiple secondary users. Furthermore, we also analyze the interference to the WiFi devices from the radar's transmissions to estimate the impact on achievable WLAN throughput as a function of distance to the primary radar.

  19. Surveillance of Endoscopes: Comparison of Different Sampling Techniques.

    Science.gov (United States)

    Cattoir, Lien; Vanzieleghem, Thomas; Florin, Lisa; Helleputte, Tania; De Vos, Martine; Verhasselt, Bruno; Boelens, Jerina; Leroux-Roels, Isabel

    2017-09-01

    OBJECTIVE To compare different techniques of endoscope sampling to assess residual bacterial contamination. DESIGN Diagnostic study. SETTING The endoscopy unit of an 1,100-bed university hospital performing ~13,000 endoscopic procedures annually. METHODS In total, 4 sampling techniques, combining flushing fluid with or without a commercial endoscope brush, were compared in an endoscope model. Based on these results, sterile physiological saline flushing with or without PULL THRU brush was selected for evaluation on 40 flexible endoscopes by adenosine triphosphate (ATP) measurement and bacterial culture. Acceptance criteria from the French National guideline (samples, culture yield using saline plus the PULL THRU (mean, 43 CFU; range, 1-400 CFU) was significantly higher than that of saline alone (mean, 17 CFU; range, 0-500 CFU; Psamples obtained using the saline+PULL THRU brush method, ATP values of samples classified as unacceptable were significantly higher than those of samples classified as acceptable (P=.001). CONCLUSION Physiological saline flushing combined with PULL THRU brush to sample endoscopes generated higher ATP values and increased the yield of microbial surveillance culture. Consequently, the acceptance rate of endoscopes based on a defined CFU limit was significantly lower when the saline+PULL THRU method was used instead of saline alone. Infect Control Hosp Epidemiol 2017;38:1062-1069.

  20. Compressive spectrum sensing of radar pulses based on photonic techniques.

    Science.gov (United States)

    Guo, Qiang; Liang, Yunhua; Chen, Minghua; Chen, Hongwei; Xie, Shizhong

    2015-02-23

    We present a photonic-assisted compressive sampling (CS) system which can acquire about 10(6) radar pulses per second spanning from 500 MHz to 5 GHz with a 520-MHz analog-to-digital converter (ADC). A rectangular pulse, a linear frequency modulated (LFM) pulse and a pulse stream is respectively reconstructed faithfully through this system with a sliding window-based recovery algorithm, demonstrating the feasibility of the proposed photonic-assisted CS system in spectral estimation for radar pulses.

  1. Ground Penetrating Radar technique for railway track characterization in Portugal

    Science.gov (United States)

    De Chiara, Francesca; Fontul, Simona; Fortunato, Eduardo; D'Andrea, Antonio

    2013-04-01

    Maintenance actions are significant for transport infrastructures but, today, costs have to be necessary limited. A proper quality control since the construction phase is a key factor for a long life cycle and for a good economy policy. For this reason, suitable techniques have to be chosen and non-destructive tests represent an efficient solution, as they allow to evaluate infrastructure characteristics in a continuous or quasi-continuous way, saving time and costs, enabling to make changes if tests results do not comply with the project requirements. Ground Penetrating Radar (GPR) is a quick and effective technique to evaluate infrastructure condition in a continuous manner, replacing or reducing the use of traditional drilling method. GPR application to railways infrastructures, during construction and monitoring phase, is relatively recent. It is based on the measuring of layers thicknesses and detection of structural changes. It also enables the assessment of materials properties that constitute the infrastructure and the evaluation of the different types of defects such as ballast pockets, fouled ballast, poor drainage, subgrade settlement and transitions problems. These deteriorations are generally the causes of vertical deviations in track geometry and they cannot be detected by the common monitoring procedures, namely the measurements of track geometry. Moreover, the development of new GPR systems with higher antenna frequencies, better data acquisition systems, more user friendly software and new algorithms for calculation of materials properties can lead to a regular use of GPR. Therefore, it represents a reliable technique to assess track geometry problems and consequently to improve maintenance planning. In Portugal, rail inspection is performed with Plasser & Theurer EM120 equipment and recently 400 MHz IDS antennas were installed on it. GPR tests were performed on the Portuguese rail network and, as case study in this paper, a renewed track was

  2. Surveillance

    DEFF Research Database (Denmark)

    Albrechtslund, Anders; Coeckelbergh, Mark; Matzner, Tobias;

    Studying surveillance involves raising questions about the very nature of concepts such as information, technology, identity, space and power. Besides the maybe all too obvious ethical issues often discussed with regard to surveillance, there are several other angles and approaches that we should...... like to encourage. Therefore, our panel will focus on the philosophical, yet non-ethical issues of surveillance in order to stimulate an intense debate with the audience on the ethical implications of our enquiries. We also hope to provide a broader and deeper understanding of surveillance....

  3. Development of the Application techniques for KMA dual-pol. radar network in Korea

    Science.gov (United States)

    Suk, Mi-Kyung; Nam, Kyung-Yeub; Jung, Sung-A.; Ko, Jeong-Seok

    2016-04-01

    Korea is located between the Eurasian continent and Northwestern pacific. So East Asian Monsoon affects the country every season and every year with the rainy season (Chang-ma front), convective stroms, snow storms, and sometimes typhoons. Korea Meteorological Administration (KMA) has been operating many kinds of meteorological observation networks, including 10 operational radars and 1 testbed radar. Weather Radar Center (WRC) of Korea Meteorological Administration (KMA) performs a task of development and application of cross governmental dual-pol. radar harmonization for the effective use of the national resources from 2013 since the tri-agencies (KMA, Ministry of Land, Infrastructure and Transport, Ministry of National Defense) singed the MOU for the co-utilization of cross governmental dual-pol. radar. This task develops the techniques of the high-quality data processing, the support of the forecasting, etc. The techniques of the high-quality data processing are the quality control for the removal of non-meteorological echoes, the classification of the hydrometeors. The techniques for support of the forecasting are the computation and verification of the rainfall estimation of dual-pol. and single-pol. radars, etc. And it is developed the application techniques by using Yong-In Testbed dual-pol. radar, the merged rainfall field of the radars and the satellites, etc. Further works are the computation of the high-resolution 3-dimensional wind field, the quantitative precipitation forecasting, the development of the application and the information service techniques for the hydrology, climate, industry, aviation for the prevention techniques against the severe weather by using multi-wavelengths ( X, C, S-band radars) of the cross governments, etc.

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

    Science.gov (United States)

    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.

  5. Probabilistic radar-gauge merging by multivariate spatiotemporal techniques

    Science.gov (United States)

    Pulkkinen, Seppo; Koistinen, Jarmo; Kuitunen, Timo; Harri, Ari-Matti

    2016-11-01

    The quality of quantitative precipitation estimation (QPE) is degraded by considerable discrepancies between radar and ground measurements, which are common due to inherent uncertainties between these two kinds of sensor systems. The causes include measurement errors and differences in sampling schemes. Nevertheless, the remaining discrepancies can be statistically modeled. A model describing detection probabilities of ground rainfall, systematic biases as well as the variance of residual discrepancies between radar and rain gauges is developed. These are modeled by means of multiple explanatory variables such as rain rate and distance from radar. The model is implemented by using nonparametric kernel methods and spatiotemporal Kriging interpolation. A key feature of the model is that for a given radar-derived rainfall field and explanatory variables, it determines probability distributions for the corresponding ground rainfall. Unbiased estimates for ground rainfall can be obtained from the expected values of the distributions. From such distributions, one can also obtain uncertainty estimates and exceedance probabilities that are important for hydrological applications. Performance of the model is assessed by cross-validation using hourly rainfall accumulations measured by the Finnish rain gauges and C-band dual polarization radars.

  6. Adverse health effects of occupational exposure to radiofrequency radiation in airport surveillance radar operators

    Directory of Open Access Journals (Sweden)

    Naser Dehghan

    2013-01-01

    Full Text Available Introduction: Radar workers are exposed to pulsed high frequency electromagnetic fields. In this study, health effects of these radiations in personnel who routinely work with radar systems are investigated. Materials and Methods: The 28-item General Health Questionnaire was used as a self-administered tool for assessment of general mental health and mental distress. One hundred workers occupationally exposed to radar radiations (14-18 GHz participated in the study. Visual reaction time was recorded with a simple blind computer-assisted-visual reaction time test. To assess the short-term memory, Wechsler Memory Scale-III test was performed. Results: Twenty to 39% of the radar workers reported different problems such as needing a good tonic, feeling run down and out of sorts, headache, tightness or pressure in the head, insomnia, getting edgy and bad-tempered. Furthermore, 47% of the radar workers reported feeling under strain. In response to this question that if they have been able to enjoy their normal day-to-day activities, 31% responded "less than usual". It was also shown that work experience had significant relationships with reaction time and short-term memory indices i.e., forward digit span, reverse digit span, word recognition and paired words. Conclusion: To the best of our knowledge, this is the first study to show that occupational exposure to radar microwave radiation leads to changes in somatic symptoms, anxiety and insomnia, social dysfunction, and severe depression. Altogether these results indicate that occupational exposure to radar microwave radiations may be linked to some adverse health effects.

  7. The use of weather surveillance radar and high-resolution three dimensional weather data to monitor a spruce budworm mass exodus flight

    Science.gov (United States)

    Yan Boulanger; Frédéric Fabry; Alamelu Kilambi; Deepa S. Pureswaran; Brian R. Sturtevant; Rémi. Saint-Amant

    2017-01-01

    The likely spread of the current spruce budworm (SBW; Choristoneura fumiferana [Clem.]) outbreak fromhigh to low density areas brings to the forefront a pressing need to understand its dispersal dynamics and to document mass exodus flights in relation to weather patterns. In this study, we used the weather surveillance radar of Val d'Irène in...

  8. Study on the Variational Assimilation Technique for the Retrieval of Wind Fields from Doppler Radar Data

    Institute of Scientific and Technical Information of China (English)

    WAN Qilin; XUE Jishan; ZHUANG Shiyu

    2006-01-01

    This paper introduces a variational assimilation technique for the retrieval of wind fields from Doppler radar data. The assimilated information included both the radial velocity (RV) and the movement of radar echo. In this assimilation technique, the key is transforming the movement of radar echo to a new radar measuring variable- "apparent velocity" (AV). Thus, the information of wind is added, and the indeterminacy of recovering two-dimensional wind only by AV was overcome effectively by combining RV with AV. By means of CMA GRAPES-3Dvar and CINRAD data, some experiments were performed. The results show that the method of retrieval of wind fields is useful in obtaining the construction of the weather system.

  9. Techniques for Mapping Synthetic Aperture Radar Processing Algorithms to Multi-GPU Clusters

    Science.gov (United States)

    2012-12-01

    are suited for threaded (parallel) execution, by labeling them as kernels using syntax specified by the GPU programming language (e.g., CUDA for an...Techniques for Mapping Synthetic Aperture Radar Processing Algorithms to Multi- GPU Clusters Eric Hayden, Mark Schmalz, William Chapman, Sanjay...Abstract - This paper presents a design for parallel processing of synthetic aperture radar (SAR) data using multiple Graphics Processing Units ( GPUs ). Our

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

    Science.gov (United States)

    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.

  11. Radar-raingauge data combination techniques: a revision and analysis of their suitability for urban hydrology.

    Science.gov (United States)

    Wang, Li-Pen; Ochoa-Rodríguez, Susana; Simões, Nuno Eduardo; Onof, Christian; Maksimović, Cedo

    2013-01-01

    The applicability of the operational radar and raingauge networks for urban hydrology is insufficient. Radar rainfall estimates provide a good description of the spatiotemporal variability of rainfall; however, their accuracy is in general insufficient. It is therefore necessary to adjust radar measurements using raingauge data, which provide accurate point rainfall information. Several gauge-based radar rainfall adjustment techniques have been developed and mainly applied at coarser spatial and temporal scales; however, their suitability for small-scale urban hydrology is seldom explored. In this paper a review of gauge-based adjustment techniques is first provided. After that, two techniques, respectively based upon the ideas of mean bias reduction and error variance minimisation, were selected and tested using as case study an urban catchment (∼8.65 km(2)) in North-East London. The radar rainfall estimates of four historical events (2010-2012) were adjusted using in situ raingauge estimates and the adjusted rainfall fields were applied to the hydraulic model of the study area. The results show that both techniques can effectively reduce mean bias; however, the technique based upon error variance minimisation can in general better reproduce the spatial and temporal variability of rainfall, which proved to have a significant impact on the subsequent hydraulic outputs. This suggests that error variance minimisation based methods may be more appropriate for urban-scale hydrological applications.

  12. Radar sensor technology developments as CSIR DPSS in support of persistent, ubiquitous surveillance systems

    CSIR Research Space (South Africa)

    Anderson, F

    2008-11-01

    Full Text Available of an S&T capability based on international technology trends in persistent, ubiquitous surveillance. The ultimate aim of this programme is to develop and produce a series of South African innovations that can be used by departments and agencies...

  13. [Screening on key techniques used for surveillance and disposal of public health emergencies].

    Science.gov (United States)

    Zhu, Q R; Yang, L; Ma, H Y; Xie, W Q; Cong, L M; Xu, L W

    2017-06-10

    Objective: To explore the key techniques used for surveillance and disposal of infectious diseases, food poisoning and hospital infection to improve the ability of surveillance and disposal on public health emergency. Methods: Framework on surveillance and disposal of infectious diseases, food poisoning and hospital infection was set up, based on literature review and expert group discussion. Delphi method and technique for order preference by similarity to ideal solution comprehensive evaluation method were used for ordering preference by similarity, to screen key techniques set for surveillance and disposal of the above said events. Results: Framework to be used for selecting key techniques was designed, based on the classification of emergency events, processing cycle of emergency events and level of techniques. Twenty six public health experts were selected for a 2-round consultation, with their authority as 0.796. Ten key techniques with important significance for surveillance and disposal of infectious diseases, food poisoning and hospital infection were selected from each event. Among these key techniques, the early-warning system was recognized as the key technique, important for the surveillance and disposal of all three emergency events. Items as technology used for unknown pathogenic microorganism detection, personal protection, gene sequencing and tracing technology, microorganism molecular typing technology, nucleic acid detection technology etc. were the key techniques and need to develop for the surveillance and disposal of infectious diseases and iatrogenic infection. Data regarding key technologies on security and privacy, early warning and forecasting, field rapid detection were sorted out that all in need to improve the surveillance programs on disposal of infectious diseases and food poisoning. Data exchange appeared another key technique on infectious diseases, with toxin detection and other 5 techniques the key techniques for food poisoning

  14. Overview of independent component analysis technique with an application to synthetic aperture radar (SAR) imagery processing.

    Science.gov (United States)

    Fiori, Simone

    2003-01-01

    We present an overview of independent component analysis, an emerging signal processing technique based on neural networks, with the aim to provide an up-to-date survey of the theoretical streams in this discipline and of the current applications in the engineering area. We also focus on a particular application, dealing with a remote sensing technique based on synthetic aperture radar imagery processing: we briefly review the features and main applications of synthetic aperture radar and show how blind signal processing by neural networks may be advantageously employed to enhance the quality of remote sensing data.

  15. Synthetic aperture radar image processing techniques for damage detection of FRP-concrete systems

    Science.gov (United States)

    Yu, Tzuyang

    2017-04-01

    Electromagnetic imaging enables researchers and engineers to assess the surface and subsurface condition of concrete structures using radar and microwave sensors. Among existing radar imaging methods, synthetic aperture radar (SAR) imaging offers flexible resolution for various purposes in condition assessment. In this paper, two novel SAR image processing techniques are reported for the subsurface condition assessment of FRP(fiber reinforced polymer)-strengthened concrete systems; mathematical morphology (MM) and the K-R-I transform. Glass FRP (GFRP) and carbon CFRP (CFRP) strengthened concrete cylinders are used as examples. From our experimental results, it is found that both techniques are capable of quantifying SAR images for condition assessment. It is also found that Euler's number and the coefficient of correlation of K-R-I curves of SAR images can be used for monitoring subsurface changes in FRP-concrete systems.

  16. On Structural Reliability Appraisal for Some Secondary Surveillance Radar Station%某空管二次监视雷达站结构可靠性鉴定

    Institute of Scientific and Technical Information of China (English)

    张腾明; 翁祖明; 刘美强; 吴钦

    2014-01-01

    Through project case, this paper introduces structural reliability appraisal for some secondary surveillance radar station, proposing its key points so as to be reference for high-rise structure.%通过工程实例,介绍空管二次监视雷达站结构可靠性鉴定方法,提出高耸结构检测鉴定工作的重点,以供参考。

  17. A frequency domain radar interferometric imaging (FII) technique based on high-resolution methods

    Science.gov (United States)

    Luce, H.; Yamamoto, M.; Fukao, S.; Helal, D.; Crochet, M.

    2001-01-01

    In the present work, we propose a frequency-domain interferometric imaging (FII) technique for a better knowledge of the vertical distribution of the atmospheric scatterers detected by MST radars. This is an extension of the dual frequency-domain interferometry (FDI) technique to multiple frequencies. Its objective is to reduce the ambiguity (resulting from the use of only two adjacent frequencies), inherent with the FDI technique. Different methods, commonly used in antenna array processing, are first described within the context of application to the FII technique. These methods are the Fourier-based imaging, the Capon's and the singular value decomposition method used with the MUSIC algorithm. Some preliminary simulations and tests performed on data collected with the middle and upper atmosphere (MU) radar (Shigaraki, Japan) are also presented. This work is a first step in the developments of the FII technique which seems to be very promising.

  18. Introduction to surveillance studies

    CERN Document Server

    Petersen, JK

    2012-01-01

    Introduction & OverviewIntroduction Brief History of Surveillance Technologies & TechniquesOptical SurveillanceAerial Surveillance Audio Surveillance Radio-Wave SurveillanceGlobal Positioning Systems Sensors Computers & the Internet Data Cards Biochemical Surveillance Animal Surveillance Biometrics Genetics Practical ConsiderationsPrevalence of Surveillance Effectiveness of Surveillance Freedom & Privacy IssuesConstitutional Freedoms Privacy Safeguards & Intrusions ResourcesReferences Glossary Index

  19. The Coplane Analysis Technique for Three-Dimensional Wind Retrieval Using the HIWRAP Airborne Doppler Radar

    Science.gov (United States)

    Didlake, Anthony C., Jr.; Heymsfield, Gerald M.; Tian, Lin; Guimond, Stephen R.

    2015-01-01

    The coplane analysis technique for mapping the three-dimensional wind field of precipitating systems is applied to the NASA High Altitude Wind and Rain Airborne Profiler (HIWRAP). HIWRAP is a dual-frequency Doppler radar system with two downward pointing and conically scanning beams. The coplane technique interpolates radar measurements to a natural coordinate frame, directly solves for two wind components, and integrates the mass continuity equation to retrieve the unobserved third wind component. This technique is tested using a model simulation of a hurricane and compared to a global optimization retrieval. The coplane method produced lower errors for the cross-track and vertical wind components, while the global optimization method produced lower errors for the along-track wind component. Cross-track and vertical wind errors were dependent upon the accuracy of the estimated boundary condition winds near the surface and at nadir, which were derived by making certain assumptions about the vertical velocity field. The coplane technique was then applied successfully to HIWRAP observations of Hurricane Ingrid (2013). Unlike the global optimization method, the coplane analysis allows for a transparent connection between the radar observations and specific analysis results. With this ability, small-scale features can be analyzed more adequately and erroneous radar measurements can be identified more easily.

  20. Information extraction and transmission techniques for spaceborne synthetic aperture radar images

    Science.gov (United States)

    Frost, V. S.; Yurovsky, L.; Watson, E.; Townsend, K.; Gardner, S.; Boberg, D.; Watson, J.; Minden, G. J.; Shanmugan, K. S.

    1984-01-01

    Information extraction and transmission techniques for synthetic aperture radar (SAR) imagery were investigated. Four interrelated problems were addressed. An optimal tonal SAR image classification algorithm was developed and evaluated. A data compression technique was developed for SAR imagery which is simple and provides a 5:1 compression with acceptable image quality. An optimal textural edge detector was developed. Several SAR image enhancement algorithms have been proposed. The effectiveness of each algorithm was compared quantitatively.

  1. Range Surveillance Using Radio Interferometry and TDOA Techniques Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation will utilize a small network of remote sensors to perform Radio Interferometry (RI) and Time Difference of Arrival (TDOA) techniques to...

  2. Maritime surveillance with synthetic aperture radar (SAR) and automatic identification system (AIS) onboard a microsatellite constellation

    Science.gov (United States)

    Peterson, E. H.; Zee, R. E.; Fotopoulos, G.

    2012-11-01

    New developments in small spacecraft capabilities will soon enable formation-flying constellations of small satellites, performing cooperative distributed remote sensing at a fraction of the cost of traditional large spacecraft missions. As part of ongoing research into applications of formation-flight technology, recent work has developed a mission concept based on combining synthetic aperture radar (SAR) with automatic identification system (AIS) data. Two or more microsatellites would trail a large SAR transmitter in orbit, each carrying a SAR receiver antenna and one carrying an AIS antenna. Spaceborne AIS can receive and decode AIS data from a large area, but accurate decoding is limited in high traffic areas, and the technology relies on voluntary vessel compliance. Furthermore, vessel detection amidst speckle in SAR imagery can be challenging. In this constellation, AIS broadcasts of position and velocity are received and decoded, and used in combination with SAR observations to form a more complete picture of maritime traffic and identify potentially non-cooperative vessels. Due to the limited transmit power and ground station downlink time of the microsatellite platform, data will be processed onboard the spacecraft. Herein we present the onboard data processing portion of the mission concept, including methods for automated SAR image registration, vessel detection, and fusion with AIS data. Georeferencing in combination with a spatial frequency domain method is used for image registration. Wavelet-based speckle reduction facilitates vessel detection using a standard CFAR algorithm, while leaving sufficient detail for registration of the filtered and compressed imagery. Moving targets appear displaced from their actual position in SAR imagery, depending on their velocity and the image acquisition geometry; multiple SAR images acquired from different locations are used to determine the actual positions of these targets. Finally, a probabilistic inference

  3. NOISE REMOVAL TECHNIQUES FOR MICROWAVE REMOTE SENSING RADAR DATA AND ITS EVALUATION

    Directory of Open Access Journals (Sweden)

    Arundhati Misra

    2013-02-01

    Full Text Available Microwave Remote Sensing data acquired by a RADAR sensor such as SAR(Synthetic Aperture Radar is affected by a peculiar kind of noise called speckle. This noise not only renders the data ineffective for classification, texture analysis, segmentation etc. which are used for image analysis purposes, but also degrades the overall contrast and radiometric quality of the image. Here we discuss the various noise removal techniques which have been widely used by scientists all over the world. Different filtering methods have their pros and cons, and no single method can give the most satisfactory result. In order to circumvent those issues, better and better methods are being attempted. One of the recent methods is that based on Wavelet technique. This paper discusses the denoising techniques based on Wavelets and the results from some of those methods. The relative merits and demerits of the filters and their evaluation is also done.

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

    Science.gov (United States)

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

    2016-04-01

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

  5. Model-based sub-Nyquist sampling and reconstruction technique for ultra-wideband (UWB) radar

    Science.gov (United States)

    Nguyen, Lam; Tran, Trac D.

    2010-04-01

    The Army Research Lab has recently developed an ultra-wideband (UWB) synthetic aperture radar (SAR). The radar has been employed to support proof-of-concept demonstration for several concealed target detection programs. The radar transmits and receives short impulses to achieve a wide-bandwidth from 300 MHz to 3000 MHz. Since the radar directly digitizes the wide-bandwidth receive signals, the challenges is to how to employ relatively slow and inexpensive analog-to-digital (A/D) converters to sample the signals with a rate that is greater than the minimum Nyquist rate. ARL has developed a sampling technique that allows us to employ inexpensive A/D converters (ADC) to digitize the widebandwidth signals. However, this technique still has a major drawback due to the longer time required to complete a data acquisition cycle. This in turn translates to lower average power and lower effective pulse repetition frequency (PRF). Compressed Sensing (CS) theory offers a new approach in data acquisition. From the CS framework, we can reconstruct certain signals or images from much fewer samples than the traditional sampling methods, provided that the signals are sparse in certain domains. However, while the CS framework offers the data compression feature, it still does not address the above mentioned drawback, that is the data acquisition must be operated in equivalent time since many global measurements (obtained from global random projections) are required as depicted by the sensing matrix Φ in the CS framework. In this paper, we propose a new technique that allows the sub-Nyquist sampling and the reconstruction of the wide-bandwidth data. In this technique, each wide-bandwidth radar data record is modeled as a superposition of many backscatter signals from reflective point targets. The technique is based on direct sparse recovery using a special dictionary containing many time-delayed versions of the transmitted probing signal. We demonstrate via simulated as well as

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

    Science.gov (United States)

    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).

  7. Monitoring of PON System Using Compound Surveillance Technique

    Institute of Scientific and Technical Information of China (English)

    Sun-Chien Ko; Hsiu-Jung Chuang; Si-Chong Chen; Chih-Yih Wang; Sheng-Fwu Lin

    2015-01-01

    A passive optical network (PON) monitoring system combined light pulse and frequency sweep techniques is proposed and verified in a field test. The light pulse surveys over the all whole network and the frequency sweep are used to investigate any fault in the link. The field test is performed with 4 PONs. Each PON is monitored at 4 ports, one is the splitter port and the other three are arbitrary chosen multiple optical units(ONUs). All the tested PONs are monitored in turns once per hour. Faults at the feeder and branch fiber have been observed in this field test and have been analyzed with the monitoring system.

  8. HF Radar Signal Processing Based on Tomographic Imaging and CS Technique

    Directory of Open Access Journals (Sweden)

    Qiang Yang

    2014-01-01

    Full Text Available This study presents the application of a spotlight-mode synthetic aperture radar (SAR imaging technique to the problem of high probablity target detection in high frequency (HF radar system, attempting to improve its spatial resolution. The effects of finite aperture on resolution, sampling constraints and reconstruction over a complete angular range of 360 degrees are discussed. A Convolution Back Projection (CBP algorithm has been applied to image reconstruction. In order to solve the range limitation of aspect angle with one radar-carrying platform, we collect data over a larger azimuthal range by making multi-aspect observations. Each straight line is a sub aperture over which we can perform the CBP algorithm. When we demand higher resolution for stationary target, it will cause blur with longer data acquisition time. Thus the application of the traditional imaging algorithm is limited. Compressed Sensing (CS has recently attracted much interest as it can reduce the number of samples without compromising the imaging quality. Within this motivation, we discuss the applicability of CS and present the application constraint for HF radar system.

  9. Optical techniques for signal distribution and control in advanced radar and communication systems

    Science.gov (United States)

    Forrest, J. R.

    1985-03-01

    It is concluded that optical techniques offer some advantages for signal distribution and control in advanced radar and communication systems. They are clearly ideal for transporting microwave signals over considerable distances, as in remote positioning of radar receivers, provided high dynamic range is not required and an enclosed transmission path is essential. They are an elegant means of distributing low level r.f. or i.f. signals around an active phased array where these signals are of relatively constant amplitude (as in mixer local oscillator applications). However, there is currently a rather restrictive limit on the size of distribution network possible. Optical techniques are obviously suitable for distributing digital control signals to phased array modules and confer considerable immunity to interference. They are less suitable for high dynamic range signals, such as the received radar returns, either at r.f. or when downcovered to i.f. Future developments in coherent optics or in fast optical A/D technology could, however, influence this conclusion. Currently, the optimum applications for optical techniques appear to be i.f. beamformers for multibeam communication satellite systems and in calibration/monitoring systems for phased arrays.

  10. Forward Scatter Radar for Air Surveillance: Characterizing the Target-Receiver Transition from Far-Field to Near-Field Regions

    Directory of Open Access Journals (Sweden)

    Marta Tecla Falconi

    2017-01-01

    Full Text Available A generalized electromagnetic model is presented in order to predict the response of forward scatter radar (FSR systems for air-target surveillance applications in both far-field and near-field conditions. The relevant scattering problem is tackled by developing the Helmholtz–Kirchhoff formula and Babinet’s principle to express the scattered and the total fields in typical FSR configurations. To fix the distinctive features of this class of problems, our approach is applied here to metallic targets with canonical rectangular shapes illuminated by a plane wave, but the model can straightforwardly be used to account for more general scenarios. By exploiting suitable approximations, a simple analytical formulation is derived allowing us to efficiently describe the characteristics of the FSR response for a target transitioning with respect to the receiver from far-field to near-field regions. The effects of different target electrical sizes and detection distances on the received signal, as well as the impact of the trajectory of the moving object, are evaluated and discussed. All of the results are shown in terms of quantities normalized to the wavelength and can be generalized to different configurations once the carrier frequency of the FSR system is set. The range of validity of the proposed closed-form approach has been checked by means of numerical analyses, involving comparisons also with a customized implementation of a full-wave commercial CAD tool. The outcomes of this study can pave the way for significant extensions on the applicability of the FSR technique.

  11. Comparative of signal processing techniques for micro-Doppler signature extraction with automotive radar systems

    Science.gov (United States)

    Rodriguez-Hervas, Berta; Maile, Michael; Flores, Benjamin C.

    2014-05-01

    In recent years, the automotive industry has experienced an evolution toward more powerful driver assistance systems that provide enhanced vehicle safety. These systems typically operate in the optical and microwave regions of the electromagnetic spectrum and have demonstrated high efficiency in collision and risk avoidance. Microwave radar systems are particularly relevant due to their operational robustness under adverse weather or illumination conditions. Our objective is to study different signal processing techniques suitable for extraction of accurate micro-Doppler signatures of slow moving objects in dense urban environments. Selection of the appropriate signal processing technique is crucial for the extraction of accurate micro-Doppler signatures that will lead to better results in a radar classifier system. For this purpose, we perform simulations of typical radar detection responses in common driving situations and conduct the analysis with several signal processing algorithms, including short time Fourier Transform, continuous wavelet or Kernel based analysis methods. We take into account factors such as the relative movement between the host vehicle and the target, and the non-stationary nature of the target's movement. A comparison of results reveals that short time Fourier Transform would be the best approach for detection and tracking purposes, while the continuous wavelet would be the best suited for classification purposes.

  12. Signal processing techniques for forward imaging using ultrawideband synthetic aperture radar

    Science.gov (United States)

    Nguyen, Lam H.; Ton, Tuan T.; Wong, David C.; Ressler, Marc A.

    2003-09-01

    The U.S. Army Research Laboratory (ARL), as part of a customer and mission-funded exploratory development program, has been developing a prototype of low-frequency, ultra-wideband (UWB) forward-imaging synthetic aperture radar (SAR) to support the U.S. Army's vision for increased mobility and survivability of unmanned ground vehicle missions. The ability of the UWB radar technology to detect objects under foilage could provide an important obstacle-avoidance capability for robotic vehicles, which could improve the speed and maneuverability of these vehicles and consequently increase the survivability of the U.S. forces. In a recent experiment at Aberdeen Proving Ground (APG), we exercised the UWB SAR radar in forward-looking mode and collected data to support the investigation. This paper discusses the signal processing algorithms and techniques that we developed and applied to the recent UWB SAR forward-looking data. The algorithms include motion data processing, self-interference signal (SIR) removal, radio frequency interference (RFI) signal removal, forward-looking image formation, and visualization techniques. We present forward-loking SAR imagery and also volumetric imagery of some targets.

  13. Adaptive coherence estimator based on the Krylov subspace technique for airborne radar

    Institute of Scientific and Technical Information of China (English)

    Weijian Liu; Wenchong Xie; Haibo Tong; Honglin Wang; Cui Zhou; Yongliang Wang

    2015-01-01

    A novel adaptive detector for airborne radar space-time adaptive detection (STAD) in partial y homogeneous environments is proposed. The novel detector combines the numerical y stable Krylov subspace technique and diagonal loading technique, and it uses the framework of the adaptive coherence estimator (ACE). It can effectively detect a target with low sample support. Compared with its natural competitors, the novel detector has higher proba-bility of detection (PD), especial y when the number of the training data is low. Moreover, it is shown to be practical y constant false alarm rate (CFAR).

  14. DNA barcoding techniques for avian influenza virus surveillance in migratory bird habitats.

    Science.gov (United States)

    Lee, Dong-Hun; Lee, Hyun-Jeong; Lee, Youn-Jeong; Kang, Hyun-Mi; Jeong, Ok-Mi; Kim, Min-Chul; Kwon, Ji-Sun; Kwon, Jun-Hun; Kim, Chang-Bae; Lee, Joong-Bok; Park, Seung-Yong; Choi, In-Soo; Song, Chang-Seon

    2010-04-01

    Avian influenza virus (AIV) circulates among free-ranging, wild birds. We optimized and validated a DNA barcoding technique for AIV isolation and host-species identification using fecal samples from wild birds. DNA barcoding was optimized using tissue and fecal samples from known bird species, and the method was shown to distinguish 26 bird species. Subsequently, fecal samples (n=743) collected from wild waterfowl habitats confirmed the findings from the laboratory tests. All identified AIV-positive hosts (n=35) were members of the order Anseriformes. We successfully applied the DNA barcoding technique to AIV surveillance and examined AIV epidemiology and host ecology in these wild waterfowl populations. This methodology may be useful in the design of AIV surveillance strategies.

  15. Emerging Endoscopic and Photodynamic Techniques for Bladder Cancer Detection and Surveillance

    Directory of Open Access Journals (Sweden)

    Prashant Patel

    2011-01-01

    Full Text Available This review provides an overview of emerging techniques, namely, photodynamic diagnosis (PDD, narrow band imaging (NBI, Raman spectroscopy, optical coherence tomography, virtual cystoscopy, and endoscopic microscopy for its use in the diagnosis and surveillance of bladder cancer. The technology, clinical evidence and future applications of these approaches are discussed with particular emphasis on PDD and NBI. These approaches show promise to optimise cystoscopy and transurethral resection of bladder tumours.

  16. An Improved Clutter Suppression Method for Weather Radars Using Multiple Pulse Repetition Time Technique

    Directory of Open Access Journals (Sweden)

    Yingjie Yu

    2017-01-01

    Full Text Available This paper describes the implementation of an improved clutter suppression method for the multiple pulse repetition time (PRT technique based on simulated radar data. The suppression method is constructed using maximum likelihood methodology in time domain and is called parametric time domain method (PTDM. The procedure relies on the assumption that precipitation and clutter signal spectra follow a Gaussian functional form. The multiple interleaved pulse repetition frequencies (PRFs that are used in this work are set to four PRFs (952, 833, 667, and 513 Hz. Based on radar simulation, it is shown that the new method can provide accurate retrieval of Doppler velocity even in the case of strong clutter contamination. The obtained velocity is nearly unbiased for all the range of Nyquist velocity interval. Also, the performance of the method is illustrated on simulated radar data for plan position indicator (PPI scan. Compared with staggered 2-PRT transmission schemes with PTDM, the proposed method presents better estimation accuracy under certain clutter situations.

  17. Modern radar techniques and the hazard of meteoroids to space platforms

    Directory of Open Access Journals (Sweden)

    G. Cevolani

    1998-06-01

    Full Text Available Modern radar techniques, and in particular ground based radars, are a powerful tool to observe space objects (natural meteoroids and artificial space debris on account of their all-weather and day-and-night performance. Natural meteoroids are an important component of the near-Earth space environment and represent a potential risk for all Earth-orbiting space platforms, which could significantly increase in coincidence of enhanced (outburst or storm activity of meteoroid streams. A review of the currently active meteoroid streams suggests that a few streams have shown a quasi-periodic outburst activity in the two last centuries and may even undergo a storm activity in the next few years. The Leonids, the most intense of meteor showers, present a potentially serious damage to spacecraft in November of 1998 and 1999, after the perihelion passage of the parent body. Impact probability values of storm meteoroids on space platforms in Low Earth Orbit (LEO were calculated using the data recorded during systematic observational campaigns carried out by the FS radar facility Bologna-Lecce in Italy. Meteoroid flux predictions and directionality, and investigation on impact parameters at very high velocities (up to 71 km/s for penetration, charge production and plasma generation, are relevant aspects to develop strategies for safe deployment of the near Earrth-orbiting space platforms.

  18. Signal processing techniques for phase-coded HF-VHF radars

    Directory of Open Access Journals (Sweden)

    J. A. Baskaradas

    2003-06-01

    Full Text Available HF-VHF radar techniques are easy to employ and commonly used in geophysical applications. They include deep radio soundings, used for probing the ionosphere, stratosphere-mesosphere measurement, weather forecast and radio-glaciology. Fast algorithms and powerful processors facilitate the development of several kinds of low power radars, but the reduction of the transmitted power has to be compensated by on-line processing of an encoded signal to maintain a favorable signal-to-noise ratio suitable for detection. Moreover, radars have to reconstruct return echoes with different travel times due to various origins (multi-path, adjacent objects, etc.. Such needs can be accomplished by means of signal phase coding and one of the most attractive is the reversal phase code. The composite echo signal must be processed to extract the physical information useful for the measurement considered. In this paper some algorithms used for on-line processing of phase-coded signals will be described, both in time and frequency domain.

  19. Applications of Radar Interferometric Techniques to Assess Natural Hazards and their Controlling Factors

    Science.gov (United States)

    Sultan, M.; Becker, R.; Gebremichael, E.; Othman, A.; Emil, M.; Ahmed, M.; Elkadiri, R.; Pankratz, H. G.; Chouinard, K.

    2015-12-01

    Radar interferometric techniques including Persistent Scatterer (PS), Small BAseline Subset (SBAS), and two and three pass (differential interferometry) methods were applied to Synthetic Aperture Radar (SAR) datasets. These include the European Space Agency (ESA) ERS-1, ERS-2, Environmental satellite (Envisat), and Phased Array type L-band Synthetic Aperture Radar (PALSAR) to conduct the following: (1) map the spatial distribution of land deformation associated with a wide range of geologic settings, (2) quantify the rates of the observed land deformation, and (3) identify the factors controlling the observed deformation. The research topics/areas include: (1) subsidence associated with sediment compaction in a Delta setting (Nile Delta, Egypt), (2) deformation in a rifting setting (Red Sea rifting along the Red Sea coastal zone and proximal basement outcrops in Egypt and Saudi Arabia), (3) deformation associated with salt dome intrusion and the dissolution of sabkha deposits (Jazan area in Saudi Arabia), (4) mass transport associated with debris flows (Jazan area in Saudi Arabia), and (5) deformation preceding, contemporaneous with, or following large earthquakes (in Nepal; magnitude: 7.8; date: April, 25, 2015) and medium earthquakes (in Harrat Lunayyir volcanic field, central Saudi Arabia; magnitude: 5.7; date: May 19, 2009). The identification of the factor(s) controlling the observed deformation was attained through spatial correlation of extracted radar velocities with relevant temporal and static ground based and remotely sensed geological and cultural data sets (e.g., lithology, structure, precipitation, land use, and earthquake location, magnitude, and focal mechanism) in a Geographical Information System (GIS) environment.

  20. Noise Reduction Analysis of Radar Rainfall Using Chaotic Dynamics and Filtering Techniques

    Directory of Open Access Journals (Sweden)

    Soojun Kim

    2014-01-01

    Full Text Available The aim of this study is to evaluate the filtering techniques which can remove the noise involved in the time series. For this, Logistic series which is chaotic series and radar rainfall series are used for the evaluation of low-pass filter (LF and Kalman filter (KF. The noise is added to Logistic series by considering noise level and the noise added series is filtered by LF and KF for the noise reduction. The analysis for the evaluation of LF and KF techniques is performed by the correlation coefficient, standard error, the attractor, and the BDS statistic from chaos theory. The analysis result for Logistic series clearly showed that KF is better tool than LF for removing the noise. Also, we used the radar rainfall series for evaluating the noise reduction capabilities of LF and KF. In this case, it was difficult to distinguish which filtering technique is better way for noise reduction when the typical statistics such as correlation coefficient and standard error were used. However, when the attractor and the BDS statistic were used for evaluating LF and KF, we could clearly identify that KF is better than LF.

  1. A comparative analysis of two wind velocity retrieval techniques by using a single Doppler radar

    Directory of Open Access Journals (Sweden)

    H.-C. Lim

    2009-05-01

    Full Text Available This study compares the theoretical basis of the two wind velocity retrieval methods, Velocity Azimuth Display (VAD and Velocity Area Display (VARD by using data obtained by a single Doppler radar. Two pre-assumed shapes of the wind velocity distribution with altitude are considered, uniform and parabolic. The former presents an approximation of the non-sheared or low-sheared wind flow in the upper troposphere, while the latter is a simplified representation of the Atmospheric Boundary Layer (ABL in lower troposphere or high-sheared wind flow at the edges of the tropospheric jet streams. Both techniques for the wind velocity retrieval considered in this study are reformulated in order to get more precise information on the wind velocity components. An algorithm is proposed to decrease the uncertainty in retrieving by evaluating the coefficients of the polynomial equation and applying a transfer function with respect to the angle formed between the wind flow direction and direction of radar beam. It is concluded that, provided the formulated transformation functions are used, the application of the VAD and VARD techniques to the single-Doppler data may be an invaluable tool for solving various climate and wind engineering problems.

  2. Multiple Target Localization with Bistatic Radar Using Heuristic Computational Intelligence Techniques

    Directory of Open Access Journals (Sweden)

    Fawad Zaman

    2015-01-01

    Full Text Available We assume Bistatic Phase Multiple Input Multiple Output radar having passive Centrosymmetric Cross Shape Sensor Array (CSCA on its receiver. Let the transmitter of this Bistatic radar send coherent signals using a subarray that gives a fairly wide beam with a large solid angle so as to cover up any potential relevant target in the near field. We developed Heuristic Computational Intelligence (HCI based techniques to jointly estimate the range, amplitude, and elevation and azimuth angles of these multiple targets impinging on the CSCA. In this connection, first the global search optimizers, that is,are developed separately Particle Swarm Optimization (PSO and Differential Evolution (DE are developed separately, and, to enhance the performances further, both of them are hybridized with a local search optimizer called Active Set Algorithm (ASA. Initially, the performance of PSO, DE, PSO hybridized with ASA, and DE hybridized with ASA are compared with each other and then with some traditional techniques available in literature using root mean square error (RMSE as figure of merit.

  3. Dynamical and Microphysical Retrieval from Simulated Doppler Radar Observations Using the 4DVAR Assimilation Technique

    Institute of Scientific and Technical Information of China (English)

    XU Xiaoyong; LIU Liping; ZHENG Guoguang

    2005-01-01

    Based on a cloud model and the four-dimensional variational (4DVAR) data assimilation method developed by Sun and Crook (1997), simulated experiments of dynamical and microphysical retrieval from Doppler radar data were performed. The 4DVAR data assimilation technique was applied to a cloud scale model with a warm rain parameterization scheme. The 3D wind, thermodynamical, and microphysical fields were determined by minimizing a cost function, defined by the difference between both radar observed radial velocities and reflectivities and their model predictions. The adjoint of the numerical model was used to provide the gradient of the cost function with respect to the control variables. Experiments have demonstrated that the 4DVAR assimilation method is able to retrieve the detailed structure of wind, thermodynamics, and microphysics by using either dual-Doppler or single-Doppler information. The quality of retrieval depends strongly on the magnitude of constraint with respect to the variables. Retrieving the temperature field,cloud water and water vapor is more difficult than the recovery of the wind field and rainwater. Accurate thermodynamic retrieval requires a longer assimilation period. The inclusion of a background term, even mean fields from a single sounding, helped reduce the retrieval errors. Less accurate velocity fields were obtained when single-Doppler data were used. It was found that the retrieved velocity is sensitive to the location of the retrieval domain relative to the radars while the other fields have very little changes. Two radar volumetric scans are generally adequate for providing the evolution, although the use of additional volumes improves the retrieval. As the amount of the observations decreases, the performance of the retrieval is degraded. However, the missing observations can be compensated by adding a background term to the cost function. The technique is robust to random errors in radial velocity and calibration errors in

  4. A Proxy Calibration Monitoring Technique for the NCAR Airborne W-band Radar

    Science.gov (United States)

    Rilling, Robert; Romatschke, Ulrike; Vivekanandan, Jothiram; Ellis, Scott M.

