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1

Lightweight SAR GMTI radar technology development  

NASA Astrophysics Data System (ADS)

A small and lightweight dual-channel radar has been developed for SAR data collections. Using standard Displaced Phase Center Antenna (DPCA) radar digital signal processing, SAR GMTI images have been obtained. The prototype radar weighs 5-lbs and has demonstrated the extraction of ground moving targets (GMTs) embedded in high-resolution SAR imagery data. Heretofore this type of capability has been reserved for much larger systems such as the JSTARS. Previously, small lightweight SARs featured only a single channel and only displayed SAR imagery. Now, with the advent of this new capability, SAR GMTI performance is now possible for small UAV class radars.

Kirk, John C.; Lin, Kai; Gray, Andrew; Hseih, Chung; Darden, Scott; Kwong, Winston; Majumder, Uttam; Scarborough, Steven

2013-05-01

2

GMTI radar minimum detectable velocity.  

SciTech Connect

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

Richards, John Alfred

2011-04-01

3

HRR profiling in GMTI search radar  

Microsoft Academic Search

This paper presents a high range resolution (HRR) profiling technique for generating range and Doppler profiles of multiple moving targets, while the radar is in ground moving target indicator (GMTI) search mode. To implement such a technique, it requires no a priori information on target velocity and\\/or phase, hence, it is a good candidate to be incorporated into a search

Pileih Chen

2000-01-01

4

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

SciTech Connect

The performance of a Ground Moving Target Indicator (GMTI) radar system depends on a variety of factors, many which are interdependent in some manner. It is often difficult to 'get your arms around' the problem of ascertaining achievable performance limits, and yet those limits exist and are dictated by physics. This report identifies and explores those limits, and how they depend on hardware system parameters and environmental conditions. Ultimately, this leads to a characterization of parameters that offer optimum performance for the overall GMTI radar system. While the information herein is not new to the literature, its collection into a single report hopes to offer some value in reducing the 'seek time'.

Doerry, Armin Walter

2010-09-01

5

Wide-Area Traffic Monitoring With the SAR\\/GMTI System PAMIR  

Microsoft Academic Search

This paper presents a wide area traffic monitoring experiment under real conditions, using the scan-MTI mode of the airborne radar sensor PAMIR. This flexible GMTI (Ground Moving Target Indication) mode was designed in order to rapidly monitor wide areas for moving targets. The scan operation enables the detection of targets from different aspect angles with a high revisit rate. The

Delphine Cerutti-Maori; Jens Klare; Andreas R. Brenner; Joachim H. G. Ender

2008-01-01

6

Gmti Motion Compensation  

DOEpatents

Movement of a GMTI radar during a coherent processing interval over which a set of radar pulses are processed may cause defocusing of a range-Doppler map in the video signal. This problem may be compensated by varying waveform or sampling parameters of each pulse to compensate for distortions caused by variations in viewing angles from the radar to the target.

Doerry, Armin W. (Albuquerque, NM)

2004-07-20

7

Tracking evasive move-stop-move targets with a GMTI radar using a VS-IMM estimator  

Microsoft Academic Search

We present the design of a variable structure interacting multiple model (VS-IMM) estimator for tracking evasive ground targets using ground moving target indicator (GMTI) reports obtained from an airborne sensor. In order to avoid detection by the GMTI sensor, the targets use a \\

T. Kirubarajan; Y. Bar-Shalom

2003-01-01

8

SAR based adaptive GMTI  

NASA Astrophysics Data System (ADS)

We consider ground moving target indication (GMTI) and target velocity estimation based on multi-channel synthetic aperture radar (SAR) images. Via forming velocity versus cross-range images, we show that small moving targets can be detected even in the presence of strong stationary ground clutter. Moreover, the velocities of the moving targets can be estimated, and the misplaced moving targets can be placed back to their original locations based on the estimated velocities. Adaptive beamforming techniques, including Capon and generalizedlikelihood ratio test (GLRT), are used to form velocity versus cross-range images for each range bin of interest. The velocity estimation ambiguities caused by the multi-channel array geometry are analyzed. We also demonstrate the effectiveness of our approaches using the Air Force Research Laboratory (AFRL) publicly-released Gotcha SAR based GMTI data set.

Vu, Duc; Guo, Bin; Xu, Luzhou; Li, Jian

2010-04-01

9

Wavelets feature aided tracking (WFAT) using GMTI\\/HRR data  

Microsoft Academic Search

This paper presents a research development of wavelets feature aided tracking, which effectively combines information from both high-resolution range (HRR) radar profiles and ground moving target indication (GMTI) radar reports. The state-of-the-art wavelets-based statistical signal processing technique: wavelets domain hidden Markov trees is used to extract robust features from HRR profiles. With the assistance of HRR wavelets features, a GMTI

Lang Hong; Shan Cong; Mark T. Pronobis; Stephen Scott

2003-01-01

10

Airborne array aperture UWB UHF radar-motivation and system considerations  

Microsoft Academic Search

The paper discusses the necessity, feasibility and technology of FOPEN GMTI. It argues that this functionality may be one mode in a multi-function UWB UHF system, which jointly possesses the capabilities for air target MTI and high resolution FOPEN SAR. The radar platform may be a UAV or an aircraft, whereas it is proposed to use the push boom type

Hans Hellsten; Lars M. H. Ulander

1999-01-01

11

Airborne array aperture UWB UHF radar-motivation and system considerations  

Microsoft Academic Search

This paper discusses the necessity, feasibility, and technology of FOPEN GMTI. It argues that this functionality may be one mode in a multi-function UWB UHF system, which jointly possesses the capabilities for air target MTI and high resolution FOPEN SAR. The radar platform may be a UAV or an aircraft, whereas, we propose to use the push boom type of

H. Hellsten; L. M. H. Ulander

2000-01-01

12

Clutter in the GMTI range-velocity map.  

SciTech Connect

Ground Moving Target Indicator (GMTI) radar maps echo data to range and range-rate, which is a function of a moving target's velocity and its position within the antenna beam footprint. Even stationary clutter will exhibit an apparent motion spectrum and can interfere with moving vehicle detections. Consequently it is very important for a radar to understand how stationary clutter maps into radar measurements of range and velocity. This mapping depends on a wide variety of factors, including details of the radar motion, orientation, and the 3-D topography of the clutter.

Doerry, Armin Walter

2009-04-01

13

The Earth rotation effect on a LEO L-band GMTI SBR and mitigation strategies  

Microsoft Academic Search

Space based radars (SBR) have been used to accomplish a number of civilian and military missions. Most recently, SBR concepts have been considered to perform ground moving target indication (GMTI) radar modes. Unlike airborne surveillance platforms, SBR clutter returns are affected by the high satellite velocity and Earth rotation. The phenomenology of the Earth's rotation, and its impact on clutter

Peter Zulch; Mark Davis; Larry Adzima; Robert Hancock; Sid Theis

2004-01-01

14

Radar antenna architectures and sampling strategies for space based moving target recognition  

Microsoft Academic Search

Ground moving target indication (GMTI) by a space based radar system demands special antenna and data acquisition concepts to overcome the problem of discriminating the target signal from the clutter returns, which - because of the high speed of the satellite - comprise a broad mixture of radial velocities within the antenna beam leading to a large Doppler spread. These

J. H. G. Ender; D. Cerutti-Maori; W. Burger

2005-01-01

15

Space-based moving target positioning using radar with a switched aperture antenna  

Microsoft Academic Search

Ground moving target indication (GMTI) by space based radar can effectively only be performed with a multi- aperture \\/ multi-channel system or a satellite cluster [1]. To keep weight, power consumption, data rate and costs low, the technique of switching subapertures from pulse to pulse has been proposed. While the detection performance using STAP (space-time adaptive processing) has been analysed

Joachim H. G. Ender; Christoph H. Gierull; Delphine Cerutti-Maori

2007-01-01

16

Millimeter Wave Polarimetric Monopulse Radar Debugging System  

Microsoft Academic Search

For testing millimeter wave polarimetric monopulse radar and testing algorithms for polarimetric radar, millimeter wave polarimetric monopulse radar debugging system is proposed in this paper. Polarimetric radar, as a kind of radar with strong counter-countermeasure capability, is more and more popular used nowadays. The cost of polarimetric radar is more expensive than traditional single-polarimetric radar. Millimeter wave polarimetric monopulse radar