    2017-04-01

    The National Center for Atmospheric Research (NCAR) has recently tested and deployed its new 94 GHz HIAPER Cloud Radar (HCR). HCR is a scanning W-band system, mounted in an under-wing pod on the National Science Foundation/NCAR High-Performance Instrumented Airborne Platform for Environmental Research (HIAPER, a Gulfstream-V). In order to ensure operational accuracy of this radar, the technique of Li, et al. (2005) has been reformulated to provide a simple means of estimating reflectivity bias using routine measurements of the ocean surface scattering. The methodology and formulation for reflectivity bias determination will be described, along with bias determination results from the 2015 Cloud Systems Evolution in the Trades (CSET) experiment. The HCR radar system is subjected to extreme changes in its operational environment that can cause changes in component response that affect radar calibration. While engineering efforts have focused on temperature and pressure stabilization of the wing pod, along with internal vessel and component temperature monitoring, it is recognized that some form of independent and ongoing verification of calibration stability is desired. When available, ocean surface scanning, with an assumed knowledge of ocean surface backscatter cross-section, can provide a useful proxy for this calibration. Therefore, during the CSET experiment, special care was taken to collect ocean scanning data during short episodes of stable flight with no clouds present; scans were coordinated with atmospheric profiling through release of dropsondes, and atmospheric attenuation calculated with the use of those data. Downward looking lidar data are also used to verify cloud and haze conditions during sampling. For HCR in CSET, eighteen usable ocean-scanning cases were found. Several of these were discarded due to cloud/haze issues that prevented accurate determination of atmospheric attenuation. Initial results show that a large (but fairly constant) bias

  5. Radar Cross Section (RCS) reduction techniques for square trihedral corner reflectors at 35 GHz: Measurements and theoretical simulations

    Science.gov (United States)

    Janssen, G. J. M.; Hulst, R. V. D.; Nennie, E.

    1988-03-01

    Radar cross section (RCS) measurements were performed at a square trihedral corner reflector to investigate RCS reduction techniques which use camouflage materials and changes in the construction. The results are compared with an RCS modeling technique. The measurement results show that a significant RCS reduction can be achieved.

  6. A New Range Sidelobe Suppression Technique for Randomly Intermittent Spectra HF Radar Signal

    Institute of Scientific and Technical Information of China (English)

    ZHANG Dong-po; LIU Xing-zhao

    2005-01-01

    The randomly intermittent spectra (RIS) signal is employed to combat spectrum congestion in radar and other radio services to evade the external interferences in high-frequency (HF) and ultrahigh-frequency (UHF)bands. However, the spectra discontinuity of the signal gets rise to high range sidelobes when matching the refleeted echo, which is much more difficult for targets detection. So it is indispensable to investigate the technique for sidelobes suppression of the range profile when RIS signal is utilized, This paper introduced a new processing technique based on time domain filtering to lower the range sidelobes. A robust and effetive algorithm is adopted to solve the coefficients of the filter, and the restriction on the desired response of the filter is derived. The simulation results show that the peak range sidelobe can be reduced to -27 dB from -9.5 dB while the frequency band span (FBS) is 200 kHz.

  7. Comparative analysis of clutter suppression techniques for landmine detection using ground-penetrating radar

    Science.gov (United States)

    Yoldemir, Ahmet Burak; Gürcan, Rıdvan; Kaplan, Gülay Büyükaksoy; Sezgin, Mehmet

    2011-06-01

    In this study, we provide an extensive comparison of different clutter suppression techniques that are proposed to enhance ground penetrating radar (GPR) data. Unlike previous studies, we directly measure and present the effect of these preprocessing algorithms on the detection performance. Basic linear prediction algorithm is selected as the detection scheme and it is applied to real GPR data after applying each of the available clutter suppression techniques. All methods are tested on an extensive data set of different surrogate mines and other objects that are commonly encountered under the ground. Among several algorithms, singular value decomposition based clutter suppression stands out with its superior performance and low computational cost, which makes it practical to use in real-time applications.

  8. Techniques radar appliquées au génie civil

    OpenAIRE

    2003-01-01

    Ce rapport est consacré aux techniques radar appliquées en génie civil. Il présente un état de l'art sur une dizaine d'années, caractérisant les performances et limites de ces techniques pour les différentes applications rencontrées dans des domaines aussi variés que sont les ouvrages d'art, les chaussées ou la géotechnique. Après une présentation du principe de la propagation des ondes électromagnétiques dans des matériaux grossiers et des matériels existants, la première partie s'intéresse...

  9. Wind and turbulence measurements by the Middle and Upper Atmosphere Radar (MUR: comparison of techniques

    Directory of Open Access Journals (Sweden)

    A. A. Praskovsky

    2004-11-01

    Full Text Available The structure-function-based method (referred to as UCAR-STARS, a technique for estimating mean horizontal winds, variances of three turbulent velocity components and horizontal momentum flux was applied to the Middle and Upper atmosphere Radar (MUR operating in spaced antenna (SA profiling mode. The method is discussed and compared with the Holloway and Doviak (HAD correlation-function-based technique. Mean horizontal winds are estimated with the STARS and HAD techniques; the Doppler Beam Swinging (DBS method is used as a reference for evaluating the SA techniques. Reasonable agreement between SA and DBS techniques is found at heights from 5km to approximately 11km, where signal-to-noise ratio was rather high. The STARS and HAD produced variances of vertical turbulent velocity are found to be in fair agreement. They are affected by beam-broadening in a different way than the DBS-produced spectral width, and to a much lesser degree. Variances of horizontal turbulent velocity components and horizontal momentum flux are estimated with the STARS method, and strong anisotropy of turbulence is found. These characteristics cannot be estimated with correlation-function-based SA methods, which could make UCAR-STARS a useful alternative to traditional SA techniques.

  10. Stereo-synthetic aperture radar technique without using control points to estimate terrain height

    Science.gov (United States)

    Chou, Hsi-Tseng; Lu, Kung-Yu; Liu, Chung-Chih

    2015-01-01

    A stereo-synthetic aperture radar (stereo-SAR)-based technique is proposed to estimate the unknown terrain profile of a target area. This technique first mathematically builds up a virtual reference profile. An algorithm is afterward developed to estimate the relative height difference between the desired and reference profiles by using the trigonometric relationship between their relative SAR range distances, which allows for building up the height of the desired profile from the reference profile. This technique is advantageous and is simple in implementation because the virtual reference profile is constructed by using the same SAR range information as that used for the terrain profile under estimation, which is established by considering the measurement difference between two SAR receivers. It does not require the use of an existing known profile as the reference. Furthermore, we present a technique for calibrating the measured SAR range information, which significantly improves the estimation accuracy. Three practical examples are presented to demonstrate the feasibility of the developed technique.

  11. General adaptive-neighborhood technique for improving synthetic aperture radar interferometric coherence estimation.

    Science.gov (United States)

    Vasile, Gabriel; Trouvé, Emmanuel; Ciuc, Mihai; Buzuloiu, Vasile

    2004-08-01

    A new method for filtering the coherence map issued from synthetic aperture radar (SAR) interferometric data is presented. For each pixel of the interferogram, an adaptive neighborhood is determined by a region-growing technique driven by the information provided by the amplitude images. Then pixels in the derived adaptive neighborhood are complex averaged to yield the filtered value of the coherence, after a phase-compensation step is performed. An extension of the algorithm is proposed for polarimetric interferometric SAR images. The proposed method has been applied to both European Remote Sensing (ERS) satellite SAR images and airborne high-resolution polarimetric interferometric SAR images. Both subjective and objective performance analysis, including coherence edge detection, shows that the proposed method provides better results than the standard phase-compensated fixed multilook filter and the Lee adaptive coherence filter.

  12. Feasibility study of synthetic aperture infrared laser radar techniques for imaging of static and moving objects.

    Science.gov (United States)

    Yoshikado, S; Aruga, T

    1998-08-20

    Techniques for two types of 10-mum band synthetic aperture infrared laser radar using a hypothetical reference point target (RPT) are presented. One is for imaging static objects with a single two-dimensional scanning aperture. Through the simple manipulation of a reference wave phase, a desired image can be obtained merely by the two-dimensional Fourier transformation of the correlator output between the intermediate frequency signals of the reference and object waves. The other, with a one-dimensional aperture array, is for moving objects that pass across the array direction without attitude change. We performed imaging by using a two-dimensional RPT correlation method. We demonstrate the capability of these methods for imaging and evaluate the necessary conditions for signal-to-noise ratio and random phase errors in signal reception through numerical simulations in terms of feasibility.

  13. Radar absorbing materials based on titanium thin film obtained by sputtering technique

    Directory of Open Access Journals (Sweden)

    Viviane Lilian Soethe

    2011-09-01

    Full Text Available Titanium thin films with nanometer thicknesses were deposited on polyethylene terephthalate (PET substrate using the triode magnetron sputtering technique. It was observed that the titanium thin film-polymeric substrate set attenuates the energy of the incident electromagnetic wave in the frequency range of 8 to 12 GHz. This result allows to consider this set as a radar absorbing material, which may be employed in automobile, telecommunication, aerospace, medical, and electroelectronic areas. Results of the reflectivity show that the attenuation depends on the thin film thickness, as a determining factor. Thin films with 25 to 100 nm thickness values show attenuation of the electromagnetic wave energy from around 20 to 50%. Analyses by Rutherford backscattering spectrometry provided information about the thickness of the thin films studied. Hall effect analyses contributed to better understand the influence of the thin film thickness on the electron mobility and consequently on absorption properties.

  14. Informing radar retrieval algorithm development using an alternative soil moisture validation technique

    Science.gov (United States)

    Crow, W. T.; Wagner, W.

    2009-12-01

    Applying basic data assimilation techniques to the evaluation of remote-sensing products can clarify the impact of sensor design issues on the value of retrievals for hydrologic applications. For instance, the impact of incidence angle on the accuracy of radar surface soil moisture retrievals is largely unknown due to discrepancies in theoretical backscatter models as well as limitations in the availability of sufficiently-extensive ground-based soil moisture observations for validation purposes. In this presentation we will describe and apply a data assimilation evaluation technique for scatterometer-based surface soil moisture retrievals that does not require ground-based soil moisture observations to examine the sensitivity of retrieval skill to variations in incidence angle. Past results with the approach have shown that it is capable of detecting relative variations in the correlation between anomalies in remotely-sensed surface soil moisture retrievals and ground-truth soil moisture measurements. Application of the evaluation approach to the TU-Wien WARP5.0 European Space Radar (ERS) soil moisture data set over two regional-scale (~1000 km) domains in the Southern United States indicates a relative reduction in anomaly correlation-based skill of between 20% and 30% when moving between the lowest ( 50 degrees) incidence angle ranges. These changes in anomaly-based correlation provide a useful proxy for relative variations in the value of estimates for data assimilation applications and can therefore be used to inform the design of appropriate retrieval algorithms. For example, the observed sensitivity of correlation-based skill with incidence angle is in approximate agreement with soil moisture retrieval uncertainty predictions made using the WARP5.0 backscatter model. However, the coupling of a bare soil backscatter model with the so-called "vegetation water cloud" model is shown to generally over-estimate the impact of incidence angle on retrieval skill

  15. Surface roughness classification using polarimetric radar data and ensemble learning techniques

    Science.gov (United States)

    Alvarez-Mozos, Jesus; Peters, Jan; Larrañaga, Arantzazu; Gonzalez-Audicana, Maria; Verhoest, Niko E. C.; Casali, Javier

    2010-05-01

    The availability of space-borne radar sensors with polarimetric capabilities, such as RADARSAT-2, brings new expectations for the retrieval of soil moisture and roughness from remote sensing. The additional information provided by those sensors is expected to enable a separation of the confounding effects of soil moisture and roughness on the radar signal, resulting in more robust surface parameter retrievals. In this study we analyze two RADARSAT-2 Fine Quad-Pol scenes acquired during October 2008 over an agricultural area surrounding Pamplona (Spain). At that time of the year agricultural fields were bare and showed a variety of roughness conditions due to the different tillage operations performed. Approximately 50 agricultural fields were visited and their roughness condition was qualitatively evaluated. Fields were classified as rough, medium or smooth and their tillage direction was measured. The objective of this study is to evaluate the ability of different polarimetric variables to classify agricultural fields according to their roughness condition. With this aim a recently developed machine learning technique called ‘Random Forests' (RF) is used. RF is an ensemble learning technique that generates many classification trees and aggregates the individual results through majority vote. RF have been applied to a wide variety of phenomena, and in the recent years they have been used with success in several geoscience and remote sensing applications. In addition, RF can be used to estimate the importance of each predictive variable and to detect variable interactions. RF classification was applied at the pixel and at the field scale. Preliminary analyses showed better classification results for smooth and medium roughness fields than for rough ones. The research is ongoing and the influence of tillage direction and surface slope needs to be studied in detail.

  16. Planetary Radar

    Science.gov (United States)

    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.

  17. Effect of radar undesirable characteristics on the performance of spectral feature landmine detection technique

    Science.gov (United States)

    Ho, K. C.; Gader, P. D.; Wilson, J. N.; Frigui, H.

    2010-04-01

    A factor that could affect the performance of ground penetrating radar for landmine detection is self-signature. The radar self-signature is created by the internal coupling of the radar itself and it appears constant in different scans. Although not varying much, the radar self-signature can create hyperbolic shape or anomaly pattern after ground alignment and thereby increasing the amount of false detections. This paper examines the effect of radar self-signature on the performance of the subspace spectral feature landmine detection algorithm. Experimental results in the presence of strong radar self-signatures will be given and performance comparison with the pre-screener that is based on anomaly detection will be made.

  18. Numerical techniques for electromagnetic applications in microelectronic and radar imaging systems

    Science.gov (United States)

    Akerson, Jerome J.

    1998-12-01

    In this thesis, the application of numerical techniques to electromagnetic problems in microelectronic and radar imaging systems are investigated. In particular the following problems are studied: (1) Dielectric rib waveguide discontinuities are analyzed with the Finite Difference Time Domain (FDTD) method. The application of Berenger's Perfectly Matched Layer to multi-layered dielectrics is analyzed and the specific conditions needed to successfully match the multiple dielectric layers are determined and justified. An FDTD method to find the fundamental mode's spatial distribution is used to excite the discontinuity problem. It is shown that the computational domain can be reduced by twenty percent over Gaussian excitations. The effects of rib waveguide bend discontinuities and the effects of the rib geometry to the bend loss are presented. (2) An Impedance Boundary Condition (IBC) for two dimensional FDTD simulations containing thin, good conductor sheets is developed. The IBC uses a recursive convolution scheme based on approximating the conductor's impedance as a sum of exponentials. The effects of FDTD parameters such as grid size and time step on simulation accuracy are presented. The IBC is shown to accurately model the conductor loss over a wide frequency range. The verification is performed by comparing the quality factors of rectangular resonant structures determined by the FDTD simulation and analytical methods. (3) Phase unwrapping techniques for the inversion of terrain height using Synthetic Aperture Radar Interferometry (InSAR) data are analyzed. The weighted least squares and branch cut phase unwrapping techniques are specifically studied. An optimal branch cut method and a hybrid least squares/branch cut method are presented and used to unwrap the phase of both simulated and real SAR interferograms. When used to invert terrain height, these new SAR phase unwrapping methods offer over fifty percent reduction in root mean square (rms) height error

  19. Fault Detection Using Polarimetric Single-Input-Multi-Output Ground Penetrating Radar Technique in Mason, Texas

    Science.gov (United States)

    Amara, A.; Everett, M. E.

    2014-12-01

    At the Mason Mountain Wildlife Management Area (MMWMA) near Mason, Texas, we conducted a 2D ground penetrating radar (GPR) survey using single-input-multi-output (SIMO) acquisition technique to image a Pennsylvanian high-angle normal fault. At the MMWMA, the surface geology is mapped extensively but the subsurface remains largely unknown. The main objective of our study is to develop a detailed subsurface structural image of the fault and evaluate existing hypotheses on fault development. Also, to develop and apply a new methodology based on Polarimetric SIMO acquisition geometry. This new methodology allows the subsurface structures to be viewed simultaneously from different angles and can help reduce noise caused by the heterogeneities that affect the electromagnetic waves. We used a pulseEKKO pro 200 GPR with 200 MHz antennae to acquire 8 north-south lines across the fault. Each line is 30 meters long with the transmitter starting on the Town Mountain Granite, footwall, with the receiver stepping 40 cm until the end of the line crossing the fault on to the Hickory Sandstone, hanging wall. Each pass consisted of a stationary transmitter antenna and the moving receiver antenna. The data were initially processed with standard steps including low-cut dewow filter, background subtraction filter and gain control. Advanced processing techniques include migration, phased array processing, velocity analysis, and normal moveout. We will compare the GPR results with existing geophysical datasets at the same site, including electromagnetic (EM), seismic, and seismoelectric.

  20. Coherent Surface Clutter Suppression Techniques with Topography Estimation for Multi-Phase-Center Radar Ice Sounding

    DEFF Research Database (Denmark)

    Nielsen, Ulrik; Dall, Jørgen; Kristensen, Steen Savstrup;

    2012-01-01

    Radar ice sounding enables measurement of the thickness and internal structures of the large ice sheets on Earth. Surface clutter masking the signal of interest is a major obstacle in ice sounding. Algorithms for surface clutter suppression based on multi-phase-center radars are presented...

  1. Coherent Surface Clutter Suppression Techniques with Topography Estimation for Multi-Phase-Center Radar Ice Sounding

    DEFF Research Database (Denmark)

    Nielsen, Ulrik; Dall, Jørgen; Kristensen, Steen Savstrup

    2012-01-01

    Radar ice sounding enables measurement of the thickness and internal structures of the large ice sheets on Earth. Surface clutter masking the signal of interest is a major obstacle in ice sounding. Algorithms for surface clutter suppression based on multi-phase-center radars are presented. These ...

  2. Kalman Filtering of Radar Technology in Air Traffic Control Surveillance System%浅析卡尔曼雷达滤波技术在空管监视系统中的应用

    Institute of Scientific and Technical Information of China (English)

    周君

    2015-01-01

    [Abstract]Kalman filter for radar surveillance technology in air traffic control systems were analyzed. Discuss the corresponding Kalman filtering techniques: Related adaptive Kalman filtering, multi-model adaptive Kalman filter, adaptive Kalman filter information based on neural network adaptive Kalman filtering, fuzzy logic adaptive Kalman filtering, and their main advantages and disadvantages of the problem.%对卡尔曼雷达滤波技术在空管监视系统中的应用进行了分析,讨论了相应的卡尔曼滤波技术:相关自适应卡尔曼滤波、多模型自适应卡尔曼滤波、基于信息的自适应卡尔曼滤波、神经网络自适应卡尔曼滤波、模糊逻辑自适应卡尔曼滤波,并对它们主要解决的问题及优缺点进行了分析。

  3. Synthetic aperture radar imaging based on attributed scatter model using sparse recovery techniques

    Institute of Scientific and Technical Information of China (English)

    苏伍各; 王宏强; 阳召成

    2014-01-01

    The sparse recovery algorithms formulate synthetic aperture radar (SAR) imaging problem in terms of sparse representation (SR) of a small number of strong scatters’ positions among a much large number of potential scatters’ positions, and provide an effective approach to improve the SAR image resolution. Based on the attributed scatter center model, several experiments were performed with different practical considerations to evaluate the performance of five representative SR techniques, namely, sparse Bayesian learning (SBL), fast Bayesian matching pursuit (FBMP), smoothed l0 norm method (SL0), sparse reconstruction by separable approximation (SpaRSA), fast iterative shrinkage-thresholding algorithm (FISTA), and the parameter settings in five SR algorithms were discussed. In different situations, the performances of these algorithms were also discussed. Through the comparison of MSE and failure rate in each algorithm simulation, FBMP and SpaRSA are found suitable for dealing with problems in the SAR imaging based on attributed scattering center model. Although the SBL is time-consuming, it always get better performance when related to failure rate and high SNR.

  4. Image segmentation techniques for improved processing of landmine responses in ground-penetrating radar data

    Science.gov (United States)

    Torrione, Peter A.; Collins, Leslie

    2007-04-01

    As ground penetrating radar sensor phenomenology improves, more advanced statistical processing approaches become applicable to the problem of landmine detection in GPR data. Most previous studies on landmine detection in GPR data have focused on the application of statistics and physics based prescreening algorithms, new feature extraction approaches, and improved feature classification techniques. In the typical framework, prescreening algorithms provide spatial location information of anomalous responses in down-track / cross-track coordinates, and feature extraction algorithms are then tasked with generating low-dimensional information-bearing feature sets from these spatial locations. However in time-domain GPR, a significant portion of the data collected at prescreener flagged locations may be unrelated to the true anomaly responses - e.g. ground bounce response, responses either temporally "before" or "after" the anomalous response, etc. The ability to segment the information-bearing region of the GPR image from the background of the image may thus provide improved performance for feature-based processing of anomaly responses. In this work we will explore the application of Markov random fields (MRFs) to the problem of anomaly/background segmentation in GPR data. Preliminary results suggest the potential for improved feature extraction and overall performance gains via application of image segmentation approaches prior to feature extraction.

  5. Status and Trends of Air Surveillance/Antimissile Muitifunctional Radar System%防空反导一体化雷达的发展状况及趋势

    Institute of Scientific and Technical Information of China (English)

    查林

    2011-01-01

    防空反导一体化雷达是新时期解决隐身飞机、弹道导弹威胁的主要手段,通过研究国外防空反导一体化雷达的发展状况,总结出防空反导一体化雷达的性能需求以及技术发展趋势,并为我国防空反导一体化多功能雷达系统的发展提出部分建议.%Status and trends of the air surveillance/antimissile multifunctional radar system are main measures of confronting stealth fighters and missile threateners. The current status of the air surveillance/ anti-ballistic missile multifunctional radar systems is reviewed. The performance requirements and technical development trend are discussed. Some suggestions for development of indigenous air surveillance/anti-ballistic missile radar systems are presented.

  6. Partially Adaptive Phased Array Fed Cylindrical Reflector Technique for High Performance Synthetic Aperture Radar System

    Science.gov (United States)

    Hussein, Z.; Hilland, J.

    2001-01-01

    Spaceborne microwave radar instruments demand a high-performance antenna with a large aperature to address key science themes such as climate variations and predictions and global water and energy cycles.

  7. Super-resolution techniques for velocity estimation using UWB random noise radar signals

    Science.gov (United States)

    Dawood, Muhammad; Quraishi, Nafish; Alejos, Ana V.

    2011-06-01

    The Doppler spread pertaining to the ultrawideband (UWB) radar signals from moving target is directly proportional to the bandwidth of the transmitted signal and the target velocity. Using typical FFT-based methods, the estimation of true velocities pertaining to two targets moving with relatively close velocities within a radar range bin is problematic. In this paper, we extend the Multiple Signal Classification (MUSIC) algorithm to resolve targets moving velocities closer to each other within a given range bin for UWB random noise radar waveforms. Simulated and experimental results are compared for various target velocities using both narrowband (200MHz) and wideband (1GHz) noise radar signals, clearly establishing the unbiased and unambiguous velocity estimations using the MUSIC algorithm.

  8. Ground penetration radar 3-D modelling using the finite difference technique; Modelagem tridimensional de dados de radar (GPR) usando a tecnica das diferencas finitas

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, Rene Santos; Botelho, Marco Antonio Barsottelli [Bahia Univ., Salvador, BA (Brazil). Inst. de Geociencias. Programa de Pesquisa e Pos-graduacao em Geofisica

    1995-12-31

    The Ground Penetration Radar (GPR) is a surface-geophysical method that can produce continuous high-resolution profiles much better than seismic methods, but phenomena of propagation of the electromagnetic (EM) pulse can be of harder interpretation than seismic pulses. The phenomena of propagation of the EM waves in the air add more reflection on the GPR data gathers. In this work we illustrate this phenomena using 3-D models with structures above the ground. The 3-D synthetic common shot gathers are important tools to analyse the GPR response in order to improve the understanding of the geometry of overburden conditions for activities such as geotechnical investigations or factors controlling groundwater flow. Groups of 3-D synthetic common shot gathers of ground penetrating radar (GPR) data are simulated using the scalar wave equation in which the velocity is controlled by the dielectric permittivity distribution. The propagation velocity in which the EM pulses travel depends on the dielectric permittivity of the material. The algorithm uses the finite difference technique with operators of second order to solve the time and spatial derivatives and also fourth order to solve the spatial derivatives. The shot gathers in association with time slices and also with snapshots constitutes a powerful tool to predict the response of buried structures. (author). 14 refs., 4 figs

  9. The detectability of archaeological structures beneath the soil using the ground penetrating radar technique

    Science.gov (United States)

    Ferrara, C.; Barone, P. M.; Pajewski, L.; Pettinelli, E.; Rossi, G.

    2012-04-01

    The traditional excavation tools applied to Archaeology (i.e. trowels, shovels, bulldozers, etc.) produce, generally, a fast and invasive reconstruction of the ancient past. The geophysical instruments, instead, seem to go in the opposite direction giving, rapidly and non-destructively, geo-archaeological information. Moreover, the economic aspect should not be underestimated: where the former invest a lot of money in order to carry out an excavation or restoration, the latter spend much less to manage a geophysical survey, locating precisely the targets. Survey information gathered using non-invasive methods contributes to the creation of site strategies, conservation, preservation and, if necessary, accurate location of excavation and restoration units, without destructive testing methods, also in well-known archaeological sites [1]-[3]. In particular, Ground Penetrating Radar (GPR) has, recently, become the most important physical technique in archaeological investigations, allowing the detection of targets with both very high vertical and horizontal resolution, and has been successfully applied both to archaeological and diagnostic purposes in historical and monumental sites [4]. GPR configuration, antenna frequency and survey modality can be different, depending on the scope of the measurements, the nature of the site or the type of targets. Two-dimensional (2D) time/depth slices and radargrams should be generated and integrated with information obtained from other buried or similar artifacts to provide age, structure and context of the surveyed sites. In the present work, we present three case-histories on well-known Roman archaeological sites in Rome, in which GPR technique has been successfully used. To obtain 2D maps of the explored area, a bistatic GPR (250MHz and 500MHz antennas) was applied, acquiring data along several parallel profiles. The GPR results reveal the presence of similar circular anomalies in all the investigated archaeological sites. In

  10. Condition assessment of concrete pavements using both ground penetrating radar and stress-wave based techniques

    Science.gov (United States)

    Li, Mengxing; Anderson, Neil; Sneed, Lesley; Torgashov, Evgeniy

    2016-12-01

    Two stress-wave based techniques, ultrasonic surface wave (USW) and impact echo (IE), as well as ground penetrating radar (GPR) were used to assess the condition of a segment of concrete pavement that includes a layer of concrete, a granular base and their interface. Core specimens retrieved at multiple locations were used to confirm the accuracy and reliability of each non-destructive testing (NDT) result. Results from this study demonstrate that the GPR method is accurate for estimating the pavement thickness and locating separations (air voids) between the concrete and granular base layers. The USW method is a rapid way to estimate the in-situ elastic modulus (dynamic elastic modulus) of the concrete, however, the existence of air voids at the interface could potentially affect the accuracy and reliability of the USW test results. The estimation of the dynamic modulus and the P-wave velocity of concrete was improved when a shorter wavelength range (3 in. to 8.5 in.) corresponding to the concrete layer thickness was applied instead of the full wavelength rage (3 in. to 11 in.) based on the standard spacing of the receiver transducers. The IE method is proved to be fairly accurate in estimating the thickness of concrete pavements. However, the flexural mode vibration could affect the accuracy and reliability of the test results. Furthermore, the existence of air voids between the concrete and granular base layers could affect the estimation of the compression wave velocity of concrete when the full wavelength range was applied (3 in. to 11 in.). Future work is needed in order to improve the accuracy and reliability of both USW and IE test results.

  11. Application of radar polarimetry techniques for retrieval snow and rain characteristics in remote sensing

    Science.gov (United States)

    Darvishi, M.; Ahmadi, Gh. R.

    2013-09-01

    The presence of snow cover has significant impacts on the both global and regional climate and water balance on earth. The accurate estimation of snow cover area can be used for forecasting runoff due to snow melt and output of hydroelectric power. With development of remote sensing techniques at different scopes in earth science, enormous algorithms for retrieval hydrometeor parameters have been developed. Some of these algorithms are used to provide snow cover map such as NLR with AVHRR/MODIS sensor for Norway, Finnish with AVHRR sensor for Finland and NASA with MODIS sensor for global maps. Monitoring snow cover at different parts of spectral electromagnetic is detectable (visible, near and thermal infrared, passive and active microwave). Recently, specific capabilities of active microwave remote sensing such as snow extent map, snow depth, snow water equivalent (SWE), snow state (wet/dry) and discrimination between rain and snow region were given a strong impetus for using this technology in snow monitoring, hydrology, climatology, avalanche research and etc. This paper evaluates the potentials and feasibility of polarimetric ground microwave measurements of snow in active remote sensing field. We will consider the behavior co- and cross-polarized backscattering coefficients of snowpack response with polarimetric scatterometer in Ku and L band at the different incident angles. Then we will show how to retrieve snow cover depth, snow permittivity and density parameters at the local scale with ground-based SAR (GB-SAR). Finally, for the sake of remarkable significant the transition region between rain and snow; the variables role of horizontal reflectivity (ZHH) and differential reflectivity (ZDR) in delineation boundary between snow and rain and some others important variables at polarimetric weather radar are presented.

  12. Application of radar polarimetry techniques for retrieval snow and rain characteristics in remote sensing

    Directory of Open Access Journals (Sweden)

    M. Darvishi

    2013-09-01

    Full Text Available The presence of snow cover has significant impacts on the both global and regional climate and water balance on earth. The accurate estimation of snow cover area can be used for forecasting runoff due to snow melt and output of hydroelectric power. With development of remote sensing techniques at different scopes in earth science, enormous algorithms for retrieval hydrometeor parameters have been developed. Some of these algorithms are used to provide snow cover map such as NLR with AVHRR/MODIS sensor for Norway, Finnish with AVHRR sensor for Finland and NASA with MODIS sensor for global maps. Monitoring snow cover at different parts of spectral electromagnetic is detectable (visible, near and thermal infrared, passive and active microwave. Recently, specific capabilities of active microwave remote sensing such as snow extent map, snow depth, snow water equivalent (SWE, snow state (wet/dry and discrimination between rain and snow region were given a strong impetus for using this technology in snow monitoring, hydrology, climatology, avalanche research and etc. This paper evaluates the potentials and feasibility of polarimetric ground microwave measurements of snow in active remote sensing field. We will consider the behavior co- and cross-polarized backscattering coefficients of snowpack response with polarimetric scatterometer in Ku and L band at the different incident angles. Then we will show how to retrieve snow cover depth, snow permittivity and density parameters at the local scale with ground-based SAR (GB-SAR. Finally, for the sake of remarkable significant the transition region between rain and snow; the variables role of horizontal reflectivity (ZHH and differential reflectivity (ZDR in delineation boundary between snow and rain and some others important variables at polarimetric weather radar are presented.

  13. Radar seeker based autonomous navigation update system using topography feature matching techniques

    Science.gov (United States)

    Lerche, H. D.; Tumbreagel, F.

    1992-11-01

    The discussed navigation update system was designed for an unmanned platform with fire and forget capability. It meets the requirement due to fully autonomous operation. The system concept will be characterized by complementary use of the radar seeker for target identification as well as for navigation function. The system works in the navigation mode during preprogrammable phases where the primary target identification function is not active or in parallel processing. The dual function radar seeker system navigates the drone during the midcourse and terminal phases of the mission. Its high resolution due to range measurement and doppler beam sharpening in context with its radar reflectivity sensing capability are the basis for topography referenced navigation computation. The detected height jumps (coming from terrain elevation and cultural objects) and radar reflectivity features will be matched together with topography referenced features. The database comprises elevation data and selected radar reflectivity features that are robust against seasonal influences. The operational benefits of the discussed system are as follows: (1) the improved navigation performance with high probability of position fixing, even over flat terrain; (2) the operation within higher altitudes; and (3) bad weather capability. The developed software modules were verified with captive flight test data running in a hardware-in-the-loop simulation.

  14. A Comparative Study on different AI Techniques towards Performance Evaluation in RRM(Radar Resource Management

    Directory of Open Access Journals (Sweden)

    Madhusudhan H S

    2012-08-01

    Full Text Available The multifunction radar (MFR has to make a decision as to which functions are to be performed first or which must be degraded or even not done at all when there are not enough resources to be allocated. The process of making these decisions and determining their allocation as a function of time is known as Radar Resource Management (RRM. The RRM has two basic issues: task prioritization and task scheduling. The task prioritization is an important factor in the task scheduler. The other factor is the required scheduling time, which is decided by the environment, the target scenario and the performance requirements of radar functions. The required scheduling time could be improved by using advanced algorithm [1, 6].

  15. Radar Cross-Section Measurement Using the Near-Field Single-Frequency Angular-Diversity Technique

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Radar cross-section(RCS)measurement with the near-field electromagnetic wave illu mination of a target has been proved to be practical.The existing methods employ the multiplefrequency angular-diversity(MFAD)technique,whereas this paper considers the single-frequency angular-diversity(SFAD)technique.The paper takes into account the scattering center modeling and the limitation of higher sidelobes in reconstructing images in the SFAD technique compared to the MFAD technique.A method of combining the SFAD technique with the RELAX approach is presented for the high-resolutionextraction of scattering centers on a target.The proposed method offers an excellent RCS recovery,which is validated by numerical results.

  16. Mean winds observed with Indian MST radar over tropical mesosphere and comparison with various techniques

    Energy Technology Data Exchange (ETDEWEB)

    Venkat Ratnam, M.; Narayana Rao, D.; Narayana Rao, T. [Sri Venkateswara Univ., Tirupati (India). Dept. of Physics; Thulasiraman, S.; Nee, J.B. [National Central Univ., Chung Li (Taiwan); Gurubaran, S.; Rajaram, R. [Equatorial Geophysical Research Lab., Indian Inst. of Geomagnetism, Tirunelveli (India)

    2001-08-01

    Temporal variation of mean winds between the 65 to 85 km height region from the data collected over the course of approximately four years (1995-99), using the Indian MST radar located at Gadanki (13.5 N, 79.2 E), India is presented in this paper. Mesospheric mean winds and their seasonal variation in the horizontal and vertical components are presented in detail. Westward flows during each of the equinoxes and eastward flows during the solstices are observed in the zonal component. The features of the semi-annual oscillation (SAO) and the quasi-biennial oscillation (QBO) in the zonal component are noted. In the meridional component, contours reveal a northward motion during the winter and a southward motion during the summer. Large inter-annual variability is found in the vertical component with magnitudes of the order of {+-}2 ms{sup -1}. The MST observed winds are also compared with the winds observed by the MF radar located at Tirunelveli (8.7 N, 77.8 E), India, the high resolution Doppler imager (HRDI) onboard the upper atmospheric research satellite (UARS), and with the CIRA-86 model. A very good agreement is found between both the ground-based instruments (MST radar and MF radar) in the zonal component and there are few discrepancies in the meridional component. UARS/HRDI observed winds usually have larger magnitudes than the ground-based mean winds. Comparison of the MST derived winds with the CIRA-86 model in the zonal component shows that during the spring equinox and the summer, the winds agree fairly well, but there are a lot of discrepancies in the other seasons and the observed winds with the MST radar are less in magnitude, though the direction is same. The strengths and limitations in estimating reliable mesospheric mean winds using the MST radar are also discussed. (orig.)

  17. Endovascular aneurysm repair: state-of-art imaging techniques for preoperative planning and surveillance

    DEFF Research Database (Denmark)

    Truijers, M; Resch, T; Van Den Berg, J C

    2009-01-01

    Endovascular aneurysm repair (EVAR) represents one of the greatest advances in vascular surgery over the past 50 years. In contrast to conventional aneurysm repair, EVAR requires accurate preoperative imaging and stringent postoperative surveillance. Duplex ultrasound (DUS), transesophageal...... echocardiography, intravascular ultrasound, computed tomography (CT) and magnetic resonance (MR), each provide useful information for patient selection, choice of endograft type and surveillance. Today most interventionists and surgeons will rely on CT or MR to assess aortic morphology, evaluate access artery...

  18. MONO-PULSE RADAR 3-D IMAGING TECHNIQUES FOR TARGET IN STEPPED TRACKING MODE

    Institute of Scientific and Technical Information of China (English)

    Zhang Tao; Ma Changzheng; Zhang Qun; Zhang Shouhong

    2002-01-01

    A method for mono-pulse radar 3-D imaging in stepped tracking mode is presented and the amplitude linear modulation of error signals in stepped tracking mode is analyzed with its compensation method followed, so the problem of precisely tracking of target is solved. Finally the validity of these methods is proven by the simulation results.

  19. MONO-PULSE RADAR 3-D IMAGING TECHNIQUES FOR TARGET IN STEPPED TRACKING MODE

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A method for mono-pulse radar 3-D imaging in stepped tracking mode is presented and the amplitude linear modulation of error signals in stepped tracking mode is analyzed with its compensation method followes,so the problem of precisely tracking of target is solved.Finally the validity of these methods is proven by the simulation results.

  20. Oil Spill Detection and Tracking Using Lipschitz Regularity and Multiscale Techniques in Synthetic Aperture Radar Imagery

    Science.gov (United States)

    Ajadi, O. A.; Meyer, F. J.

    2014-12-01

    Automatic oil spill detection and tracking from Synthetic Aperture Radar (SAR) images is a difficult task, due in large part to the inhomogeneous properties of the sea surface, the high level of speckle inherent in SAR data, the complexity and the highly non-Gaussian nature of amplitude information, and the low temporal sampling that is often achieved with SAR systems. This research presents a promising new oil spill detection and tracking method that is based on time series of SAR images. Through the combination of a number of advanced image processing techniques, the develop approach is able to mitigate some of these previously mentioned limitations of SAR-based oil-spill detection and enables fully automatic spill detection and tracking across a wide range of spatial scales. The method combines an initial automatic texture analysis with a consecutive change detection approach based on multi-scale image decomposition. The first step of the approach, a texture transformation of the original SAR images, is performed in order to normalize the ocean background and enhance the contrast between oil-covered and oil-free ocean surfaces. The Lipschitz regularity (LR), a local texture parameter, is used here due to its proven ability to normalize the reflectivity properties of ocean water and maximize the visibly of oil in water. To calculate LR, the images are decomposed using two-dimensional continuous wavelet transform (2D-CWT), and transformed into Holder space to measure LR. After texture transformation, the now normalized images are inserted into our multi-temporal change detection algorithm. The multi-temporal change detection approach is a two-step procedure including (1) data enhancement and filtering and (2) multi-scale automatic change detection. The performance of the developed approach is demonstrated by an application to oil spill areas in the Gulf of Mexico. In this example, areas affected by oil spills were identified from a series of ALOS PALSAR images

  1. Adaptive radar resource management

    CERN Document Server

    Moo, Peter

    2015-01-01

    Radar Resource Management (RRM) is vital for optimizing the performance of modern phased array radars, which are the primary sensor for aircraft, ships, and land platforms. Adaptive Radar Resource Management gives an introduction to radar resource management (RRM), presenting a clear overview of different approaches and techniques, making it very suitable for radar practitioners and researchers in industry and universities. Coverage includes: RRM's role in optimizing the performance of modern phased array radars The advantages of adaptivity in implementing RRMThe role that modelling and

  2. Ultra-wideband Radar Methods and Techniques of Medical Sensing and Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Paulson, C N; Chang, J T; Romero, C E; Watson, J; Pearce, F J; Levin, N

    2005-10-07

    Ultra-wideband radar holds great promise for a variety of medical applications. We have demonstrated the feasibility of using ultra-wideband sensors for detection of internal injuries, monitoring of respiratory and cardiac functions, and continuous non-contact imaging of the human body. Sensors are low-power, portable, and do not require physical contact with the patient. They are ideal for use by emergency responders to make rapid diagnosis and triage decisions. In the hospital, vital signs monitoring and imaging application could improve patient outcomes. In this paper we present an overview of ultra-wideband radar technology, discuss key design tradeoffs, and give examples of ongoing research in applying ultra-wideband technology to the medical field.

  3. Measurements of Partial Reflections at 3.18 Mhz Using the CW Radar Technique

    Science.gov (United States)

    Priese, J.; Singer, W.

    1984-01-01

    An equipment for measuring partial reflections using the FM-CW-radar principle at 3.18 MHz, installed at the Ionospheric Observatory Juliusruh of the CISTP (HHI), is described. The linear FM-chirp of 325 kHz bandwidth is Gaussian-weighted in amplitude and gives a height resolution of 1.5 km (chirp length is 0.6 sec). Preliminary results are presented for the first observation period in winter 1982/83.

  4. A bat inspired technique for clutter reduction in radar sounder systems

    Science.gov (United States)

    Carrer, L.; Bruzzone, L.

    2016-10-01

    Radar Sounders are valuable instruments for subsurface investigation. They are widely employed for the study of planetary bodies around the solar system. Due to their wide antenna beam pattern, off-nadir surface reflections (i.e. clutter) of the transmitted signal can compete with echoes coming from the subsurface thus masking them. Different strategies have been adopted for clutter mitigation. However, none of them proved to be the final solution for this specific problem. Bats are very well known for their ability in discriminating between a prey and unwanted clutter (e.g. foliage) by effectively employing their sonar. According to recent studies, big brown bats can discriminate clutter by transmitting two different carrier frequencies. Most interestingly, there are many striking analogies between the characteristics of the bat sonar and the one of a radar sounder. Among the most important ones, they share the same nadir acquisition geometry and transmitted signal type (i.e. linear frequency modulation). In this paper, we explore the feasibility of exploiting frequency diversity for the purpose of clutter discrimination in radar sounding by mimicking unique bats signal processing strategies. Accordingly, we propose a frequency diversity clutter reduction method based on specific mathematical conditions that, if verified, allow the disambiguation between the clutter and the subsurface signal to be performed. These analytic conditions depend on factors such as difference in central carrier frequencies, surface roughness and subsurface material properties. The method performance has been evaluated by different simulations of meaningful acquisition scenarios which confirm its clutter reduction effectiveness.

  5. Surveillance in Programming Plagiarism beyond Techniques: An Incentive-Based Fishbone Model

    Science.gov (United States)

    Wang, Yanqing; Chen, Min; Liang, Yaowen; Jiang, Yu

    2013-01-01

    Lots of researches have showed that plagiarism becomes a severe problem in higher education around the world, especially in programming learning for its essence. Therefore, an effective strategy for plagiarism surveillance in program learning is much essential. Some literature focus on code similarity algorithm and the related tools can help to…

  6. Comparison of Two Detection Combination Algorithms for Phased Array Radars

    Science.gov (United States)

    2015-07-01

    weapon guidance. It can also be used effectively for secure communications [1]. In an MFR, the radar surveillance plays a critical role to optimize the...horizon/surface search, detection confirmation, multi-target tracking and cued search. The simulated radar has an aperture of 1 m2. The antennas...Comparison of Two Detection Combination Algorithms for Phased Array Radars Zhen Ding and Peter Moo Wide Area Surveillance Radar Group Radar

  7. COST Action TU1208 - Working Group 3 - Electromagnetic modelling, inversion, imaging and data-processing techniques for Ground Penetrating Radar

    Science.gov (United States)

    Pajewski, Lara; Giannopoulos, Antonios; Sesnic, Silvestar; Randazzo, Andrea; Lambot, Sébastien; Benedetto, Francesco; Economou, Nikos

    2017-04-01

    This work aims at presenting the main results achieved by Working Group (WG) 3 "Electromagnetic methods for near-field scattering problems by buried structures; data processing techniques" of the COST (European COoperation in Science and Technology) Action TU1208 "Civil Engineering Applications of Ground Penetrating Radar" (www.GPRadar.eu, www.cost.eu). The main objective of the Action, started in April 2013 and ending in October 2017, is to exchange and increase scientific-technical knowledge and experience of Ground Penetrating Radar (GPR) techniques in civil engineering, whilst promoting in Europe the effective use of this safe non-destructive technique. The Action involves more than 150 Institutions from 28 COST Countries, a Cooperating State, 6 Near Neighbour Countries and 6 International Partner Countries. Among the most interesting achievements of WG3, we wish to mention the following ones: (i) A new open-source version of the finite-difference time-domain simulator gprMax was developed and released. The new gprMax is written in Python and includes many advanced features such as anisotropic and dispersive-material modelling, building of realistic heterogeneous objects with rough surfaces, built-in libraries of antenna models, optimisation of parameters based on Taguchi's method - and more. (ii) A new freeware CAD was developed and released, for the construction of two-dimensional gprMax models. This tool also includes scripts easing the execution of gprMax on multi-core machines or network of computers and scripts for a basic plotting of gprMax results. (iii) A series of interesting freeware codes were developed will be released by the end of the Action, implementing differential and integral forward-scattering methods, for the solution of simple electromagnetic problems by buried objects. (iv) An open database of synthetic and experimental GPR radargrams was created, in cooperation with WG2. The idea behind this initiative is to give researchers the

  8. Optimization of a Novel Non-invasive Oral Sampling Technique for Zoonotic Pathogen Surveillance in Nonhuman Primates.

    Science.gov (United States)

    Smiley Evans, Tierra; Barry, Peter A; Gilardi, Kirsten V; Goldstein, Tracey; Deere, Jesse D; Fike, Joseph; Yee, JoAnn; Ssebide, Benard J; Karmacharya, Dibesh; Cranfield, Michael R; Wolking, David; Smith, Brett; Mazet, Jonna A K; Johnson, Christine K

    2015-01-01

    Free-ranging nonhuman primates are frequent sources of zoonotic pathogens due to their physiologic similarity and in many tropical regions, close contact with humans. Many high-risk disease transmission interfaces have not been monitored for zoonotic pathogens due to difficulties inherent to invasive sampling of free-ranging wildlife. Non-invasive surveillance of nonhuman primates for pathogens with high potential for spillover into humans is therefore critical for understanding disease ecology of existing zoonotic pathogen burdens and identifying communities where zoonotic diseases are likely to emerge in the future. We developed a non-invasive oral sampling technique using ropes distributed to nonhuman primates to target viruses shed in the oral cavity, which through bite wounds and discarded food, could be transmitted to people. Optimization was performed by testing paired rope and oral swabs from laboratory colony rhesus macaques for rhesus cytomegalovirus (RhCMV) and simian foamy virus (SFV) and implementing the technique with free-ranging terrestrial and arboreal nonhuman primate species in Uganda and Nepal. Both ubiquitous DNA and RNA viruses, RhCMV and SFV, were detected in oral samples collected from ropes distributed to laboratory colony macaques and SFV was detected in free-ranging macaques and olive baboons. Our study describes a technique that can be used for disease surveillance in free-ranging nonhuman primates and, potentially, other wildlife species when invasive sampling techniques may not be feasible.

  9. Biological Inspired Stochastic Optimization Technique (PSO for DOA and Amplitude Estimation of Antenna Arrays Signal Processing in RADAR Communication System

    Directory of Open Access Journals (Sweden)

    Khurram Hammed

    2016-01-01

    Full Text Available This paper presents a stochastic global optimization technique known as Particle Swarm Optimization (PSO for joint estimation of amplitude and direction of arrival of the targets in RADAR communication system. The proposed scheme is an excellent optimization methodology and a promising approach for solving the DOA problems in communication systems. Moreover, PSO is quite suitable for real time scenario and easy to implement in hardware. In this study, uniform linear array is used and targets are supposed to be in far field of the arrays. Formulation of the fitness function is based on mean square error and this function requires a single snapshot to obtain the best possible solution. To check the accuracy of the algorithm, all of the results are taken by varying the number of antenna elements and targets. Finally, these results are compared with existing heuristic techniques to show the accuracy of PSO.

  10. Interval colon cancer in a Lynch syndrome patient under annual colonoscopic surveillance: a case for advanced imaging techniques?

    Directory of Open Access Journals (Sweden)

    Oxentenko Amy S

    2012-05-01

    Full Text Available Abstract Background Lynch syndrome confers increased risk for various malignancies, including colorectal cancer. Colonoscopic surveillance programs have led to reduced incidence of colorectal cancer and reduced mortality from colorectal cancer. Colonoscopy every 1–2 years beginning at age 20–25, or 10 years earlier than the first diagnosis of colorectal cancer in a family, with annual colonoscopy after age 40, is the recommended management for mutation carriers. Screening programs have reduced colon cancer mortality, but interval cancers may occur. Case presentation We describe a 48-year-old woman with Lynch syndrome who was found to have an adenoma with invasive colorectal cancer within one year after a normal colonoscopy. Conclusion Our patient illustrates two current concepts about Lynch syndrome: 1 adenomas are the cancer precursor and 2 such adenomas may be “aggressive,” in the sense that the adenoma progresses more readily and more rapidly to carcinoma in this setting compared to usual colorectal adenomas. Our patient’s resected tumor invaded only into submucosa and all lymph nodes were negative; in that sense, she represents a success for annual colonoscopic surveillance. Still, this case does raise the question of whether advanced imaging techniques are advisable for surveillance colonoscopy in these high-risk patients.

  11. Radar detection

    CERN Document Server

    DiFranco, Julius

    2004-01-01

    This book presents a comprehensive tutorial exposition of radar detection using the methods and techniques of mathematical statistics. The material presented is as current and useful to today's engineers as when the book was first published by Prentice-Hall in 1968 and then republished by Artech House in 1980. The book is divided into six parts.

  12. POSSIBILITIES OF IMPROVING THE METHODS AND TECHNIQUES USED IN THE SURVEILLANCE OF CREDIT RISK MANAGEMENT

    Directory of Open Access Journals (Sweden)

    Balogh Peter

    2010-12-01

    Full Text Available Through their daily activities, credit institutions are subject to various risks which could affect both the bank and the whole banking system, national and transnational. The activity field of the banks, marked by volatility, by the internationalization and liberalization of the financial markets, is in a continuous change. The contagion effect, as it has been proved by the spread of the financial crisis effects, determines the surveillance authorities to pay increased attention to the financial risks and implicitly to the systemic risk. In this study, to start with, there shall be presented some aspects regarding the banking rating systems used by the surveillance authorities and then some ways of improving the models of managing credit risk in banks. In the end, there will be demonstrated that the risk profile of the banking institution has a determining role in the management of the credit portfolio.

  13. Estimation techniques and simulation platforms for 77 GHz FMCW ACC radars

    Science.gov (United States)

    Bazzi, A.; Kärnfelt, C.; Péden, A.; Chonavel, T.; Galaup, P.; Bodereau, F.

    2012-01-01

    This paper presents two radar simulation platforms that have been developed and evaluated. One is based on the Advanced Design System (ADS) and the other on Matlab. Both platforms are modeled using homodyne front-end 77 GHz radar, based on commercially available monolithic microwave integrated circuits (MMIC). Known linear modulation formats such as the frequency modulation continuous wave (FMCW) and three-segment FMCW have been studied, and a new variant, the dual FMCW, is proposed for easier association between beat frequencies, while maintaining an excellent distance estimation of the targets. In the signal processing domain, new algorithms are proposed for the three-segment FMCW and for the dual FMCW. While both of these algorithms present the choice of either using complex or real data, the former allows faster signal processing, whereas the latter enables a simplified front-end architecture. The estimation performance of the modulation formats has been evaluated using the Cramer-Rao and Barankin bounds. It is found that the dual FMCW modulation format is slightly better than the other two formats tested in this work. A threshold effect is found at a signal-to-noise ratio (SNR) of 12 dB which means that, to be able to detect a target, the SNR should be above this value. In real hardware, the SNR detection limit should be set to about at least 15 dB.

  14. Effect of DRFM phase responsext on the doppler spectrum of a coherent radar: critical implications and possible mitigation techniques

    CSIR Research Space (South Africa)

    Herselman, PL

    2006-02-01

    Full Text Available In this research, the critical implications of the phase response of a Digital Radio Frequency Memory (DRFM) based repeater system on the Doppler spectrum of a modern, coherently processing radar system (for example pulsed Doppler radar...

  15. 基于 OpenGL 的空间目标监视雷达三维显示系统%3D Display System for Space Target Surveillance Radar Based on OpenGL

    Institute of Scientific and Technical Information of China (English)

    沈静波; 刘扬

    2015-01-01

    Due to large detection range of space target surveillance radar and great height of target,a 3D display system is needed to reflect the target’s real spatial position.A framework of radar 3D display system based on OpenGL is proposed,and its modules are divided.For the demands of assistant display for space target,a design for radar beam and search sectors display is put forward to reflect the real-time beam schedu-ling of radar.An earth texture management based on quadtree dynamic fractal is proposed for high resolution display of the surface.A rotation method of 3D earth based on virtual trace ball is proposed to adjust the user’s angle of view agilely.The system is implemented in a space target surveillance radar successfully, achieving smooth display and fluent image.%空间目标监视雷达探测范围较远,目标高度较高,所以需要三维显示软件来反映目标实际的空间位置信息。基于 OpenGL 提出了一种雷达三维显示系统的设计框架和模块划分。针对空间目标的辅助显示需求,提出了雷达波束和搜索屏的显示设计,可以实时反映雷达的波束调度情况;提出了一种基于四叉树动态分形的地球纹理管理方法,用于实现高精度的地表纹理显示;提出了一种基于虚拟轨迹球的三维地球旋转设计,实现了灵活的用户视角调整。该系统已在某型空间目标监视雷达上成功应用,画面显示平滑流畅。

  16. a Comparison Between Zero-Offset and Vertical Radar Profiling Gpr Techniques with Emphasis on Problematic Borehole Effects

    Science.gov (United States)

    Rossi, M.; Vignoli, G.; Cassiani, G.; Deiana, R.

    2012-12-01

    Non-invasive geophysical techniques are increasingly used to study the unsaturated zone. In particular, cross-hole methods can are able to infer more detailed information about the subsoil than surface measurements. Two borehole Ground Penetrating Radar (GPR) techniques are discussed in our contribution: Zero-Offset Profiling (ZOP) and Vertical Radar Profiling (VRP). We make a direct comparison of these methods in a field case (Trecate site, Northern Italy), to explore each method's capabilities and limitations. Our analysis is focused on the results in the vadose zone and shows that the dielectric relative permittivity profiles recovered from ZOP and VRP first-break inversions are in strong disagreement, providing very different permittivity profiles. The analysis of synthetic radargrams shows the presence of an electromagnetic (EM) wave established by the joint presence of the air-filled borehole within a higher permittivity surrounding soil. This event has a velocity intermediate between the soil and air speed values, and interferes with the picking of first arrivals in the VRP mode. The numerical simulations are performed with different borehole diameters, confirming that the velocity of the first recorded event depends on the ratio between the wave length in air and the finite dimension of the borehole. Once these arrivals in the simulated VRP radargrams are recognized, their contribution can be removed by picking the "direct" arrivals, that correspond to the waves that directly propagates from source to receiver, through the unsaturated zone. Once the borehole effects are accounted for, the comparison between the ZOP and VRP permittivity profiles is reasonable and reveals the different resolution of these techniques, focusing on the information that can be inferred for hydrological characterizations. Thus, VRP surveys in vadose zone must be accurately interpreted, as the electromagnetic waves may propagate via guided modes along the borehole. Neglecting this

  17. Fusion techniques for hybrid ground-penetrating radar: electromagnetic induction landmine detection systems

    Science.gov (United States)

    Laffin, Matt; Mohamed, Magdi A.; Etebari, Ali; Hibbard, Mark

    2010-04-01

    Hybrid ground penetrating radar (GPR) and electromagnetic induction (EMI) sensors have advanced landmine detection far beyond the capabilities of a single sensing modality. Both probability of detection (PD) and false alarm rate (FAR) are impacted by the algorithms utilized by each sensing mode and the manner in which the information is fused. Algorithm development and fusion will be discussed, with an aim at achieving a threshold probability of detection (PD) of 0.98 with a low false alarm rate (FAR) of less than 1 false alarm per 2 square meters. Stochastic evaluation of prescreeners and classifiers is presented with subdivisions determined based on mine type, metal content, and depth. Training and testing of an optimal prescreener on lanes that contain mostly low metal anti-personnel mines is presented. Several fusion operators for pre-screeners and classifiers, including confidence map multiplication, will be investigated and discussed for integration into the algorithm architecture.

  18. HF omnidirectional spectral CW auroral radar (HF-OSCAR) at very high latitude. Part 1: Technique

    Science.gov (United States)

    Olesen, J. K.; Jacobsen, K. E.; Stauning, P.; Henriksen, S.

    1983-12-01

    An HF system for studies of very high latitude ionospheric irregularities was described. Radio aurora from field-aligned E-region irregularities of the Slant E Condition type were discussed. The complete system combines an ionosonde, a 12 MHz pulse radar and a 12 MHz bistatic CW Doppler-range set-up. The two latter units use alternately a 360 deg rotating Yagi antenna. High precision oscillators secure the frequency stability of the Doppler system in which the received signal is mixed down to a center frequency of 500 Hz. The Doppler shift range is max + or - 500 Hz. The received signal is recorded in analog form on magnetic tape and may be monitored visually and audibly. Echo range of the CW Doppler signal is obtained by a 150 Hz amplitude modulation of the transmitted signal and phase comparison with the backscattered signal.

  19. Review of Ship Surveillance Technologies Based on High-Resolution Wide-Swath Synthetic Aperture Radar Imaging%HRWS SAR图像舰船目标监视技术研究综述

    Institute of Scientific and Technical Information of China (English)

    邢相薇; 计科峰; 康利鸿; 詹明

    2015-01-01

    合成孔径雷达(Synthetic Aperture Radar, SAR)是实现舰船目标监视应用的重要遥感手段之一。高分辨率宽测绘带(High Resolution Wide Swath, HRWS) SAR 能够同时获取方位向高分辨率和宽测绘带SAR数据,为SAR图像舰船目标监视带来了新的机遇和挑战。该文综述了国内外SAR图像舰船目标监视技术研究现状,总结了舰船监视对SAR成像系统基本性能要求,结合HRWS SAR成像特点,分析了舰船目标监视面临的关键技术问题,重点介绍了研究小组在HRWS SAR图像舰船目标检测、特征提取、分类识别等关键问题的解决方案和初步研究成果,并指出需进一步研究的方向。%Synthetic Aperture Radar (SAR) is widely used in ship surveillance. High-Resolution Wide-Swath (HRWS) SAR data are simultaneously collected, which introduces challenges and offers new research opportunities. SAR-based ship-surveillance technologies and the performance requirements of SAR systems are reviewed and summarized. Furthermore, the characteristics of HRWS SAR imaging and ship surveillance technologies are considered in tandem, and preliminary research results on ship detection, feature extraction, and classification are discussed. Finally, we point out issues to be addressed in future work.

  20. Measurements of Land Subsidence Rates on the North-western Portion of the Nile Delta Using Radar Interferometry Techniques

    Science.gov (United States)

    Fugate, Joseph M.

    The Nile Delta is home to around 75 million people and most of Egypt's farmland and agricultural production. This area is currently threatened by Mediterranean Sea waters due to factors such as sediment starvation, climate change, and sea level fluctuations as well as subsidence. The low elevation and relief of the Nile Delta exposes many coastal communities, including the city of Alexandria, to potential inundation. This situation has become a concern for the area's residents but a better understanding of the processes occurring there can aid in deciding a suitable response. Recent studies have documented Holocene subsidence rates in the northeast part of the Nile Delta that average up to 8mm/year. In this study, PS-InSAR techniques are used to measure modern land subsidence rates on the north-central and north-western Nile Delta. Persistent Scatterer Interferometric Synthetic Aperture Radar (PS-InSAR) techniques were applied to 23 ESA radar scenes from 2 orbital tracks spanning from 1992 to 2000 in the north-central and north-west portions of the Nile Delta. The area includes the cities of Alexandria, Greater Mahala, and Mansoura as well as the Rosetta promontory and lake Burullus, Idku Lagoon, and Maryut Lagoon. Results indicate that modern average-vertical ground motion velocities for the north-western and north-central Nile Delta range from emergent to subsidence of 8.5 mm/yr. The range of velocities measured are spatially varied in a complex way across the study area. Patterns of subsidence correlate closely to areas of most recent sediment deposition such as along coastlines and rivers, as well as in lagoons and lakes. Average subsidence velocities are also lower across the western sections of the Nile Delta than in the northeastern delta.

  1. A survey of imagery techniques for semantic labeling of human-vehicle interactions in persistent surveillance systems

    Science.gov (United States)

    Elangovan, Vinayak; Shirkhodaie, Amir

    2011-06-01

    Understanding and semantic annotation of Human-Vehicle Interactions (HVI) facilitate fusion of Hard sensor (HS) and Human Intelligence (HUMINT) in a cohesive way. By characterization, classification, and discrimination of HVI patterns pertinent threats may be realized. Various Persistent Surveillance System (PSS) imagery techniques have been proposed in the past decade for identifying human interactions with various objects in the environment. Understanding of such interactions facilitates to discover human intentions and motives. However, without consideration of incidental context, reasoning and analysis of such behavioral activities is a very challenging and difficult task. This paper presents a current survey of related publications in the area of context-based Imagery techniques applied for HVI recognition, in particular, it discusses taxonomy and ontology of HVI and presents a summary of reported robust image processing techniques for spatiotemporal characterization and tracking of human targets in urban environments. The discussed techniques include model-based, shape-based and appearance-based techniques employed for identification and classification of objects. A detailed overview of major past research activities related to HVI in PSS with exploitation of spatiotemporal reasoning techniques applied to semantic labeling of the HVI is also presented.

  2. Command and Control for Multifunction Phased Array Radar

    OpenAIRE

    Weber, Mark E.; Cho, John Y. N.; Thomas, Henry G

    2017-01-01

    We discuss the challenge of managing the Multifunction Phased Array Radar (MPAR) timeline to satisfy the requirements of its multiple missions, with a particular focus on weather surveillance. This command and control (C2) function partitions the available scan time among these missions, exploits opportunities to service multiple missions simultaneously, and utilizes techniques for increasing scan rate where feasible. After reviewing the candidate MPAR architectures and relevant previous rese...

  3. Application of ground-penetrating radar technique to evaluate the waterfront location in hardened concrete

    Science.gov (United States)

    Rodríguez-Abad, Isabel; Klysz, Gilles; Martínez-Sala, Rosa; Balayssac, Jean Paul; Mené-Aparicio, Jesús

    2016-12-01

    The long-term performance of concrete structures is directly tied to two factors: concrete durability and strength. When assessing the durability of concrete structures, the study of the water penetration is paramount, because almost all reactions like corrosion, alkali-silica, sulfate, etc., which produce their deterioration, require the presence of water. Ground-penetrating radar (GPR) has shown to be very sensitive to water variations. On this basis, the objective of this experimental study is, firstly, to analyze the correlation between the water penetration depth in concrete samples and the GPR wave parameters. To do this, the samples were immersed into water for different time intervals and the wave parameters were obtained from signals registered when the antenna was placed on the immersed surface of the samples. Secondly, a procedure has been developed to be able to determine, from those signals, the reliability in the detection and location of waterfront depths. The results have revealed that GPR may have an enormous potential in this field, because excellent agreements were found between the correlated variables. In addition, when comparing the waterfront depths calculated from GPR measurements and those visually registered after breaking the samples, we observed that they totally agreed when the waterfront was more than 4 cm depth.

  4. Extraction of convective cloud parameters from Doppler Weather Radar MAX(Z) product using Image Processing Technique

    Science.gov (United States)

    Arunachalam, M. S.; Puli, Anil; Anuradha, B.

    2016-07-01

    In the present work continuous extraction of convective cloud optical information and reflectivity (MAX(Z) in dBZ) using online retrieval technique for time series data production from Doppler Weather Radar (DWR) located at Indian Meteorological Department, Chennai has been developed in MATLAB. Reflectivity measurements for different locations within the DWR range of 250 Km radii of circular disc area can be retrieved using this technique. It gives both time series reflectivity of point location and also Range Time Intensity (RTI) maps of reflectivity for the corresponding location. The Graphical User Interface (GUI) developed for the cloud reflectivity is user friendly; it also provides the convective cloud optical information such as cloud base height (CBH), cloud top height (CTH) and cloud optical depth (COD). This technique is also applicable for retrieving other DWR products such as Plan Position Indicator (Z, in dBZ), Plan Position Indicator (Z, in dBZ)-Close Range, Volume Velocity Processing (V, in knots), Plan Position Indicator (V, in m/s), Surface Rainfall Intensity (SRI, mm/hr), Precipitation Accumulation (PAC) 24 hrs at 0300UTC. Keywords: Reflectivity, cloud top height, cloud base, cloud optical depth

  5. Mapping forested wetlands in the Great Zhan River Basin through integrating optical, radar, and topographical data classification techniques.

    Science.gov (United States)

    Na, X D; Zang, S Y; Wu, C S; Li, W L

    2015-11-01

    Knowledge of the spatial extent of forested wetlands is essential to many studies including wetland functioning assessment, greenhouse gas flux estimation, and wildlife suitable habitat identification. For discriminating forested wetlands from their adjacent land cover types, researchers have resorted to image analysis techniques applied to numerous remotely sensed data. While with some success, there is still no consensus on the optimal approaches for mapping forested wetlands. To address this problem, we examined two machine learning approaches, random forest (RF) and K-nearest neighbor (KNN) algorithms, and applied these two approaches to the framework of pixel-based and object-based classifications. The RF and KNN algorithms were constructed using predictors derived from Landsat 8 imagery, Radarsat-2 advanced synthetic aperture radar (SAR), and topographical indices. The results show that the objected-based classifications performed better than per-pixel classifications using the same algorithm (RF) in terms of overall accuracy and the difference of their kappa coefficients are statistically significant (pclassifications using the RF algorithm. As for the object-based image analysis, there were also statistically significant differences (palgorithms. The object-based classification using RF provided a more visually adequate distribution of interested land cover types, while the object classifications based on the KNN algorithm showed noticeably commissions for forested wetlands and omissions for agriculture land. This research proves that the object-based classification with RF using optical, radar, and topographical data improved the mapping accuracy of land covers and provided a feasible approach to discriminate the forested wetlands from the other land cover types in forestry area.

  6. A survey and proposed framework on the soft biometrics technique for human identification in intelligent video surveillance system.

    Science.gov (United States)

    Kim, Min-Gu; Moon, Hae-Min; Chung, Yongwha; Pan, Sung Bum

    2012-01-01

    Biometrics verification can be efficiently used for intrusion detection and intruder identification in video surveillance systems. Biometrics techniques can be largely divided into traditional and the so-called soft biometrics. Whereas traditional biometrics deals with physical characteristics such as face features, eye iris, and fingerprints, soft biometrics is concerned with such information as gender, national origin, and height. Traditional biometrics is versatile and highly accurate. But it is very difficult to get traditional biometric data from a distance and without personal cooperation. Soft biometrics, although featuring less accuracy, can be used much more freely though. Recently, many researchers have been made on human identification using soft biometrics data collected from a distance. In this paper, we use both traditional and soft biometrics for human identification and propose a framework for solving such problems as lighting, occlusion, and shadowing.

  7. A Survey and Proposed Framework on the Soft Biometrics Technique for Human Identification in Intelligent Video Surveillance System

    Directory of Open Access Journals (Sweden)

    Min-Gu Kim

    2012-01-01

    Full Text Available Biometrics verification can be efficiently used for intrusion detection and intruder identification in video surveillance systems. Biometrics techniques can be largely divided into traditional and the so-called soft biometrics. Whereas traditional biometrics deals with physical characteristics such as face features, eye iris, and fingerprints, soft biometrics is concerned with such information as gender, national origin, and height. Traditional biometrics is versatile and highly accurate. But it is very difficult to get traditional biometric data from a distance and without personal cooperation. Soft biometrics, although featuring less accuracy, can be used much more freely though. Recently, many researchers have been made on human identification using soft biometrics data collected from a distance. In this paper, we use both traditional and soft biometrics for human identification and propose a framework for solving such problems as lighting, occlusion, and shadowing.

  8. Radar rainfall estimation for the post-event analysis of a Slovenian flash-flood case: application of the mountain reference technique at C-band frequency

    Directory of Open Access Journals (Sweden)

    L. Bouilloud

    2009-01-01

    Full Text Available This article is dedicated to radar rainfall estimation for the post-event analysis of a Slovenian flash flood that occurred on 18 September 2007. The utility of the Mountain Reference Technique is demonstrated to quantify rain attenuation effects that affect C-band radar measurements in heavy rain. Maximum path-integrated attenuation between 15 and 20 dB were measured thanks to mountain returns for path-averaged rain rates between 10 and 15 mm h−1 over a 120-km path. The proposed technique allowed estimation of an effective radar calibration correction factor, assuming the reflectivity-attenuation relationship to be known. Screening effects were quantified using a geometrical calculation based on a digitized terrain model of the region. The vertical structure of the reflectivity was modelled with a normalized apparent vertical profile of reflectivity. Implementation of the radar data processing indicated that: (1 attenuation correction using the Hitschfeld Bordan algorithm allowed obtaining satisfactory radar rain estimates (Nash criterion of 0.8 at the event time scale; (2 due to the attenuation equation instability, it is however compulsory to limit the maximum path-integrated attenuation to be corrected to about 10 dB; (3 the results also proved to be sensitive on the parameterization of reflectivity-attenuation-rainrate relationships. The convective nature of the precipitation explains the rather good performance obtained. For more contrasted rainy systems with convective and stratiform regions, the combination of the vertical (VPR and radial (attenuation, screening sources of heterogeneity yields a still very challenging problem for radar quantitative precipitation estimation at C-band.

  9. Multidimensional radar picture

    Science.gov (United States)

    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.

  10. Real-time implementations of acoustic signal enhancement techniques for aerial based surveillance and rescue applications

    Science.gov (United States)

    Ramos, Antonio L. L.; Shao, Zhili; Holthe, Aleksander; Sandli, Mathias F.

    2017-05-01

    The introduction of the System-on-Chip (SoC) technology has brought exciting new opportunities for the development of smart low cost embedded systems spanning a wide range of applications. Currently available SoC devices are capable of performing high speed digital signal processing tasks in software while featuring relatively low development costs and reduced time-to-market. Unmanned aerial vehicles (UAV) are an application example that has shown tremendous potential in an increasing number of scenarios, ranging from leisure to surveillance as well as in search and rescue missions. Video capturing from UAV platforms is a relatively straightforward task that requires almost no preprocessing. However, that does not apply to audio signals, especially in cases where the data is to be used to support real-time decision making. In fact, the enormous amount of acoustic interference from the surroundings, including the noise from the UAVs propellers, becomes a huge problem. This paper discusses a real-time implementation of the NLMS adaptive filtering algorithm applied to enhancing acoustic signals captured from UAV platforms. The model relies on a combination of acoustic sensors and a computational inexpensive algorithm running on a digital signal processor. Given its simplicity, this solution can be incorporated into the main processing system of an UAV using the SoC technology, and run concurrently with other required tasks, such as flight control and communications. Simulations and real-time DSP-based implementations have shown significant signal enhancement results by efficiently mitigating the interference from the noise generated by the UAVs propellers as well as from other external noise sources.

  11. An evolutionary algorithm technique for intelligence, surveillance, and reconnaissance plan optimization

    Science.gov (United States)

    Langton, John T.; Caroli, Joseph A.; Rosenberg, Brad

    2008-04-01

    To support an Effects Based Approach to Operations (EBAO), Intelligence, Surveillance, and Reconnaissance (ISR) planners must optimize collection plans within an evolving battlespace. A need exists for a decision support tool that allows ISR planners to rapidly generate and rehearse high-performing ISR plans that balance multiple objectives and constraints to address dynamic collection requirements for assessment. To meet this need we have designed an evolutionary algorithm (EA)-based "Integrated ISR Plan Analysis and Rehearsal System" (I2PARS) to support Effects-based Assessment (EBA). I2PARS supports ISR mission planning and dynamic replanning to coordinate assets and optimize their routes, allocation and tasking. It uses an evolutionary algorithm to address the large parametric space of route-finding problems which is sometimes discontinuous in the ISR domain because of conflicting objectives such as minimizing asset utilization yet maximizing ISR coverage. EAs are uniquely suited for generating solutions in dynamic environments and also allow user feedback. They are therefore ideal for "streaming optimization" and dynamic replanning of ISR mission plans. I2PARS uses the Non-dominated Sorting Genetic Algorithm (NSGA-II) to automatically generate a diverse set of high performing collection plans given multiple objectives, constraints, and assets. Intended end users of I2PARS include ISR planners in the Combined Air Operations Centers and Joint Intelligence Centers. Here we show the feasibility of applying the NSGA-II algorithm and EAs in general to the ISR planning domain. Unique genetic representations and operators for optimization within the ISR domain are presented along with multi-objective optimization criteria for ISR planning. Promising results of the I2PARS architecture design, early software prototype, and limited domain testing of the new algorithm are discussed. We also present plans for future research and development, as well as technology

  12. Ultra Wide Band localization and tracking hybrid technique using VRTs

    Directory of Open Access Journals (Sweden)

    Mohd Shamian Zianal

    2012-12-01

    Full Text Available This research presents hybrid radar tracking technique consisting of Time Of Arrival (TOA and Received Signal Strength (RSS techniques. This hybrid design increases efficiency, accuracy and sensitivity of radar system. The radar used in this research is multistatic radar with one transmitter and three receivers. One common drawback in RSS and TOA techniques is high level synchronization in transmitter and receivers. The hybrid design also suffers from transmitter-receiver synchronization. To overcome TX-RX synchronization problem Virtual Reference Tags (VRTs are used. These tags are virtually mapped over the surveillance area giving radar design different reference points from which it can accurately locate intruder and monitor its movements. Also four cases of different

  13. Application of radar polarimetry techniques for retrieval snow and rain characteristics in remote sensing

    OpenAIRE

    2013-01-01

    The presence of snow cover has significant impacts on the both global and regional climate and water balance on earth. The accurate estimation of snow cover area can be used for forecasting runoff due to snow melt and output of hydroelectric power. With development of remote sensing techniques at different scopes in earth science, enormous algorithms for retrieval hydrometeor parameters have been developed. Some of these algorithms are used to provide snow cover map such as NLR with AVHRR/MOD...

  14. Continuous Surveillance Technique for Flow Accelerated Corrosion of Pipe Wall Using Electromagnetic Acoustic Transducer

    Science.gov (United States)

    Kojima, F.; Kosaka, D.; Umetani, K.

    2011-06-01

    In this paper, we propose a on-line monitoring technique using electromagnetic acoustic transducer (EMAT). In the series of laboratory experiments, carbon steel pipes were used and each sample was fabricated to simulate FAC. Electromagnetic acoustic resonance method (EMAR) is successfully tested for pipe wall thickness measurements. The validity and the feasibility of our method are also demonstrated through the laboratory experiments.

  15. 78 FR 49520 - Scientific Information Request on Imaging Techniques for the Surveillance, Diagnosis, and Staging...

    Science.gov (United States)

    2013-08-14

    ... are considered confidential; marketing materials; study types not included in the review; or... or core biopsy? c. What is the comparative effectiveness of the various imaging techniques on... reference standard comparators will be histopathology (based on explanted liver specimens or biopsy)...

  16. Yangon River Geomorphology Identification and its Enviromental Imapacts Analsysi by Optical and Radar Sensing Techniques

    Science.gov (United States)

    Lwin, A.; Khaing, M. M.

    2012-07-01

    The Yangon river, also known as the Rangoon river, is about 40 km long (25miles), and flows from southern Myanmar as an outlet of the Irrawaddy (Ayeyarwady) river into the Ayeyarwady delta. The Yangon river drains the Pegu Mountains; both the Yangon and the Pathein rivers enter the Ayeyarwady at the delta. Fluvial geomorphology is based primarily on rivers of manageable dimensions. The emphasis is on geomorphology, sedimentology of Yangon river and techniques for their identification and management. Present techniques such as remote sensing have made it easier to investigate and interpret in details analysis of river geomorphology. In this paper, attempt has been made the complicated issues of geomorphology, sedimentation patterns and management of river system and evolution studied. The analysis was carried out for the impact of land use/ land cover (LULC) changes on stream flow patterns. The hydrologic response to intense, flood producing rainfall events bears the signatures of the geomorphic structure of the channel network and of the characteristic slope lengths defining the drainage density of the basin. The interpretation of the hydrologic response as the travel time distribution of a water particle randomly injected in a distributed manner across the landscape inspired many geomorphic insights. In 2008, Cyclone Nargis was seriously damaged to mangrove area and its biodiversity system in and around of Yangon river terraces. A combination of digital image processing techniques was employed for enhancement and classification process. It is observed from the study that middle infra red band (0.77mm - 0.86mm) is highly suitable for mapping mangroves. Two major classes of mangroves, dense and open mangroves were delineated from the digital data.

  17. Techniques for Clutter Suppression in the Presence of Body Movements during the Detection of Respiratory Activity through UWB Radars

    Directory of Open Access Journals (Sweden)

    Antonio Lazaro

    2014-02-01

    Full Text Available This paper focuses on the feasibility of tracking the chest wall movement of a human subject during respiration from the waveforms recorded using an impulse-radio (IR ultra-wideband radar. The paper describes the signal processing to estimate sleep apnea detection and breathing rate. Some techniques to solve several problems in these types of measurements, such as the clutter suppression, body movement and body orientation detection are described. Clutter suppression is achieved using a moving averaging filter to dynamically estimate it. The artifacts caused by body movements are removed using a threshold method before analyzing the breathing signal. The motion is detected using the time delay that maximizes the received signal after a clutter removing algorithm is applied. The periods in which the standard deviations of the time delay exceed a threshold are considered macro-movements and they are neglected. The sleep apnea intervals are detected when the breathing signal is below a threshold. The breathing rate is determined from the robust spectrum estimation based on Lomb periodogram algorithm. On the other hand the breathing signal amplitude depends on the body orientation respect to the antennas, and this could be a problem. In this case, in order to maximize the signal-to-noise ratio, multiple sensors are proposed to ensure that the backscattered signal can be detected by at least one sensor, regardless of the direction the human subject is facing. The feasibility of the system is compared with signals recorded by a microphone.

  18. Ground deformation detection of the greater area of Thessaloniki (Northern Greece using radar interferometry techniques

    Directory of Open Access Journals (Sweden)

    D. Raucoules

    2008-07-01

    Full Text Available In the present study SAR interferometric techniques (stacking of conventional interferograms and Permanent Scatterers, using images from satellites ERS-1 and 2, have been applied to the region of Thessaloniki (northern Greece. The period covered by the images is 1992–2000. Both techniques gave good quantitative and qualitative results. The interferometric products were used to study ground surface deformation phenomena that could be related to the local tectonic context, the exploitation of underground water and sediments compaction.

    The city of Thessaloniki shows relatively stable ground conditions. Subsidence in four locations, mainly in the area surrounding the city of Thessaloniki, has been detected and assessed. Two of the sites (Sindos-Kalochori and Langadhas were already known from previous studies as subsiding areas, using ground base measurements. On the contrary the other two sites in the northern suburbs of Thessaloniki (Oreokastro and in the south-east (airport area were unknown as areas of subsidence. A further investigation based on fieldwork is needed in these two areas. Finally, an attempt to interpret the observed deformation, according to the geological regime of the area and its anthropogenic activities, has been carried out.

  19. Detecting Faults in Southern California using Computer-Vision Techniques and Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) Interferometry

    Science.gov (United States)

    Barba, M.; Rains, C.; von Dassow, W.; Parker, J. W.; Glasscoe, M. T.

    2013-12-01

    Knowing the location and behavior of active faults is essential for earthquake hazard assessment and disaster response. In Interferometric Synthetic Aperture Radar (InSAR) images, faults are revealed as linear discontinuities. Currently, interferograms are manually inspected to locate faults. During the summer of 2013, the NASA-JPL DEVELOP California Disasters team contributed to the development of a method to expedite fault detection in California using remote-sensing technology. The team utilized InSAR images created from polarimetric L-band data from NASA's Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) project. A computer-vision technique known as 'edge-detection' was used to automate the fault-identification process. We tested and refined an edge-detection algorithm under development through NASA's Earthquake Data Enhanced Cyber-Infrastructure for Disaster Evaluation and Response (E-DECIDER) project. To optimize the algorithm we used both UAVSAR interferograms and synthetic interferograms generated through Disloc, a web-based modeling program available through NASA's QuakeSim project. The edge-detection algorithm detected seismic, aseismic, and co-seismic slip along faults that were identified and compared with databases of known fault systems. Our optimization process was the first step toward integration of the edge-detection code into E-DECIDER to provide decision support for earthquake preparation and disaster management. E-DECIDER partners that will use the edge-detection code include the California Earthquake Clearinghouse and the US Department of Homeland Security through delivery of products using the Unified Incident Command and Decision Support (UICDS) service. Through these partnerships, researchers, earthquake disaster response teams, and policy-makers will be able to use this new methodology to examine the details of ground and fault motions for moderate to large earthquakes. Following an earthquake, the newly discovered faults can

  20. DATA MULTIPLEXING TECHNIQUES FOR INCREASE THE INFORMATION SECURITY OF AERONAVIGATION SYSTEM AT THE CORRELATED SURVEILLANCE

    Directory of Open Access Journals (Sweden)

    Oleg Slyunyaev

    2011-03-01

    Full Text Available Abstract. The optimization technique of the statistically up-diffused exposure is considered.The operation of the lumped processor, which provides more rapid decision-making, uniting the decision ofseparate receivers is considered, unlike the existent systems in which a lot of physically distributed receiversare used. Different strategies of association of the lumped processor in a context of the whole systemoptimization are studied.Keywords: information security, peripheral receiver, strategies of association, the lumped processer,up-diffused exposure.

  1. Surveillance of arthropod vector-borne infectious diseases using remote sensing techniques: a review.

    Science.gov (United States)

    Kalluri, Satya; Gilruth, Peter; Rogers, David; Szczur, Martha

    2007-10-26

    Epidemiologists are adopting new remote sensing techniques to study a variety of vector-borne diseases. Associations between satellite-derived environmental variables such as temperature, humidity, and land cover type and vector density are used to identify and characterize vector habitats. The convergence of factors such as the availability of multi-temporal satellite data and georeferenced epidemiological data, collaboration between remote sensing scientists and biologists, and the availability of sophisticated, statistical geographic information system and image processing algorithms in a desktop environment creates a fertile research environment. The use of remote sensing techniques to map vector-borne diseases has evolved significantly over the past 25 years. In this paper, we review the status of remote sensing studies of arthropod vector-borne diseases due to mosquitoes, ticks, blackflies, tsetse flies, and sandflies, which are responsible for the majority of vector-borne diseases in the world. Examples of simple image classification techniques that associate land use and land cover types with vector habitats, as well as complex statistical models that link satellite-derived multi-temporal meteorological observations with vector biology and abundance, are discussed here. Future improvements in remote sensing applications in epidemiology are also discussed.

  2. Surveillance of arthropod vector-borne infectious diseases using remote sensing techniques: a review.

    Directory of Open Access Journals (Sweden)

    Satya Kalluri

    2007-10-01

    Full Text Available Epidemiologists are adopting new remote sensing techniques to study a variety of vector-borne diseases. Associations between satellite-derived environmental variables such as temperature, humidity, and land cover type and vector density are used to identify and characterize vector habitats. The convergence of factors such as the availability of multi-temporal satellite data and georeferenced epidemiological data, collaboration between remote sensing scientists and biologists, and the availability of sophisticated, statistical geographic information system and image processing algorithms in a desktop environment creates a fertile research environment. The use of remote sensing techniques to map vector-borne diseases has evolved significantly over the past 25 years. In this paper, we review the status of remote sensing studies of arthropod vector-borne diseases due to mosquitoes, ticks, blackflies, tsetse flies, and sandflies, which are responsible for the majority of vector-borne diseases in the world. Examples of simple image classification techniques that associate land use and land cover types with vector habitats, as well as complex statistical models that link satellite-derived multi-temporal meteorological observations with vector biology and abundance, are discussed here. Future improvements in remote sensing applications in epidemiology are also discussed.

  3. Doppler radar physiological sensing

    CERN Document Server

    Lubecke, Victor M; Droitcour, Amy D; Park, Byung-Kwon; Singh, Aditya

    2016-01-01

    Presents a comprehensive description of the theory and practical implementation of Doppler radar-based physiological monitoring. This book includes an overview of current physiological monitoring techniques and explains the fundamental technology used in remote non-contact monitoring methods. Basic radio wave propagation and radar principles are introduced along with the fundamentals of physiological motion and measurement. Specific design and implementation considerations for physiological monitoring radar systems are then discussed in detail. The authors address current research and commercial development of Doppler radar based physiological monitoring for healthcare and other applications.

  4. Signal Processing for Radar with Array Antennas and for Radar with Micro-Doppler Measurements

    OpenAIRE

    Björklund, Svante

    2017-01-01

    Radar (RAdio Detection And Ranging) uses radio waves to detect the presence of a target and measure its position and other properties. This sensor has found many civilian and military applications due to advantages such as possible large surveillance areas and operation day and night and in all weather. The contributions of this thesis are within applied signal processing for radar in two somewhat separate research areas: 1) radar with array antennas and 2) radar with micro-Doppler measuremen...

  5. MF and HF radar techniques for investigating the dynamics and structure of the 50 to 110 km height region: a review

    Science.gov (United States)

    Reid, Iain Murray

    2015-12-01

    The application of medium-frequency (MF) and high-frequency (HF) partial reflection radar to investigate the neutral upper atmosphere is one of the oldest such techniques still regularly in use. The techniques have been continuously improved and remain a robust and reliable method of obtaining wind velocities, turbulence intensities, electron densities, and measurements of atmospheric structure in the mesosphere lower thermosphere (MLT) region (50 to 110 km). In this paper, we review recent developments, discuss the strengths and weaknesses of the technique, and consider possible improvements.

  6. Detecting and classifying low probability of intercept radar

    CERN Document Server

    Pace, Philip E

    2008-01-01

    This revised and expanded second edition brings you to the cutting edge with new chapters on LPI radar design, including over-the-horizon radar, random noise radar, and netted LPI radar. You also discover critical LPI detection techniques, parameter extraction signal processing techniques, and anti-radiation missile design strategies to counter LPI radar.

  7. Algorithm for Fast Registration of Radar Images

    Directory of Open Access Journals (Sweden)

    Subrata Rakshit

    2002-07-01

    Full Text Available Radar imagery provides an all-weather and 24 h coverage, making it ideal for critical defence applications. In some applications, multiple images acquired of an area need to be registered for further processing. Such situations arise for battlefield surveillance based on satellite imagery. The registration has to be done between an earlier (reference image and a new (live image. For automated surveillance, registration is a prerequisite for change detection. Speed is essential due to large volumes of data involved and the need for quick responses. The registration transformation is quite simple, being mainly a global translation. (Scale and rotation corrections can be applied based on known camera parameters. The challenge lies in the fact that the radar images are not as feature-rich as optical images and the image content variation can be as high as 90 per cent. Even though the change on the ground may not be drastic, seasonal variations can significantly alter the radar signatures of ground, vegetation, and water bodies. This necessitates a novel approach different from the techniques developed for optical images. An algorithm has been developed that leads to fast registration of radar images, even in the presence of specular noise and significant scene content variation. The key features of this approach are adaptability to sensor/terrain types, ability to handle large content variations and false positive rejection. The present work shows that this algorithm allows for various cost-performance trade-offs, making it suitable for a wide variety of applications. The algorithm, in various cost-performance configurations, is tested on a set of ERS images. Results of such tests have been reported, indicating the performance of the algorithm for various cost-performance trade-offs.

  8. Investigation of the Qadimah Fault in Western Saudi Arabia using Satellite Radar Interferometry and Geomorphology Analysis Techniques

    KAUST Repository

    Smith, Robert

    2012-07-01

    The Qadimah Fault has been mapped as a normal fault running through the middle of a planned $50 billion city. For this reason, there is an urgent need to evaluate the seismic hazard that the fault poses to the new development. Although several geophysical studies have supported the existence of a fault, the driving mechanism remains unclear. While a fault controlled by gravity gliding of the overburden on a mobile salt layer is unlikely to be of concern to the city, one caused by the continued extension of a normal rotational fault due to Red Sea rifting could result in a major earthquake. A number of geomorphology and geodetic techniques were used to better understand the fault. An analysis of topographic data revealed a sharp discontinuity in slope aspect and hanging wall tilting which strongly supports the existence of a normal fault. A GPS survey of an emergent reef platform which revealed a tilted coral surface also indicates that deformation has occurred in the region. An interferometric synthetic aperture radar investigation has also been performed to establish whether active deformation is occurring on the fault. Ground movements that could be consistent with inter-seismic strain accumulation have been observed, although the analysis is restricted by the limited data available. However, a simple fault model suggests that the deformation is unlikely due to continued crustal stretching. This, in addition to the lack of footwall uplift in the topography data, suggests that the fault is more likely controlled by a shallow salt layer. However, more work will need to be done in the future to confirm these findings.