Jin Tao; Qi Xiaohui; Zhang Min; Qiao Xiaolin; Yuan Shuqing; Zhang Qunxing

2007-01-01

17

Threat radar system simulations  

NASA Astrophysics Data System (ADS)

The capabilities, requirements, and goals of radar emitter simulators are discussed. Simulators are used to evaluate competing receiver designs, to quantify the performance envelope of a radar system, and to model the characteristics of a transmitted signal waveform. A database of candidate threat systems is developed and, in concert with intelligence data on a given weapons system, permits upgrading simulators to new projected threat capabilities. Four currently available simulation techniques are summarized, noting the usefulness of developing modular software for fast controlled-cost upgrades of simulation capabilities.

Miller, L.

18

Doppler Radar System.  

National Technical Information Service (NTIS)

The radar system is utilized to guide a fused guided missile to an aircraft target. The secondary doppler effects are utilized between a moving object and a secondary reflecting surface to detect the presence of the object and indicate its point of closes...

A. E. Resnik

1964-01-01

19

Laser Imaging Radar System.  

National Technical Information Service (NTIS)

The simplicity, compactness, and reasonable cost of direct detection diode-laser range finders provide incentive for their use in laser imaging radar systems (LIRS). Efforts have been made to increase range performance of a diode-laser range finder by mea...

S. P. Yun R. A. Olson

1993-01-01

20

Goldstone Solar System Radar.  

National Technical Information Service (NTIS)

Planning, direction, experimental design, and coordination of data-acquisition and engineering activities in support of all Goldstone planetary radar astronomy were performed. This work demands familiarity with the various components of a planetary radar ...

R. F. Jurgens

1988-01-01

21

Synchronisation of bistatic radar systems  

Microsoft Academic Search

Bistatic radar is gaining more and more interest over the last years. It offers more freedom to deploy the transmitter and the receiver, e.g. in a way to enhance the signature of stealthy targets. Furthermore, the bi- or multistatic system can be realized without using expensive transmit\\/receive-modules. An additional feature of bistatic radar is that continuous wave signals can be

M. Weib

2004-01-01

22

Instrumental Principles of MST Radars and Incoherent Scatter Radars and the Configuration of Radar System Hardware.  

National Technical Information Service (NTIS)

The principle of pulse modulation used in the case of coherent scatter radars (MST radars) is discussed. Coherent detection and the corresponding system configuration is delineated. Antenna requirements and design are outlined and the phase-coherent trans...

J. Roettger

1989-01-01

23

Goldstone solar system radar  

Microsoft Academic Search

Information is provided about physical nature planetary surfaces and their topography as well as dynamical properties such as orbits and spin states using ground based radar as a remote sensing tool. Accessible targets are the terrestrial planets: the Earth's Moon, Mercury, Venus and Mars, the outer planets rings and major moons, and many transient objects such as asteroids and comets.

R. F. Jurgens; P. E. Clark; R. M. Goldstein; S. J. Ostro; M. A. Slade; T. W. Thompson; R. S. Saunders

1986-01-01

24

Object recognation with surveillance radar systems  

Microsoft Academic Search

In this thesis have written description and principle of radar systems and them classification. As well as radar systems are used where and for what. The most optimal signal transmission and principles of systems in general.

Gun Sergiy

2010-01-01

25

Embedding technologies for an automotive radar system  

Microsoft Academic Search

Radar sensors are already employed in production model vehicles e.g. for adaptive cruise control (ACC) systems. Further development of driver assistance systems has also led to the use of radar sensors in active safety systems (active brake assistance, collision warning, emergency braking, etc). However, the costs of manufacturing such radar-based systems, capable of gathering reliable information from surroundings, for vehicles

K.-F. Becker; M. Koch; R. Kahle; T. Braun; L. Bottcher; A. Ostmann; J. Kostelnik; F. Ebling; E. Noack; J. P. Sommer; M. Richter; M. Schneider; H. Reichl

2009-01-01

26

3D Laser Radar Vision Processor System.  

National Technical Information Service (NTIS)

Loral Defense Systems (LDS) developed a 3D Laser Radar Vision Processor system capable of detecting, classifying, and identifying small mobile targets as well as larger fixed targets using three dimensional laser radar imagery for use with a robotic type ...

T. M. Sebok

1990-01-01

27

Bistatic radar using satellite-borne illuminators  

Microsoft Academic Search

Bistatic radar has long been recognised as an interesting variant of radar, with a number of potential advantages for air defence. Space-based radar is seen by the US Department of Defense as a key technique for future AMTI and GMTI applications, and the DISCOVERER II programme is indicative of current thinking, aiming ultimately at a network of several tens of

H. D. Griffiths; C. J. Baker; J. Baubert; N. Kitchen; M. Treagust

2002-01-01

28

Radar cross section statistics of cultural clutter at Ku-band  

NASA Astrophysics Data System (ADS)

Knowing the statistical characteristics of the radar cross-section (RCS) of man-made, or cultural clutter, is crucial to the success of clutter mitigation, radar target detection algorithms, and radar system requirements in urban environments. Open literature studies regarding the statistical nature of cultural clutter focus primarily on radar probability models or limited experimental data analysis of specific locations and frequencies. This paper seeks to expand the existing body of work on cultural clutter RCS statistics at Ku-band for ground moving target indication (GMTI) and synthetic aperture radar (SAR) applications. We examine the normalized RCS probability distributions of cultural clutter in several urban scenes, across aspect and elevation angle, for vertical transmit/receive (VV) polarizations, and at diverse resolutions, using experimental data collected at Ku-band. We further describe frequency and RCS strength statistics of clutter discretes per unit area to understand system demands on radars operating in urban environments in this band.

Raynal, Ann Marie; Bickel, Douglas L.; Dubbert, Dale F.; Verge, Tobias J.; Burns, Bryan L.; Dunkel, Ralf; Doerry, Armin W.

2012-05-01

29

Downhole radar system for fracture detection  

Microsoft Academic Search

A borehole radar prototype was designed based on theoretical considerations. Experiments were conducted at a granite quarry where an existing flame-cut slot was used to simulate a fracture. The radar returns from this simulated fracture were detectable in boreholes located at distances of up to 12 meters from the fracture. Engineering design for a downhole radar system is almost complete.

1986-01-01

30

A scan converter radar display system  

Microsoft Academic Search

A radar display system, designed to integrate on a single display target information from several radars, has been designed and evaluated. Integration is obtained through the use of single gun scan converter tubes. The resultant image on the TV monitor is a bright steady PPI image which is updated at the end of each radar scan. Limitations imposed on the

N. V. Oneal; P. M. Thiebaud

1975-01-01

31

Monitoring by holographic radar systems  

NASA Astrophysics Data System (ADS)

Nowadays, radar technology represents a significant opportunity to collect useful information for the monitoring and conservation of critical infrastructures. Radar systems exploit the non-invasive interaction between the matter and the electromagnetic waves at microwave frequencies. Such an interaction allows obtaining images of the region under test from which one can infer the presence of potential anomalies such as deformations, cracks, water infiltrations, etc. This information turns out to be of primary importance in practical scenarios where the probed structure is in a poor state of preservation and renovation works must be planned. In this framework, the aim of this contribution is to describe the potentialities of the holographic radar Rascan 4/4000, a holographic radar developed by Remote Sensing Laboratory of Bauman Moscow State Technical University, as a non-destructive diagnostic tool capable to provide, in real-time, high resolution subsurface images of the sounded structure [1]. This radar provides holograms of hidden anomalies from the amplitude of the interference signal arising between the backscattered signal and a reference signal. The performance of the holographic radar is appraised by means of several experiments. Preliminary tests concerning the imaging below the floor and inside wood structures are carried out in controlled conditions at the Electromagnetic Diagnostic Laboratory of IREA-CNR. After, with reference to bridge monitoring for security aim, the results of a measurement campaign performed on the Musmeci bridge are presented [2]. Acknowledgments This research has been performed in the framework of the "Active and Passive Microwaves for Security and Subsurface imaging (AMISS)" EU 7th Framework Marie Curie Actions IRSES project (PIRSES-GA-2010-269157). REFERENCES [1] S. Ivashov, V. Razevig, I. Vasilyev, A. Zhuravlev, T. Bechtel, L. Capineri, The holographic principle in subsurface radar technology, International Symposium to Commemorate the 60th Anniversary of the Invention of Holography, Springfield, Massachusetts USA, October 27-29, pp. 183-197, 2008. [2] I. Catapano, L. Crocco, A. F. Morabito, F. Soldovieri, "Tomographic imaging of holographic GPR data for non-invasive structural assessment: the Musmeci bridge investigation", Nondestructive testing and evaluation, vol. 27, pp. 229-237, 2012.