  9. Probabilistic hydrological nowcasting using radar based nowcasting techniques and distributed hydrological models: application in the Mediterranean area

    Science.gov (United States)

    Poletti, Maria Laura; Pignone, Flavio; Rebora, Nicola; Silvestro, Francesco

    2017-04-01

    The exposure of the urban areas to flash-floods is particularly significant to Mediterranean coastal cities, generally densely-inhabited. Severe rainfall events often associated to intense and organized thunderstorms produced, during the last century, flash-floods and landslides causing serious damages to urban areas and in the worst events led to human losses. The temporal scale of these events has been observed strictly linked to the size of the catchments involved: in the Mediterranean area a great number of catchments that pass through coastal cities have a small drainage area (less than 100 km2) and a corresponding hydrologic response timescale in the order of a few hours. A suitable nowcasting chain is essential for the on time forecast of this kind of events. In fact meteorological forecast systems are unable to predict precipitation at the scale of these events, small both at spatial (few km) and temporal (hourly) scales. Nowcasting models, covering the time interval of the following two hours starting from the observation try to extend the predictability limits of the forecasting models in support of real-time flood alert system operations. This work aims to present the use of hydrological models coupled with nowcasting techniques. The nowcasting model PhaSt furnishes an ensemble of equi-probable future precipitation scenarios on time horizons of 1-3 h starting from the most recent radar observations. The coupling of the nowcasting model PhaSt with the hydrological model Continuum allows to forecast the flood with a few hours in advance. In this way it is possible to generate different discharge prediction for the following hours and associated return period maps: these maps can be used as a support in the decisional process for the warning system.

  10. Imaging Radar Polarimetry

    Science.gov (United States)

    vanZyl, J. J.; Zebker, H. A.

    1993-01-01

    In this paper, we review the state of the art in imaging radar polarimetry, examine current developments in sensor technology and implementation for recording polarimetric measurements, and describe techniques and areas of application for the new remote sensing data.

  11. Radar signal analysis and processing using Matlab

    CERN Document Server

    Mahafza, Bassem R

    2008-01-01

    Offering radar-related software for the analysis and design of radar waveform and signal processing, this book provides comprehensive coverage of radar signals and signal processing techniques and algorithms. It contains numerous graphical plots, common radar-related functions, table format outputs, and end-of-chapter problems. The complete set of MATLAB[registered] functions and routines are available for download online.

  12. A Technique to Measure Energy Partitioning and Absolute Gas Pressures of Strombolian Explosions Using Doppler Radar at Erebus Volcano

    Science.gov (United States)

    Gerst, A.; Hort, M.; Kyle, P. R.; Voege, M.

    2008-12-01

    In 2005/06 we deployed three 24GHz (K-Band) continuous wave Doppler radar instruments at the crater rim of Erebus volcano in Antarctica. At the time there was a ~40 m wide, ~1000°C hot convecting phonolite lava lake, which was the source of ~0-6 Strombolian gas bubble explosions per day. We measured the velocities of ~50 explosions using a sample rate of 1-15 Hz. Data were downloaded in real-time through a wireless network. The measurements provide new insights into the still largely unknown mechanism of Strombolian eruptions, and help improve existing eruption models. We present a technique for a quasi in-situ measurement of the absolute pressure inside an eruption gas bubble. Pressures were derived using a simple eruption model and measured high resolution bubble surface velocities during explosions. Additionally, this technique allows us to present a comprehensive energy budget of a volcanic explosion as a time series of all important energy terms (i.e. potential, kinetic, dissipative, infrasonic, surface, seismic and thermal energy output). The absolute gas pressure inside rising expanding gas bubbles rapidly drops from ~3-10 atm (at the time when the lake starts to bulge) to ~1 atm before the bubble bursts, which usually occurs at radii of ~15-20m. These pressures are significantly lower than previously assumed for such explosions. The according internal energy of the gas agrees well with the observed total energy output. The results show that large explosions released about 109 to 1010 J each (equivalent to about 200-2000 kg of TNT), at a peak discharge rate frequently exceeding 109 W (the power output of a typical nuclear power plant). This dynamic output is mainly controlled by the kinetic and potential energy of the exploding magma shell, while other energy types were found to be much smaller (with the exception of thermal energy). Remarkably, most explosions at Erebus show two distinct surface acceleration peaks separated by ~0.3 seconds. This suggests

  13. 雷达极化问题和铁氧体变极化技术%Problem of Radar Polarization and Technique ofFerrite Variable Polarization

    Institute of Scientific and Technical Information of China (English)

    蒋仁培; 苏丽萍

    2001-01-01

    描述了雷达极化问题的基本概念,提出了两类铁氧体全(变)极化器的机制。从理论上解决了这种器件的收发功能,并介绍了它在极化雷达中可实现极化扫描和接收的功能。%In this paper ,a basic conception of the problem on radar polarimetry is described. Two types of ferrite all-variable polarizer and its polarization mechanism are proposed. The polarizer acts as all polarization received/transmitted, it can be used in polarization-scan and polarization-receive technique in polarimetric radar.

  14. Ultra-wideband radar sensors and networks

    Science.gov (United States)

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

    2013-08-06

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

  15. Study on interception technique to airborne LPI radar with high probability%对机载LPI雷达的高概率截获技术研究

    Institute of Scientific and Technical Information of China (English)

    邹顺; 胡元奎; 张海黎

    2011-01-01

    The anti-reconnaissance ability and anti-jamming ability of airborne radars can be improved greatly through flexible beam control technique and advanced waveform design technique.A kind of reconnaissance method is put for ward by comprehensively using reconnaissance technique based on digital array,channelized detecting technique based on poly-phase filtering and signal sorting technique based on fuzzy clustering,and the method is hopeful to intercept airborne LPI radar with high probability.%采用先进的功率管理技术和灵活的波形设计技术,能大大提高机载雷达的反侦察和抗干扰能力。提出了一种综合利用数字阵列侦察技术、基于多相滤波的信道化检测技术以及基于模糊聚类的信号分选技术的侦察截获方法,有望实现对机载LPI雷达的高概率截获。

  16. Collaborative Point Paper on Border Surveillance Technology

    Science.gov (United States)

    2007-12-01

    conditions. Closed circuit television (CCTV), infrared image cameras, surveillance UAVs, long range radar and laser radar ( LIDAR ) are often deployed... Photodetector ) long-wave infrared focal plane array, the Star Q provides long-range imaging capabilities from altitudes and standoff ranges

  17. Application of Preliminary Hazard Analysis in Operation and Management at Secondary Surveillance Radar Station%预先危险分析方法在航管二次雷达站运行管理中的应用

    Institute of Scientific and Technical Information of China (English)

    舒涛

    2012-01-01

    本文对预先危险分析方法作了简单介绍。重点研究了PHA在航管二次雷达站运行管理中的应用,找出了广汉机场航管二次雷达站运行管理中存在的危险源,采用定性和定量的方法从危险的后果严重程度和发生可能性两方面对风险进行了分析,提出了控制危险性的有效措施。%This paper gives a brief introduction of preliminary hazard analysis and keys the study on application of preliminary hazard analysis in the operation and management at Secondary Surveillance Radar (SSR) Stations. It finds out the dangerous source in the operation and management of SSR Station at Guanghan Airport and analyzes the risks with the qualitative and quantitative meth- ods from the viewpoints of serious corisequences and potential dangers. It proposes effective measures to control the risks, reduce the probability of accidents, ensure the normal operation of the SSR, and secure the flight training of our college.

  18. A COMPARISON BETWEEN ZERO-OFFSET AND VERTICAL RADAR PROFILING GPR TECHNIQUES WITH EMPHASIS ON PROBLEMATIC BOREHOLE EFFECTS

    DEFF Research Database (Denmark)

    Rossi, Matteo; Vignoli, Giulio; Cassiani, Giorgio;

    contribution: Zero-Offset Profiling (ZOP) and Vertical Radar Profiling (VRP). We make a direct comparison of these methods in a field case (Trecate site, Northern Italy), to explore each method’s capabilities and limitations. Our analysis is focused on the results in the vadose zone and shows...

  19. Quantum radar

    CERN Document Server

    Lanzagorta, Marco

    2011-01-01

    This book offers a concise review of quantum radar theory. Our approach is pedagogical, making emphasis on the physics behind the operation of a hypothetical quantum radar. We concentrate our discussion on the two major models proposed to date: interferometric quantum radar and quantum illumination. In addition, this book offers some new results, including an analytical study of quantum interferometry in the X-band radar region with a variety of atmospheric conditions, a derivation of a quantum radar equation, and a discussion of quantum radar jamming.This book assumes the reader is familiar w

  20. Characterization of seepage surfaces from Space-borne radar interferometry stacking techniques, Southern Dead Sea area, Jordan

    Science.gov (United States)

    Tessari, Giulia; Closson, Damien; Abou Karaki, Najib; Atzori, Simone; Fiaschi, Simone; Floris, Mario; Pasquali, Paolo; Riccardi, Paolo

    2014-05-01

    The Dead Sea is a terminal lake located in a pull-apart basin of the Dead Sea Transform fault zone. It is the lowest emerged place on Earth at about -428 m bsl. Since the 1960s, the over-pumping of its tributaries leads to a decrease in the water level. Eventually, it became more pronounced decades after decades. In 2014, it is more than 1m/year. The overall drop is around 33 m. With salinity ten times greater than the ocean water one, the lake body and its underground lateral extensions act as a high density layer over which the fresh ground waters are in hydrostatic equilibrium. The slope of the interface between saline and fresh waters is ten times shallower than normally expected near the ocean. According to a number of wells along the Jordanian Dead Sea coast, the water table level does not drop at the same speed than the Dead Sea. An increasingly important gradient is constantly being created along the coastal zone. In many places, the fresh ground waters move very rapidly towards the base level to compensate for the imbalance. This statement is supported by a body of observations: a) appearance of vegetation (Tamarisk) in arid areas (precipitation: 50 to 70 mm/year) dominated by salt deposits such as the Lisan peninsula; b) presence of submarine circular collapses visible along the coast. Their diameters decreasing with distance from the shore line; c) appearances of springs and recurring landslides along the coast. With the exception of the submarine features, all these elements are located in the land strip that emerged progressively from the 1960s, 33 m in elevation, ranging from a few decameters up to several kilometers wide. In many places, the surface is characterized by superficial seepages causing subtle to very pronounced subsidence, and sinkholes. In this contribution, we show that advanced differential radar interferometry techniques applied to ERS, ENVISAT and COSMO-SkyMed images stacks are able to underscore the most affected places. The mapping

  1. Autofocus technique for three-dimensional imaging, direct-detection laser radar using Geiger-mode avalanche photodiode focal-plane array.

    Science.gov (United States)

    Oh, Min Seok; Kong, Hong Jin; Kim, Tae Hoon; Jo, Sung Eun

    2010-12-15

    An autofocus technique is proposed for a three-dimensional imaging, direct-detection laser radar system that uses a Geiger-mode avalanche photodiode focal plane array (GmAPD-FPA). This technique is implemented by pointing laser pulses on a target of interest and observing its scattered photon distribution on a GmAPD-FPA. Measuring the standard deviation of the photon distribution on a GmAPD-FPA enables the best focus condition to be found. The feasibility of this technique is demonstrated experimentally by employing a 1 × 8 pixel GmAPD-FPA. It is shown that the spatial resolution improves when the GmAPD-FPA is located in the best focus position found by the autofocus technique.

  2. Radar operation in a hostile electromagnetic environment

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2014-03-01

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

  3. Passive Radar based on WiFi transmissions: signal processing schemes and experimental results

    OpenAIRE

    Falcone, Paolo

    2013-01-01

    Aim of this work is to study innovative techniques and processing strategies for a new passive sensor for short range surveillance. The principle of work of the sensor will be based on the passive radar principle, and WiFi transmissions - which usually provide Internet access within local areas - will be exploited by the passive sensor to detect, localize and classify targets. EU ATOM Project (FP7)

  4. Radar Chart

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Radar Chart collection is an archived product of summarized radar data. The geographic coverage is the 48 contiguous states of the United States. These hourly...

  5. Signal processing in noise waveform radar

    CERN Document Server

    Kulpa, Krzysztof

    2013-01-01

    This book is devoted to the emerging technology of noise waveform radar and its signal processing aspects. It is a new kind of radar, which use noise-like waveform to illuminate the target. The book includes an introduction to basic radar theory, starting from classical pulse radar, signal compression, and wave radar. The book then discusses the properties, difficulties and potential of noise radar systems, primarily for low-power and short-range civil applications. The contribution of modern signal processing techniques to making noise radar practical are emphasized, and application examples

  6. Topical report on subsurface fracture mapping from geothermal wellbores. Phase I. Pulsed radar techniques. Phase II. Conventional logging methods. Phase III. Magnetic borehole ranging

    Energy Technology Data Exchange (ETDEWEB)

    Hartenbaum, B.A.; Rawson, G.

    1980-09-01

    To advance the state-of-the-art in Hot Dry Rock technology, an evaluation is made of (i) the use of radar to map far-field fractures, (ii) the use of more than twenty different conventional well logging tools to map borehole-fracture intercepts, and (iii) the use of magnetic dipole ranging to determine the relative positions of the injection well and the production well within the fractured zone. It is found that according to calculations, VHF backscatter radar has the potential for mapping fractures within a distance of 50 +- 20 meters from the wellbore. A new technique for improving fracture identification is presented. Analyses of extant data indicate that when used synergistically the (1) caliper, (2) resistivity dipmeter, (3) televiewer, (4) television, (5) impression packer, and (6) acoustic transmission are useful for mapping borehole-fracture intercepts. Improvements in both data interpretation techniques and high temperature operation are required. The surveying of one borehole from another appears feasible at ranges of up to 200 to 500 meters by using a low frequency magnetic field generated by a moderately strong dipole source (a solenoid) located in one borehole, a sensitive B field detector that traverses part of the second borehole, narrow band filtering, and special data inversion techniques.

  7. Non-Invasive, Non-Contact Heart Monitoring of Hemodialysis Patients with a Micropower Impulse Radar Technique

    Energy Technology Data Exchange (ETDEWEB)

    Chang, J; Levin, N; Poland, D; Welsh, P; Paulsen, C; Trebes, J; Rosenbury, R; Killip, T

    2002-02-01

    This report summarizes the LLNL LDRD funded portion of a collaborative project to demonstrate and clinically evaluate the micropower impulse radar technology as a means to non-invasively monitor the heart of chronic care patients undergoing hemodialysis. The development is based upon technologies and expertise unique to LLNL. The LLNL LDRD funded portion of this project was used to assist in the definition, design, construction, and evaluation of the prototype.

  8. A vision-based driver nighttime assistance and surveillance system based on intelligent image sensing techniques and a heterogamous dual-core embedded system architecture.

    Science.gov (United States)

    Chen, Yen-Lin; Chiang, Hsin-Han; Chiang, Chuan-Yen; Liu, Chuan-Ming; Yuan, Shyan-Ming; Wang, Jenq-Haur

    2012-01-01

    This study proposes a vision-based intelligent nighttime driver assistance and surveillance system (VIDASS system) implemented by a set of embedded software components and modules, and integrates these modules to accomplish a component-based system framework on an embedded heterogamous dual-core platform. Therefore, this study develops and implements computer vision and sensing techniques of nighttime vehicle detection, collision warning determination, and traffic event recording. The proposed system processes the road-scene frames in front of the host car captured from CCD sensors mounted on the host vehicle. These vision-based sensing and processing technologies are integrated and implemented on an ARM-DSP heterogamous dual-core embedded platform. Peripheral devices, including image grabbing devices, communication modules, and other in-vehicle control devices, are also integrated to form an in-vehicle-embedded vision-based nighttime driver assistance and surveillance system.

  9. Radar Fundamentals, Presentation

    OpenAIRE

    Jenn, David

    2008-01-01

    Topics include: introduction, radar functions, antennas basics, radar range equation, system parameters, electromagnetic waves, scattering mechanisms, radar cross section and stealth, and sample radar systems.

  10. Radar Fundamentals, Presentation

    OpenAIRE

    Jenn, David

    2008-01-01

    Topics include: introduction, radar functions, antennas basics, radar range equation, system parameters, electromagnetic waves, scattering mechanisms, radar cross section and stealth, and sample radar systems.

  11. Sense and avoid radar for micro/nano robots

    Science.gov (United States)

    Molchanov, Pavlo A.; Asmolova, Olha

    2014-10-01

    Revolutionary new fly eye radar sensor technologies based on an array of directional antennas is eliminating the need for a mechanical scanning antenna or complicated phase processor. Proposed sense and avoid radar based on fly eye radar technology can be very small, provides continuous surveillance of entire sky (360 degree by azimuth and elevation) and can be applied for separate or swarm of micro/nano UAS or UGS. Monopulse technology increases bearing accuracy several folds and radar can be multi-functional, multi-frequency. Fly eye micro-radars are inexpensive, can be expendable. Prototype of sense and avoid radar with two directional antennas has been designed and bench tested.

  12. Radar equations for modern radar

    CERN Document Server

    Barton, David K

    2012-01-01

    Based on the classic Radar Range-Performance Analysis from 1980, this practical volume extends that work to ensure applicability of radar equations to the design and analysis of modern radars. This unique book helps you identify what information on the radar and its environment is needed to predict detection range. Moreover, it provides equations and data to improve the accuracy of range calculations. You find detailed information on propagation effects, methods of range calculation in environments that include clutter, jamming and thermal noise, as well as loss factors that reduce radar perfo

  13. Electromagnetic models and inversion techniques for Titan’s Ontario Lacus depth estimation from Cassini RADAR data

    Science.gov (United States)

    Ventura, Bartolomeo; Notarnicola, Claudia; Casarano, Domenico; Posa, Francesco; Hayes, Alexander G.; Wye, Lauren

    2012-11-01

    Since 2004, Cassini RADAR, operating at 13.8 GHz as a radiometer, scatterometer, altimeter and synthetic aperture radar (SAR), provides a vast amount of data, suggesting new scenarios for Titan’s morphology and evolution. An important result was the detection of lakes constituted by liquid hydrocarbons, thus supporting the hypothesis of a methane and ethane cycle similar to water cycle on Earth. In 2007 Ontario Lacus, a 200 km × 70 km lake, was detected near the South pole. To date Ontario is the only large liquid area sensed by Cassini RADAR in the southern hemisphere of Titan. In this work, we analyze the SAR data using two different electromagnetic modeling approaches to retrieve the optical thickness parameter of the liquid hydrocarbon layer. A physically-based model, IEM combined with a gravity capillary wave spectra and integrated into a Bayesian statistical inversion is compared with a semi-empirical model also based on a double-layer description. We consider the impact of the dielectric constant of the surface constituents, as well as wind speed and wave motion scenarios, on the retrieved optical thickness, and by extension, the lake depth and volume estimation. Wind speed can be constrained below 0.7 m/s, in good agreement with the forecasts of Global Circulation Models on Titan. Lake depths estimates depend on the hypotheses on wind speed and loss tangent of the liquid. The average depth lake estimates obtained with the physically based approach range from 2.7 and 8.3 m, with the 95% of the lake area not exceeding 30 m depth. The semiempirical model results confirm this interval, also considering the hypothesis of a low reflectivity lake bed: this would imply lower depth, with a significant part of the lake area not liquid-filled at the present.

  14. Synthetic Aperture Radar Interferometry

    Science.gov (United States)

    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.

  15. A Parallel, High-Fidelity Radar Model

    Science.gov (United States)

    Horsley, M.; Fasenfest, B.

    2010-09-01

    Accurate modeling of Space Surveillance sensors is necessary for a variety of applications. Accurate models can be used to perform trade studies on sensor designs, locations, and scheduling. In addition, they can be used to predict system-level performance of the Space Surveillance Network to a collision or satellite break-up event. A high fidelity physics-based radar simulator has been developed for Space Surveillance applications. This simulator is designed in a modular fashion, where each module describes a particular physical process or radar function (radio wave propagation & scattering, waveform generation, noise sources, etc.) involved in simulating the radar and its environment. For each of these modules, multiple versions are available in order to meet the end-users needs and requirements. For instance, the radar simulator supports different atmospheric models in order to facilitate different methods of simulating refraction of the radar beam. The radar model also has the capability to use highly accurate radar cross sections generated by the method of moments, accelerated by the fast multipole method. To accelerate this computationally expensive model, it is parallelized using MPI. As a testing framework for the radar model, it is incorporated into the Testbed Environment for Space Situational Awareness (TESSA). TESSA is based on a flexible, scalable architecture, designed to exploit high-performance computing resources and allow physics-based simulation of the SSA enterprise. In addition to the radar models, TESSA includes hydrodynamic models of satellite intercept and debris generation, orbital propagation algorithms, optical brightness calculations, optical system models, object detection algorithms, orbit determination algorithms, simulation analysis and visualization tools. Within this framework, observations and tracks generated by the new radar model are compared to results from a phenomenological radar model. In particular, the new model will be

  16. Ocean surveillance satellites

    Science.gov (United States)

    Laurent, D.

    Soviet and U.S. programs involving satellites for surveillance of ships and submarines are discussed, considering differences in approaches. The Soviet program began with the Cosmos 198 in 1967 and the latest, the Cosmos 1400 series, 15 m long and weighing 5 tons, carry radar for monitoring ships and a nuclear reactor for a power supply. Other Soviet spacecraft carrying passive microwave sensors and ion drives powered by solar panels have recently been detonated in orbit for unknown reasons. It has also been observed that the Soviet satellites are controlled in pairs, with sequential orbital changes for one following the other, and both satellites then overflying the same points. In contrast, U.S. surveillance satellites have been placed in higher orbits, thus placing greater demands on the capabilities of the on-board radar and camera systems. Project White Cloud and the Clipper Bow program are described, noting the continued operation of the White Cloud spacecraft, which are equipped to intercept radio signals from surface ships. Currently, the integrated tactical surveillance system program has completed its study and a decision is expected soon.

  17. Design and Implementation of a FPGA and DSP Based MIMO Radar Imaging System

    Directory of Open Access Journals (Sweden)

    Wei Wang

    2015-06-01

    Full Text Available The work presented in this paper is aimed at the implementation of a real-time multiple-input multiple-output (MIMO imaging radar used for area surveillance. In this radar, the equivalent virtual array method and time-division technique are applied to make 16 virtual elements synthesized from the MIMO antenna array. The chirp signal generater is based on a combination of direct digital synthesizer (DDS and phase locked loop (PLL. A signal conditioning circuit is used to deal with the coupling effect within the array. The signal processing platform is based on an efficient field programmable gates array (FPGA and digital signal processor (DSP pipeline where a robust beamforming imaging algorithm is running on. The radar system was evaluated through a real field experiment. Imaging capability and real-time performance shown in the results demonstrate the practical feasibility of the implementation.

  18. A COMPARISON BETWEEN ZERO-OFFSET AND VERTICAL RADAR PROFILING GPR TECHNIQUES WITH EMPHASIS ON PROBLEMATIC BOREHOLE EFFECTS

    DEFF Research Database (Denmark)

    Rossi, Matteo; Vignoli, Giulio; Cassiani, Giorgio

    contribution: Zero-Offset Profiling (ZOP) and Vertical Radar Profiling (VRP). We make a direct comparison of these methods in a field case (Trecate site, Northern Italy), to explore each method’s capabilities and limitations. Our analysis is focused on the results in the vadose zone and shows...... that the dielectric relative permittivity profiles recovered from ZOP and VRP first-break inversions are in strong disagreement, providing very different permittivity profiles. The analysis of synthetic radargrams shows the presence of an electromagnetic (EM) wave established by the joint presence of the air......-filled borehole within a higher permittivity surrounding soil. This event has a velocity intermediate between the soil and air speed values, and interferes with the picking of first arrivals in the VRP mode. The numerical simulations are performed with different borehole diameters, confirming that the velocity...

  19. MICROBIOLOGICAL SURVEILLANCE OF AIR QUALITY IN OPE RATION THEATRES - COMPARISON OF THE CONVENTIONAL SETTLE PL ATE TECHNIQUES VS USE OF AN AIR SAMPLING DEVICE.

    Directory of Open Access Journals (Sweden)

    Prathab

    2012-10-01

    Full Text Available ABSTRACT: BACKGROUND: Air as a means of nosocomial transmission has alw ays remained as a cause of concern for health care providers and especially personnel involved in infection control activities. Although there are no uniform c onsensus on either the standards for surveillance, methodology for monitoring or the lev els of acceptable contamination, it still remains a fact that we need to have some criteria t o monitor air quality in atleast the critical care areas like the operation theatres. METHODOLOGY: Air quality surveillance in the operation theatres was performed simultaneously usin g the settle plate technique and an air sampling device. A total of 9 operation theatres were subjected to 4 surveillance cycles with a minimum of 2 recordings in each theatre following standard protocols and accepted method used to calculate bioburden. RESULTS: A comparison was made between the two methods using the data available with 72 recordings . In th e settle plate technique, the mean cfu /mm3 was found to be 17.11 and 22cfu/mm3 at less than 30 cm and at a point more than 30cms of the operating table where as the corresponding means usi ng the air sampler was137.83 and 164.11cfu/mm3 respectively which showed considerable statistical significance . CONCLUSION : The use of an air sampler would be more appropriate in monitoring the air quality in critical care areas ensuring a more stringent method of qual ity check without compromising on the the standard accepted norms and addressing the issue of patient safety with reference to infection prevention

  20. Ground penetrating radar

    CERN Document Server

    Daniels, David J

    2004-01-01

    Ground-penetrating radar has come to public attention in recent criminal investigations, but has actually been a developing and maturing remote sensing field for some time. In the light of recent expansion of the technique to a wide range of applications, the need for an up-to-date reference has become pressing. This fully revised and expanded edition of the best-selling Surface-Penetrating Radar (IEE, 1996) presents, for the non-specialist user or engineer, all the key elements of this technique, which span several disciplines including electromagnetics, geophysics and signal processing. The

  1. Reconfigurable L-Band Radar

    Science.gov (United States)

    Rincon, Rafael F.

    2008-01-01

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

  2. Progress report on the NASA/JPL airborne synthetic aperture radar system

    Science.gov (United States)

    Lou, Y.; Imel, D.; Chu, A.; Miller, T.; Moller, D.; Skotnicki, W.

    2001-01-01

    AIRSAR has served as a test-bed for both imaging radar techniques and radar technologies for over a decade. In fact, the polarimetric, cross-track interferometric, and along-track introferometric radar techniques were all developed using AIRSAR.

  3. Introduction to radar target recognition

    CERN Document Server

    Tait, P

    2006-01-01

    This new text provides an overview of the radar target recognition process and covers the key techniques being developed for operational systems. It is based on the fundamental scientific principles of high resolution radar, and explains how the techniques can be used in real systems, taking into account the characteristics of practical radar system designs and component limitations. It also addresses operational aspects, such as how high resolution modes would fit in with other functions such as detection and tracking. Mathematics is kept to a minimum and the complex techniques and issues are

  4. FMCW Radar with Broadband Communication Capability

    NARCIS (Netherlands)

    Barrenechea, P.; Elferink, F.H.; Janssen, J.A.A.J.

    2007-01-01

    The use of amplitude modulation to encode information onto an FMCW radar signal is proposed in this paper. This new technique, that has been named AM-FMCW communicating radar, provides a new channel for broadband communication by reusing the radar frequencies and without introducing any distortion i

  5. Small-scale loess landslide monitoring with small baseline subsets interferometric synthetic aperture radar technique-case study of Xingyuan landslide, Shaanxi, China

    Science.gov (United States)

    Zhao, Chaoying; Zhang, Qin; He, Yang; Peng, Jianbing; Yang, Chengsheng; Kang, Ya

    2016-04-01

    Small baseline subsets interferometric synthetic aperture radar technique is analyzed to detect and monitor the loess landslide in the southern bank of the Jinghe River, Shaanxi province, China. Aiming to achieve the accurate preslide time-series deformation results over small spatial scale and abrupt temporal deformation loess landslide, digital elevation model error, coherence threshold for phase unwrapping, and quality of unwrapping interferograms must be carefully checked in advance. In this experience, land subsidence accompanying a landslide with the distance <1 km is obtained, which gives a sound precursor for small-scale loess landslide detection. Moreover, the longer and continuous land subsidence has been monitored while deformation starting point for the landslide is successfully inverted, which is key to monitoring the similar loess landslide. In addition, the accelerated landslide deformation from one to two months before the landslide can provide a critical clue to early warning of this kind of landslide.

  6. Innovative SAR/MTI Concepts for Digital Radar

    NARCIS (Netherlands)

    Wit, J.J.M. de

    2008-01-01

    Contemporary military operations make high demands on the capabilities of sensors. Modern sensors must have the capability to perform different tasks, such as ground surveillance and target tracking, simultaneously. Multifunction digital radar may provide the required capabilities and meet the

  7. Radar image registration and rectification

    Science.gov (United States)

    Naraghi, M.; Stromberg, W. D.

    1983-01-01

    Two techniques for radar image registration and rectification are presented. In the registration method, a general 2-D polynomial transform is defined to accomplish the geometric mapping from one image into the other. The degree and coefficients of the polynomial are obtained using an a priori found tiepoint data set. In the second part of the paper, a rectification procedure is developed that models the distortion present in the radar image in terms of the radar sensor's platform parameters and the topographic variations of the imaged scene. This model, the ephemeris data and the digital topographic data are then used in rectifying the radar image. The two techniques are then used in registering and rectifying two examples of radar imagery. Each method is discussed as to its benefits, shortcomings and registration accuracy.

  8. Research of mobile multi-function ATC radar system%机动多功能航管雷达系统研究

    Institute of Scientific and Technical Information of China (English)

    张家勇; 徐鹏; 任翔

    2014-01-01

    The mobile multi-function ATC radar system is the new radar technology system with high mobility,high reliability, multifunction,intelligentization and high data rate,which is based on the traditional fixed station aerial surveillance radar,so as to meet the specific circumstances of low-medium altitude airspace and airport aerial surveillance requirements. The radar system is divided into radar subsystem,ATC subsystem and emergency communication subsystem according to its function. The design principle and the technique features of mobile multi-function ATC radar system are described briefly in this paper.%机动多功能航管雷达系统是在传统固定站式航路监视雷达研究基础上,具有高机动、高可靠、多功能、智能化、高数据率的新雷达技术系统,以满足在特定环境下对中低空和机场空域航路监视的要求。该雷达系统按照功能划分为雷达子系统、ATC子系统、应急通信子系统。叙述了机动多功能航管雷达系统的设计原理和技术特点。

  9. Recent Advances in Radar Polarimetry and Polarimetric SAR Interferometry

    Science.gov (United States)

    Boerner, Wolfgang-Martin

    2005-01-01

    The development of Radar Polarimetry and Radar Interferometry is advancing rapidly, and these novel radar technologies are revamping Synthetic Aperture Radar Imaging decisively. In this exposition the successive advancements are sketched; beginning with the fundamental formulations and high-lighting the salient points of these diverse remote sensing techniques. Whereas with radar polarimetry the textural fine-structure, target-orientation and shape, symmetries and material constituents can be recovered with considerable improvements above that of standard amplitude-only Polarization Radar ; with radar interferometry the spatial (in depth) structure can be explored. In Polarimetric-Interferometric Synthetic Aperture Radar (POL-IN-SAR) Imaging it is possible to recover such co-registered textural plus spatial properties simultaneously. This includes the extraction of Digital Elevation Maps (DEM) from either fully Polarimetric (scattering matrix) or Interferometric (dual antenna) SAR image data takes with the additional benefit of obtaining co-registered three-dimensional POL-IN-DEM information. Extra-Wide-Band POL-IN-SAR Imaging - when applied to Repeat-Pass Image Overlay Interferometry - provides differential background validation and measurement, stress assessment, and environmental stress-change monitoring capabilities with hitherto unattained accuracy, which are essential tools for improved global biomass estimation. More recently, by applying multiple parallel repeat-pass EWB-POL-D(RP)-IN-SAR imaging along stacked (altitudinal) or displaced (horizontal) flight-lines will result in Tomographic (Multi- Interferometric) Polarimetric SAR Stereo-Imaging , including foliage and ground penetrating capabilities. It is shown that the accelerated advancement of these modern EWB-POL-D(RP)-IN-SAR imaging techniques is of direct relevance and of paramount priority to wide-area dynamic homeland security surveillance and local-to-global environmental ground-truth measurement

  10. Fast image-formation algorithm for ultrahigh-resolution airborne squint spotlight synthetic aperture radar based on adaptive sliding receive-window technique

    Science.gov (United States)

    Yang, Wei; Zeng, Hong-cheng; Chen, Jie; Wang, Peng-bo

    2014-01-01

    Adaptive sliding receive-window (ASRW) technique was usually introduced in airborne squint synthetic aperture radar (SAR) systems. Airborne squint spotlight SAR varies its receive-window starting time pulse-by-pulse as a function of range-walk, namely, the linear term of range cell migration (RCM). As a result, a huge data volume of the highly squint spotlight SAR echo signal can be significantly reduced. Because the ASRW technique changes the echo-receive starting time and Doppler history, the conventional image algorithm cannot be employed to directly focus airborne squint spotlight ASRW-SAR data. Therefore, a fast image-formation algorithm, based on the principle of the wave number domain algorithm (WDA) and azimuth deramping processing, was proposed for accurately and efficiently focusing the squint spotlight ASRW-SAR data. Azimuth deramping preprocessing was implemented for eliminating azimuth spectrum aliasing. Moreover, bulk compression and modified Stolt mapping were utilized for high-precision focusing. Additionally, geometric correction was employed for compensating the image distortion resulting from the ASRW technique. The proposed algorithm was verified by evaluating the image performance of point targets in different squint angles. In addition, a detailed analysis of computation loads in the appendix indicates that the processing efficiency can be greatly improved, e.g., the processing efficiency could be improved by 17 times in the 70-deg squint angle by applying the proposed image algorithm to the squint spotlight ASRW-SAR data.

  11. Detection of small, slow ground targets using Synthetic Aperture Radar

    Science.gov (United States)

    Chen, Curtis; Chapin, Elaine; Rosen, Paul

    2005-01-01

    Synthetic aperture radar (SAR) along-track interferometry (ATI) is a technique for sensing Earth-surface motion. The technique involves interferometrically combining data from two radar images acquired from phase centers separated along the platform flight track.

  12. Search Radar ECM/EA Simulator

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Tests the effectiveness of electronic countermeasures/electronic attack (ECM/EA) equipment and techniques for jamming airborne search and targeting radars....

  13. Discussing State-of-the-Art Spatial Visualization Techniques Applicable for the Epidemiological Surveillance Data on the Example of Campylobacter spp. in Raw Chicken Meat.

    Science.gov (United States)

    Plaza-Rodríguez, C; Appel, B; Kaesbohrer, A; Filter, M

    2016-08-01

    Within the European activities for the 'Monitoring and Collection of Information on Zoonoses', annually EFSA publishes a European report, including information related to the prevalence of Campylobacter spp. in Germany. Spatial epidemiology becomes here a fundamental tool for the generation of these reports, including the representation of prevalence as an essential element. Until now, choropleth maps are the default visualization technique applied in epidemiological monitoring and surveillance reports made by EFSA and German authorities. However, due to its limitations, it seems to be reasonable to explore alternative chart type. Four maps including choropleth, cartogram, graduated symbols and dot-density maps were created to visualize real-world sample data on the prevalence of Campylobacter spp. in raw chicken meat samples in Germany in 2011. In addition, adjacent and coincident maps were created to visualize also the associated uncertainty. As an outcome, we found that there is not a single data visualization technique that encompasses all the necessary features to visualize prevalence data alone or prevalence data together with their associated uncertainty. All the visualization techniques contemplated in this study demonstrated to have both advantages and disadvantages. To determine which visualization technique should be used for future reports, we recommend to create a dialogue between end-users and epidemiologists on the basis of sample data and charts. The final decision should also consider the knowledge and experience of end-users as well as the specific objective to be achieved with the charts.

  14. Pathfinder radar development at Sandia National Laboratories

    Science.gov (United States)

    Castillo, Steven

    2016-05-01

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

  15. Moving Target Indication for Multi-channel Airborne Radar Systems

    NARCIS (Netherlands)

    Lidicky, L.

    2010-01-01

    Moving target indication (MTI) using radar is of great interest in civil and military applications. Its uses include airborne or space-borne surveillance of ground moving vehicles (cars, trains) or ships at sea, for instance. Airborne (space-borne) radar offers several advantages when compared to op

  16. Human Target Tracking in Multistatic Ultra-Wideband Radar

    NARCIS (Netherlands)

    He, Y.

    2014-01-01

    Multistatic ultra-wideband radar is acknowledged to be useful for human tracking in indoor surveillance. In this thesis, a global signal processing chain for detection and localization of moving human targets using a multistatic ultra-wideband radar system is proposed. The design options for the sys

  17. Moving Target Indication for Multi-channel Airborne Radar Systems

    NARCIS (Netherlands)

    Lidicky, L.

    2010-01-01

    Moving target indication (MTI) using radar is of great interest in civil and military applications. Its uses include airborne or space-borne surveillance of ground moving vehicles (cars, trains) or ships at sea, for instance. Airborne (space-borne) radar offers several advantages when compared to op

  18. Evaluation of four sampling techniques for surveillance of Culex quinquefasciatus (Diptera: Culicidae) and other mosquitoes in African rice agroecosystems.

    Science.gov (United States)

    Muturi, Ephantus J; Mwangangi, Joseph; Shililu, Josephat; Muriu, Simon; Jacob, Benjamin; Mbogo, Charles M; John, Githure; Novak, Robert

    2007-05-01

    Field studies were conducted in a rice, Oryza sativa L., agroecosystem in Mwea Kenya to compare the efficiency of CO2-baited Centers for Disease Control (CDC) light traps against nonbaited CDC light traps and gravid traps against oviposition traps in outdoor collection of Culex quinquefasciatus Say (Diptera: Culicidae) and other mosquitoes. Collectively, 21 mosquito species from the genera Culex, Anopheles, Mansonia, Ficalbia, and Aedes were captured during the 10-wk study period. Cx. quinquefasciatus was the predominant species in all trap types with proportions ranging from 57% in the nonbaited CDC light traps to 95% in the gravid traps. Significantly higher numbers of Cx. quinquefasciatus and Culex annulioris Theobald were collected in the CO2-baited CDC light traps than in the nonbaited CDC light traps, but the numbers of other mosquito species, including malaria vectors Anopheles arabiensis Patton and Anopheles funestus Giles did not differ significantly between the two trap types. More Cx. quinquefasciatus females were collected in grass infusion-baited gravid traps than egg rafts of this species in oviposition traps containing the same infusion. Although most mosquitoes captured in CO,-baited and nonbaited CDC light traps were unfed, most of those collected in gravid traps were gravid. From these findings, it is concluded that at least in the rice-growing area of Mwea Kenya, CO2-baited CDC light traps in conjunction with gravid traps can be used in monitoring of Cx. quinquefasciatus both for control and disease surveillance.

  19. A radar image time series

    Science.gov (United States)

    Leberl, F.; Fuchs, H.; Ford, J. P.

    1981-01-01

    A set of ten side-looking radar images of a mining area in Arizona that were aquired over a period of 14 yr are studied to demonstrate the photogrammetric differential-rectification technique applied to radar images and to examine changes that occurred in the area over time. Five of the images are rectified by using ground control points and a digital height model taken from a map. Residual coordinate errors in ground control are reduced from several hundred meters in all cases to + or - 19 to 70 m. The contents of the radar images are compared with a Landsat image and with aerial photographs. Effects of radar system parameters on radar images are briefly reviewed.

  20. Surveillance Pleasures

    DEFF Research Database (Denmark)

    Albrechtslund, Anders

    and leisure have not been studied with the same intensity as e.g. policing, civil liberties and social sorting. This paper offers a study of trends in surveillance pleasures, i.e. watching and eavesdropping in popular culture. My focus is the existential aspects and ethical dilemmas of surveillance...

  1. Coherent MUSIC technique for range/angle information retrieval: Application to a frequency modulated continuous wave MIMO radar

    NARCIS (Netherlands)

    Belfiori, F.; Rossum, W. van; Hoogeboom, P.

    2014-01-01

    A coherent two-dimensional (2D) multiple signal classification (MUSIC) processing for the simultaneous estimation of angular and range target positions has been presented. A 2D spatial smoothing technique is also introduced to cope with the coherent behaviour of the received echoes, which may result

  2. Weather Radar Stations

    Data.gov (United States)

    Department of Homeland Security — These data represent Next-Generation Radar (NEXRAD) and Terminal Doppler Weather Radar (TDWR) weather radar stations within the US. The NEXRAD radar stations are...

  3. Mars Radar Opens a Planet's Third Dimension

    Science.gov (United States)

    2008-01-01

    Radar sounder instruments orbiting Mars have looked beneath the Martian surface and opened up the third dimension for planetary exploration. The technique's success is prompting scientists to think of all the other places in the Solar System where they would like to use radar sounders. The first radar sounder at Mars was the Mars Advanced Radar for Subsurface and Ionospheric Sounding (MARSIS) on the European Space Agency's Mars Express Orbiter. It has been joined by the complementary Shallow Subsurface Radar (SHARAD), operating at a different wavelength aboard NASA's Mars Reconnaissance Orbiter. The data in this animation are from SHARAD.

  4. High resolution shallow geologic characterization of a late Pleistocene eolian environment using ground penetrating radar and optically stimulated luminescence techniques: North Carolina, USA

    Science.gov (United States)

    Mallinson, D.; Mahan, S.; Moore, Christine

    2008-01-01

    Geophysical surveys, sedimentology, and optically-stimulated luminescence age analyses were used to assess the geologic development of a coastal system near Swansboro, NC. This area is a significant Woodland Period Native American habitation and is designated the "Broad Reach" archaeological site. 2-d and 3-d subsurface geophysical surveys were performed using a ground penetrating radar system to define the stratigraphic framework and depositional facies. Sediment samples were collected and analyzed for grain-size to determine depositional environments. Samples were acquired and analyzed using optically stimulated luminescence techniques to derive the depositional age of the various features. The data support a low eolian to shallow subtidal coastal depositional setting for this area. Li-DAR data reveal ridge and swale topography, most likely related to beach ridges, and eolian features including low-relief, low-angle transverse and parabolic dunes, blowouts, and a low-relief eolian sand sheet. Geophysical data reveal dominantly seaward dipping units, and low-angle mounded features. Sedimentological data reveal mostly moderately-well to well-sorted fine-grained symmetrical to coarse skewed sands, suggesting initial aqueous transport and deposition, followed by eolian reworking and bioturbation. OSL data indicate initial coastal deposition prior to ca. 45,000 yBP, followed by eolian reworking and low dune stabilization at ca. 13,000 to 11,500 yBP, and again at ca. 10,000 yBP (during, and slightly after the Younger Dryas chronozone).

  5. Investigation of the winds and electron concentration variability in the D region of the ionosphere by the partial-reflection radar technique

    Science.gov (United States)

    Weiland, R. M.; Bowhill, S. A.

    1981-01-01

    The development and first observations of the partial-reflection drifts experiment at Urbana, Illinois (40 N) are described. The winds data from the drifts experiment are compared with electron concentration data obtained by the differential-absorption technique to study the possible meteorological causes of the winter anomaly in the mesosphere at midlatitudes. winds data obtained by the meteor-radar experiment at Urbana are also compared with electron concentration data measured at Urban. A significant correlation is shown is both cases between southward winds and increasing electron concentration measured at the same location during winter. The possibility of stratospheric/mesospheric coupling is investigated by comparing satellite-measured 0.4 mbar geopotential data with mesospheric electron concentration data. No significant coupling was observed. The winds measured at Saskatoon, Saskatchewan (52 N) are compared with the electron concentrations measured at Urban, yielding constant fixed relationship, but significant correlations for short segments of the winter. A significant coherence is observed at discrete frequencies during segments of the winter.

  6. Analiza kontinualnih frekvencijski modulisanih radarskih signala primenom vremensko-frekvencijskih transformacija i korelacionih tehnika / FMCW radar signal analysis by time-frequency representations and correlation techniques

    Directory of Open Access Journals (Sweden)

    Slobodan Simić

    2007-10-01

    Full Text Available U radu su analizirana dva metoda za detekciju i procenu parametara radarskih signala s malom verovatnoćom presretanja, pri čemu ne postoji saradnja između prijemnika i predajnika. Prvi algoritam čini analiza signala pomoću vremensko-frekvencijskih transformacija zajedno sa tehnikama za prepoznavanje oblika. U osnovi drugog algoritma detekcije je procena periodične autokorelacione funkcije. Analizirani su kontinualni frekvencijski modulisani radarski signali (FMCW, često primenjivani u radarima s malom verovatnoćom presretanja. Korišćeni su test-signali, dobijeni eksperimentalnim putem. Realizovan je eksperiment s realnim predajnikom i prijemnikom FMCW signala, a rezultati obrade primljenih signala prikazani su u radu. / Two LPI signal detection and parameter estimation methods are analyzed in a non-cooperative context. The first method is based on the time-frequency signal analysis along with pattern recognition techniques. The second one is based on the estimation of a periodic autocorrelation function. Frequency modulation continuous wave (FMCW signals are analyzed as a class of waveforms often used in LPI radars. Experimentally obtained signals are used in tests. An experiment with a real FMCW signal transceiver and a receiver is carried out and the obtained signal analysis results are presented.