Catapano, Ilaria; Crocco, Lorenzo; Affinito, Antonio; Gennarelli, Gianluca; Soldovieri, Francesco

2013-04-01

32

Radar System Analysis Algorithms. Radar System Analysis Models of Performance Degradation by Mutual Interference.  

National Technical Information Service (NTIS)

This report provides an overview of current radar system analysis models. It is an initial effort toward a radar system analysis capability as part of the Electromagnetic Environment (EMX) Program. The principles and approach of the EMX Program are outlin...

S. T. Li

1978-01-01

33

Knowledge-based design support system for radar system design  

Microsoft Academic Search

The radar system design is the most important part of the design process during which alternative design solutions are generated. In this paper we present and develop the knowledge-based design support system (KBDSS) for radar system scheme design. The KBDSS consists of five parts: user interface, knowledge base, expert system, inference engine, design case base and model base for radar

Qi Rundong; Wang Shijin; Mao Quan; Shu Yiqiang; Zhou Ji; Yu Jun

1993-01-01

34

Basic characteristics of FM-CW radar systems  

Microsoft Academic Search

Due to rapid technological progress in real-time signal processing, FM-CW radar systems are expected to become a more serious competitor to pulse radar systems. This paper deals with basic radar principles such as modulating waveforms and ambiguity functions characteristics. Advantages and disadvantages of FM-CW radar systems are compared to pulse radar systems. The inherent signal processing used in FM-CW radar

L. P. Ligthart; L. R. Nieuwkerk; J. S. Vansinttruyen

1986-01-01

35

Recent Goldstone Solar System Radar Observations  

Microsoft Academic Search

Planetary radar exploration started on the ground with the detection of the Moon in 1946. In recent years, the Goldstone Solar System Radar (GSSR) has for example made contributions to (i) understanding of the hazards and trafficability at various proposed Mars robotic landing sites, (ii) under-standing of polar water ice for the terrestrial planets and the surfaces of the icy

A. F. Haldemann; L. Benner; B. J. Butler; L. Harcke; R. F. Jurgens; K. W. Larsen; J. Margot; S. J. Ostro; M. A. Slade

2003-01-01

36

Compilation System for Venus Radar Mission (Magellan).  

National Technical Information Service (NTIS)

A synthetic aperture radar (SAR) compilation system was developed for extraction of topographic information of Venus from stereoradar imagery to be obtained from the Magellan mission. The system was developed for an AS-11AM analytical stereoplotter. Exten...

S. S. C. Wu F. J. Schafer A. Howington

1987-01-01

37

Management of radar tracking systems for air traffic control  

Microsoft Academic Search

This paper describes a novel methodology for the adaptive management of radar systems or radar networks used for air traffic control. It is based on linking radar tracking system overall resources consumption with air traffic control operational requirements. The method is exemplified with the design of a tracking function for a multifunction ESA radar. Some simulation results for this system

Juan A. Besada; Jesus Garcia; G. de Miguel; J. R. Casar

2002-01-01

38

Incremental fusion of GMTI tracks for road map estimation  

Microsoft Academic Search

Vector roadmaps are invaluable for various applications such as navigation and tracking. A new algorithm is presented aimed at incrementally producing exact, up-to-date vector roadmaps using GMTI tracks. In most existing work the track points are processed independently. Track points are individually associated with segments of existing roads and the road segment locations are corrected accordingly. In this work, rather