  7. Bistatic radar

    CERN Document Server

    Willis, Nick

    2004-01-01

    Annotation his book is a major extension of a chapter on bistatic radar written by the author for the Radar Handbook, 2nd edition, edited by Merrill Skolnik. It provides a history of bistatic systems that points out to potential designers the applications that have worked and the dead-ends not worth pursuing. The text reviews the basic concepts and definitions, and explains the mathematical development of relationships, such as geometry, Ovals of Cassini, dynamic range, isorange and isodoppler contours, target doppler, and clutter doppler spread.Key Features * All development and analysis are

  8. Phased-MIMO Radar: A Tradeoff Between Phased-Array and MIMO Radars

    CERN Document Server

    Hassanien, Aboulnasr

    2009-01-01

    We propose a new technique for multiple-input multiple-output (MIMO) radar with colocated antennas which we call phased-MIMO radar. The new technique enjoys the advantages of MIMO radar without sacrificing the main advantage of phased-array radar which is the coherent processing gain at the transmitting side. The essence of the proposed technique is to partition the transmitting array into a number of subarrays that are allowed to overlap. Then, each subarray is used to coherently transmit a waveform which is orthogonal to the waveforms transmitted by other subarrays. Coherent processing gain can be achieved by designing a weight vector for each subarray to form a beam towards a certain direction in space. Moreover, the subarrays are combined jointly to form a MIMO radar resulting in higher resolution capabilities. The substantial improvements offered by the proposed phased-MIMO radar technique as compared to previous techniques are demonstrated analytically and by simulations through analysis of the correspo...

  9. Commercially Available Low Probability of Intercept Radars and Non-Cooperative ELINT Receiver Capabilities

    Science.gov (United States)

    2014-09-01

    radar . The radar also has an integrated low probability of intercept ( LPI ) I/J- band surface surveillance mode, using FMCW ...SUBJECT TERMS Low Probability of Intercept ( LPI ) Radar , ES/ELINT Systems, Receivers, Electronic Warfare 16. SECURITY CLASSIFICATION OF: 17. LIMITATION...BLANK iv TABLE OF CONTENTS I. SECTION ONE – LPI RADARS ……………………………………………..1 A.

  10. Evaluation of the information content of wideband and ultra-wideband radar returns from an F14, F15 and F16 using asymptotic electromagnetic techniques

    CSIR Research Space (South Africa)

    Cilliers, Jacques E

    2012-10-01

    Full Text Available . Returns from an F14, F15 and F16 were simulated using an asymptotic RCS prediction code. The information content of the three targets is evaluated for four sets of radar waveforms....

  11. Radar reflection off extensive air showers

    Directory of Open Access Journals (Sweden)

    Werner F.

    2013-06-01

    Full Text Available We investigate the possibility of detecting extensive air showers by the radar technique. Considering a bistatic radar system and different shower geometries, we simulate reflection of radio waves off the static plasma produced by the shower in the air. Using the Thomson cross-section for radio wave reflection, we obtain the time evolution of the signal received by the antennas. The frequency upshift of the radar echo and the power received are studied to verify the feasibility of the radar detection technique.

  12. Recent advances in geologic mapping by radar

    Science.gov (United States)

    Farr, T. G.

    1984-01-01

    Quantitative techniques are available which allow the analysis of SAR images for the derivation of geological surface and process data. In conjunction with calibrated radar sensors operating at several incidence angles, wavelengths, and polarizations, the compilation of multiparameter radar signatures of lithological and geomorphic units can accordingly proceed for geological mapping in unknown areas. While radar image tone can be used in arid zones to derive surface micromorphology, heavily vegetated tropical regions require the analysis of radar image texture by means of Fourier techniques which decompose the image into bandpasses that represent different scales of texture.

  13. Mapping Ground Subsidence Phenomena in Ho Chi Minh City through the Radar Interferometry Technique Using ALOS PALSAR Data

    Directory of Open Access Journals (Sweden)

    Dinh Ho Tong Minh

    2015-07-01

    Full Text Available The rapidly developing urbanization since the last decade of the 20th century has led to extensive groundwater extraction, resulting in subsidence in Ho Chi Minh City, Vietnam. Recent advances in multi-temporal spaceborne SAR interferometry, especially with a persistent scatters interferometry (PSI approach, has made this a robust remote sensing technique for measuring large-scale ground subsidence with millimetric accuracy. This work has presented an advanced PSI analysis, to provide an unprecedented spatial extent and continuous temporal coverage of the subsidence in Ho Chi Minh City from 2006 to 2010. The study shows that subsidence is most severe in the Holocene silt loam areas along the Sai Gon River and in the southwest of the city. The groundwater extraction resulting from urbanization and urban growth is mainly responsible for the subsidence. Subsidence in turn leads to more flooding and water nuisance. The correlation between the reference leveling velocity and the estimated PSI result is R2 = 0.88, and the root mean square error is 4.3 (mm/year, confirming their good agreement. From 2006 to 2010, the estimation of the average subsidence rate is -8.0 mm/year, with the maximum value up to -70 mm/year. After four years, in regions along Sai Gon River and in the southwest of the city, the land has sunk up to -12 cm. If not addressed, subsidence leads to the increase of inundation, both in frequency and spatial extent. Finally, regarding climate change, the effects of subsidence should be considered as appreciably greater than those resulting from rising sea level. It is essential to consider these two factors, because the city is inhabited by more than 7.5 million people, where subsidence directly impacts urban structures and infrastructure.

  14. Land Deformation at the Thessaloniki - Giannitsa Plain (Greece) Deduced from 20- years Radar Observations using Persistent Scatterers Techniques

    Science.gov (United States)

    Svigkas, N.; Papoutsis, I.; Loupasakis, K.; Kiratzi, A. A.; Kontoes, C.

    2015-12-01

    We present the detected deformation and interpret the results in the light of ground-truth hydrological data, for the Thessaloniki-Giannitsa plain, the largest deltaic plain in Greece, encircled by Mounts Vermio, Paiko and Pieria. The contemporary morphology was gradually developed from the tectonic variations of the upper Pleistocene. The area has been subjected to many changes due to both natural causes and to human intervention. ERS-1, 2 and Envisat data provided from the European Space Agency were analysed to produce a time-series analysis based on Persistent Scatterer techniques. The mass processing of the 81 satellite images led to the creation of more than 250 Interferograms. The broader area of interest consists primarily of agricultural lands, leading to limited Interferometric coherence, and therefore careful Interferogram filtering and phase unwrapping of the input stack was crucial for reliable velocity generation. Our results show a strong deformation signal in regions of significant lifelines, as the railway and road network. Moreover, the satellite imagery revealed two significantly deforming sites: Kalochori and Sindos. The broader Kalochori region, the locus of the industrial activity of the city of Thessaloniki, is located below sea level. Both sites are suffering from land subsidence for more than 50 years, with several marine invasions reported in the past. Interestingly enough the two datasets -that represent two decades- show a reversed deformation pattern: The period in-between 1993 to 2000 is characterized by subsidence up to 34 mm/y, whereas from 2002 to 2010 there is an uplifting trend (more than 20 mm/yr). This result is crosschecked with hydrogeological data; the interpretation depicts that at Kalochori and Sindos the human factor (i.e. over pumping) is the dominant driver of these surface displacements. Although this was an assumption of previous studies, here we present for the first time, systematic proof that the detected uplift of

  15. A coherent through-wall MIMO phased array imaging radar based on time-duplexed switching

    Science.gov (United States)

    Chen, Qingchao; Chetty, Kevin; Brennan, Paul; Lok, Lai Bun; Ritchie, Matthiew; Woodbridge, Karl

    2017-05-01

    Through-the-Wall (TW) radar sensors are gaining increasing interest for security, surveillance and search and rescue applications. Additionally, the integration of Multiple-Input, Multiple-Output (MIMO) techniques with phased array radar is allowing higher performance at lower cost. In this paper we present a 4-by-4 TW MIMO phased array imaging radar operating at 2.4 GHz with 200 MHz bandwidth. To achieve high imaging resolution in a cost-effective manner, the 4 Tx and 4 Rx elements are used to synthesize a uniform linear array (ULA) of 16 virtual elements. Furthermore, the transmitter is based on a single-channel 4-element time-multiplexed switched array. In transmission, the radar utilizes frequency modulated continuous wave (FMCW) waveforms that undergo de-ramping on receive to allow digitization at relatively low sampling rates, which then simplifies the imaging process. This architecture has been designed for the short-range TW scenarios envisaged, and permits sufficient time to switch between antenna elements. The paper first outlines the system characteristics before describing the key signal processing and imaging algorithms which are based on traditional Fast Fourier Transform (FFT) processing. These techniques are implemented in LabVIEW software. Finally, we report results from an experimental campaign that investigated the imaging capabilities of the system and demonstrated the detection of personnel targets. Moreover, we show that multiple targets within a room with greater than approximately 1 meter separation can be distinguished from one another.

  16. The Radar Roadmap

    Science.gov (United States)

    2013-01-01

    LIMITATION OF ABSTRACT Same as Report ( SAR ) 18. NUMBER OF PAGES 25 19a. NAME OF RESPONSIBLE PERSON a. REPORT unclassified b. ABSTRACT unclassified c...ABSTRACT Same as Report ( SAR ) 18. NUMBER OF PAGES 25 19a. NAME OF RESPONSIBLE PERSON a. REPORT unclassified b. ABSTRACT unclassified c. THIS PAGE...object bistatic radars. The former allows high resolution without the use of pulse compression techniques and the latter promises cheaper systems by

  17. Coastal city subsidence in Shenzhen (China), monitored using multi-frequency radar interferometry time-series techniques

    Science.gov (United States)

    Liu, Peng; Li, Yongsheng; Singleton, Andrew; Li, Qingquan; Zhang, Jingfa; Li, Zhenhong

    2014-05-01

    In just 26 years, the coastal city of Shenzhen (Southern China) has been transformed from a small fishing village to a modern city with a population exceeding 8.5 million people. Following its designation as a Special Economic Zone in the 1980s, the city became a test bed for China's economic reforms and currently leads many new practices in urban planning. The rapid economic development was matched by a sharp increase in the demand for usable land and consequently, extensive coastal reclamation has been undertaken by piling rock fragments from nearby hills onto the seabed. However, it has recently been reported that new apartments, offices and transport networks built on the reclaimed land have become unusable due to ground subsidence. The additional threat of coastal inundation from sea-level rise also requires serious consideration. InSAR time-series techniques (such as Persistent Scatterer and Small Baseline InSAR) are capable of detecting sub-centimetre elevation changes of the Earth's surface over large areas and at a density far exceeding the capabilities of a GPS network - particularly for such an urban environment as Shenzhen. This study uses numerous independent tracks of SAR data (two ENVISAT C-band tracks and two ALOS L-band tracks) to determine the surface movements between 2004 and 2013. Quantitative comparative analyses are carried out in the overlapping area between two adjacent tracks, and thus no ground data is required to validate InSAR results. The results show greatest subsidence in coastal areas with the areas of reclaimed land also predominantly undergoing subsidence. The combination of different ascending and descending tracks allows 2D velocity fields to be estimated and it will be important to determine whether the subsidence from the recently reclaimed land is consolidation or part of a longer-term trend. This ability to provide accurate measurements of ground stability for the city of Shenzhen will help focus investigations into areas of

  18. Radar Target Classification using Recursive Knowledge-Based Methods

    DEFF Research Database (Denmark)

    Jochumsen, Lars Wurtz

    The topic of this thesis is target classification of radar tracks from a 2D mechanically scanning coastal surveillance radar. The measurements provided by the radar are position data and therefore the classification is mainly based on kinematic data, which is deduced from the position. The target...... been terminated. Therefore, an update of the classification results must be made for each measurement of the target. The data for this work are collected throughout the PhD and are both collected from radars and other sensors such as GPS....

  19. Automotive Radar Sensors in Silicon Technologies

    CERN Document Server

    Jain, Vipul

    2013-01-01

    This book presents architectures and design techniques for mm-wave automotive radar transceivers. Several fully-integrated transceivers and receivers operating at 22-29 GHz and 77-81 GHz are demonstrated in both CMOS and SiGe BiCMOS technologies. Excellent performance is achieved indicating the suitability of silicon technologies for automotive radar sensors.  This book bridges an existing gap between information available on dependable system/architecture design and circuit design.  It provides the background of the field and detailed description of recent research and development of silicon-based radar sensors.  System-level requirements and circuit topologies for radar transceivers are described in detail. Holistic approaches towards designing radar sensors are validated with several examples of highly-integrated radar ICs in silicon technologies. Circuit techniques to design millimeter-wave circuits in silicon technologies are discussed in depth.  Describes concepts and fundamentals of automotive rada...

  20. Development of automatic surveillance of animal behaviour and welfare using image analysis and machine learned segmentation technique.

    Science.gov (United States)

    Nilsson, M; Herlin, A H; Ardö, H; Guzhva, O; Åström, K; Bergsten, C

    2015-11-01

    In this paper the feasibility to extract the proportion of pigs located in different areas of a pig pen by advanced image analysis technique is explored and discussed for possible applications. For example, pigs generally locate themselves in the wet dunging area at high ambient temperatures in order to avoid heat stress, as wetting the body surface is the major path to dissipate the heat by evaporation. Thus, the portion of pigs in the dunging area and resting area, respectively, could be used as an indicator of failure of controlling the climate in the pig environment as pigs are not supposed to rest in the dunging area. The computer vision methodology utilizes a learning based segmentation approach using several features extracted from the image. The learning based approach applied is based on extended state-of-the-art features in combination with a structured prediction framework based on a logistic regression solver using elastic net regularization. In addition, the method is able to produce a probability per pixel rather than form a hard decision. This overcomes some of the limitations found in a setup using grey-scale information only. The pig pen is a difficult imaging environment because of challenging lighting conditions like shadows, poor lighting and poor contrast between pig and background. In order to test practical conditions, a pen containing nine young pigs was filmed from a top view perspective by an Axis M3006 camera with a resolution of 640 × 480 in three, 10-min sessions under different lighting conditions. The results indicate that a learning based method improves, in comparison with greyscale methods, the possibility to reliable identify proportions of pigs in different areas of the pen. Pigs with a changed behaviour (location) in the pen may indicate changed climate conditions. Changed individual behaviour may also indicate inferior health or acute illness.

  1. Using radar interferometry and SBAS technique to detect surface subsidence relating to coal mining in Upper Silesia from 1993-2000 and 2003-2010

    Directory of Open Access Journals (Sweden)

    Nádudvari Ádám

    2016-03-01

    Full Text Available In the presented research ERS1-2 and Envisat ASAR archive data were used for the periods 1993 – 2000 and 2003 – 2010. The radar images were acquired over Upper Silesia in southern Poland. DinSAR (Differential InSAR and SBAS (Small Baseline Subset methods were applied for the detection of the most subsided areas. The DinSAR images were layer stacked for an image using 26 interferometry pairs of ERS1-2 SAR and 16 pairs from Envisat ASAR images in an ascending-descending orbit combination. The stacking of these images showed the most subsided parts of these cities even under low coherent areas, but the results are less precise. In the Upper Silesian Coal Basin, intensive underground coal exploitation has resulted in several surface deformations under Bytom (~8-17 km2, Piekary Śląskie (~9-15 km2, Ruda Śląska (~32-42 km2 and Katowice (~20-23 km2 with 25-40 cm of subsidence (in general in the studied time periods. The SBAS technique has also shown that coal mining caused subsidence in the cities of Bytom, Katowice, and Piekary Śląskie of 5-7 cm/yr. The presented SBAS method did not work for low coherent areas, e.g. dense forested areas. DInSAR data also pointed to several decreasingly less active mining areas, which relate to the mine closures in Bytom and Ruda Śląska, which is also verified by the time series analysis.

  2. Status and Prospects of Radar Polarimetry Techniques%雷达极化技术研究现状与展望

    Institute of Scientific and Technical Information of China (English)

    王雪松

    2016-01-01

    Radar polarimetry is an applied fundamental science field that is focused on understanding interaction processes between radar waves and targets and disclosing their mechanisms. Radar polarimetry has significant application prospects in the fields of microwave remote sensing, earth observation, meteorological measurement, battlefield reconnaissance, anti-interference, target recognition, and so on. This study briefly reviews the development history of radar polarization theory and technology. Next, the state of the art of several key technologies within radar polarimetry, including the precise acquisition of radar polarization information, polarization-sensitive array signal processing, target polarization characteristics, polarization anti-interference, and target polarization classification and recognition, is summarized. Finally, the future developments of radar polarization technology are considered.%雷达极化学是研究雷达波与目标相互作用过程中的变极化效应、揭示其作用机理的一门应用基础科学,在微波遥感、对地勘察、气象探测、战场侦察、抗干扰、目标识别等领域有重大应用前景。该文简要回顾了雷达极化理论与技术的发展历程,综述了雷达极化信息精确获取、极化敏感阵列信号处理、目标极化特性、极化抗干扰、目标极化分类识别等关键技术的研究现状,最后对雷达极化技术的发展做了展望。

  3. Surveillance Metrics Sensitivity Study

    Energy Technology Data Exchange (ETDEWEB)

    Bierbaum, R; Hamada, M; Robertson, A

    2011-11-01

    In September of 2009, a Tri-Lab team was formed to develop a set of metrics relating to the NNSA nuclear weapon surveillance program. The purpose of the metrics was to develop a more quantitative and/or qualitative metric(s) describing the results of realized or non-realized surveillance activities on our confidence in reporting reliability and assessing the stockpile. As a part of this effort, a statistical sub-team investigated various techniques and developed a complementary set of statistical metrics that could serve as a foundation for characterizing aspects of meeting the surveillance program objectives. The metrics are a combination of tolerance limit calculations and power calculations, intending to answer level-of-confidence type questions with respect to the ability to detect certain undesirable behaviors (catastrophic defects, margin insufficiency defects, and deviations from a model). Note that the metrics are not intended to gauge product performance but instead the adequacy of surveillance. This report gives a short description of four metrics types that were explored and the results of a sensitivity study conducted to investigate their behavior for various inputs. The results of the sensitivity study can be used to set the risk parameters that specify the level of stockpile problem that the surveillance program should be addressing.

  4. A novel technique using three-dimensionally documented biopsy mapping allows precise re-visiting of prostate cancer foci with serial surveillance of cell cycle progression gene panel.

    Science.gov (United States)

    Ukimura, Osamu; Gross, Mitchell E; de Castro Abreu, Andre Luis; Azhar, Raed A; Matsugasumi, Toru; Ushijima, So; Kanazawa, Motohiro; Aron, Manju; Gill, Inderbir S

    2015-06-01

    Conventional systematic biopsy has the shortcoming of sampling error and reveals "no evidence of cancer" with a rate of >50% on active surveillance (AS). The objective of this study is to report our initial experience of applying a 3D-documented biopsy-mapping technology to precisely re-visit geographically documented low-risk prostate cancer and to perform serial analysis of cell-cycle-progression (CCP) gene-panel. Over a period of 40 months (1/2010-4/2013), the 3D-biopsy-mapping technique, in which the spatial location of biopsy-trajectory was digitally recorded (Koelis), was carried out. A pair of diagnostic (1st-look) and surveillance (2nd-look) biopsy were performed per subject (n = 25), with median interval of 12 months. The documented biopsy-trajectory was used as a target to guide the re-visiting biopsy from the documented cancer focus, as well as the targeted field-biopsy from the un-sampled prostatic field adjacent to negative diagnostic biopsies. The accuracy of re-visiting biopsy and biopsy-derived CCP signatures were evaluated in the pair of the serial biopsy-cores. The 1st-look-biopsy revealed a total of 43 cancer lesions (1.7 per patient). The accuracy of re-visiting cancer was 86% (37/43) per lesion, 76% (65/86) per core, and 80% (20/25) per patient. This technology also provided an opportunity for 3D-targeted field-biopsy in order to potentially minimize sampling errors. The CCP gene-panel of the 1st-look (-0.59) versus 2nd-look (-0.37) samples had no significant difference (P = 0.4); which suggested consistency in the molecular signature of the known cancer foci during the short-time interval of median 12 months. Any change in CCP of the same cancer foci would be likely due to change in sampling location from the less to more significant portion in the cancer foci rather than true molecular progression. The study limitations include a small number of the patients. The 3D-documented biopsy-mapping technology achieved an encouraging re

  5. Measurements of radar ground returns

    NARCIS (Netherlands)

    Loor, G.P. de

    1974-01-01

    The ground based measurement techniques for the determination of the radar back-scatter of vegetation and soils as used in The Netherlands will be described. Two techniques are employed: one covering a large sample area (> 1000 m2) but working at low grazing angels only and one (short range) coverin

  6. More Poop, More Precision: Improving Epidemiologic Surveillance of Soil-Transmitted Helminths with Multiple Fecal Sampling using the Kato-Katz Technique.

    Science.gov (United States)

    Liu, Chengfang; Lu, Louise; Zhang, Linxiu; Bai, Yu; Medina, Alexis; Rozelle, Scott; Smith, Darvin Scott; Zhou, Changhai; Zang, Wei

    2017-07-03

    Soil-transmitted helminths, or parasitic intestinal worms, are among the most prevalent and geographically widespread parasitic infections in the world. Accurate diagnosis and quantification of helminth infection are critical for informing and assessing deworming interventions. The Kato-Katz thick smear technique, the most widely used laboratory method to quantitatively assess infection prevalence and infection intensity of helminths, has often been compared with other methods. Only a few small-scale studies, however, have considered ways to improve its diagnostic sensitivity. This study, conducted among 4,985 school-age children in an area of rural China with moderate prevalence of helminth infection, examines the effect on diagnostic sensitivity of the Kato-Katz technique when two fecal samples collected over consecutive days are examined and compared with a single sample. A secondary aim was to consider cost-effectiveness by calculating an estimate of the marginal costs of obtaining an additional fecal sample. Our findings show that analysis of an additional fecal sample led to increases of 23%, 26%, and 100% for Ascaris lumbricoides, Trichuris trichiura, and hookworm prevalence, respectively. The cost of collecting a second fecal sample for our study population was approximately USD4.60 per fecal sample. Overall, the findings suggest that investing 31% more capital in fecal sample collection prevents an underestimation of prevalence by about 21%, and hence improves the diagnostic sensitivity of the Kato-Katz method. Especially in areas with light-intensity infections of soil-transmitted helminths and limited public health resources, more accurate epidemiological surveillance using multiple fecal samples will critically inform decisions regarding infection control and prevention.

  7. Limitations of Radar Coordinates

    OpenAIRE

    Bini, Donato; Lusanna, Luca; Mashhoon, Bahram

    2004-01-01

    The construction of a radar coordinate system about the world line of an observer is discussed. Radar coordinates for a hyperbolic observer as well as a uniformly rotating observer are described in detail. The utility of the notion of radar distance and the admissibility of radar coordinates are investigated. Our results provide a critical assessment of the physical significance of radar coordinates.

  8. Using a low-order model to detect and characterize intense vortices in multiple-Doppler radar data

    Science.gov (United States)

    Potvin, Corey Keith

    A new multiple-Doppler radar analysis technique is presented for the objective detection and characterization of intense vortices. The technique consists of fitting radial wind data from two or more radars to a simple analytical model of a vortex and its near-environment. The model combines a uniform flow, linear shear flow, linear divergence flow (all of which comprise a broadscale flow), and modified combined Rankine vortex. The vortex and its environment are allowed to translate. A cost-function accounting for the discrepancy between the model and observed radial winds is evaluated over space and time so that observations can be used at the actual times and locations they were acquired. The parameters in the low-order model are determined by minimizing this cost function. The development of the method is initially guided by emulated radial velocity observations of analytical vortices. A high-resolution Advanced Regional Prediction System (ARPS) simulation of a supercellular tornado is then used to generate more realistic pseudo-observations. Finally, the technique is tested using real dual-Doppler tornado and mesocyclone observations from a variety of radar platforms including Weather Surveillance Radar - 1988 Doppler (WSR-88D), Terminal Doppler Weather Radar (TDWR), Shared Mobile Atmospheric Research and Teaching Radar (SMART-R), and Doppler on Wheels (DOW). The technique shows skill in detecting intense vortices and, when the vortex is well-resolved, in retrieving key model parameters including vortex location, translational velocity, radius and maximum tangential wind speed. In cases where the vortex is not well-resolved, additional vortex characteristics computed from the retrieved model parameters and verified against radial velocity observations can still provide useful information about vortex size and strength.

  9. Doppler visibility of coherent random noise radar systems

    Science.gov (United States)

    Li, Zhixi; Narayanan, Ram M.

    2005-05-01

    Random noise radar has recently been used in a variety of imaging and surveillance applications. These systems can be made phase coherent using the technique of heterodyne correlation. Phase coherence has been exploited to measure Doppler and thereby the velocity of moving targets. The Doppler visibility, i.e., the ability to extract Doppler information over the inherent clutter spectra, is constrained by system parameters, especially the phase noise generated by microwave components. Our paper proposes a new phase noise model for the heterodyne mixer as applicable for ultrawideband (UWB) random noise radar and for the local oscillator in the time domain. The Doppler spectra are simulated by including phase noise contamination effects and compared to our previous experimental results. A Genetic Algorithm (GA) optimization routine is applied to synthesize the effects of a variety of parameter combinations to derive a suitable empirical formula for estimating the Doppler visibility in dB. According to the phase noise analysis and the simulation results, the Doppler visibility of UWB random noise radar depends primarily on the following parameters: (a) the local oscillator (LO) drive level of the receiver heterodyne mixer; (b) the saturation current in the receiver heterodyne mixer; (c) the bandwidth of the transmit noise source, and; (d) the target velocity. Other parameters such as the carrier frequency of the receiver LO and the loaded quality factor of the LO have a small effect over the range of applicability of the model and are therefore neglected in the model formulation. The Doppler visibility curves generated from this formula match the simulation results very well over the applicable parameter range within 1 dB. Our model may therefore be used to quickly estimate the Doppler visibility of random noise radars for trade-off analysis.

  10. Inversion of X-band nautical radar data for sea-state monitoring: a new technique to estimate the surface currents

    Science.gov (United States)

    Serafino, F.; Lugni, C.; Raffa, F.; Soldovieri, F.

    2009-04-01

    The inversion of X-band marine images sequences allows obtaining the sea state parameter estimation and the reconstruction of the wave height evolution [1-4]. This result is possible tanks to the fact that the backscattering from the sea is "visible", under some conditions, on the marine radar images. These radar signatures, that typically are suppressed because represent a noise (clutter) for the navigation, are the "useful signal" to be processed in order to achieve information about the sea state: peak wave length, period and direction, current speed and direction and the evolution of surface elevation. The backscattering phenomena is due to the Bragg resonance with ocean waves of wavelengths similar to those of the transmitted electromagnetic waves. In particular, the longer waves modulate the backscattering phenomenon and thus they become visible in the "radar" images. As a consequence, the radar image is not a direct representation of the sea state and thus a processing procedure is needed in order to reconstruct the sea state. After a Fourier Transform of the data, a spectral filter is used to erase all the undesired phenomenon via a dispersion relation. The use of the Modulation Transfer Function (MTF) allows the passage from the radar spectrum to sea spectrum; finally, the resulting spectrum is Fourier transformed to return to the space-time domain. A key step of the whole procedure is the generation of the spectral filter. To built the filter the surface currents have to be estimated, if they are not correctly determined the results of the overall inversion are quite poor. This drawback is further increased when the values of the surface current become high or the data are acquired by a moving vessel, since the problem of the determination of the current is quite complicated and particular attention needs the filtering procedure. This work presents an innovative procedure able to estimate the free-surface current values with high accuracy compared to the

  11. Low-Cost Mini Radar: Design Prototyping and Tests

    Directory of Open Access Journals (Sweden)

    Dario Tarchi

    2017-01-01

    Full Text Available Radar systems are largely employed for surveillance of wide and remote areas; the recent advent of drones gives the opportunity to exploit radar sensors on board of unmanned aerial platforms. Nevertheless, whereas drone radars are currently available for military applications, their employment in the civilian domain is still limited. The present research focuses on design, prototyping, and testing of an agile, low-cost, mini radar system, to be carried on board of Remotely Piloted Aircraft (RPAs or tethered aerostats. In particular, the paper faces the challenge to integrate the in-house developed radar sensor with a low-cost navigation board, which is used to estimate attitude and positioning data. In fact, a suitable synchronization between radar and navigation data is essential to properly reconstruct the radar picture whenever the platform is moving or the radar is scanning different azimuthal sectors. Preliminary results, relative to tests conducted in preoperational conditions, are provided and exploited to assert the suitable consistency of the obtained radar pictures. From the results, there is a high consistency between the radar images and the picture of the current environment emerges; finally, the comparison of radar images obtained in different scans shows the stability of the platform.

  12. Mechanism Analysis of Air Surveillance Radar Network System Dense False Target Jamming%对空情报雷达网密集假目标干扰机理分析

    Institute of Scientific and Technical Information of China (English)

    赵源; 熊英; 唐斌

    2015-01-01

    针对雷达网欺骗干扰问题,首先讨论了雷达网数据关联处理方法薄弱环节,给出了可以欺骗雷达网的假目标应该满足的条件,然后分析对空情报雷达网密集假目标干扰的产生机理和作用机理,为产生高逼真的假目标,将空间分布转化为非线性最优化问题. 当进行多干扰机协同干扰时,将干扰机功率资源在空间的分配问题转化为非线性规划问题. 仿真研究了对网络化雷达的假目标欺骗干扰效果以及影响干扰效果的因素,该结果可为对空情报雷达网电子对抗提供理论指导.%The weakness of data processing algorithms for radar network is discussed,requirements of false targets for combating the victim radar network is given. Then the mechanism of dense false target jamming against radar network is analyzed. The false target distribution is transformed into a nonlinear optimization in order to generate the false target acting like a real target. For multiple jammers scenario,power resource allocation is turned into a nonlinear programming. The effectiveness of jamming is simulated and the influ-ence factors are studied. This research will provide a theoretical guidance for the radar network electronic countermeasure( ECM) .

  13. Radar based autonomous sensor module

    Science.gov (United States)

    Styles, Tim

    2016-10-01

    Most surveillance systems combine camera sensors with other detection sensors that trigger an alert to a human operator when an object is detected. The detection sensors typically require careful installation and configuration for each application and there is a significant burden on the operator to react to each alert by viewing camera video feeds. A demonstration system known as Sensing for Asset Protection with Integrated Electronic Networked Technology (SAPIENT) has been developed to address these issues using Autonomous Sensor Modules (ASM) and a central High Level Decision Making Module (HLDMM) that can fuse the detections from multiple sensors. This paper describes the 24 GHz radar based ASM, which provides an all-weather, low power and license exempt solution to the problem of wide area surveillance. The radar module autonomously configures itself in response to tasks provided by the HLDMM, steering the transmit beam and setting range resolution and power levels for optimum performance. The results show the detection and classification performance for pedestrians and vehicles in an area of interest, which can be modified by the HLDMM without physical adjustment. The module uses range-Doppler processing for reliable detection of moving objects and combines Radar Cross Section and micro-Doppler characteristics for object classification. Objects are classified as pedestrian or vehicle, with vehicle sub classes based on size. Detections are reported only if the object is detected in a task coverage area and it is classified as an object of interest. The system was shown in a perimeter protection scenario using multiple radar ASMs, laser scanners, thermal cameras and visible band cameras. This combination of sensors enabled the HLDMM to generate reliable alerts with improved discrimination of objects and behaviours of interest.

  14. RADAR PPI Scope Overlay

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — RADAR PPI Scope Overlays are used to position a RADAR image over a station at the correct resolution. The archive maintains several different RADAR resolution types,...

  15. Surveillance of Autism.

    Science.gov (United States)

    Boyle, Coleen A.; Bertrand, Jacquelyn; Yeargin-Allsopp, Marshalyn

    1999-01-01

    This article describes the autism surveillance activities of the Center for Disease Control and Prevention. It considers why surveillance to track prevalence of autistic disorders is needed, how such surveillance is conducted, and the special challenges of autism surveillance. (DB)

  16. Surveillance Angels

    NARCIS (Netherlands)

    Rothkrantz, L.J.M.

    2014-01-01

    The use of sensor networks has been proposed for military surveillance and environmental monitoring applications. Those systems are composed of a heterogeneous set of sensors to observe the environment. In centralised systems the observed data will be conveyed to the control room to process the

  17. Surveillance Angels

    NARCIS (Netherlands)

    Rothkrantz, L.J.M.

    2014-01-01

    The use of sensor networks has been proposed for military surveillance and environmental monitoring applications. Those systems are composed of a heterogeneous set of sensors to observe the environment. In centralised systems the observed data will be conveyed to the control room to process the data

  18. Radar Subsurface Imaging by Phase Shift Migration Algorithm

    OpenAIRE

    Zhang, Hui; Benedix, Wolf-Stefan; Plettemeier, Dirk; Ciarletti, Valérie

    2013-01-01

    In this paper the phase shift migration based Syn- thetic Aperture Radar (SAR) is described and applied on radar imaging for dual polarized ground penetrating radar system (GPR). Conventional techniques for SAR imaging focusing use the matched filter concept and convolve the measurement data with a filter impulse response (convolution kernel) which is modified by the range. In fact, conventional techniques for SAR imaging technique can be considered as ray-tracing based SAR imaging technique....

  19. Advances in bistatic radar

    CERN Document Server

    Willis, Nick

    2007-01-01

    Advances in Bistatic Radar updates and extends bistatic and multistatic radar developments since publication of Willis' Bistatic Radar in 1991. New and recently declassified military applications are documented. Civil applications are detailed including commercial and scientific systems. Leading radar engineers provide expertise to each of these applications. Advances in Bistatic Radar consists of two major sections: Bistatic/Multistatic Radar Systems and Bistatic Clutter and Signal Processing. Starting with a history update, the first section documents the early and now declassified military

  20. Radar hydrology principles, models, and applications

    CERN Document Server

    Hong, Yang

    2014-01-01

    ""This is the first book on radar hydrology written by hydrologists. Whereas the excellent knowledge of radar technology by the authors permits an adequate coverage of the principles of rainfall rate estimation by radar, their hydrological background allows them to provide a unique message on the benefits (and on the remaining challenges) in exploiting radar techniques in hydrology. … In a clear and concise manner, the book combines topics from different scientific disciplines into a unified approach aiming to guide the reader through the requirements, strengths, and pitfalls of the applica

  1. Radar activities of the DFVLR Institute for Radio Frequency Technology

    Science.gov (United States)

    Keydel, W.

    1983-01-01

    Aerospace research and the respective applications microwave tasks with respect to remote sensing, position finding and communication are discussed. The radar activities are directed at point targets, area targets and volume targets; they center around signature research for earth and ocean remote sensing, target recognition, reconnaissance and camouflage and imaging and area observation radar techniques (SAR and SLAR). The radar activities cover a frequency range from 1 GHz up to 94 GHz. The radar program is oriented to four possible application levels: ground, air, shuttle orbits and satellite orbits. Ground based studies and measurements, airborne scatterometers and imaging radars, a space shuttle radar, the MRSE, and follow on experiments are considered.

  2. Radar activities of the DFVLR Institute for Radio Frequency Technology

    Science.gov (United States)

    Keydel, W.

    1983-01-01

    Aerospace research and the respective applications microwave tasks with respect to remote sensing, position finding and communication are discussed. The radar activities are directed at point targets, area targets and volume targets; they center around signature research for earth and ocean remote sensing, target recognition, reconnaissance and camouflage and imaging and area observation radar techniques (SAR and SLAR). The radar activities cover a frequency range from 1 GHz up to 94 GHz. The radar program is oriented to four possible application levels: ground, air, shuttle orbits and satellite orbits. Ground based studies and measurements, airborne scatterometers and imaging radars, a space shuttle radar, the MRSE, and follow on experiments are considered.

  3. Orbit Determination Analysis for a Joint UK-Australian Space Surveillance Experiment

    Science.gov (United States)

    Rutten, M.; Harwood, N.; Bennett, J.; Donnelly, P.; Ash, A.; Eastment, J.; Ladd, D.; Gordon, N.; Bessell, T.; Smith, C.; Ritchie, I.

    2014-09-01

    In February 2014 the UK and Australia carried out a joint space surveillance target tracking, cueing, and sensor data fusion experiment involving the STFC Chilbolton Observatory radar in the UK, the EOS laser-ranging system in Australia and a small telescope operated by DSTO, also in Australia. The experiment, coordinated by DSTL (UK) and DSTO (Aus), was designed to explore the combination of several different, geographically separated sensors for space situational awareness. The primary goal of the experiment was to use data from the radar in the UK to generate an orbital cue to the EOS SLR. A variety of targets sizes and orbits were chosen, under the limitations of observability by both the radar and EOS SLR, in order to explore the variation of cueing accuracy with amount of data incorporated and timeliness from generation. As a secondary objective the effect on cue accuracy of targets in lower orbital regimes was examined. This paper examines the orbit determination techniques used to generate cues from radar and the refined orbits resulting from accumulating SLR data. The construction of tracks using data from all three sensors is explored. Analysis of the accuracy of the orbital reconstructions is made based on comparisons with the measured data and accurate ephemerides provided by the ILRS. The accuracy is tested against the cueing precision requirements for each sensor. Two companion papers describe the experimental goals, execution and achievements (Harwood et. al.) and the sensor aspects of the experiment (Eastment et al.).

  4. Penn State Radar Systems: Implementation and Observations

    Science.gov (United States)

    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.

  5. Quality assessment of weather radar wind profiles during bird migration

    NARCIS (Netherlands)

    Holleman, I.; van Gasteren, H.; Bouten, W.

    2008-01-01

    Wind profiles from an operational C-band Doppler radar have been combined with data from a bird tracking radar to assess the wind profile quality during bird migration. The weather radar wind profiles (WRWPs) are retrieved using the well-known volume velocity processing (VVP) technique. The X-band

  6. Towards photometry pipeline of the Indonesian space surveillance system

    CERN Document Server

    Priyatikanto, R; Rachman, A; Dani, T

    2015-01-01

    Optical observation through sub-meter telescope equipped with CCD camera becomes alternative method for increasing orbital debris detection and surveillance. This observational mode is expected to eye medium-sized objects in higher orbits (e.g. MEO, GTO, GSO \\& GEO), beyond the reach of usual radar system. However, such observation of fast-moving objects demands special treatment and analysis technique. In this study, we performed photometric analysis of the satellite track images photographed using rehabilitated Schmidt Bima Sakti telescope in Bosscha Observatory. The Hough transformation was implemented to automatically detect linear streak from the images. From this analysis and comparison to USSPACECOM catalog, two satellites were identified and associated with inactive Thuraya-3 satellite and Satcom-3 debris which are located at geostationary orbit. Further aperture photometry analysis revealed the periodicity of tumbling Satcom-3 debris. In the near future, it is not impossible to apply similar sche...

  7. Low Altitude Target Detection Technique Based on Signal Detection of Radar Altimeter%基于雷达高度表信号的低空目标检测技术

    Institute of Scientific and Technical Information of China (English)

    韩兴斌; 颜坤玉; 冯富强

    2015-01-01

    针对低空目标突袭的威胁,根据低空目标普遍携带雷达高度表的特征,提出了基于雷达高度表信号探测的低空目标检测技术。针对海面飞行环境,根据双基地雷达的原理,对海面雷达散射信号进行了理论计算,从功率角度对低空目标检测可行性进行了分析,并给出了将侦察系统升空探测低空目标所携雷达高度表信号的方法,达到了对低空突防目标预警探测的要求。%A Low altitude target detection technique based on signal detection of radar altimeter is proposed to resolve the problem of low altitude target attack, as low altitude targets widely take radar altimeter. The method of heightening reconnaissance system to detect radar altimeter signal of low altitude target is proposed in environment of sea surface, which can satisfy the de-sire of warning detect of low altitude targets.

  8. Air surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Patton, G.W.

    1995-06-01

    This section of the 1994 Hanford Site Environmental Report summarizes the air surveillance and monitoring programs currently in operation at that Hanford Site. Atmospheric releases of pollutants from Hanford to the surrounding region are a potential source of human exposure. For that reason, both radioactive and nonradioactive materials in air are monitored at a number of locations. The influence of Hanford emissions on local radionuclide concentrations was evaluated by comparing concentrations measured at distant locations within the region to concentrations measured at the Site perimeter. This section discusses sample collection, analytical methods, and the results of the Hanford air surveillance program. A complete listing of all analytical results summarized in this section is reported separately by Bisping (1995).

  9. Radar-to-Radar Interference Suppression for Distributed Radar Sensor Networks

    OpenAIRE

    Wen-Qin Wang; Huaizong Shao

    2014-01-01

    Radar sensor networks, including bi- and multi-static radars, provide several operational advantages, like reduced vulnerability, good system flexibility and an increased radar cross-section. However, radar-to-radar interference suppression is a major problem in distributed radar sensor networks. In this paper, we present a cross-matched filtering-based radar-to-radar interference suppression algorithm. This algorithm first uses an iterative filtering algorithm to suppress the radar-to-radar ...

  10. Radar Analysis of Fall Bird Migration Stopover Sites in the Northeastern U.S.

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — The national network of weather surveillance radars (WSR-88D/NEXRAD) detects birds in flight, and has proven to be a useful remote-sensing tool for ornithological...

  11. PRS前沿判别法抗三点源诱偏性能研究%Countering Performance of PRS's Pulse Leading-Edge Distinguishing Technique to Three-Source Decoy Radar System

    Institute of Scientific and Technical Information of China (English)

    许端; 董文锋; 齐秀青; 王正国; 王欢

    2013-01-01

    Aiming at the problem that the tradition passive radar seeker ( PRS) can hardly counter multi-source decoy radar system effectively,we proposed a pulse leading-edge distinguishing technique based on time discrimination technique and wavelet analysis .PRS uses fixed strobe gate to sample the pulse leading-edge,and wavelet analysis and feature extraction are made to the signals obtained .After the analysis result verifies that the sample includes only single radiation source,the PRS can measure the sample signal direction and its frequency,track the sample signal,and attack the source target .Taking three-source decoy radar system with triangular deployment as an example,the usability of this technique was simulated and analyzed .It is verified that the PRS can track the early arriving decoy signal in most position of the airspace,which verifies that this technique can effectively counter three-source decoy radar system .%针对采用传统测向方法的被动雷达导引头( PRS)对抗多点源诱偏系统效果不理想的情况,提出了一种基于时域鉴别技术和小波分析的前沿判别法。由PRS使用固定波门对辐射源脉冲前沿进行采样,对所得信号作小波分析和特征提取,当判定采样信号内为单辐射源信号时对其进行测频、测向、跟踪和打击。以正三角形布阵的三点源诱偏系统为例,仿真分析了该方法的可用性,结果表明在大部分空域中,PRS总能跟踪提前到达的诱饵信号,从而验证了该方法能够有效对抗三点源诱偏系统。

  12. Advancements on Radar Polarization Information Acquisition and Processing

    Directory of Open Access Journals (Sweden)

    Dai Dahai

    2016-04-01

    Full Text Available The study on radar polarization information acquisition and processing has currently been one important part of radar techniques. The development of the polarization theory is simply reviewed firstly. Subsequently, some key techniques which include polarization measurement, polarization anti-jamming, polarization recognition, imaging and parameters inversion using radar polarimetry are emphatically analyzed in this paper. The basic theories, the present states and the development trends of these key techniques are presented and some meaningful conclusions are derived.

  13. Radar tracking and classification of littoral targets

    Science.gov (United States)

    Silvious, Jerry; Tahmoush, Dave

    2012-06-01

    Radar can provide inexpensive wide-area surveillance of river and port traffic for both security and emergency response. We demonstrate the tracking of multiple vessels as well as the micro-Doppler signatures of different classes of small vessels, including kayaks and zodiacs. The pattern of life of a river is analyzed over several days and can be used to easily identify suspicious or unusual cases.

  14. Robust adaptive beamforming for MIMO monopulse radar

    Science.gov (United States)

    Rowe, William; Ström, Marie; Li, Jian; Stoica, Petre

    2013-05-01

    Researchers have recently proposed a widely separated multiple-input multiple-output (MIMO) radar using monopulse angle estimation techniques for target tracking. The widely separated antennas provide improved tracking performance by mitigating complex target radar cross-section fades and angle scintillation. An adaptive array is necessary in this paradigm because the direct path from any transmitter could act as a jammer at a receiver. When the target-free covariance matrix is not available, it is critical to include robustness into the adaptive beamformer weights. This work explores methods of robust adaptive monopulse beamforming techniques for MIMO tracking radar.