S. E. Sklarz; A. Novoselsky; M. Dorfan

2008-01-01

39

Accurate 3D rigid-body target motion and structure estimation by using GMTI/HRR with template information  

NASA Astrophysics Data System (ADS)

A framework of simultaneously estimating the motion and structure parameters of a 3D object by using high range resolution (HRR) and ground moving target indicator (GMTI) measurements with template information is given. By decoupling the motion and structure information and employing rigid-body constraints, we have developed the kinematic and measurement equations of the problem. Since the kinematic system is unobservable by using only one scan HRR and GMTI measurements, we designed an architecture to run the motion and structure filters in parallel by using multi-scan measurements. Moreover, to improve the estimation accuracy in large noise and/or false alarm environments, an interacting multi-template joint tracking (IMTJT) algorithm is proposed. Simulation results have shown that the averaged root mean square errors for both motion and structure state vectors have been significantly reduced by using the template information.

Wu, Shunguang; Hong, Lang

2008-05-01

40

Phased-array radar for airborne systems  

NASA Astrophysics Data System (ADS)

Phased array antenna systems, which support high pulse rates and high transmit power, are well suited for radar and large-scale surveillance. Sensors and communication systems can function as the eyes and ears for ballistic missile defense applications, providing early warning of attack, target detection and identification, target tracking, and countermeasure decision. In such applications, active array radar systems that contain solid-state transmitter sources and low-noise preamplifiers for transmission and reception are preferred over the conventional radar antennas, because the phased array radar offers the advantages of power management and efficiency, reliability, signal reception, beam steering target detection. The current phased array radar designs are very large, complex and expensive and less efficient because of high RF losses in the phase control circuits used for beam scan. Several thousands of phase shifters and drivers may be required for a single system thus making the system very complex and expensive. This paper describes the phased array radar system based on high power T/R modules, wide-band radiating planar antenna elements and very low loss wide-band phase control circuits (requiring reduced power levels) for beam scan. The phase shifter design is based on micro-strip feed lines perturbed by the proximity of voltage controlled piezoelectric transducer (PET). Measured results have shown an added insertion loss of less than 1 dB for a phase shift of 450 degrees from 2 to 20 GHz. The new wideband phased array radar design provides significant reduction in size cost and weight. Compared to the conventional phased array systems, the cost saving is more than 15 to 1.

Tahim, Raghbir S.; Foshee, James J.; Chang, Kai

2003-09-01

41

Beacon Splits in Air Traffic Control Radar Beacon System (ATCRBS)  

Microsoft Academic Search

The ATC radar beacon system is today's primary source of surveillance ance data for air traffic control. For en route traffic control, radar and beacon data are collected at numerous long range radar (LRR) facilities and typically sent by remote control to the air traffic control center (ARTCC) by a radar microwave link (RML). Selfsupporting or guyed RML towers are

Narayan Murarka; Peter Toulios; Domenico Lanera

1975-01-01

42

The EISCAT Svalbard radar: A case study in modern incoherent scatter radar system design  

Microsoft Academic Search

The EISCAT (European incoherent scatter) Svalbard radar (ESR) was officially inaugurated on August 22, 1996. This event marked the successful completion on schedule of the first phase of the EISCAT Svalbard radar project. In contrast to previous incoherent scatter radars, the ESR system design was adapted to make use of commercial off-the-shelf TV transmitter hardware, thereby reducing design risk, lead

G. Wannberg; I. Wolf; L.-G. Vanhainen; K. Koskenniemi; J. Röttger; M. Postila; J. Markkanen; R. Jacobsen; A. Stenberg; R. Larsen; S. Eliassen; S. Heck; A. Huuskonen

1997-01-01

43

The Air Traffic Control Radar Beacon System  

Microsoft Academic Search

This paper outlines the major advantages and limitations of the Air Traffic Control Radar Beacon System under evaluation at the Civil Aeronautics Administration Technical Development Center. It discusses the advantages and disadvantages of compatibility, the system traffic capacity problems, and the need for an operational doctrine to restrict the use of interrogators. System coverage, ground antenna, reply-code garbling, and reflection