  15. Comments on airborne ISR radar utilization

    Science.gov (United States)

    Doerry, A. W.

    2016-05-01

    A sensor/payload operator for modern multi-sensor multi-mode Intelligence, Surveillance, and Reconnaissance (ISR) platforms is often confronted with a plethora of options in sensors and sensor modes. This often leads an over-worked operator to down-select to favorite sensors and modes; for example a justifiably favorite Full Motion Video (FMV) sensor at the expense of radar modes, even if radar modes can offer unique and advantageous information. At best, sensors might be used in a serial monogamous fashion with some cross-cueing. The challenge is then to increase the utilization of the radar modes in a manner attractive to the sensor/payload operator. We propose that this is best accomplished by combining sensor modes and displays into `super-modes'.

  16. Target classification by surveillance radar based on multifractal features%基于多重分形特征的防空雷达目标分类方法

    Institute of Scientific and Technical Information of China (English)

    李秋生; 谢维信

    2013-01-01

    On basis of introducing the mathematical model of aircraft returns in the conventional radar, by means of the multi-fractal measure analysis, this paper analyzed the multifractal characteristic of the aircraft returns as well as the extraction method of their multifractal signatures, and proposed the classification method for three types of aircraft containing jets, propeller aircrafts and helicopters from the angle of pattern recognition. The experimental analysis shows, the conventional radar returns from three types of aircraft targets, containing jets, propeller aircrafts and helicopters, have significantly different multifractal characteristic curves, and the defined multifractal characteristic parameters can be used as effective features for aircraft target classification and recognition. The simulation validated the validity of the proposed method.%在介绍常规雷达飞机目标回波数学模型的基础上,利用多重分形测度分析手段,分析了常规雷达飞机目标回波的多重分形特性及其多重分形特征的提取方法,并从模式分类的角度,提出了利用多重分形特征对喷气式飞机、螺旋桨飞机和直升机等三类飞机目标进行分类的方法.实验表明,上述三类飞机的目标回波数据具有显著不同的多重分形特征,所定义的多重分形特征参数可以作为飞机目标分类和识别的有效特征,仿真实验验证了所提方法的有效性.

  17. A low-cost FMCW radar for footprint detection from a mobile platform

    Science.gov (United States)

    Boutte, David; Taylor, Paul; Hunt, Allan

    2015-05-01

    Footprint and human trail detection in rugged all-weather environments is an important and challenging problem for perimeter security, passive surveillance and reconnaissance. To address this challenge a low-cost, wideband, frequency-modulated continuous wave (FMCW) radar operating at 33.4GHz - 35.5GHz is being developed through a Department of Homeland Security Science and Technology Directorate Phase I SBIR and has been experimentally demonstrated to be capable of detecting footprints and footprint trails on unimproved roads in an experimental setting. It uses a low-cost digital signal processor (DSP) that makes important operating parameters reconfigurable and allows for frequency sweep linearization, a key technique developed to increase footprint signal-to-noise ratio (SNR). This paper discusses the design, DSP implementation and experimental results of a low-cost FMCW radar for mobile footprint detection. A technique for wideband sweep linearization is detailed along with system performance metrics and experimental results showing receive-SNR from footprint trails in sand and on unimproved dirt roads. Results from a second stepped frequency CW (SFCW) Ka-band system are also shown, verifying the ability of both systems to detect footprints and footprint trails in an experimental setting. The results show that there is sufficient receive-SNR to detect even shallow footprints (~1cm) using a radar based detection system in Ka-band. Field experimental results focus on system proof of concept from a static position with mobile results also presented highlighting necessary improvements to both systems.

  18. Surveillance of Space in Australia

    Science.gov (United States)

    Newsam, G.

    Australia's geography and technology base got it off to a flying start in the early days of surveillance of space, starting with CSIRO's first radio telescope in the 1940's and climaxing in NASA's establishment of station 43 in the Deep Space Network at Tidbinbilla in 1965. But Britain's exit from space and the subsequent closure of the Woomera launch range and associated space tracking facilities in the early 1970's saw the start of a long draw-down of capability. Programs such as CSIRO's radio astronomy telescopes, Electro-Optic Systems' adoption of laser technology for satellite laser ranging and tracking system, and the exploration of the use of technology developed in Australia's over-the-horizon-radar program for surveillance of space, kept some interest in the problem alive, but there has been no serious national investment in the area for the last thirty years. Recently, however, increased awareness of the vulnerability of space systems and the need to include potential opponents' space capabilities in operations planning has led to a revival of interest in space situational awareness within the Australian Defence Organisation. While firm commitments to new systems must wait on the next Defence White Paper due out at the end of 2007 and the policy directions it formally endorses, discussions have already started with the US on participating in the Space Surveillance Network (SSN) and developing a comprehensive space situational awareness capability. In support of these initiatives the Defence Science and Technology Organisation (DSTO) is drawing up an inventory of relevant Australian capabilities, technologies and activities: the paper will describe the findings of this inventory, and in particular local technologies and systems that might be deployed in Australia to contribute to the SSN. In the optical regime the available options are rather limited; they centre primarily on the satellite laser ranging technology developed by Electro-Optic Systems and

  19. Extracting bird migration information from C-band Doppler weather radars

    NARCIS (Netherlands)

    van Gasteren, H.; Holleman, I.; Bouten, W.; van Loon, E.; Shamoun-Baranes, J.

    2008-01-01

    Although radar has been used in studies of bird migration for 60 years, there is still no network in Europe for comprehensive monitoring of bird migration. Europe has a dense network of military air surveillance radars but most systems are not directly suitable for reliable bird monitoring. Since

  20. Compact networked radars for Army unattended ground sensors

    Science.gov (United States)

    Wikner, David A.; Viveiros, Edward A.; Wellman, Ronald; Clark, John; Kurtz, Jim; Pulskamp, Jeff; Proie, Robert; Ivanov, Tony; Polcawich, Ronald G.; Adler, Eric D.

    2010-04-01

    The Army Research Laboratory is in partnership with the University of Florida - Electronics Communications Laboratory to develop compact radar technology and demonstrate that it is scalable to a variety of ultra-lightweight platforms (<10 lbs.) to meet Army mission needs in persistent surveillance, unattended ground sensor (UGS), unmanned systems, and man-portable sensor applications. The advantage of this compact radar is its steerable beam technology and relatively long-range capability compared to other small, battery-powered radar concepts. This paper will review the ongoing development of the sensor and presents a sample of the collected data thus far.

  1. Radar Observation of Insects - Mosquitoes

    Science.gov (United States)

    Frost, E.; Downing, J.

    1979-01-01

    Tests were conducted at several sites over the coastal lowlands of New Jersey and over a region of high plains and low mountains in Oklahoma. In one area, a salt marsh in New Jersey, extensive ground tests were combined with laboratory data on expected insect backscatter to arrive at an extremely convincing model of the insect origin of most Dot Angels. A great deal of insight was studied from radar on the buildup and dispersal of insect swarms, since radar can follow where other means of trapping and observation cannot. Data on large-scale behavior as a function of wind and topography are presented. Displayed techniques which show individual or small swarm motion within some larger cloud or mass, or which can show the overall motion over great distances were developed. The influence of wind and terrain on insect motion and dispersal is determined from radar data.

  2. Assessing collision risk for birds and bats : radar survey

    Energy Technology Data Exchange (ETDEWEB)

    Brunet, R. [Genivar SEC, Sherbrooke, PQ (Canada)

    2010-07-01

    This PowerPoint presentation described some of the inventories and instrumentation available for monitoring winged fauna in and around wind farms. In addition to visual observations, bird calls and songs can be recorded to determine the amount and different types of birds located at wind farm sites. Radio-telemetry devices are also used to evaluate bird activities, and nest searches are conducted to determine the amount of eggs or young birds that will soon add to the bird population. Between 90 and 100 percent of birds and bats migrate at night. Acoustic radar, Doppler radar, and maritime surveillance radar instruments are used to monitor night-time activities in wind farm locations. Doppler radar is also used to detect bird and bat migration corridors. Screen-shots of various radar interfaces were presented. tabs., figs.

  3. Next Generation Space Surveillance System-of-Systems

    Science.gov (United States)

    McShane, B.

    2014-09-01

    International economic and military dependence on space assets is pervasive and ever-growing in an environment that is now congested, contested, and competitive. There are a number of natural and man-made risks that need to be monitored and characterized to protect and preserve the space environment and the assets within it. Unfortunately, today's space surveillance network (SSN) has gaps in coverage, is not resilient, and has a growing number of objects that get lost. Risks can be efficiently and effectively mitigated, gaps closed, resiliency improved, and performance increased within a next generation space surveillance network implemented as a system-of-systems with modern information architectures and analytic techniques. This also includes consideration for the newest SSN sensors (e.g. Space Fence) which are born Net-Centric out-of-the-box and able to seamlessly interface with the JSpOC Mission System, global information grid, and future unanticipated users. Significant opportunity exists to integrate legacy, traditional, and non-traditional sensors into a larger space system-of-systems (including command and control centers) for multiple clients through low cost sustainment, modification, and modernization efforts. Clients include operations centers (e.g. JSpOC, USSTRATCOM, CANSPOC), Intelligence centers (e.g. NASIC), space surveillance sensor sites (e.g. AMOS, GEODSS), international governments (e.g. Germany, UK), space agencies (e.g. NASA), and academic institutions. Each has differing priorities, networks, data needs, timeliness, security, accuracy requirements and formats. Enabling processes and technologies include: Standardized and type accredited methods for secure connections to multiple networks, machine-to-machine interfaces for near real-time data sharing and tip-and-queue activities, common data models for analytical processing across multiple radar and optical sensor types, an efficient way to automatically translate between differing client and

  4. Changes in drug use patterns reported on the web after the introduction of ADF OxyContin: findings from the Researched Abuse, Diversion, and Addiction-Related Surveillance (RADARS) System Web Monitoring Program.

    Science.gov (United States)

    Vosburg, Suzanne K; Haynes, Colleen; Besharat, Andrea; Green, Jody L

    2017-09-01

    This qualitative study summarizes information that individuals shared online about use of OxyContin following the August 2010 introduction of the abuse deterrent formulation (ADF). The primary objective was to study online posts that endorsed continued use of OxyContin or a switch from OxyContin to another formulation of oxycodone or another substance altogether following the introduction of the ADF. A secondary objective was to determine whether posts revealed that the ADF led to cessation of OxyContin use. Data were collected with the Researched Abuse, Diversion, and Addiction-Related Surveillance System Web Monitoring Program, an online surveillance system that collects and organizes posts about prescription drugs from social media websites, blogs, and forums from 3Q2009 to 4Q2014 using a commercially available web platform. Posts were categorized by whether they conveyed a switch to drugs other than reformulated OxyContin or a continuation of reformulated OxyContin abuse. "Switch posts" primarily discussed switching to immediate-release opioids. "Continue abusing" posts identified tampering strategies for alternate routes of administration, oral use, and continued use although post authors were generally unhappy with the experience. No reference to OxyContin cessation as a function of the introduction of the ADF was found; however, discontinued use was discussed. Web Monitoring data are useful for capturing cross sections of Internet conversation reflecting reactions to new drug formulations. These data support the notion that users will gravitate to non-ADFs generally, and to immediate-release non-ADF opioid formulations, specifically, as long as these options remain on the market. Copyright © 2017 John Wiley & Sons, Ltd.

  5. Detecting and mitigating wind turbine clutter for airspace radar systems.

    Science.gov (United States)

    Wang, Wen-Qin

    2013-01-01

    It is well recognized that a wind turbine has a large radar cross-section (RCS) and, due to the movement of the blades, the wind turbine will generate a Doppler frequency shift. This scattering behavior may cause severe interferences on existing radar systems including static ground-based radars and spaceborne or airborne radars. To resolve this problem, efficient techniques or algorithms should be developed to mitigate the effects of wind farms on radars. Herein, one transponder-based mitigation technique is presented. The transponder is not a new concept, which has been proposed for calibrating high-resolution imaging radars. It modulates the radar signal in a manner that the retransmitted signals can be separated from the scene echoes. As wind farms often occupy only a small area, mitigation processing in the whole radar operation will be redundant and cost inefficient. Hence, this paper uses a transponder to determine whether the radar is impacted by the wind farms. If so, the effects of wind farms are then mitigated with subsequent Kalman filtering or plot target extraction algorithms. Taking airborne synthetic aperture radar (SAR) and pulse Doppler radar as the examples, this paper provides the corresponding system configuration and processing algorithms. The effectiveness of the mitigation technique is validated by numerical simulation results.

  6. Surveillance and Critical Theory

    Directory of Open Access Journals (Sweden)

    Christian Fuchs

    2015-09-01

    Full Text Available In this comment, the author reflects on surveillance from a critical theory approach, his involvement in surveillance research and projects, and the status of the study of surveillance. The comment ascertains a lack of critical thinking about surveillance, questions the existence of something called “surveillance studies” as opposed to a critical theory of society, and reflects on issues such as Edward Snowden’s revelations, and Foucault and Marx in the context of surveillance.

  7. Radar and ARPA manual

    CERN Document Server

    Bole, A G

    2013-01-01

    Radar and ARPA Manual focuses on the theoretical and practical aspects of electronic navigation. The manual first discusses basic radar principles, including principles of range and bearing measurements and picture orientation and presentation. The text then looks at the operational principles of radar systems. Function of units; aerial, receiver, and display principles; transmitter principles; and sitting of units on board ships are discussed. The book also describes target detection, Automatic Radar Plotting Aids (ARPA), and operational controls of radar systems, and then discusses radar plo

  8. 毫米波远程测量雷达性能提高技术%Techniques for Improving Performance of Long-range Millimeter-wave Instrumentation Radar

    Institute of Scientific and Technical Information of China (English)

    卞雷祥; 徐春林

    2013-01-01

    针对远程毫米波雷达的应用需求,探讨了提高毫米波雷达性能的技术途径:(1)采用回旋管器件,可获得高功率毫米波源,通过空间功率合成技术可进一步提高辐射功率;(2)采用波束波导和过模波导系统,可在保证耐功率的同时获得极低的传输损耗;(3)超导接收机具备低噪声系数和高接收灵敏度,相比常温器件,在Ka波段和W波段可分别获得约4 dB和7 dB得益.分析表明,采用上述3方面措施可显著提高毫米波雷达系统的性能指标.%According to the application requirements of long-range millimeter radar, methods of improving the radar performances are discussed from three aspects; (1) Millimeter wave sources with high output power are available by gyro-amplifier, and higher power could be achieved by quasi-optical or phased array based power combining; (2 ) Extremely low-loss and high withstanding power could be ensured by beam waveguide and overmoded transmission line; (3) Superconducting receiver provides highly sensitive and ultra-low noise figure, and system sensitivity could be increased by about 4 dB and 7 dB respectively at Ka band and W band when compared to normal temperature receivers. It is believed that the performances of millimeter wave radar can be greatly improved by the above three techniques.

  9. A nonlinear spatio-temporal lumping of radar rainfall for modeling multi-step-ahead inflow forecasts by data-driven techniques

    Science.gov (United States)

    Chang, Fi-John; Tsai, Meng-Jung

    2016-04-01

    Accurate multi-step-ahead inflow forecasting during typhoon periods is extremely crucial for real-time reservoir flood control. We propose a spatio-temporal lumping of radar rainfall for modeling inflow forecasts to mitigate time-lag problems and improve forecasting accuracy. Spatial aggregation of radar cells is made based on the sub-catchment partitioning obtained from the Self-Organizing Map (SOM), and then flood forecasting is made by the Adaptive Neuro Fuzzy Inference System (ANFIS) models coupled with a 2-staged Gamma Test (2-GT) procedure that identifies the optimal non-trivial rainfall inputs. The Shihmen Reservoir in northern Taiwan is used as a case study. The results show that the proposed methods can, in general, precisely make 1- to 4-hour-ahead forecasts and the lag time between predicted and observed flood peaks could be mitigated. The constructed ANFIS models with only two fuzzy if-then rules can effectively categorize inputs into two levels (i.e. high and low) and provide an insightful view (perspective) of the rainfall-runoff process, which demonstrate their capability in modeling the complex rainfall-runoff process. In addition, the confidence level of forecasts with acceptable error can reach as high as 97% at horizon t+1 and 77% at horizon t+4, respectively, which evidently promotes model reliability and leads to better decisions on real-time reservoir operation during typhoon events.

  10. Joint application of Geoelectrical Resistivity and Ground Penetrating Radar techniques for the study of hyper-saturated zones. Case study in Egypt

    Science.gov (United States)

    Mesbah, Hany S.; Morsy, Essam A.; Soliman, Mamdouh M.; Kabeel, Khamis

    2017-06-01

    This paper presents the results of the application of the Geoelectrical Resistivity Sounding (GRS) and Ground Penetrating Radar (GPR) for outlining and investigating of surface springing out (flow) of groundwater to the base of an service building site, and determining the reason(s) for the zone of maximum degree of saturation; in addition to provide stratigraphic information for this site. The studied economic building is constructed lower than the ground surface by about 7 m. A Vertical Electrical Sounding (VES) survey was performed at 12 points around the studied building in order to investigate the vertical and lateral extent of the subsurface sequence, three VES's were conducted at each side of the building at discrete distances. And a total of 9 GPR profiles with 100- and 200-MHz antennae were conducted, with the objective of evaluating the depth and the degree of saturation of the subsurface layers. The qualitative and quantitative interpretation of the acquired VES's showed easily the levels of saturations close to and around the studied building. From the interpretation of GPR profiles, it was possible to locate and determine the saturated layers. The radar signals are penetrated and enabled the identification of the subsurface reflectors. The results of GPR and VES showed a good agreement and the integrated interpretations were supported by local geology. Finally, the new constructed geoelectrical resistivity cross-sections (in contoured-form), are easily clarifying the direction of groundwater flow toward the studied building.

  11. Detection of MAVs (Micro Aerial Vehicles) based on millimeter wave radar

    Science.gov (United States)

    Noetel, Denis; Johannes, Winfried; Caris, Michael; Hommes, Alexander; Stanko, Stephan

    2016-10-01

    In this paper we present two system approaches for perimeter surveillance with radar techniques focused on the detection of Micro Aerial Vehicles (MAVs). The main task of such radars is to detect movements of targets such as an individual or a vehicle approaching a facility. The systems typically cover a range of several hundred meters up to several kilometers. In particular, the capability of identifying Remotely Piloted Aircraft Systems (RPAS), which pose a growing threat on critical infrastructure areas, is of great importance nowadays. The low costs, the ease of handling and a considerable payload make them an excellent tool for unwanted surveillance or attacks. Most platforms can be equipped with all kind of sensors or, in the worst case, with destructive devices. A typical MAV is able to take off and land vertically, to hover, and in many cases to fly forward at high speed. Thus, it can reach all kinds of places in short time while the concealed operator of the MAV resides at a remote and riskless place.

  12. A comprehensive review on intelligent surveillance systems

    Directory of Open Access Journals (Sweden)

    Sutrisno Warsono Ibrahim

    2016-05-01

    Full Text Available Intelligent surveillance system (ISS has received growing attention due to the increasing demand on security and safety. ISS is able to automatically analyze image, video, audio or other type of surveillance data without or with limited human intervention. The recent developments in sensor devices, computer vision, and machine learning have an important role in enabling such intelligent system. This paper aims to provide general overview of intelligent surveillance system and discuss some possible sensor modalities and their fusion scenarios such as visible camera (CCTV, infrared camera, thermal camera and radar. This paper also discusses main processing steps in ISS: background-foreground segmentation, object detection and classification, tracking, and behavioral analysis.

  13. SMAP RADAR Processing and Calibration

    Science.gov (United States)

    West, R. D.; Jaruwatanadilok, S.; Kwoun, O.; Chaubell, M. J.

    2013-12-01

    The Soil Moisture Active Passive (SMAP) mission uses L-band radar and radiometer measurements to estimate soil moisture with 4% volumetric accuracy at a resolution of 10 km, and freeze-thaw state at a resolution of 1-3 km. Model sensitivities translate the soil moisture accuracy to a radar backscatter accuracy of 1 dB at 3 km resolution and a brightness temperature accuracy of 1.3 K at 40 km resolution. This presentation will describe the level 1 radar processing and calibration challenges and the choices made so far for the algorithms and software implementation. To obtain the desired high spatial resolution the level 1 radar ground processor employs synthetic aperture radar (SAR) imaging techniques. Part of the challenge of the SMAP data processing comes from doing SAR imaging on a conically scanned system with rapidly varying squint angles. The radar echo energy will be divided into range/Doppler bins using time domain processing algorithms that can easily follow the varying squint angle. For SMAP, projected range resolution is about 250 meters, while azimuth resolution varies from 400 meters to 1.2 km. Radiometric calibration of the SMAP radar means measuring, characterizing, and where necessary correcting the gain and noise contributions from every part of the system from the antenna radiation pattern all the way to the ground processing algorithms. The SMAP antenna pattern will be computed using an accurate antenna model, and then validated post-launch using homogeneous external targets such as the Amazon rain forest to look for uncorrected gain variation. Noise subtraction is applied after image processing using measurements from a noise only channel. Variations of the internal electronics are tracked by a loopback measurement which will capture most of the time and temperature variations of the transmit power and receiver gain. Long-term variations of system performance due to component aging will be tracked and corrected using stable external reference

  14. Principles of modern radar systems

    CERN Document Server

    Carpentier, Michel H

    1988-01-01

    Introduction to random functions ; signal and noise : the ideal receiver ; performance of radar systems equipped with ideal receivers ; analysis of the operating principles of some types of radar ; behavior of real targets, fluctuation of targets ; angle measurement using radar ; data processing of radar information, radar coverage ; applications to electronic scanning antennas to radar ; introduction to Hilbert spaces.

  15. Passive MIMO Radar Detection

    Science.gov (United States)

    2013-09-01

    cumulative distribution function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 CORA COvert RAdar...PaRaDe), developed by the Insti- tute of Electronic Systems at the Warsaw University of Technology [59, 60]; COvert RAdar ( CORA ), developed by the German

  16. Weather Radar Impact Zones

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — These data represent an inventory of the national impacts of wind turbine interference with NEXRAD radar stations. This inventory was developed by the NOAA Radar...

  17. Innovative SAR/MTI Concepts for Digital Radar

    NARCIS (Netherlands)

    Wit, J.J.M. de

    2008-01-01

    Contemporary military operations make high demands on the capabilities of sensors. Modern sensors must have the capability to perform different tasks, such as ground surveillance and target tracking, simultaneously. Multifunction digital radar may provide the required capabilities and meet the strin

  18. Digital LPI Radar Detector

    OpenAIRE

    Ong, Peng Ghee; Teng, Haw Kiad

    2001-01-01

    Approved for public release; distribution is unlimited The function of a Low Probability ofIntercept (LPI) radar is to prevent its interception by an Electronic Support (ES) receiver. This objective is generally achieved through the use of a radar waveform that is mismatched to those waveforms for which an ES receiver is tuned. This allows the radar to achieve a processing gain, with respect to the ES receiver, that is equal to the time-bandwidth product ofthe radar waveform. This...

  19. Network radar countermeasure systems integrating radar and radar countermeasures

    CERN Document Server

    Jiang, Qiuxi

    2016-01-01

    This is the very first book to present the network radar countermeasure system. It explains in detail the systematic concept of combining radar and radar countermeasures from the perspective of the information acquisition of target location, the optimization of the reconnaissance and detection, the integrated attack of the signals and facilities, and technological and legal developments concerning the networked system. It achieves the integration of the initiative and passivity, detection and jamming. The book explains how the system locates targets, completes target identification, tracks targets and compiles the data.

  20. Satellite radar for monitoring forest resources

    Science.gov (United States)

    Hoffer, Roger M.; Lee, Kyu-Sung

    1990-01-01

    An evaluation is made of the computer analysis results of a study which used Seasat satellite radar data obtained in 1978 and Shuttle Imaging Radar-B data obtained in 1984. The change-detection procedures employed demonstrate that deforestation and reforestation activities can be effectively monitored on the basis of radar data gathered at satellite altitudes. The computer-processing techniques applied to the data encompassed (1) overlay display, (2) ratios, (3) differences, (4) principal-component analysis, and (5) classification; of these, overlay display is noted to quickly and easily yield a qualitative display of the multidate data.

  1. Noise radar with broadband microwave ring correlator

    Science.gov (United States)

    Susek, Waldemar; Stec, Bronislaw

    2011-06-01

    A principle of quadrature correlation detection of noise signals using an analog broadband microwave correlator is presented in the paper. Measurement results for the correlation function of noise signals are shown and application of such solution in the noise radar for precise determination of distance changes and velocity of these changes is also presented. Results for short range noise radar operation are presented both for static and moving objects. Experimental results using 2,6 - 3,6 GHz noise like waveform for the signal from a breathing human is presented. Conclusions and future plans for applications of presented detection technique in broadband noise radars bring the paper to an end.

  2. Deep Stochastic Radar Models

    OpenAIRE

    Wheeler, Tim Allan; Holder, Martin; Winner, Hermann; Kochenderfer, Mykel

    2017-01-01

    Accurate simulation and validation of advanced driver assistance systems requires accurate sensor models. Modeling automotive radar is complicated by effects such as multipath reflections, interference, reflective surfaces, discrete cells, and attenuation. Detailed radar simulations based on physical principles exist but are computationally intractable for realistic automotive scenes. This paper describes a methodology for the construction of stochastic automotive radar models based on deep l...

  3. Radar: Human Safety Net

    Science.gov (United States)

    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…

  4. Radar and wind turbines; Radar en windturbines

    Energy Technology Data Exchange (ETDEWEB)

    Van Doorn, H.

    2010-03-15

    In the last years the developments of wind parks were hampered because of their possible effect on the radar for observation of air traffic. Work is currently being done on a new assessment model for wind turbines under the auspices of the steering group National Security for the military radar systems. Air traffic control Netherlands (LVNL) will look at the options for civil radars to join in. [Dutch] In de afgelopen jaren zijn windparkontwikkelingen onder meer belemmerd vanwege mogelijke effecten op radar voor de waarneming van luchtverkeer. Onder auspicien van de stuurgroep Nationale Veiligheid voor de militaire radarsystemen op land wordt gewerkt aan een nieuw beoordelingsmodel voor windturbines. De Luchtverkeersleiding Nederland (LVNL) zal bezien in hoeverre de civiele radars hierbij kunnen aansluiten.

  5. Radar-based remote sensing monitoring of roads

    OpenAIRE

    Crosetto, Michele; Monserrat, Oriol; Luzi, Guido; Cuevas-González, María; Devanthéry, Núria

    2014-01-01

    This paper provides a brief description of two powerful radar-based remote sensing techniques to monitor the deformations of roads, their associated infrastructures and, more in general, their surroundings. The first technique is the satellite radar interferometric technique. In this work a specific technique, named Persistent Scatterer Interferometry (PSI), is considered. This technique has wide-area coverage capability (e.g. covering thousands of square kilometres at the time) and,at the...

  6. The surveillant assemblage.

    Science.gov (United States)

    Haggerty, K D; Ericson, R V

    2000-12-01

    George Orwell's 'Big Brother' and Michel Foucault's 'panopticon' have dominated discussion of contemporary developments in surveillance. While such metaphors draw our attention to important attributes of surveillance, they also miss some recent dynamics in its operation. The work of Gilles Deleuze and Felix Guattari is used to analyse the convergence of once discrete surveillance systems. The resultant 'surveillant assemblage' operates by abstracting human bodies from their territorial settings, and separating them into a series of discrete flows. These flows are then reassembled in different locations as discrete and virtual 'data doubles'. The surveillant assemblage transforms the purposes of surveillance and the hierarchies of surveillance, as well as the institution of privacy.

  7. Signal processing method of a novel polarized array radar seeker

    Institute of Scientific and Technical Information of China (English)

    Lizhong Song; Xiaolin Qiao

    2013-01-01

    This paper proposes a novel polarized radar seeker based on the polarized antenna array. A ful y polarized signal processing method for the proposed radar seeker is studied un-der the environments with electromagnetic interferences. A dual polarized antenna array is employed to transmit and receive the radar signals. The instantaneous polarization signal processing technique is used to detect and recognize the targets. The di-rection of arrival (DOA) of the target is measured through the spatial spectrum with high resolution for the polarized array radar seeker system. The ful y polarized signal model of the polarized array radar seeker is formulated and a specific signal processing algorithm is expounded. The theoretical research and numerical simulation results demonstrate that the proposed radar seeker has good performances in target detection and electronic warfare. The research results can provide an effective technical approach to develop and research the new generation radar seeker.

  8. Surveillance issues in inflammatory bowel disease: ulcerative colitis.

    Science.gov (United States)

    Provenzale, D; Onken, J

    2001-02-01

    This review article on the surveillance of patients with ulcerative colitis provides an overview of the criteria for evaluating screening and surveillance programs and applies the criteria to the available evidence to determine the effectiveness of the surveillance of patients with ulcerative colitis. We examine the clinical outcomes associated with surveillance, the additional clinical time required to confirm the diagnosis of dysplasia and cancer, compliance with surveillance and follow-up, and the effectiveness of the individual components of a surveillance program, including colonoscopy and pathologist's interpretation. The disability associated with colectomy is considered, as are the cost and acceptability of surveillance programs. Patients with long-standing ulcerative colitis are at risk for developing colorectal cancer. Recommended surveillance colonoscopy should be supported. New endoscopic and histopathologic techniques to improve the identification of high-risk patients may enhance the effectiveness and cost-effectiveness of surveillance practices.

  9. Radar image preprocessing. [of SEASAT-A SAR data

    Science.gov (United States)

    Frost, V. S.; Stiles, J. A.; Holtzman, J. C.; Held, D. N.

    1980-01-01

    Standard image processing techniques are not applicable to radar images because of the coherent nature of the sensor. Therefore there is a need to develop preprocessing techniques for radar images which will then allow these standard methods to be applied. A random field model for radar image data is developed. This model describes the image data as the result of a multiplicative-convolved process. Standard techniques, those based on additive noise and homomorphic processing are not directly applicable to this class of sensor data. Therefore, a minimum mean square error (MMSE) filter was designed to treat this class of sensor data. The resulting filter was implemented in an adaptive format to account for changes in local statistics and edges. A radar image processing technique which provides the MMSE estimate inside homogeneous areas and tends to preserve edge structure was the result of this study. Digitally correlated Seasat-A synthetic aperture radar (SAR) imagery was used to test the technique.

  10. Pulse Doppler radar

    CERN Document Server

    Alabaster, Clive

    2012-01-01

    This book is a practitioner's guide to all aspects of pulse Doppler radar. It concentrates on airborne military radar systems since they are the most used, most complex, and most interesting of the pulse Doppler radars; however, ground-based and non-military systems are also included. It covers the fundamental science, signal processing, hardware issues, systems design and case studies of typical systems. It will be a useful resource for engineers of all types (hardware, software and systems), academics, post-graduate students, scientists in radar and radar electronic warfare sectors and milit

  11. Understanding radar systems

    CERN Document Server

    Kingsley, Simon

    1999-01-01

    What is radar? What systems are currently in use? How do they work? This book provides engineers and scientists with answers to these critical questions, focusing on actual radar systems in use today. It is a perfect resource for those just entering the field, or as a quick refresher for experienced practitioners. The book leads readers through the specialized language and calculations that comprise the complex world of radar engineering as seen in dozens of state-of-the-art radar systems. An easy to read, wide ranging guide to the world of modern radar systems.

  12. Millimeter-wave circuits and pulse compression radar baseband/analog signal processing blocks in silicon processes

    OpenAIRE

    2012-01-01

    The power dissipation and cost of the next generation pulse radar beamforming systems needs to be reduced for the imaging and surveillance sensors. This research work aims at developing and innovating the next generation, mobile hand-held, high performance radar systems for outdoor surveillance applications, i.e. pedestrian detection sensor. Integrating the low cost millimeter-wave (mm-wave) imaging array platforms with advanced analog/ baseband signal processing on silicon is proposed for re...

  13. Surveillance and Datenschutz in Virtual Environments

    Science.gov (United States)

    Cikic, Sabine; Lehmann-Grube, Fritz; Sablatnig, Jan

    Virtual environments are becoming more and more accepted, and part of the everyday online experience for many users. This offers new potential for both surveillance and data mining. Some of the techniques used are discussed in this paper.

  14. Reduction of snapshots for MIMO radar detection by block/group orthogonal matching pursuit

    KAUST Repository

    Ali, Hussain El Hosiny

    2014-10-01

    Multiple-input multiple-output (MIMO) radar works on the principle of transmission of independent waveforms at each element of its antenna array and is widely used for surveillance purposes. In this work, we investigate MIMO radar target localization problem with compressive sensing. Specifically, we try to solve the problem of estimation of target location in MIMO radar by group and block sparsity algorithms. It will lead us to a reduced number of snapshots required and also we can achieve better radar resolution. We will use group orthogonal matching pursuit (GOMP) and block orthogonal matching pursuit (BOMP) for our problem. © 2014 IEEE.

  15. The development of deep learning in synthetic aperture radar imagery

    CSIR Research Space (South Africa)

    Schwegmann, Colin P

    2017-05-01

    Full Text Available sensing techniques but comes at the price of additional complexities. To adequately cope with these, researchers have begun to employ advanced machine learning techniques known as deep learning to Synthetic Aperture Radar data. Deep learning represents...

  16. Reduction of radar cross-section of a wind turbine

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, Jacob Jeremiah; Brock, Billy C.; Clem, Paul G.; Loui, Hung; Allen, Steven E.

    2016-08-02

    The various technologies presented herein relate to formation of a wind turbine blade having a reduced radar signature in comparison with a turbine blade fabricated using conventional techniques. Various techniques and materials are presented to facilitate reduction in radar signature of a wind turbine blade, where such techniques and materials are amenable for incorporation into existing manufacturing techniques without degradation in mechanical or physical performance of the blade or major alteration of the blade profile.

  17. Digital Beamforming Synthetic Aperture Radar (DBSAR) Polarimetric Upgrade

    Science.gov (United States)

    Rincon, Rafael F.; Perrine, Martin; McLinden, Matthew; Valett, Susan

    2011-01-01

    The Digital Beamforming Synthetic Aperture Radar (DBSAR) is a state-of-the-art radar system developed at NASA/Goddard Space Flight Center for the development and implementation of digital beamforming radar techniques. DBSAR was recently upgraded to polarimetric operation in order to enhance its capability as a science instrument. Two polarimetric approaches were carried out which will be demonstrated in upcoming flight campaigns.

  18. HF Over-the-Horizon Radar System Performance Analysis

    Science.gov (United States)

    2007-09-01

    target detection technique and radar equations are applied. Chapter V uses PROPLAB model simulation to bring in the principle of raytracing and... RADAR SYSTEM PERFORMANCE ANALYSIS by Bin-Yi Liu September 2007 Thesis Co-Advisors: Phillip E. Pace Jeffrey B. Knorr THIS PAGE...Thesis 4. TITLE AND SUBTITLE HF Over-the-Horizon Radar System Performance Analysis 6. AUTHOR(S) Bin-Yi Liu 5. FUNDING NUMBERS 7. PERFORMING

  19. 激光雷达技术在河南栾川县山洪灾害调查中的示范应用%Application of laser radar technique in flash flood disaster investigation in Luanchuan County

    Institute of Scientific and Technical Information of China (English)

    张琦建; 刘昌军; 唐学哲; 孙涛; 郭良

    2015-01-01

    In recent years, the airborne Lidar is widely applied due to its ability to quickly obtain the third degree ground terrain information with efficiency and accuracy. Using UAV laser radar measurement technique, this research acquired flash flood data in two typical smal watersheds of Luanchuan County and introduced the process of the technique. Considering requirements of flash flood disaster evaluations, this paper detailed various methods including classification of laser point cloud data, DEM production, data processing technique of river cross-sections, and key technology of the automatic extraction of houses location and elevation. UAV laser radar technology features rapid data acquisition speed and high precision; it can meet the requirements of flash flood disaster investigations and provides the application demonstration of this technology. Consequently, this technique wil play an important role in investigation of flash flood disasters and have great application prospect.%机载LiDAR技术获取地面三维地物信息快捷、高效,近年来发展迅速,应用广泛。介绍了无人机雷达技术的航测技术流程,结合山洪灾害调查评价的应用需求,论述了激光点云数据的分类方法,数字高程模型(DEM)制作方法,河道断面批处理方法,居民户位置和高程的自动提取方法等应用关键技术,并以栾川县2个山洪灾害典型小流域为例,开展了示范应用。研究表明,无人机激光雷达测量技术获取数据速度快、精度高,能够满足山洪灾害调查的工作要求,为全国无资料地区山洪灾害调查工作提供了新技术的应用示范,将在全国山洪灾害调查工作中发挥巨大作用,具有较大的应用前景。

  20. Basic Radar Altimetry Toolbox & Tutorial

    Science.gov (United States)

    Rosmorduc, Vinca; Benveniste, Jerome; Breebaart, Leo; Bronner, Emilie; Dinardo, Salvatore; Earith, Didier; Lucas, Bruno Manuel; Niejmeier, Sander; Picot, Nicolas

    2010-12-01

    The Basic Radar Altimetry Toolbox is an "all-altimeter" collection of tools, tutorials and documents designed to facilitate the use of radar altimetry data, including the last mission launched, CryoSat. It has been available from April 2007, and had been demonstrated during training courses and scientific meetings. Nearly 1200 people downloaded it (as of end of June 2010), with many "newcomers" to altimetry among them. Users' feedbacks, developments in altimetry, and practice, showed that new interesting features could be added. Some have been added and/or improved in version 2. Others are ongoing, some are in discussion. The Basic Radar Altimetry Toolbox is able: - to read most distributed radar altimetry data, from ERS-1 & 2, Topex/Poseidon, Geosat Follow-on, Jason- 1, Envisat, Jason- 2, CryoSat and also the future Saral and Sentinel 3 missions, - to perform some processing, data editing and statistic, - and to visualize the results. It can be used at several levels/several ways: - as a data reading tool, with APIs for C, Fortran, Matlab and IDL - as processing/extraction routines, through the on-line command mode - as an educational and a quick-look tool both, with the graphical user interface As part of the Toolbox, a Radar Altimetry Tutorial gives general information about altimetry, the technique involved and its applications, as well as an overview of past, present and future missions, including information on how to access data, additional software and documentation. It also presents a series of data use cases, covering all uses of altimetry over ocean, cryosphere and land, showing the basic methods for some of the most frequent manners of using altimetry data. BRAT is developed under contract with ESA and CNES. It is available at http://www.altimetry.info and http://earth.esa.int/brat/

  1. Lunar topography - Global determination by radar.

    Science.gov (United States)

    Shapiro, I. I.; Zisk, S. H.; Rogers, A. E. E.; Slade, M. A.; Thompson, T. W.

    1972-01-01

    Previous methods used for two-dimensional radar mapping of the moon are contrasted with new techniques that add altitude information to the radar map. Delay-Doppler stereoscopy and delay-Doppler interferometry are shown to provide surface-height variations with higher accuracy and better global fidelity than has been possible previously. Sample results are presented for altitude contours on the moon as obtained with the Haystack and Westford radar systems of the Massachusetts Institute of Technology. An appendix describes the mathematical principles of delay-Doppler interferometry in determining the position of an arbitrary reflecting region of the lunar surface from measurements of the time delay, Doppler shift, and fringe phase of radar echoes from that region.

  2. Design of Millimeter-wave SiGe Frequency Doubler and Output Buffer for Automotive Radar Applications

    OpenAIRE

    2007-01-01

    Automotive Radars have introduced various functions on automobiles for driver’s safety and comfort, as part of the Intelligent Transportation System (ITS) including Adaptive Cruise Control (ACC), collision warning or avoidance, blind spot surveillance and parking assistance. Although such radar systems with 24 GHz carrier frequency are already in use but due to some regulatory issues, recently a permanent band has been allocated at 77-81 GHz, allowing for long-term development of the radar se...

  3. The Sharper Image for Surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Hazi, A

    2006-01-13

    A technique adapted by Livermore scientists to take the twinkle out of stars is now being used to improve the resolution of long-range surveillance systems trained on earthbound objects. The speckle-imaging technique involves taking tens to hundreds of pictures with short-exposure times and reconstructing a single, sharp image using image-processing software. The technique drew the interest of Livermore engineer Carmen Carrano. She developed a prototype remote-surveillance system that can produce a detailed image of a face from a couple of kilometers away. The system also helps identify vehicles tens of kilometers away and improves the viewing of large structures more than 60 kilometers away.

  4. Development and Testing of the VAHIRR Radar Product

    Science.gov (United States)

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

    2008-01-01

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

  5. Phased-array radar design application of radar fundamentals

    CERN Document Server

    Jeffrey, Thomas

    2009-01-01

    Phased-Array Radar Design is a text-reference designed for electrical engineering graduate students in colleges and universities as well as for corporate in-house training programs for radar design engineers, especially systems engineers and analysts who would like to gain hands-on, practical knowledge and skills in radar design fundamentals, advanced radar concepts, trade-offs for radar design and radar performance analysis.

  6. Radar Signature Calculation Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: The calculation, analysis, and visualization of the spatially extended radar signatures of complex objects such as ships in a sea multipath environment and...

  7. Evaluation of multivariate surveillance

    OpenAIRE

    Frisén,Marianne; Andersson, Eva; Schiöler, Linus

    2009-01-01

    Multivariate surveillance is of interest in many areas such as industrial production, bioterrorism detection, spatial surveillance, and financial transaction strategies. Some of the suggested approaches to multivariate surveillance have been multivariate counterparts to the univariate Shewhart, EWMA, and CUSUM methods. Our emphasis is on the special challenges of evaluating multivariate surveillance methods. Some new measures are suggested and the properties of several measures are demonstrat...

  8. Alpine radar conversion for LAWR

    Science.gov (United States)

    Savina, M.; Burlando, P.

    2012-04-01

    The Local Area Weather Radar (LAWR) is a ship-born weather radar system operating in X-band developed by the DHI Group to detect precipitation in urban areas. To date more than thirty units are installed in different settings around the world. A LAWR was also deployed in the Alps, at 3883 m a.s.l. on the Kl. Matterhorn (Valais, Switzerland). This was the highest LAWR of the world and it led to the development of an Alpine LAWR system that, besides featuring important technological improvements needed to withstand the severe Alpine conditions, required the development of a new Alpine Radar COnversion Model (ARCOM), which is the main focus of this contribution. The LAWR system is equipped with the original FURUNO fan-beam slotted antenna and the original logarithmic receiver, which limits the radar observations to the video signal (L) withour providing the reflectivity (Z). The beam is 0.95 deg wide and 20 deg high. It can detect precipitation to a max range of 60 km. In order to account for the limited availability of raw signal and information and the specific mountain set-up, the conversion model had to be developed differently from the state-of-the-art radar conversion technique used for this class of radars. In particular, the ARCOM is based on a model used to simulate a spatial dependent factor, hereafter called ACF, which is in turn function of parameters that take in account climatological conditions, also used in other conversion methods, but additionally accounting for local radar beam features and for orographic forcings such as the effective sampling power (sP), which is modelled by means of antenna pattern, geometric ground clutter and their interaction. The result is a conversion factor formulated to account for a range correction that is based on the increase of the sampling volume, partial beam blocking and local climatological conditions. The importance of the latter in this study is double with respect to the standard conversion technique for this

  9. Surveillance for West Nile Virus in Clinic-admitted Raptors, Colorado

    OpenAIRE

    Nemeth, Nicole; Kratz, Gail; Edwards, Eric; Scherpelz, Judy; Bowen, Richard; Komar, Nicholas

    2007-01-01

    In 2005, 13.5% of clinic-admitted raptors in northern Colorado tested positive for West Nile virus (WNV). Clinic-admitted–raptor surveillance detected WNV activity nearly 14 weeks earlier than other surveillance systems. WNV surveillance using live raptor admissions to rehabilitation clinics may offer a novel surveillance method and should be considered along with other techniques already in use.

  10. Surveillance for West Nile virus in clinic-admitted raptors, Colorado.

    Science.gov (United States)

    Nemeth, Nicole; Kratz, Gail; Edwards, Eric; Scherpelz, Judy; Bowen, Richard; Komar, Nicholas

    2007-02-01

    In 2005, 13.5% of clinic-admitted raptors in northern Colorado tested positive for West Nile virus (WNV). Clinic-admitted-raptor surveillance detected WNV activity nearly 14 weeks earlier than other surveillance systems. WNV surveillance using live raptor admissions to rehabilitation clinics may offer a novel surveillance method and should be considered along with other techniques already in use.

  11. GEIS Surveillance Network Program

    Science.gov (United States)

    2013-10-01

    resistance surveillance, diarrhea etiology and antimicrobial resistance surveillance, sexually transmitted illness surveillance, and capacity building...vomiting, diarrhea , joint pains, general malaise. Of the samples analyzed, only 53.7% had an associated etiology: Malaria (47.0%, EBV (39.7...immunity to the disease. Many adults in those situations are reservoirs, facilitating continuing disease transmission to those without immunity. In Kenya

  12. SOA-surveillance Nederland

    NARCIS (Netherlands)

    Rijlaarsdam J; Bosman A; Laar MJW van de; CIE

    2000-01-01

    In May 1999 a working group was started to evaluate the current surveillance systems for sexually transmitted diseases (STD) and to make suggestions for a renewed effective and efficient STD surveillance system in the Netherlands. The surveillance system has to provide insight into the prevalence an

  13. SOA-surveillance Nederland

    NARCIS (Netherlands)

    Rijlaarsdam J; Bosman A; Laar MJW van de; CIE

    2000-01-01

    In May 1999 a working group was started to evaluate the current surveillance systems for sexually transmitted diseases (STD) and to make suggestions for a renewed effective and efficient STD surveillance system in the Netherlands. The surveillance system has to provide insight into the prevalence

  14. Ground Penetrating Radar for SMART CITIES

    Science.gov (United States)

    Soldovieri, Francesco; Catapano, Ilaria; Gennarelli, Gianluca

    2016-04-01

    The use of monitoring and surveillance technologies is now recognized as a reliable option of the overall smart cities management cycle, for the advantages that they offer in terms of: economically sustainable planning of the ordinary and extraordinary maintenance interventions; situational awareness of possible risks factors in view of a reliable early warning; improvement of the security of the communities especially in public environments. In this frame, the abstract will deal with the recent advances in the development and deployment of radar systems for the urban surveillance, exploitation of the subsurface resources and civil engineering structures. In particular, we will present the recent scientific developments and several examples of use of these systems in operational conditions.

  15. Adaptable Bandwidth for Harmonic Step-Frequency Radar

    Directory of Open Access Journals (Sweden)

    Anthony F. Martone

    2015-01-01

    Full Text Available A spectrum sensing technique is described which is used to enhance the performance of harmonic step-frequency radar in the presence of harmful radio frequency (RF interference (RFI. This technique passively monitors the RF spectrum for subbands of high signal-to-interference-plus-noise ratio (SINR within a constrained bandwidth of interest. An optimal subband is selected for the harmonic radar that maximizes SINR and minimizes the range resolution cell size, two conflicting objectives. The approach is tested using an experimental setup that injects high power RFI into a harmonic step-frequency radar, which significantly degrades radar performance. It is shown that the proposed spectrum sensing technique significantly improves the SINR and the peak-to-average sidelobe power level of the harmonic radar at the sacrifice of range resolution.

  16. Combined radar and telemetry system

    Energy Technology Data Exchange (ETDEWEB)

    Rodenbeck, Christopher T.; Young, Derek; Chou, Tina; Hsieh, Lung-Hwa; Conover, Kurt; Heintzleman, Richard

    2017-08-01

    A combined radar and telemetry system is described. The combined radar and telemetry system includes a processing unit that executes instructions, where the instructions define a radar waveform and a telemetry waveform. The processor outputs a digital baseband signal based upon the instructions, where the digital baseband signal is based upon the radar waveform and the telemetry waveform. A radar and telemetry circuit transmits, simultaneously, a radar signal and telemetry signal based upon the digital baseband signal.

  17. A comparison between EDA-EnVar and ETKF-EnVar data assimilation techniques using radar observations at convective scales through a case study of Hurricane Ike (2008)

    Science.gov (United States)

    Shen, Feifei; Xu, Dongmei; Xue, Ming; Min, Jinzhong

    2017-07-01

    This study examines the impacts of assimilating radar radial velocity (Vr) data for the simulation of hurricane Ike (2008) with two different ensemble generation techniques in the framework of the hybrid ensemble-variational (EnVar) data assimilation system of Weather Research and Forecasting model. For the generation of ensemble perturbations we apply two techniques, the ensemble transform Kalman filter (ETKF) and the ensemble of data assimilation (EDA). For the ETKF-EnVar, the forecast ensemble perturbations are updated by the ETKF, while for the EDA-EnVar, the hybrid is employed to update each ensemble member with perturbed observations. The ensemble mean is analyzed by the hybrid method with flow-dependent ensemble covariance for both EnVar. The sensitivity of analyses and forecasts to the two applied ensemble generation techniques is investigated in our current study. It is found that the EnVar system is rather stable with different ensemble update techniques in terms of its skill on improving the analyses and forecasts. The EDA-EnVar-based ensemble perturbations are likely to include slightly less organized spatial structures than those in ETKF-EnVar, and the perturbations of the latter are constructed more dynamically. Detailed diagnostics reveal that both of the EnVar schemes not only produce positive temperature increments around the hurricane center but also systematically adjust the hurricane location with the hurricane-specific error covariance. On average, the analysis and forecast from the ETKF-EnVar have slightly smaller errors than that from the EDA-EnVar in terms of track, intensity, and precipitation forecast. Moreover, ETKF-EnVar yields better forecasts when verified against conventional observations.

  18. Detecting and classifying low probability of intercept radar

    CERN Document Server

    Pace, Phillip E

    2003-01-01

    The drive is on to devise LPI radar systems that evade hostile detection as well as develop non-cooperative intercept devices that outsmart enemy LPI radar. Based on the author's own design experience, this comprehensive, hands-on book gives you the latest design and development techniques to innovate new LPI radar systems and discover new ways to intercept enemy LPI radar. and help you visually identify waveform parameters. Filled with more than 500 equations that provide rigorous mathematical detail, this book can be used by both entry-level and seasoned engineers. Besides thoroughly treatin

  19. Radar fall detection using principal component analysis

    Science.gov (United States)

    Jokanovic, Branka; Amin, Moeness; Ahmad, Fauzia; Boashash, Boualem

    2016-05-01

    Falls are a major cause of fatal and nonfatal injuries in people aged 65 years and older. Radar has the potential to become one of the leading technologies for fall detection, thereby enabling the elderly to live independently. Existing techniques for fall detection using radar are based on manual feature extraction and require significant parameter tuning in order to provide successful detections. In this paper, we employ principal component analysis for fall detection, wherein eigen images of observed motions are employed for classification. Using real data, we demonstrate that the PCA based technique provides performance improvement over the conventional feature extraction methods.

  20. Real-Time Radar-Based Tracking and State Estimation of Multiple Non-Conformant Aircraft

    Science.gov (United States)

    Cook, Brandon; Arnett, Timothy; Macmann, Owen; Kumar, Manish

    2017-01-01

    In this study, a novel solution for automated tracking of multiple unknown aircraft is proposed. Many current methods use transponders to self-report state information and augment track identification. While conformant aircraft typically report transponder information to alert surrounding aircraft of its state, vehicles may exist in the airspace that are non-compliant and need to be accurately tracked using alternative methods. In this study, a multi-agent tracking solution is presented that solely utilizes primary surveillance radar data to estimate aircraft state information. Main research challenges include state estimation, track management, data association, and establishing persistent track validity. In an effort to realize these challenges, techniques such as Maximum a Posteriori estimation, Kalman filtering, degree of membership data association, and Nearest Neighbor Spanning Tree clustering are implemented for this application.

  1. Research at the Stanford Center for Radar Astronomy

    Science.gov (United States)

    1972-01-01

    The research is reported in the applications of radar and radio techniques to the study of the solar system, and to space programs. Experiments reported include: bistatic-radar on Apollo missions, development of an unmanned geophysical observatory in the Antartic, Bragg scattering probes of sea states, characteristics of dense solar wind disturbances, and satellite communications for Alaska.

  2. SURVEILLANCE OF MOVING TARGET BEHIND PARTITIONS USING A UWB-TWDR

    Institute of Scientific and Technical Information of China (English)

    Li Yu; Huang Chunlin; Su Yi

    2005-01-01

    This paper firstly analyzes the property of the low frequency electromagnetic wave,which can penetrate many types of non-metallic materials, and the ability of Ultra-Wide Band (UWB) impulse signal which has high range resolution. Then the methods are discussed for conducting surveillance through walls, detecting and locating the moving persons behind the partitions. The schematic diagram of Through-Wall Detecting Radar (TWDR) and the models of moving target are shown and the principle of detecting the moving target is also proyided with coherent superimposing technique on a range gate. Finally an algorithm for estimating the location of targets is given. The performance of TWDR is validated by the experiments of penetrating a wood block, a red brick wall and a reinforced concrete wall.

  3. Investigation of hopped frequency waveforms for range and velocity measurements of radar targets

    CSIR Research Space (South Africa)

    Kathree, U

    2015-10-01

    Full Text Available In the field of radar, High Range Resolution (HRR) profiles are often used to improve target tracking accuracy in range and to allow the radar system to produce an image of an object using techniques such as inverse synthetic aperture radar (ISAR...

  4. Radar illusion via metamaterials

    Science.gov (United States)

    Jiang, Wei Xiang; Cui, Tie Jun

    2011-02-01

    An optical illusion is an image of a real target perceived by the eye that is deceptive or misleading due to a physiological illusion or a specific visual trick. The recently developed metamaterials provide efficient approaches to generate a perfect optical illusion. However, all existing research on metamaterial illusions has been limited to theory and numerical simulations. Here, we propose the concept of a radar illusion, which can make the electromagnetic (EM) image of a target gathered by radar look like a different target, and we realize a radar illusion device experimentally to change the radar image of a metallic target into a dielectric target with predesigned size and material parameters. It is well known that the radar signatures of metallic and dielectric objects are significantly different. However, when a metallic target is enclosed by the proposed illusion device, its EM scattering characteristics will be identical to that of a predesigned dielectric object under the illumination of radar waves. Such an illusion device will confuse the radar, and hence the real EM properties of the metallic target cannot be perceived. We designed and fabricated the radar illusion device using artificial metamaterials in the microwave frequency, and good illusion performances are observed in the experimental results.

  5. Java Radar Analysis Tool

    Science.gov (United States)

    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.

  6. Determination of radar MTF

    Energy Technology Data Exchange (ETDEWEB)

    Chambers, D. [Lawrence Livermore National Lab., CA (United States)

    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.

  7. Aspects of Radar Polarimetry

    OpenAIRE

    Lüneburg, Ernst

    2002-01-01

    This contribution is a tutorial introduction to the phenomenological theory of radar polarimetry for the coherent scatter case emphasizing monostatic backscattering and forward scattering (transmission). Characteristic similarities and differences between radar polarimetry and optical polarimetry and the role of linear and antilinear operators (time-reversal) are pointed out and typical polarimetric invariants are identified.

  8. The Cloud Radar System

    Science.gov (United States)

    Racette, Paul; Heymsfield, Gerald; Li, Lihua; Tian, Lin; Zenker, Ed

    2003-01-01

    Improvement in our understanding of the radiative impact of clouds on the climate system requires a comprehensive view of clouds including their physical dimensions, dynamical generation processes, and detailed microphysical properties. To this end, millimeter vave radar is a powerful tool by which clouds can be remotely sensed. The NASA Goddard Space Flight Center has developed the Cloud Radar System (CRS). CRS is a highly sensitive 94 GHz (W-band) pulsed-Doppler polarimetric radar that is designed to fly on board the NASA high-altitude ER-2 aircraft. The instrument is currently the only millimeter wave radar capable of cloud and precipitation measurements from above most all clouds. Because it operates from high-altitude, the CRS provides a unique measurement perspective for cirrus cloud studies. The CRS emulates a satellite view of clouds and precipitation systems thus providing valuable measurements for the implementation and algorithm validation for the upcoming NASA CloudSat mission that is designed to measure ice cloud distributions on the global scale using a spaceborne 94 GHz radar. This paper describes the CRS instrument and preliminary data from the recent Cirrus Regional Study of Tropical Anvils and Cirrus Layers - Florida Area Cirrus Experiment (CRYSTAL-FACE). The radar design is discussed. Characteristics of the radar are given. A block diagram illustrating functional components of the radar is shown. The performance of the CRS during the CRYSTAL-FACE campaign is discussed.

  9. Surveillance and Monitoring of Dialysis Access

    Directory of Open Access Journals (Sweden)

    Lalathaksha Kumbar

    2012-01-01

    Full Text Available Vascular access is the lifeline of a hemodialysis patient. Currently arteriovenous fistula and graft are considered the permanent options for vascular access. Monitoring and surveillance of vascular access are an integral part of the care of hemodialysis patient. Although different techniques and methods are available for identifying access dysfunction, the scientific evidence for the optimal methodology is lacking. A small number of randomized controlled trials have been performed evaluating different surveillance techniques. We performed a study of the recent literature published in the PUBMED, to review the scientific evidence on different methodologies currently being used for surveillance and monitoring and their impact on the care of the dialysis access. The limited randomized studies especially involving fistulae and small sample size of the published studies with conflicting results highlight the need for a larger multicentered randomized study with hard clinical end points to evaluate the optimal surveillance strategy for both fistula and graft.

  10. Micropower impulse radar imaging

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. A User Guide for Smoothing Air Traffic Radar Data

    Science.gov (United States)

    Bach, Ralph E.; Paielli, Russell A.

    2014-01-01

    Matlab software was written to provide smoothing of radar tracking data to simulate ADS-B (Automatic Dependent Surveillance-Broadcast) data in order to test a tactical conflict probe. The probe, called TSAFE (Tactical Separation-Assured Flight Environment), is designed to handle air-traffic conflicts left undetected or unresolved when loss-of-separation is predicted to occur within approximately two minutes. The data stream that is down-linked from an aircraft equipped with an ADS-B system would include accurate GPS-derived position and velocity information at sample rates of 1 Hz. Nation-wide ADS-B equipage (mandated by 2020) should improve surveillance accuracy and TSAFE performance. Currently, position data are provided by Center radar (nominal 12-sec samples) and Terminal radar (nominal 4.8-sec samples). Aircraft ground speed and ground track are estimated using real-time filtering, causing lags up to 60 sec, compromising performance of a tactical resolution tool. Offline smoothing of radar data reduces wild-point errors, provides a sample rate as high as 1 Hz, and yields more accurate and lag-free estimates of ground speed, ground track, and climb rate. Until full ADS-B implementation is available, smoothed radar data should provide reasonable track estimates for testing TSAFE in an ADS-B-like environment. An example illustrates the smoothing of radar data and shows a comparison of smoothed-radar and ADS-B tracking. This document is intended to serve as a guide for using the smoothing software.

  12. Principles of modern radar radar applications

    CERN Document Server

    Scheer, James A

    2013-01-01

    Principles of Modern Radar: Radar Applications is the third of the three-volume seriesof what was originally designed to be accomplished in one volume. As the final volumeof the set, it finishes the original vision of a complete yet bounded reference for radartechnology. This volume describes fifteen different system applications or class ofapplications in more detail than can be found in Volumes I or II.As different as the applications described, there is a difference in how these topicsare treated by the authors. Whereas in Volumes I and II there is strict adherence tochapter format and leve

  13. Implementation of complex digital PLL for phase detection in software defined radar

    OpenAIRE

    2016-01-01

    Software defined radar (SDR) has been the latest trend in developing enhanced radar signal processing techniques for state-of-the-art radar systems. SDR provides tremendous flexibility in reconfigurable design and rapid prototyping capabilities on FPGA platform. To cater real-time processing for high-speed radar, COordinate Rotation Digital Computer (CORDIC) unit has been utilized as a core processing element in a complex digital phase locked loop (DPLL) for digital demodulation of received s...

  14. Three-dimensional mosaicking of the South Korean radar network

    Science.gov (United States)

    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.

  15. Health environmental risks surveillance systems: toxicological surveillance

    OpenAIRE

    Ana Ferrer Dufol; Santiago Nogué Xarau; Francisco Vargas Marcos; Olivia Castillo Soria; Pilar Gascó Alberich; Ana de la Torre Reoyo; Eduardo de la Peña de Torres

    2004-01-01

    A study of the Clinical Toxicological Section, about the Epidemiological Surveillance in Emergency Services, in relation to chemical products intoxications during the 1999-2003 period, is presented. This work is a result of an agreement between the Spanish Toxicological Association (AETOX) and the Spanish Ministry of Health and Consumption, and was presented in the National Congress of Environment (CONAMA) within the “Health Environmental Risks Surveillance Systems” working group.

  16. Probabilistic forecasts based on radar rainfall uncertainty

    Science.gov (United States)

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

    2012-04-01

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

  17. A Combination of Different Synthetic Aperture Radar (SAR) Techniques for Bottom-Fast Ice and Permafrost Monitoring in Canadian Polar Region (Mackenzie Delta)

    Science.gov (United States)

    Alasset, P.; Parsons, G.; Yue, B.; Chamberland, J.; Mulvie, J.

    2009-12-01

    The Mackenzie Delta is a unique region in the Canadian North which is rich in hydrocarbons and supports a fragile ecosystem. A need exists to define nominal remote coastal conditions prior to hydrocarbon extraction and to assist in monitoring conditions once the extraction will be underway. Near shore the formation of Bottom-Fast Ice (BFI) plays an important role in the region’s seasonal environmental changes and in the understanding of arctic coastal environmental and geophysical control processes. BFI is ice that has frozen to the seabed in shallow sea water and forms in areas where the sea water is shallow. These regions control permafrost distribution, spring overflow and potential strudel scours - holes in the frozen seafloor from flowing fresh water in rivers and streams during spring in the Beaufort Sea - and influence channel mouth constraints and early breakup season flood routing. BFI has been studied by generating D-InSAR (Differential SAR Interferometry) coherence maps during the winter of 2007-2008 and 2008-2009 using a combination of SAR image pairs from the TerraSAR-X space borne sensor. The results derived from these data were compared to results obtained from ALOS-PALSAR and RADARSAT-2 using advanced polarimetric techniques for BFI delineation. All coherence maps of the winter 2008-2009 data were assembled and compiled to demonstrate seasonal changes throughout the winter. The results of these analyses indicate that deriving coherence maps from repeat-pass data generates a product that is indicative of BFI regions; though relying on an entirely different land characteristic than polarimetric BFI delineation (e.g. ground stability vs. dielectric constants). Through the use of various polarimetric channels, a good discrimination between BFI regions and ice-covered land regions has been noted in the past. With specialised analysts, it is possible to reasonably outline BFI regions from these polarimetric datasets. Additional to these standard

  18. Imaging radar polarimetry - A review

    Science.gov (United States)

    Zebker, Howard A.; Van Zyl, Jakob J.

    1991-01-01

    The authors present a tutorial review of the broad sweep of topics relating to imaging radar polarimetry, ranging from mathematical foundations to hardware and from implementation approaches to signal processing and calibration. The authors examine current developments in sensor technology and implementation for recording polarimetric measurements, and describe techniques and areas of application for this form of remotely sensed data. Those aspects of ground signal processing and calibration peculiar to the polarimetric signals are addressed. Several of the currently operating instruments and some of the implementations planned for future use are discussed.

  19. To See the Unseen: A History of Planetary Radar Astronomy

    Science.gov (United States)

    Butrica, Andrew J.

    1996-01-01

    -based facilities by this transformed planetary radar astronomy, as well as the upgrading of the Arecibo and Goldstone radars. A technical essay appended to this book provides an overview of planetary radar techniques, especially range-Doppler mapping.

  20. Illicit Drug Trafficking in West Africa -- Primary Surveillance Radar Introduction

    Science.gov (United States)

    2012-03-22

    rich-quick message and a devaluation of traditional values which have always kept these societies cohesive and united. This tension breeds violence...commodities, such as kola and cannabis . Imported American rum, French brandy and Dutch gin was also traded along these coasts for more than 500 5 years...Kola stimulant, cannabis and alcohol were all legally traded between Europe, the Middle East and the Sahara. Given West Africa’s long history of

  1. Enhancing Arctic Surveillance With Space-Based Radars

    Science.gov (United States)

    2013-06-01

    satellite’s orbital plane coincides with the plane that divides half of the Earth which is illuminated by the Sun from the half that is dark . This angle...having a lifecycle or more than two years; continuing and recurrent (Dictionary.com, 2012). Polar Orbit: a spacecraft orbit that travels over or near...shipping, hydrocarbon extraction, fishing, and tourism activities (to name but just a few) are increasing in frequency, duration, and intensity and

  2. Multiple hypothesis clustering in radar plot extraction

    NARCIS (Netherlands)

    Huizing, A.G.; Theil, A.; Dorp, Ph. van; Ligthart, L.P.

    1995-01-01

    False plots and plots with inaccurate range and Doppler estimates may severely degrade the performance of tracking algorithms in radar systems. This paper describes how a multiple hypothesis clustering technique can be applied to mitigate the problems involved in plot extraction. The measures of

  3. Borehole radar modeling for reservoir monitoring applications

    NARCIS (Netherlands)

    Miorali, M.; Slob, E.C.; Arts, R.J.

    2010-01-01

    The use of down-hole sensors and remotely controlled valves in wells provide enormous benefits to reservoir management and oil production. We suggest borehole radar measurements as a promising technique capable of monitoring the arrival of undesired fluids in the proximity of production wells. The h

  4. Borehole radar modeling for reservoir monitoring applications

    NARCIS (Netherlands)

    Miorali, M.; Slob, E.C.; Arts, R.J.

    2010-01-01

    The use of down-hole sensors and remotely controlled valves in wells provide enormous benefits to reservoir management and oil production. We suggest borehole radar measurements as a promising technique capable of monitoring the arrival of undesired fluids in the proximity of production wells. The

  5. Generating nonlinear FM chirp waveforms for radar.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin Walter

    2006-09-01

    Nonlinear FM waveforms offer a radar matched filter output with inherently low range sidelobes. This yields a 1-2 dB advantage in Signal-to-Noise Ratio over the output of a Linear FM waveform with equivalent sidelobe filtering. This report presents design and implementation techniques for Nonlinear FM waveforms.

  6. Monitoring civil infrastructure using satellite radar interferometry

    NARCIS (Netherlands)

    Chang, L.

    2015-01-01

    Satellite radar interferometry (InSAR) is a precise and efficient technique to monitor deformation on Earth with millimeter precision. Most InSAR applications focus on geophysical phenomena, such as earthquakes, volcanoes, or subsidence. Monitoring civil infrastructure with InSAR is relatively new,

  7. Radar ambiguity function in Lp frame

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In modern radar techniques, pulse signal can be replaced by the chirps, which is taken to be signals in Lp space. Wigner's function and ambiguity functions are constructed in an Lp frame and a partial generalization of the uncertainty principle is given by means of the notion of coherent dual.

  8. Multiple hypothesis clustering in radar plot extraction

    NARCIS (Netherlands)

    Huizing, A.G.; Theil, A.; Dorp, Ph. van; Ligthart, L.P.

    1995-01-01

    False plots and plots with inaccurate range and Doppler estimates may severely degrade the performance of tracking algorithms in radar systems. This paper describes how a multiple hypothesis clustering technique can be applied to mitigate the problems involved in plot extraction. The measures of con

  9. Radar cross section

    CERN Document Server

    Knott, Gene; Tuley, Michael

    2004-01-01

    This is the second edition of the first and foremost book on this subject for self-study, training, and course work. Radar cross section (RCS) is a comparison of two radar signal strengths. One is the strength of the radar beam sweeping over a target, the other is the strength of the reflected echo sensed by the receiver. This book shows how the RCS ?gauge? can be predicted for theoretical objects and how it can be measured for real targets. Predicting RCS is not easy, even for simple objects like spheres or cylinders, but this book explains the two ?exact? forms of theory so well that even a

  10. Radar and electronic navigation

    CERN Document Server

    Sonnenberg, G J

    2013-01-01

    Radar and Electronic Navigation, Sixth Edition discusses radar in marine navigation, underwater navigational aids, direction finding, the Decca navigator system, and the Omega system. The book also describes the Loran system for position fixing, the navy navigation satellite system, and the global positioning system (GPS). It reviews the principles, operation, presentations, specifications, and uses of radar. It also describes GPS, a real time position-fixing system in three dimensions (longitude, latitude, altitude), plus velocity information with Universal Time Coordinated (UTC). It is accur

  11. Reassembling Surveillance Creep

    DEFF Research Database (Denmark)

    Bøge, Ask Risom; Lauritsen, Peter

    2017-01-01

    We live in societies in which surveillance technologies are constantly introduced, are transformed, and spread to new practices for new purposes. How and why does this happen? In other words, why does surveillance “creep”? This question has received little attention either in theoretical...... development or in empirical analyses. Accordingly, this article contributes to this special issue on the usefulness of Actor-Network Theory (ANT) by suggesting that ANT can advance our understanding of ‘surveillance creep’. Based on ANT’s model of translation and a historical study of the Danish DNA database......, we argue that surveillance creep involves reassembling the relations in surveillance networks between heterogeneous actors such as the watchers, the watched, laws, and technologies. Second, surveillance creeps only when these heterogeneous actors are adequately interested and aligned. However...

  12. Concept Development for Advanced Spaceborne Synthetic Aperture Radar Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The effort will focus on P-Band and L-band polarimetric radar architectures that employ advanced and innovative techniques to increase the science value of the...

  13. Advanced Meteor radar at Tirupati: System details and first results

    Science.gov (United States)

    Sunkara, Eswaraiah; Gurubaran, Subramanian; Sundararaman, Sathishkumar; Venkat Ratnam, Madineni; Karanam, Kishore Kumar; Eethamakula, Kosalendra; Vijaya Bhaskara Rao, S.

    An advanced meteor radar viz., Enhanced Meteor Detection Radar (EMDR) operating at 35.25 MHz is installed at Sri Venkateswara University (SVU), Tirupati (13.63oN, 79.4oE), India, in the month of August 2013. Present communication describes the need for the meteor radar at present location, system description, its measurement techniques, its variables and comparison of measured mean winds with contemporary radars over the Indian region. The present radar site is selected to fill the blind region of Gadanki (13.5oN, 79.2oE) MST radar, which covers mesosphere and lower thermosphere (MLT) region (70-110 km). By modifying the receiving antenna structure and elements, this radar is capable of providing accurate wind information between 70 and 110 km unlike other similar radars. Height covering region is extended by increasing the meteor counting capacity by modifying the receiving antenna structure and elements and hence its wind estimation limits extended below and above of 80 and 100 km, respectively. In the present study, we also made comparison of horizontal winds in the MLT region with those measured by similar and different (MST and MF radars) techniques over the Indian region including the model (HWM 07) data sets. The comparison showed a very good agreement between the overlapping altitudes (82-98 km) of different radars. Zonal winds compared very well as that of meridional winds. The observed discrepancies and limitations in the wind measurement are discussed. This new radar is expected to play important role in understanding the vertical and lateral coupling by forming a unique local network.

  14. Handbook of surveillance technologies

    CERN Document Server

    Petersen, JK

    2012-01-01

    From officially sanctioned, high-tech operations to budget spy cameras and cell phone video, this updated and expanded edition of a bestselling handbook reflects the rapid and significant growth of the surveillance industry. The Handbook of Surveillance Technologies, Third Edition is the only comprehensive work to chronicle the background and current applications of the full-range of surveillance technologies--offering the latest in surveillance and privacy issues.Cutting-Edge--updates its bestselling predecessor with discussions on social media, GPS circuits in cell phones and PDAs, new GIS s

  15. Redefining syndromic surveillance.

    Science.gov (United States)

    Katz, Rebecca; May, Larissa; Baker, Julia; Test, Elisa

    2011-12-01

    With growing concerns about international spread of disease and expanding use of early disease detection surveillance methods, the field of syndromic surveillance has received increased attention over the last decade. The purpose of this article is to clarify the various meanings that have been assigned to the term syndromic surveillance and to propose a refined categorization of the characteristics of these systems. Existing literature and conference proceedings were examined on syndromic surveillance from 1998 to 2010, focusing on low- and middle-income settings. Based on the 36 unique definitions of syndromic surveillance found in the literature, five commonly accepted principles of syndromic surveillance systems were identified, as well as two fundamental categories: specific and non-specific disease detection. Ultimately, the proposed categorization of syndromic surveillance distinguishes between systems that focus on detecting defined syndromes or outcomes of interest and those that aim to uncover non-specific trends that suggest an outbreak may be occurring. By providing an accurate and comprehensive picture of this field's capabilities, and differentiating among system types, a unified understanding of the syndromic surveillance field can be developed, encouraging the adoption, investment in, and implementation of these systems in settings that need bolstered surveillance capacity, particularly low- and middle-income countries. Copyright © 2011 Ministry of Health, Saudi Arabia. Published by Elsevier Ltd. All rights reserved.

  16. Surveillance of antibiotic resistance

    National Research Council Canada - National Science Library

    Johnson, Alan P

    2015-01-01

    .... Surveillance of antibiotic resistance involves the collection of antibiotic susceptibility test results undertaken by microbiology laboratories on bacteria isolated from clinical samples sent for investigation...

  17. Radar efficiency and the calculation of decade-long PMSE backscatter cross-section for the Resolute Bay VHF radar

    Directory of Open Access Journals (Sweden)

    N. Swarnalingam

    2009-04-01

    Full Text Available The Resolute Bay VHF radar, located in Nunavut, Canada (75.0° N, 95.0° W and operating at 51.5 MHz, has been used to investigate Polar Mesosphere Summer Echoes (PMSE since 1997. PMSE are a unique form of strong coherent radar echoes, and their understanding has been a challenge to the scientific community since their discovery more than three decades ago. While other high latitude radars have recorded strong levels of PMSE activities, the Resolute Bay radar has observed relatively lower levels of PMSE strengths. In order to derive absolute measurements of PMSE strength at this site, a technique is developed to determine the radar efficiency using cosmic (sky noise variations along with the help of a calibrated noise source. VHF radars are only rarely calibrated, but determination of efficiency is even less common. Here we emphasize the importance of efficiency for determination of cross-section measurements. The significant advantage of this method is that it can be directly applied to any MST radar system anywhere in the world as long as the sky noise variations are known. The radar efficiencies for two on-site radars at Resolute Bay are determined. PMSE backscatter cross-section is estimated, and decade-long PMSE strength variations at this location are investigated. It was noticed that the median of the backscatter cross-section distribution remains relatively unchanged, but over the years a great level of variability occurs in the high power tail of the distribution.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  19. Multi-antenna synthetic aperture radar

    CERN Document Server

    Wang, Wen-Qin

    2013-01-01

    Synthetic aperture radar (SAR) is a well-known remote sensing technique, but conventional single-antenna SAR is inherently limited by the minimum antenna area constraint. Although there are still technical issues to overcome, multi-antenna SAR offers many benefits, from improved system gain to increased degrees-of-freedom and system flexibility. Multi-Antenna Synthetic Aperture Radar explores the potential and challenges of using multi-antenna SAR in microwave remote sensing applications. These applications include high-resolution imaging, wide-swath remote sensing, ground moving target indica

  20. Application Research on High Resolution Radar Target Aggregation

    Directory of Open Access Journals (Sweden)

    Zhongzhi Li

    2010-11-01

    Full Text Available In high resolution radar system, the same target always has original data; so we need to merge multiple data from the same target as one target. Because of the system’s real-time requirement, we usually have to carry out target aggregation as quickly as possible. In this paper, we propose a quick target aggregation method based on clustering algorithm. The proposed method divides original data into subsets by single dimensional distance, and then merges subsets according to single dimensional distance and setdensity. At last we apply the proposed method to carry out target aggregation for airport scene surveillance radar system. Experimental result shows the proposed method has high execution efficiency and is not sensitive to noise data; it is useful for high resolution radar target aggregation.

  1. Localization Capability of Cooperative Anti-Intruder Radar Systems

    Directory of Open Access Journals (Sweden)

    Mauro Montanari

    2008-06-01

    Full Text Available System aspects of an anti-intruder multistatic radar based on impulse radio ultrawideband (UWB technology are addressed. The investigated system is composed of one transmitting node and at least three receiving nodes, positioned in the surveillance area with the aim of detecting and locating a human intruder (target that moves inside the area. Such systems, referred to also as UWB radar sensor networks, must satisfy severe power constraints worldwide imposed by, for example, the Federal Communications Commission (FCC and by the European Commission (EC power spectral density masks. A single transmitter-receiver pair (bistatic radar is considered at first. Given the available transmitted power and the capability of the receiving node to resolve the UWB pulses in the time domain, the surveillance area regions where the target is detectable, and those where it is not, are obtained. Moreover, the range estimation error for the transmitter-receiver pair is discussed. By employing this analysis, a multistatic system is then considered, composed of one transmitter and three or four cooperating receivers. For this multistatic system, the impact of the nodes location on area coverage, necessary transmitted power and localization uncertainty is studied, assuming a circular surveillance area. It is highlighted how area coverage and transmitted power, on one side, and localization uncertainty, on the other side, require opposite criteria of nodes placement. Consequently, the need for a system compromising between these factors is shown. Finally, a simple and effective criterion for placing the transmitter and the receivers is drawn.

  2. Wind Profiling Radar

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Clutter present in radar return signals as used for wind profiling is substantially removed by carrying out a Daubechies wavelet transformation on a time series of...

  3. Radar Landmass Simulation Computer Programming (Interim Report).

    Science.gov (United States)

    RADAR SCANNING, TERRAIN), (*NAVAL TRAINING, RADAR OPERATORS), (*FLIGHT SIMULATORS, TERRAIN AVOIDANCE), (* COMPUTER PROGRAMMING , INSTRUCTION MANUALS), PLAN POSITION INDICATORS, REAL TIME, DISPLAY SYSTEMS, RADAR IMAGES, SIMULATION

  4. Security and Privacy in Video Surveillance: Requirements and Challenges

    DEFF Research Database (Denmark)

    Mahmood Rajpoot, Qasim; Jensen, Christian D.

    2014-01-01

    Use of video surveillance has substantially increased in the last few decades. Modern video surveillance systems are equipped with techniques that allow traversal of data in an effective and efficient manner, giving massive powers to operators and potentially compromising the privacy of anyone...... observed by the system. Several techniques to protect the privacy of individuals have therefore been proposed, but very little research work has focused on the specific security requirements of video surveillance data (in transit or in storage) and on authorizing access to this data. In this paper, we...... present a general model of video surveillance systems that will help identify the major security and privacy requirements for a video surveillance system and we use this model to identify practical challenges in ensuring the security of video surveillance data in all stages (in transit and at rest). Our...

  5. Downhole pulse radar

    Science.gov (United States)

    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.

  6. Model of human breathing reflected signal received by PN-UWB radar.

    Science.gov (United States)

    Mabrouk, Mohamed; Rajan, Sreeraman; Bolic, Miodrag; Batkin, Izmail; Dajani, Hilmi R; Groza, Voicu Z

    2014-01-01

    Human detection is an integral component of civilian and military rescue operations, military surveillance and combat operations. Human detection can be achieved through monitoring of vital signs. In this article, a mathematical model of human breathing reflected signal received in PN-UWB radar is proposed. Unlike earlier published works, both chest and abdomen movements are considered for modeling the radar return signal along with the contributions of fundamental breathing frequency and its harmonics. Analyses of recorded reflected signals from three subjects in different postures and at different ranges from the radar indicate that ratios of the amplitudes of the harmonics contain information about posture and posture change.

  7. Optical-network-connected multi-channel 96-GHz-band distributed radar system

    Science.gov (United States)

    Kanno, Atsushi; Kuri, Toshiaki; Kawanishi, Tetsuya

    2015-05-01

    The millimeter-wave (MMW) radar is a promising candidate for high-precision imaging because of its short wavelength and broad range of available bandwidths. In particular in the frequency range of 92-100 GHz, which is regulated for radiolocation, an atmospheric attenuation coefficient less than 1 dB/km limits the imaging range. Therefore, a combination of MMW radar and distributed antenna system directly connected to optical fiber networks can realize both high-precision imaging and large-area surveillance. In this paper, we demonstrate a multi-channel MMW frequency-modulated continuous-wave distributed radar system connected to an analog radio-over-fiber network.

  8. Bird radar validation in the field by time-referencing line-transect surveys.

    Science.gov (United States)

    Dokter, Adriaan M; Baptist, Martin J; Ens, Bruno J; Krijgsveld, Karen L; van Loon, E Emiel

    2013-01-01

    Track-while-scan bird radars are widely used in ornithological studies, but often the precise detection capabilities of these systems are unknown. Quantification of radar performance is essential to avoid observational biases, which requires practical methods for validating a radar's detection capability in specific field settings. In this study a method to quantify the detection capability of a bird radar is presented, as well a demonstration of this method in a case study. By time-referencing line-transect surveys, visually identified birds were automatically linked to individual tracks using their transect crossing time. Detection probabilities were determined as the fraction of the total set of visual observations that could be linked to radar tracks. To avoid ambiguities in assigning radar tracks to visual observations, the observer's accuracy in determining a bird's transect crossing time was taken into account. The accuracy was determined by examining the effect of a time lag applied to the visual observations on the number of matches found with radar tracks. Effects of flight altitude, distance, surface substrate and species size on the detection probability by the radar were quantified in a marine intertidal study area. Detection probability varied strongly with all these factors, as well as species-specific flight behaviour. The effective detection range for single birds flying at low altitude for an X-band marine radar based system was estimated at ~1.5 km. Within this range the fraction of individual flying birds that were detected by the radar was 0.50 ± 0.06 with a detection bias towards higher flight altitudes, larger birds and high tide situations. Besides radar validation, which we consider essential when quantification of bird numbers is important, our method of linking radar tracks to ground-truthed field observations can facilitate species-specific studies using surveillance radars. The methodology may prove equally useful for optimising

  9. Plasma-based radar cross section reduction

    CERN Document Server

    Singh, Hema; Jha, Rakesh Mohan

    2016-01-01

    This book presents a comprehensive review of plasma-based stealth, covering the basics, methods, parametric analysis, and challenges towards the realization of the idea. The concealment of aircraft from radar sources, or stealth, is achieved through shaping, radar absorbing coatings, engineered materials, or plasma, etc. Plasma-based stealth is a radar cross section (RCS) reduction technique associated with the reflection and absorption of incident electromagnetic (EM) waves by the plasma layer surrounding the structure. A plasma cloud covering the aircraft may give rise to other signatures such as thermal, acoustic, infrared, or visual. Thus it is a matter of concern that the RCS reduction by plasma enhances its detectability due to other signatures. This needs a careful approach towards the plasma generation and its EM wave interaction. The book starts with the basics of EM wave interactions with plasma, briefly discuss the methods used to analyze the propagation characteristics of plasma, and its generatio...

  10. Ionospheric Impacts on UHF Space Surveillance

    Science.gov (United States)

    Jones, J.; Ceron-Gomez, D.; Richards, G.

    2016-09-01

    Earth's atmosphere contains regions of ionized plasma caused by the interaction of highly energetic solar radiation. This region of ionization is called the ionosphere and varies significantly with altitude, latitude, local solar time, season, and solar cycle. Significant ionization begins at about 100 km (E layer) with a peak in the ionization at about 350 km (F2 layer). Above the F2 layer, the atmosphere is mostly ionized but the ion and electron densities are low due to the unavailability of neutral molecules for ionization so the electron density decreases exponentially with height to well over 1000 km. The gradients of these variations in the ionosphere play a significant role in radio wave propagation. These gradients induce variations in the index of refraction and cause some radio waves to refract. The amount of refraction depends on the magnitude and direction of the electron density gradient and the frequency of the radio wave. The refraction is significant at HF frequencies (3-30 MHz) with decreasing effects toward the UHF (300-3000 MHz) range. UHF is commonly used for tracking of space objects in low Earth orbit (LEO). While ionospheric refraction is small for UHF frequencies, it can cause errors in range, azimuth angle, and elevation angle estimation by ground-based radars tracking space objects. These errors can cause significant uncertainty in precise orbit determinations. For radio waves transiting the ionosphere, it is important to understand and account for these effects. Using a sophisticated radio wave propagation tool suite and an empirical ionospheric model, we calculate the errors induced by the ionosphere in a simulation of a notional space surveillance radar tracking objects in LEO. These errors are analyzed to determine correlations with ionospheric variability. Corrections to surveillance radar measurements can be adapted from our simulation capability.

  11. Using satellites to improve civilian aircraft surveillance coverage

    Science.gov (United States)

    Mcgraw, K.

    1984-01-01

    Surveillance of aircraft is presently accomplished through the use of terrestrial based secondary radar sensors, which are capable of interrogating transponders aboard aircraft. Transponder responses provide the basis for determining radial distance by measuring round-trip signal time while antenna angular position is used to determine azimuthal position. These interrogating radar beams are line-of-sight and thus have their coverage obscured by mountains and tall buildings. The addition of more radar sites is rendered unfeasible by the lack of easy access to the required additional site locations. A possible solution to this problem is to deploy satellites that interrogate transponder-equipped aircraft from a position that provides an unobstructed view.

  12. Transport infrastructure surveillance and monitoring by electromagnetic sensing: the ISTIMES project.

    Science.gov (United States)

    Proto, Monica; Bavusi, Massimo; Bernini, Romeo; Bigagli, Lorenzo; Bost, Marie; Bourquin, Frédrèric; Cottineau, Louis-Marie; Cuomo, Vincenzo; Della Vecchia, Pietro; Dolce, Mauro; Dumoulin, Jean; Eppelbaum, Lev; Fornaro, Gianfranco; Gustafsson, Mats; Hugenschmidt, Johannes; Kaspersen, Peter; Kim, Hyunwook; Lapenna, Vincenzo; Leggio, Mario; Loperte, Antonio; Mazzetti, Paolo; Moroni, Claudio; Nativi, Stefano; Nordebo, Sven; Pacini, Fabrizio; Palombo, Angelo; Pascucci, Simone; Perrone, Angela; Pignatti, Stefano; Ponzo, Felice Carlo; Rizzo, Enzo; Soldovieri, Francesco; Taillade, Fédrèric

    2010-01-01

    The ISTIMES project, funded by the European Commission in the frame of a joint Call "ICT and Security" of the Seventh Framework Programme, is presented and preliminary research results are discussed. The main objective of the ISTIMES project is to design, assess and promote an Information and Communication Technologies (ICT)-based system, exploiting distributed and local sensors, for non-destructive electromagnetic monitoring of critical transport infrastructures. The integration of electromagnetic technologies with new ICT information and telecommunications systems enables remotely controlled monitoring and surveillance and real time data imaging of the critical transport infrastructures. The project exploits different non-invasive imaging technologies based on electromagnetic sensing (optic fiber sensors, Synthetic Aperture Radar satellite platform based, hyperspectral spectroscopy, Infrared thermography, Ground Penetrating Radar-, low-frequency geophysical techniques, Ground based systems for displacement monitoring). In this paper, we show the preliminary results arising from the GPR and infrared thermographic measurements carried out on the Musmeci bridge in Potenza, located in a highly seismic area of the Apennine chain (Southern Italy) and representing one of the test beds of the project.

  13. Transport Infrastructure Surveillance and Monitoring by Electromagnetic Sensing: The ISTIMES Project

    Directory of Open Access Journals (Sweden)

    Marie Bost

    2010-11-01

    Full Text Available The ISTIMES project, funded by the European Commission in the frame of a joint Call “ICT and Security” of the Seventh Framework Programme, is presented and preliminary research results are discussed. The main objective of the ISTIMES project is to design, assess and promote an Information and Communication Technologies (ICT-based system, exploiting distributed and local sensors, for non-destructive electromagnetic monitoring of critical transport infrastructures. The integration of electromagnetic technologies with new ICT information and telecommunications systems enables remotely controlled monitoring and surveillance and real time data imaging of the critical transport infrastructures. The project exploits different non-invasive imaging technologies based on electromagnetic sensing (optic fiber sensors, Synthetic Aperture Radar satellite platform based, hyperspectral spectroscopy, Infrared thermography, Ground Penetrating Radar-, low-frequency geophysical techniques, Ground based systems for displacement monitoring. In this paper, we show the preliminary results arising from the GPR and infrared thermographic measurements carried out on the Musmeci bridge in Potenza, located in a highly seismic area of the Apennine chain (Southern Italy and representing one of the test beds of the project.

  14. Ground penetrating radar for asparagus detection

    Science.gov (United States)

    Seyfried, Daniel; Schoebel, Joerg

    2016-03-01

    Ground penetrating radar is a promising technique for detection of buried objects. Recently, radar has more and more been identified to provide benefits for a plurality of applications, where it can increase efficiency of operation. One of these fields is the industrial automatic harvesting process of asparagus, which is performed so far by cutting the soil ridge at a certain height including all the asparagus spears and subsequently sieving the latter out of the soil. However, the height where the soil is cut is a critical parameter, since a wrong value leads to either damage of the roots of the asparagus plants or to a reduced crop yield as a consequence of too much biomass remaining in the soil. In this paper we present a new approach which utilizes ground penetrating radar for non-invasive sensing in order to obtain information on the optimal height for cutting the soil. Hence, asparagus spears of maximal length can be obtained, while keeping the roots at the same time undamaged. We describe our radar system as well as the subsequent digital signal processing steps utilized for extracting the information required from the recorded radar data, which then can be fed into some harvesting unit for setting up the optimal cutting height.

  15. 多站时差定位技术提升野战机场航管与空情监视能力%Advanced Aviation Management and Air Situation Surveillance Ability of Field Operation Airport by Multi-station TDOA Location Technique

    Institute of Scientific and Technical Information of China (English)

    郑志娟; 刘建

    2011-01-01

    In the condition of network-centric operation, the viability of active aviation management system in the former airport faces the strict challenges of air defence suppression. The passive aviation management system based on multil-station time difference of arrival (TDOA)location technique presents the superior viability than that of the second radar aviation management system. This paper introduces the advantages and disadvantages of passive radars, and introduces in detail the core techniques of passive aviation management system, discusses the passive radar based on multi-station TDOA location technique can make the aviation management system more perfect.%在网络中心战条件下,前沿机场有源航管系统的抗毁性面临防空压制的严峻挑战。基于多站到达时间差(TDOA)定位技术的无源航管系统呈现比二次雷达航管系统更为优越的抗毁性。介绍了无源雷达的优缺点,并详细介绍了无源航管系统的核心技术,论述了基于多站TDOA定位技术的无源雷达能使航管系统功能更完善。

  16. Assessment of African Swine Fever Diagnostic Techniques as a Response to the Epidemic Outbreaks in Eastern European Union Countries: How To Improve Surveillance and Control Programs.

    Science.gov (United States)

    Gallardo, C; Nieto, R; Soler, A; Pelayo, V; Fernández-Pinero, J; Markowska-Daniel, I; Pridotkas, G; Nurmoja, I; Granta, R; Simón, A; Pérez, C; Martín, E; Fernández-Pacheco, P; Arias, M

    2015-08-01

    This study represents a complete comparative analysis of the most widely used African swine fever (ASF) diagnostic techniques in the European Union (EU) using field and experimental samples from animals infected with genotype II ASF virus (ASFV) isolates circulating in Europe. To detect ASFV, three different PCRs were evaluated in parallel using 785 field and experimental samples. The results showed almost perfect agreement between the Universal ProbeLibrary (UPL-PCR) and the real-time (κ = 0.94 [95% confidence interval {CI}, 0.91 to 0.97]) and conventional (κ = 0.88 [95% CI, 0.83 to 0.92]) World Organisation for Animal Health (OIE)-prescribed PCRs. The UPL-PCR had greater diagnostic sensitivity for detecting survivors and allows earlier detection of the disease. Compared to the commercial antigen enzyme-linked immunosorbent assay (ELISA), good-to-moderate agreement (κ = 0.67 [95% CI, 0.58 to 0.76]) was obtained, with a sensitivity of 77.2% in the commercial test. For ASF antibody detection, five serological methods were tested, including three commercial ELISAs, the OIE-ELISA, and the confirmatory immunoperoxidase test (IPT). Greater sensitivity was obtained with the IPT than with the ELISAs, since the IPT was able to detect ASF antibodies at an earlier point in the serological response, when few antibodies are present. The analysis of the exudate tissues from dead wild boars showed that IPT might be a useful serological tool for determining whether or not animals had been exposed to virus infection, regardless of whether antibodies were present. In conclusion, the UPL-PCR in combination with the IPT was the most trustworthy method for detecting ASF during the epidemic outbreaks affecting EU countries in 2014. The use of the most appropriate diagnostic tools is critical when implementing effective control programs.

  17. Surveillance and persuasion

    NARCIS (Netherlands)

    Nagenborg, Michael

    2014-01-01

    This paper is as much about surveillance as about persuasive technologies (PTs). With regard to PTs it raises the question about the ethical limits of persuasion. It will be argued that even some forms of self-imposed persuasive soft surveillance technologies may be considered unethical. Therefore,

  18. Soil and vegetation surveillance

    Energy Technology Data Exchange (ETDEWEB)

    Antonio, E.J.

    1995-06-01

    Soil sampling and analysis evaluates long-term contamination trends and monitors environmental radionuclide inventories. This section of the 1994 Hanford Site Environmental Report summarizes the soil and vegetation surveillance programs which were conducted during 1994. Vegetation surveillance is conducted offsite to monitor atmospheric deposition of radioactive materials in areas not under cultivation and onsite at locations adjacent to potential sources of radioactivity.

  19. Micro-doppler radar classification of human motions under various training scenarios

    Science.gov (United States)

    Fairchild, Dustin P.; Narayanan, Ram M.

    2013-05-01

    The identification and classification of human motions has become a popular area of research due to its broad range of applications. Knowledge of a person's movements can be a useful tool in surveillance, security, military combat, search and rescue operations, and the medical fields. Classification of common stationary human movements has been performed under various scenarios for two different micro-Doppler radar systems: S-band radar and millimeter-wave (mm-wave) radar. Each radar system has been designed for a specific scenario. The S-band radar is intended for through-the-wall situations at close distances, whereas the mm-wave radar is designed for long distance applications and also for through light foliage. Here, the performance of these radars for different training scenarios is investigated. The S-band radar will be analyzed for classification without a wall barrier, through a brick wall, and also through a cinder block wall. The effect of a wall barrier on micro-Doppler signatures will be briefly discussed. The mm-wave radar will be analyzed for classification at distances of 30, 60, and 91 meters.

  20. 2012 Sexually Transmitted Diseases Surveillance

    Science.gov (United States)

    ... National Summary Chlamydia Gonorrhea Syphilis Chancroid Selected STDs Appendix Appendix Interpreting STD Surveillance Data Appendix Tables A1 - A4 STD Surveillance Case Definitions Contributors ...

  1. Classification of ground moving targets using bicepstrum-based features extracted from Micro-Doppler radar signatures

    Science.gov (United States)

    Molchanov, Pavlo O.; Astola, Jaakko T.; Egiazarian, Karen O.; Totsky, Alexander V.

    2013-12-01

    In this article, a novel bicepstrum-based approach is suggested for ground moving radar target classification. Distinctive classification features were extracted from short-time backscattering bispectrum estimates of the micro-Doppler signature. Real radar data were obtained using surveillance Doppler microwave radar operating at 34 GHz. Classifier performance was studied in detail using the Gaussian Mixture Mode and Maximum Likelihood decision making rule, and the results were verified on a multilayer perceptron and Support Vector Machine. Experimental real radar measurements demonstrated that it is quite feasible to discern three classes of humans (single, two and three persons) walking in a vegetation cluttered environment using proposed bicepstrum-based classification features. Sophisticated bispectrum-based signal processing provides the extraction of new classification features in the form of phase relationships in the radar data. It provides a novel insight into moving radar target classification compared to the commonly used energy-based strategy.

  2. AN/FPS-108 COBRA DANE Space Surveillance Mission Evolution

    Science.gov (United States)

    Chorman, P.; Boggs, J.

    2013-09-01

    It has been ten years since the COBRA DANE radar was restored to continuous full power operations in a more dedicated role of space debris tracking. Over this time, the satellite catalog population has grown and the overall average RCS value of cataloged objects has decreased dramatically, due to a combination of breakups and collisions together with the increased sensitivity offered by COBRA DANE's support to the network. This shift in catalog composition places new challenges on COBRA DANE and other debris tracking radars (PARCS and Eglin/FPS-85) to consistently track the ever-increasing number of small objects. Space Surveillance Network radars now operate at the limits of their detection performance, tracking several thousand new objects in a size category that only the most powerful and sensitive radars can observe (i.e., system's overall architectural design (power-aperture envelope and radar resources). This paper captures specific opportunities to improve COBRA DANE's Spacetrack mission performance, several of which are currently implemented and slated to become operational with the next two software releases. With one of the more prominent enhancements, COBRA DANE will be capable of autonomously 'fence tasking' all newly acquired small objects. Under the current operating paradigm, the radar detects satellites in its debris fences, correlates them to known (cataloged) objects, and subsequently drops the correlated objects from track, many times per day for thousands of objects. This response occurs under the (false) premise that the known objects will be successfully reacquired later by automatic satellite acquisition searches, when the objects are expected to present more optimal data collection passes, as determined by the radar's Spacetrack mission planning algorithm. Unfortunately, for the bulk of the challenging objects in question, this opportunity seldom presents itself and most reacquisition attempts are unsuccessful, causing the radar to

  3. Synchronization of Radar Observations with Multi-Scale Storm Tracking

    Institute of Scientific and Technical Information of China (English)

    YANG Hongping; Jian ZHANG; Carrie LANGSTON

    2009-01-01

    The 3-D radar reflectivity data has become increasingly important for use in data assimilation towards convective scale numerical weather prediction as well as next generation precipitation estimation. Typically, reflectivity data from multiple radars are objectively analyzed and mosaiced onto a regional 3-D Cartesian grid prior to being assimilated into the models. One of the scientific issues associated with the mosaic of multi-radar observations is the synchronization of all the observations. Since radar data is usually rapidly updated (~every 5-10 min), it is common in current multi-radar mosaic techniques to combine multiple radar' observations within a time window by assuming that the storms are steady within the window. The assumption holds well for slow evolving precipitation systems, but for fast evolving convective storms, this assumption may be violated and the mosaic of radar observations at different times may result in inaccurate storm structure depictions. This study investigates the impact of synchronization on storm structures in multiple radar data analyses using a multi-scale storm tracking algorithm.

  4. A barrier radar concept

    Science.gov (United States)

    Marshall, J.; Ball, C.; Weissman, I.

    A description is given of a low power, light-weight radar that can be quickly set up and operated on batteries for extended periods of time to detect airborne intruders. With low equipment and operating costs, it becomes practical to employ a multiplicity of such radars to provide an unbroken intrusion fence over the desired perimeter. Each radar establishes a single transmitted fan beam extending vertically from horizon to horizon. The beam is generated by a two-face array antenna built in an A-frame configuration and is shaped, through phasing of the array elements, to concentrate the transmitter power in a manner consistent with the expected operating altitude ceiling of the targets of interest. The angular width of this beam in the dimension transverse to the fan depends on the radar transmission frequency and the antenna aperture dimension, but is typically wide enough so that a target at the maximum altitude or range will require tens of seconds to pass through the beam. A large number of independent samples of radar data will thus be available to provide many opportunities for target detection.

  5. Liberal luxury: Decentering Snowden, surveillance and privilege

    Directory of Open Access Journals (Sweden)

    Piro Rexhepi

    2016-11-01

    Full Text Available This paper reflects on the continued potency of veillance theories to traverse beyond the taxonomies of surveillance inside liberal democracies. It provides a commentary on the ability of sousveillance to destabilise and disrupt suer/violence by shifting its focus from the centre to the periphery, where Big Data surveillance is tantamount to sur/violence. In these peripheral political spaces, surveillance is not framed by concerns over privacy, democracy and civil society; rather, it is a matter of life and death, a technique of both biopolitical and thanatopolitical power. I argue that the universalist, and universalizing, debates over surveillance cannot be mapped through the anxieties of privileged middle classes as they would neither transcend nor make possible alternative ways of tackling the intersection of surveillance and violence so long as they are couched in the liberal concerns for democracy. I call this phenomenon “liberal luxury,” whereby debates over surveillance have over-emphasised liberal proclivities at the expense of disengaging those peripheral populations most severely affected by sur/violence.

  6. Security and Privacy in Video Surveillance: Requirements and Challenges

    DEFF Research Database (Denmark)

    Mahmood Rajpoot, Qasim; Jensen, Christian D.

    2014-01-01

    Use of video surveillance has substantially increased in the last few decades. Modern video surveillance systems are equipped with techniques that allow traversal of data in an effective and efficient manner, giving massive powers to operators and potentially compromising the privacy of anyone ob...

  7. [Recommendations for the surveillance of Aedes aegypti].

    Science.gov (United States)

    Barrera, Roberto

    2016-09-01

    Diseases caused by arboviruses transmitted by Aedes aegypti, such as dengue, chikungunya and Zika, continue to rise in annual incidence and geographic expansion. A key limitation for achieving control of A. aegypti has been the lack of effective tools for monitoring its population, and thus determine what control measures actually work. Surveillance of A. aegypti has been based mainly on immature indexes, but they bear little relation to the number of mosquito females, which are the ones capable of transmitting the viruses. The recent development of sampling techniques for adults of this vector species promises to facilitate surveillance and control activities. In this review, we present the various monitoring techniques for this mosquito, along with a discussion of their usefulness, and recommendations for improved entomological surveillance.

  8. TCAR, the Transatlantic Cooperative AGS Radar: A Programmatic and Technical Overview

    NARCIS (Netherlands)

    Hoogeboom, P.; Hommel, H.; Hausle, J.; Hubeek, J.; Lopez, L.; Canafoglia, G.

    2004-01-01

    In view of the NATO Air to Ground Surveillance requirement a feasibility study on the development of an advanced SAR/MTI radar system has been conducted by a group of industries from 6 nations (FR, GE, IT, NL, SP, USA). The architectural design of the system is based on knowledge from currently ongo

  9. Radar for tracer particles

    CERN Document Server

    Ott, Felix; Huang, Kai

    2016-01-01

    We introduce a radar system capable of tracking a $5$mm spherical target continuously in three dimensions. The $10$GHz (X-band) radar system has a transmission power of $1$W and operates in the near field of the horn antennae. By comparing the phase shift of the electromagnetic wave traveling through the free space with an IQ-Mixer, we obtain the relative movement of the target with respect to the antennae. From the azimuth and inclination angles of the receiving antennae obtained in the calibration, we reconstruct the target trajectory in a three-dimensional Cartesian system. Finally, we test the tracking algorithm with target moving in circular as well as in pendulum motions, and discuss the capability of the radar system.

  10. Experimental uses of short pulse radar in coal seams

    Energy Technology Data Exchange (ETDEWEB)

    Coon, J.B.; Fowler, J.C.; Schafers, C.J.

    1980-04-01

    Radar tests in coal mines conducted by the Mining Research Division of Conoco and Ensco, Inc. are presented. The purpose was to determine penetration distances and reflection ranges which are obtainable with currently available short pulse radar. The tests were conducted in mines operated by Consolidation Coal Co. during 1977 and 1978. The first test examined penetration distances, velocity of propagation, and attenuation versus frequency for a large coal pillar. These tests also showed the definite polarization effects which had previously been measured in coal. The second series of tests was designed to show maximum reflection distances for a radar with a centre frequency of 100 MHz. Using common-depth-point reflection techniques, a ten-fold CDP line obtained reflections from distances in excess of 50 ft. This was the first time such techniques have been used with short pulse radar. The final series of tests was conducted to locate a six-inch borehole within a coal pillar. The radar system located the hole quickly and easily even though it was 20 ft into the pillar. These tests show it is possible to use short pulse radar as a hazard detection device in coal mines. The major limitations with a current equipment are that it cannot be used in return air and it is not easily transported in the mine. As a result of these tests, Conoco and Ensco have started a development program to build and test a truly portable mine radar system capable of operation in return air.

  11. Colorectal cancer surveillance in inflammatory bowel disease: A critical analysis

    Institute of Scientific and Technical Information of China (English)

    Devendra; Desai; Nutan; Desai

    2014-01-01

    Colonoscopic surveillance is advocated in patients with inflammatory bowel disease(IBD) for detection of dys-plasia. There are many issues regarding surveillance in IBD: the risk of colorectal cancer seems to be de-creasing in the majority of recently published studies, necessitating revisions of surveillance strategy; surveil-lance guidelines are not based on concrete evidence; commencement and frequency of surveillance, cost-effectiveness and adherence to surveillance have been issues that are only partly answered. The traditional technique of random biopsy is neither evidence-based nor easy to practice. Therefore, highlighting abnormal areas with newer technology and biopsy from these areas are the way forward. Of the newer technology, digital mucosal enhancement, such as high-definition white light endoscopy and chromoendoscopy(with magnification) have been incorporated in guidelines. Dyeless chromoendoscopy(narrow band imaging) has not yet shown potential, whereas some forms of digital chromoendoscopy(i-Scan more than Fujinon intelligent color enhancement) have shown promise for colonoscopic surveillance in IBD. Other techniquessuch as autofluorescence imaging, endomicroscopy and endocytoscopy need further evidence. Surveillance with genetic markers(tissue, serum or stool) is at an early stage. This article discusses changing epidemiology of colorectal cancer development in IBD and critically evaluates issues regarding colonoscopic surveillance in IBD.

  12. Localizing Ground-Penetrating Radar

    Science.gov (United States)

    2014-11-01

    ing Ground-Penetrating Radar (LGPR) uses very high frequency (VHF) radar reflections of underground features to generate base- line maps and then...Innovative ground- penetrating radar that maps underground geological features provides autonomous vehicles with real-time localization. Localizing...NOV 2014 2. REPORT TYPE 3. DATES COVERED 00-00-2014 to 00-00-2014 4. TITLE AND SUBTITLE Localizing Ground-Penetrating Radar 5a. CONTRACT NUMBER

  13. Mode S Baseline Radar Tracking.

    Science.gov (United States)

    1982-11-01

    range units and 20 azimuth units) overlaying the position of the beacon reports. In the cases analyzed where beacon reports were not radar reinforced ...82/53 j~ C ~ 7 C _ _ _ _ _ _ 4. Title end Su.btitle 5. Neget at. November 1982 MDDE S BASELINE RADAR TRACKIN4G 6. Poelin Orgeuianti.. Cede ACT-100...Ground Clutter 33 Mode S/ARTS III 100-Scan False Radar Track Summary 74 34 Percent Beacon Radar Reinforcement 77 vii INTRODUCTION PURPOSE. The purpose of

  14. Systems and Methods for Radar Data Communication

    Science.gov (United States)

    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.

  15. Geostatistical inference using crosshole ground-penetrating radar

    DEFF Research Database (Denmark)

    Looms, Majken C; Hansen, Thomas Mejer; Cordua, Knud Skou

    2010-01-01

    , the moisture content will reflect the variation of the physical properties of the subsurface, which determine the flow patterns in the unsaturated zone. Deterministic least-squares inversion of crosshole groundpenetrating-radar GPR traveltimes result in smooth, minimumvariance estimates of the subsurface radar...... wave velocity structure, which may diminish the utility of these images for geostatistical inference. We have used a linearized stochastic inversion technique to infer the geostatistical properties of the subsurface radar wave velocity distribution using crosshole GPR traveltimes directly. Expanding...

  16. Principles and applications of coherent random noise radar technology

    Science.gov (United States)

    Narayanan, Ram M.; Xu, Xiaojian

    2003-05-01

    Random noise radar is rapidly emerging as a promising technique for high-resolution probing and imaging of obscured objects and interfaces. The University of Nebraska-Lincoln has developed and field-tested coherent ultra wideband polarimetric random noise radar systems that show great promise in their ability to estimate Doppler and image target and terrain features. Theoretical studies and extensive field tests using these systems confirm their ability to respond to and utilize phase information from the received signals. This paper summarizes our recent developments in coherent random noise radar imaging and discusses future research directions in this area.

  17. Noise Radar Technology Basics

    Science.gov (United States)

    2006-12-01

    poursuite, estimation Doppler, polarimétrie, interférométrie, sondage du sol ou profilage de la sous- surface , détection, imagerie SAR (radar à synthèse...mesure de distance et d’estimation Doppler. Deux récepteurs de traitement cohérent, soit le récepteur de corrélation et le récep- teur de traitement DSP... traitement spectral double) des échos radar sont décrits et une estimation de leur portée est présentée. Les capacités LPI (faible probabilité

  18. Delphi Technique Used in Laser Incident Surveillance

    Science.gov (United States)

    2004-01-01

    personnel may not know that an exposure has occurred [1]. Non-injury or near - miss data is valuable, in addition to objective injury data, for studying...procedure. No injury is defined as the malfunction of equipment not resulting in an exposure ( near miss ). Side effects are primarily generated by medical

  19. Human walking estimation with radar

    NARCIS (Netherlands)

    Dorp, Ph. van; Groen, F.C.A.

    2003-01-01

    Radar can be used to observe humans that are obscured by objects such as walls. These humans cannot be visually observed. The radar measurements are used to animate an obscured human in virtual reality. This requires detailed information about the motion. The radar measurements give detailed informa

  20. Radar Test Range Design Considerations.

    Science.gov (United States)

    1980-04-29

    radar cross section associated with dihedral and trihedral corner reflectors is highly dependent upon the squareness or alignment of the...slightly misaligned. We now show how the radar cross section for dihedral and trihedral corner reflectors depends upon their surface misalignment. All...coefficients, p and q, for the dihedral corner reflector , one must consider the radar cross section

  1. Status Of Imaging Radar Polarimetry

    Science.gov (United States)

    Van Zyl, Jakob J.; Zebker, Howard A.

    1991-01-01

    Report pulls together information on imaging radar polarimetry from a variety of sources. Topics include theory, equipment, and experimental data. Reviews state of the art, examines current applicable developments in radar equipment, describes recording and processing of radar polarimetric measurements, and discusses interpretation and application of resulting polarimetric images.

  2. Human walking estimation with radar

    NARCIS (Netherlands)

    Dorp, Ph. van; Groen, F.C.A.

    2003-01-01

    Radar can be used to observe humans that are obscured by objects such as walls. These humans cannot be visually observed. The radar measurements are used to animate an obscured human in virtual reality. This requires detailed information about the motion. The radar measurements give detailed

  3. Coded continuous wave meteor radar

    OpenAIRE

    2015-01-01

    The concept of coded continuous wave meteor radar is introduced. The radar uses a continuously transmitted pseudo-random waveform, which has several advantages: coding avoids range aliased echoes, which are often seen with commonly used pulsed specular meteor radars (SMRs); continuous transmissions maximize pulse compression gain, allowing operation with significantly lower peak transmit power; the temporal resolution can be changed after ...

  4. Time-frequency analysis of synthetic aperture radar signals

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, Brooks [Univ. of California, Davis, CA (United States)

    1996-08-01

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

  5. Children's Mental Health Surveillance

    Science.gov (United States)

    Children’s Mental Health Surveillance What are childhood mental disorders? The term childhood mental disorder means all mental disorders that can ... is the impact of mental disorders in children? Mental health is important to overall health. Mental disorders are ...

  6. Between visibility and surveillance

    DEFF Research Database (Denmark)

    Uldam, Julie

    visible. It thus enables activists to monitor and expose corporate misconduct, but simultaneously renders them vulnerable to surveillance from corporations. In this presentation, I examine these practices and discuss their implications for political participation by drawing on examples of companies...

  7. Autonomous surveillance for biosecurity.

    Science.gov (United States)

    Jurdak, Raja; Elfes, Alberto; Kusy, Branislav; Tews, Ashley; Hu, Wen; Hernandez, Emili; Kottege, Navinda; Sikka, Pavan

    2015-04-01

    The global movement of people and goods has increased the risk of biosecurity threats and their potential to incur large economic, social, and environmental costs. Conventional manual biosecurity surveillance methods are limited by their scalability in space and time. This article focuses on autonomous surveillance systems, comprising sensor networks, robots, and intelligent algorithms, and their applicability to biosecurity threats. We discuss the spatial and temporal attributes of autonomous surveillance technologies and map them to three broad categories of biosecurity threat: (i) vector-borne diseases; (ii) plant pests; and (iii) aquatic pests. Our discussion reveals a broad range of opportunities to serve biosecurity needs through autonomous surveillance. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  8. 522 Postmarket Surveillance Studies

    Data.gov (United States)

    U.S. Department of Health & Human Services — The 522 Postmarket Surveillance Studies Program encompasses design, tracking, oversight, and review responsibilities for studies mandated under section 522 of the...

  9. 522 Postmarket Surveillance Studies

    Data.gov (United States)

    U.S. Department of Health & Human Services — The 522 Postmarket Surveillance Studies Program encompasses design, tracking, oversight, and review responsibilities for studies mandated under section 522 of the...

  10. Sense and Avoid Airborne Radar Implementations on a Low-Cost Weather Radar Platform

    Directory of Open Access Journals (Sweden)

    Ramesh Nepal

    2017-03-01

    Full Text Available Traditionally, multi-mission applications in airborne radar are implemented through very expensive phased array architectures. The emerging applications from civilian surveillance, on the other hand, prefer low-cost and low-SWaP (space, weight and power systems. This study introduces asoftware-basedsolutionthatintendstouselow-costhardwareandadvancedalgorithms/processing backend to meet the remote sensing goals for multi-mission applications. The low-cost airborne radar platform from Garmin International is used as a representative example of the system platform. The focus of this study is the optimal operating mode, data quality and algorithm development in cases of all-weather sense and avoid (SAA applications. The main challenges for the solution are the resolution limitation due to the small aperture size, limitations from the field-of-view (FOV and the scan speed from mechanical scanning. We show that the basic operational needs can be satisfied with software processing through various algorithms. The concept and progress of polarimetric airborne radar for dual-function operations at X-band Generation 1 (PARADOX1 based on the platform are also discussed.

  11. On the Design of Radar Corner Reflectors for Deformation Monitoring in Multi-Frequency InSAR

    OpenAIRE

    Garthwaite, Matthew C.

    2017-01-01

    Trihedral corner reflectors are being increasingly used as point targets in deformation monitoring studies using interferometric synthetic aperture radar (InSAR) techniques. The frequency and size dependence of the corner reflector Radar Cross Section (RCS) means that no single design can perform equally in all the possible imaging modes and radar frequencies available on the currently orbiting Synthetic Aperture Radar (SAR) satellites. Therefore, either a corner reflector design tailored to ...

  12. Ray-Trace of an Abnormal Radar Echo Using Geographic Information System

    Directory of Open Access Journals (Sweden)

    Chi-Nan Chen

    2009-01-01

    Full Text Available Weather radar plays a key role in natural disaster mitigation just as surveillance radar does in detecting objects that threaten homeland security. Both together comprise an instrumental part of radar observation. Therefore, quality control of the data gathered through radar detection is extremely important. However, radar waves propagate in the atmosphere, and an anomalous echo can occur if there are significant discontinuities in temperature and humidity in the lower boundary layer. The refractive curvature of the earth makes some errors in observation inevitable. On the night of July 3, 2003, Next Generation Radar (NEXRAD weather radar detected an abnormal echo. The Weather Research and Forecast (WRF model was utilized to simulate the atmospheric conditions. Radar propagation was simulated using the Advanced Refractivity Engineering Prediction System (AREPS as well as the GIS. The results show the feasibility of establishing an abnormal propagation early-warning system and extending the application of the GIS in serving as the foundation of a Common Operation Picture (COP. Furthermore, the parameters of the boundary layer near the sea's surface in the numerical weather forecasting model need remodification.Defence Science Journal, 2009, 59(1, pp.63-72, DOI:http://dx.doi.org/10.14429/dsj.59.1487

  13. Knowledge-aided multisensor data fusion for maritime surveillance

    Science.gov (United States)

    Battistello, Giulia; Ulmke, Martin; Koch, Wolfgang

    2011-06-01

    Multi sensor fusion techniques are widely employed in several surveillance applications (e.g., battlefield monitoring, air traffic control, camp protection, etc). The necessity of tracking the elements of a dynamic system usually requires combining information from heterogeneous data sources in order to overcome the limitations of each sensor. The gathered information might be related to the target kinematics (position, velocity), its physical features (shape, size, composition) or intentions (route plan, friend/foe, engaged sensor modes, etc). The combination of such heterogeneous sensor data proved to benefit from the exploitation of context information, i.e., static and dynamic features of the scenario, represented in a Knowledge Base (KB). A Geographic Information System (GIS) is a typical example for a KB that can be exploited for the enhancement of multi sensor data fusion. The present paper describes potential strategies for "knowledge-based" data fusion in the area of Maritime Situational Awareness (MSA). MSA is founded on the data from heterogeneous sources, including radars, Navigation Aids, air- and space-based monitoring services, and recently-conceived passive sensors. Several strategies for optimally fusing two or more of these information data flows have been proposed for MSA applications. Relevant KB information comprises port locations, coastal lines, preferred routes, traffic rules, and potentially a maritime vessel database. We propose mathematical models and techniques to integrate kinematic constraints, e.g., in terms of navigation fields, and different object behaviour into a data fusion approach. For an exemplary sensor suite, we evaluate performance measures in the framework of centralised and decentralised fusion architectures.

  14. Noise Radar Technology as an Interference Prevention Method

    OpenAIRE

    2013-01-01

    In some applications, such as automotive and marine/navigation, hundreds of radars may operate in a small environment (e.g., a road complex or a strait) and in an allocated frequency band with limited width. Therefore, a compatibility problem between different radars arises that is not easily solved by time, frequency, space, or polarization diversity. The advent of fast digital signal processing and signal generation techniques makes it possible to use waveform diversity to solve this probl...

  15. Autonomous non-linear classification of LPI radar signal modulations

    OpenAIRE

    Gulum, Taylan O.

    2007-01-01

    In this thesis, an autonomous feature extraction algorithm for classification of Low Probability of Intercept (LPI) radar modulations is investigated. A software engineering architecture that allows a full investigation of various preprocessing algorithms and classification techniques is applied to a database of important LPI radar waveform modulations including Frequency Modulation Continuous Waveform (FMCW), Phase Shift Keying (PSK), Frequency Shift Keying (FSK) and combined PSK and FSK. Th...

  16. Waveform design and diversity for advanced radar systems

    CERN Document Server

    Gini, Fulvio

    2012-01-01

    In recent years, various algorithms for radar signal design, that rely heavily upon complicated processing and/or antenna architectures, have been suggested. These techniques owe their genesis to several factors, including revolutionary technological advances (new flexible waveform generators, high speed signal processing hardware, digital array radar technology, etc.) and the stressing performance requirements, often imposed by defence applications in areas such as airborne early warning and homeland security.Increasingly complex operating scenarios calls for sophisticated algorithms with the

  17. The Newcastle meteor radar

    Science.gov (United States)

    Keay, Colin

    1987-01-01

    A brief history and development of the Newcastle Meteor Radar system is given. Also described are its geographical coordinates and its method of operation. The initial objective when the project was commenced was to develop an entirely digital analyzer capable of recognizing meteor echo signals and recording as many of their parameters as possible. This objective was achieved.

  18. Compressive CFAR radar detection

    NARCIS (Netherlands)

    Anitori, L.; Otten, M.P.G.; Rossum, W.L. van; Maleki, A.; Baraniuk, R.

    2012-01-01

    In this paper we develop the first Compressive Sensing (CS) adaptive radar detector. We propose three novel architectures and demonstrate how a classical Constant False Alarm Rate (CFAR) detector can be combined with ℓ1-norm minimization. Using asymptotic arguments and the Complex Approximate Messag

  19. Compressive CFAR Radar Processing

    NARCIS (Netherlands)

    Anitori, L.; Rossum, W.L. van; Otten, M.P.G.; Maleki, A.; Baraniuk, R.

    2013-01-01

    In this paper we investigate the performance of a combined Compressive Sensing (CS) Constant False Alarm Rate (CFAR) radar processor under different interference scenarios using both the Cell Averaging (CA) and Order Statistic (OS) CFAR detectors. Using the properties of the Complex Approximate Mess

  20. Spaceborne Radar Study

    Science.gov (United States)

    1974-06-28

    via either the oomm beam or the omnichannel . Satellite instrumentation data are sent to the ground station following every radar signal transmission...If comm beam contact is lost, the instrumentation data are sent via the omnichannel transmitter on command of the ground station. There are six ways

  1. Analyses of the temporal and spatial structures of heavy rainfall from a catalog of high-resolution radar rainfall fields

    DEFF Research Database (Denmark)

    Thorndahl, Søren; Smith, James A.; Baeck, Mary Lynn

    2014-01-01

    In this paper, we develop a storm catalog of heavy rainfall events for a region centered on the Milwaukee, Wisconsin WSR-88D (Weather Surveillance Radar – 1988 Doppler) radar. The study region includes portions of southern Wisconsin, northern Illinois and Lake Michigan. The long-term objective of...... area exceeding 25 mm h− 1 and development of a large stratiform rain area during the night and early morning....

  2. Signals and processing for random signal radars

    Science.gov (United States)

    Moore, G. S.

    1980-06-01

    Signals and associated processing techniques are developed which improve the performance, simplify the implementation, and are more amenable to adaptive operation for radars using the random signal concept. These goals are accomplished through the use of a signal set that is composed of a deterministic spreading function, a binary random or pseudo-random noise source, and a possibly random or pseudo-random pulsing sequence. Techniques are developed for determining the parameters of the spreading function that result in signals with desirable ambiguity functions and high effective power. These techniques are based on the use of window functions for sidelobe control and the theory of chirp waveforms for effective power enhancement.

  3. The Adelaide MF partial-reflection radar and VHF ST radar

    Science.gov (United States)

    Vincent, R. A.

    1986-01-01

    The microwave frequency (MF) partial-reflection radar ran continuously since November 1983, with data being analyzed in real time. The spaced antenna technique was used routinely to produce a climatology of the mean circulation, atmospheric tides, and gravity waves. Since the beginning of 1985, the system was also used as a Doppler radar to measure the spectral widths of the mesospheric echoes. This has enabled the turbulence dissipation rates to be determined. The Stratosphere-Troposphere (ST) radar was operated in the spaced antenna mode to measure winds in November 1984, in conjunction with a cooperative campaign to study the propagation of cold fronts across SE Australia. Observations were also performed to study the structure of the more intense and deeper cold fronts, which occur in late winter.

  4. A brief history of the development of wind-profiling or MST radars

    Directory of Open Access Journals (Sweden)

    T. E. Van Zandt

    Full Text Available The history of the development of the wind-profiling or MST radar technique is reviewed from its inception in the late 1960s to the present. Extensions of the technique by the development of boundary-layer radars and the radio-acoustic sounding system (RASS technique to measure temperature are documented. Applications are described briefly, particularly practical applications to weather forecasting, with data from networks of radars, and scientific applications to the study of rapidly varying atmospheric phenomena such as gravity waves and turbulence.

    Key words: Meteorology and atmospheric dynamics (instruments and techniques · Radio science (remote sensing; instruments and techniques

  5. Mathematical analysis study for radar data processing and enhancement. Part 1: Radar data analysis

    Science.gov (United States)

    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.

  6. Temperature sheets and aspect sensitive radar echoes

    Directory of Open Access Journals (Sweden)

    H. Luce

    Full Text Available here have been years of discussion and controversy about the existence of very thin and stable temperature sheets and their relationship to the VHF radar aspect sensitivity. It is only recently that very high-resolution in situ temperature observations have brought credence to the reality and ubiquity of these structures in the free atmosphere and to their contribution to radar echo enhancements along the vertical. Indeed, measurements with very high-resolution sensors are still extremely rare and rather difficult to obtain outside of the planetary boundary layer. They have only been carried out up to the lower stratosphere by Service d’A´ eronomie (CNRS, France for about 10 years. The controversy also persisted due to the volume resolution of the (Mesosphere-Stratosphere-Troposphere VHF radars which is coarse with respect to sheet thickness, although widely sufficient for meteorological or mesoscale investigations. The contribution within the range gate of many of these structures, which are advected by the wind, and decay and grow at different instants and could be distorted either by internal gravity waves or turbulence fields, could lead to radar echoes with statistical properties similar to those produced by anisotropic turbulence. Some questions thus remain regarding the manner in which temperature sheets contribute to VHF radar echoes. In particular, the zenithal and azimuthal angular dependence of the echo power may not only be produced by diffuse reflection on stable distorted or corrugated sheets, but also by extra contributions from anisotropic turbulence occurring in the stratified atmosphere. Thus, for several years, efforts have been put forth to improve the radar height resolution in order to better describe thin structures. Frequency interferometric techniques are widely used and have been recently further developed with the implementation of high-resolution data processings. We begin by reviewing briefly some characteristics

  7. Industrial espionage and technical surveillance counter measurers

    CERN Document Server

    Androulidakis, Iosif

    2016-01-01

    This book examines technical aspects of industrial espionage and its impact in modern companies, organizations, and individuals while emphasizing the importance of intellectual property in the information era. The authors discuss the problem itself and then provide statistics and real world cases. The main contribution provides a detailed discussion of the actual equipment, tools and techniques concerning technical surveillance in the framework of espionage. Moreover, they present the best practices and methods of detection (technical surveillance counter measures) as well as means of intellectual property protection.

  8. Radar Observations of Asteroids

    Science.gov (United States)

    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.

  9. Motion measurement for synthetic aperture radar

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-01-01

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

  10. Bistatic Forward Scattering Radar Detection and Imaging

    Directory of Open Access Journals (Sweden)

    Hu Cheng

    2016-06-01

    Full Text Available Forward Scattering Radar (FSR is a special type of bistatic radar that can implement image detection, imaging, and identification using the forward scattering signals provided by the moving targets that cross the baseline between the transmitter and receiver. Because the forward scattering effect has a vital significance in increasing the targets’ Radar Cross Section (RCS, FSR is quite advantageous for use in counter stealth detection. This paper first introduces the front line technology used in forward scattering RCS, FSR detection, and Shadow Inverse Synthetic Aperture Radar (SISAR imaging and key problems such as the statistical characteristics of forward scattering clutter, accurate parameter estimation, and multitarget discrimination are then analyzed. Subsequently, the current research progress in FSR detection and SISAR imaging are described in detail, including the theories and experiments. In addition, with reference to the BeiDou navigation satellite, the results of forward scattering experiments in civil aircraft detection are shown. Finally, this paper considers future developments in FSR target detection and imaging and presents a new, promising technique for stealth target detection.

  11. Motion Measurement for Synthetic Aperture Radar.

    Energy Technology Data Exchange (ETDEWEB)

    Doerry, Armin W.

    2015-01-01

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

  12. Integrated design of intelligent surveillance systems and their user interface

    NARCIS (Netherlands)

    Toet, A.

    2005-01-01

    Modern complex surveillance systems consisting of multiple and heterogeneous sensors, automatic information registration and data analysis techniques, and decision support tools should provide the human operator an integrated, transparent and easily comprehensible view of the surveyed scene. Display

  13. Higher-order techniques in computational electromagnetics

    CERN Document Server

    Graglia, Roberto D

    2016-01-01

    Higher-Order Techniques in Computational Electromagnetics explains 'high-order' techniques that can significantly improve the accuracy, computational cost, and reliability of computational techniques for high-frequency electromagnetics, such as antennas, microwave devices and radar scattering applications.

  14. Multi-mission, autonomous, synthetic aperture radar

    Science.gov (United States)

    Walls, Thomas J.; Wilson, Michael L.; Madsen, David; Jensen, Mark; Sullivan, Stephanie; Addario, Michael; Hally, Iain

    2014-05-01

    Unmanned aerial systems (UASs) have become a critical asset in current battlespaces and continue to play an increasing role for intelligence, surveillance and reconnaissance (ISR) missions. With the development of medium-to-low altitude, rapidly deployable aircraft platforms, the ISR community has seen an increasing push to develop ISR sensors and systems with real-time mission support capabilities. This paper describes recent flight demonstrations and test results of the RASAR (Real-time, Autonomous, Synthetic Aperture Radar) sensor system. RASAR is a modular, multi-band (L and X) synthetic aperture radar (SAR) imaging sensor designed for self-contained, autonomous, real-time operation with mission flexibility to support a wide range of ISR needs within the size, weight and power constraints of Group III UASs. The sensor command and control and real-time image formation processing are designed to allow integration of RASAR into a larger, multi-intelligence system of systems. The multi-intelligence architecture and a demonstration of real-time autonomous cross-cueing of a separate optical sensor will be presented.

  15. Comparison Between Radar and Automatic Weather Station Refractivity Variability

    Science.gov (United States)

    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.

  16. An inverse method to retrieve 3D radar reflectivity composites

    Science.gov (United States)

    Roca-Sancho, Jordi; Berenguer, Marc; Sempere-Torres, Daniel

    2014-11-01

    Dense radar networks offer the possibility of getting better Quantitative Precipitation Estimates (QPE) than those obtained with individual radars, as they allow increasing the coverage and improving quality of rainfall estimates in overlapping areas. Well-known sources of error such as attenuation by intense rainfall or errors associated with range can be mitigated through radar composites. Many compositing techniques are devoted to operational uses and do not exploit all the information that the network is providing. In this work an inverse method to obtain high-resolution radar reflectivity composites is presented. The method uses a model of radar sampling of the atmosphere that accounts for path attenuation and radar measurement geometry. Two significantly different rainfall situations are used to show detailed results of the proposed inverse method in comparison to other existing methodologies. A quantitative evaluation is carried out in a 12 h-event using two independent sources of information: a radar not involved in the composition process and a raingauge network. The proposed inverse method shows better performance in retrieving high reflectivity values and reproducing variability at convective scales than existing methods.

  17. Universal Library for Building Radar Operator Interface

    Directory of Open Access Journals (Sweden)

    A. A. Karankevich

    2014-01-01

    Full Text Available The article contains the results of the development of a software library, used for building software interfaces for radars being developed in BMSTU Radioelectronic Technics Scientific and Research Institute. The library is a software application library written in C++ using Qt and OpenGL libraries.The article describes the requirements, that the library is supposed to meet, in particular — cross-platform capabilities and versatility of the solution. The data types, that library uses, are described. The description of theinterface elements developed is shown, and some pictures of their operation are given.The article shows the main interface elements used. They are: «Matrix» that shows twodimensional data, «Waterfall», that is used for time scanning of the parameter specified, and «Plan Position Indicator» that shows circular scan from surveillance radar without geometric distortions.The part «Library implementation» shows the example of radiolocation station interface, that was based on this library, used in the working model of ultrashortpulse radar. Some results of the operation of this interface are also shown. The experiment shows the system working with two people in the field. As people start to move, the system becomes capable of distinguishing moving targets and stationary surface. The article shows the system operation the same way as the system operator can see it through his interface.The conclusion contains brief results of the development, the sphere of application of the software, and the prospects of the further development of the library.

  18. SIRE: a MIMO radar for landmine/IED detection

    Science.gov (United States)

    Ojowu, Ode; Wu, Yue; Li, Jian; Nguyen, Lam

    2013-05-01

    Multiple-input multiple-output (MIMO) radar systems have been shown to have significant performance improvements over their single-input multiple-output (SIMO) counterparts. For transmit and receive elements that are collocated, the waveform diversity afforded by this radar is exploited for performance improvements. These improvements include but are not limited to improved target detection, improved parameter identifiability and better resolvability. In this paper, we present the Synchronous Impulse Reconstruction Radar (SIRE) Ultra-wideband (UWB) radar designed by the Army Research Lab (ARL) for landmine and improvised explosive device (IED) detection as a 2 by 16 MIMO radar (with collocated antennas). Its improvement over its SIMO counterpart in terms of beampattern/cross range resolution are discussed and demonstrated using simulated data herein. The limitations of this radar for Radio Frequency Interference (RFI) suppression are also discussed in this paper. A relaxation method (RELAX) combined with averaging of multiple realizations of the measured data is presented for RFI suppression; results show no noticeable target signature distortion after suppression. In this paper, the back-projection (delay and sum) data independent method is used for generating SAR images. A side-lobe minimization technique called recursive side-lobe minimization (RSM) is also discussed for reducing side-lobes in this data independent approach. We introduce a data-dependent sparsity based spectral estimation technique called Sparse Learning via Iterative Minimization (SLIM) as well as a data-dependent CLEAN approach for generating SAR images for the SIRE radar. These data-adaptive techniques show improvement in side-lobe reduction and resolution for simulated data for the SIRE radar.

  19. Subsurface radar location of the putative ocean on Ganymede: Numerical simulation of the surface terrain impact

    Science.gov (United States)

    Ilyushin, Ya. A.

    2014-03-01

    Exploration of subsurface oceans on Jupiter's icy moons is a key issue of the icy moons' geology. Radar is in fact the only sounding technique which is able to penetrate their icy mantles, which can be many kilometers thick. Surface clutter, i.e. scattering of the radio waves on the rough surface, is known to be one of the most important problems of subsurface radar probing. Adequate numerical modeling of this scattering is required on all stages of subsurface radar experiment, including design of an instrument, operational strategy planning and data interpretation. In the present paper, a computer simulation technique for numerical simulations of radar sounding of rough surfaces is formulated in general form. Subsurface radar location of the ocean beneath Ganymedian ice with chirp radar signals has been simulated.

  20. An MSK Radar Waveform

    Science.gov (United States)

    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