David S. Crippen

1957-01-01

44

Three-channel processing for improved geo-location performance in SAR-based GMTI interferometry  

NASA Astrophysics Data System (ADS)

This paper describes a method for accurately geo-locating moving targets using three-channel SAR-based GMTI interferometry. The main goals in GMTI processing are moving target detection and geo-location. In a 2011 SPIE paper we showed that reliable target detection is possible using two-channel interferometry, even in the presence of main-beam clutter. Unfortunately, accurate geo-location is problematic when using two-channel interferometry, since azimuth estimation is corrupted by interfering clutter. However, we show here that by performing three-channel processing in an appropriate sequence, clutter effects can be diminished and significant improvement can be obtained in geo-location accuracy. The method described here is similar to an existing technique known as Clutter Suppression Interferometry (CSI), although there are new aspects of our implementation. The main contribution of this paper is the mathematical discussion, which explains in a straightforward manner why three-channel CSI outperforms standard two-channel interferometry when target signatures are embedded in main-beam clutter. Also, to our knowledge this paper presents the first results of CSI applied to the Gotcha Challange data set, collected using an X-band circular SAR system in an urban environment.

Deming, Ross W.; MacIntosh, Scott; Best, Matthew

2012-05-01

45

Cassini radar : system concept and simulation results  

NASA Astrophysics Data System (ADS)

The Cassini mission is an international venture, involving NASA, the European Space Agency (ESA) and the Italian Space Agency (ASI), for the investigation of the Saturn system and, in particular, Titan. The Cassini radar will be able to see through Titan's thick, optically opaque atmosphere, allowing us to better understand the composition and the morphology of its surface, but the interpretation of the results, due to the complex interplay of many different factors determining the radar echo, will not be possible without an extensive modellization of the radar system functioning and of the surface reflectivity. In this paper, a simulator of the multimode Cassini radar will be described, after a brief review of our current knowledge of Titan and a discussion of the contribution of the Cassini radar in answering to currently open questions. Finally, the results of the simulator will be discussed. The simulator has been implemented on a RISC 6000 computer by considering only the active modes of operation, that is altimeter and synthetic aperture radar. In the instrument simulation, strict reference has been made to the present planned sequence of observations and to the radar settings, including burst and single pulse duration, pulse bandwidth, pulse repetition frequency and all other parameters which may be changed, and possibly optimized, according to the operative mode. The observed surfaces are simulated by a facet model, allowing the generation of surfaces with Gaussian or non-Gaussian roughness statistic, together with the possibility of assigning to the surface an average behaviour which can represent, for instance, a flat surface or a crater. The results of the simulation will be discussed, in order to check the analytical evaluations of the models of the average received echoes and of the attainable performances. In conclusion, the simulation results should allow the validation of the theoretical evaluations of the capabilities of microwave instruments, when considering topics like the surface topography, stratigraphy and identification of different materials.

Melacci, P. T.; Orosei, R.; Picardi, G.; Seu, R.

1998-10-01

46

Superregenerative Incoherent UWB Pulse Radar System  

Microsoft Academic Search

A new short range ultra wideband (UWB) radar system with a very simple design due to its superregenerative receiver concept has been studied. The system does not require any amplification of RF or IF signals which allows to build a very inexpensive low-power sensor. With measurements, simple mathematical models and a simulation in time-domain the voltage amplitude of the measurement

T. Wuchenauer; M. Nalezinski; W. Menzel

2006-01-01

47

An experimental adaptive radar array system  

NASA Astrophysics Data System (ADS)

An experimental adaptive array incorporated in an FMCW radar system is described. An FMCW radar is relatively simple and compact. It is easy to realize high range resolution and low probability of interception, and it has many promising applications in anticollision, missile guidance, navigation, and MW imaging radars. The Gram-Schmidt adaptive algorithm was used for the system and proven quite effective. For one interference case the interference null depth was better than -38 dB and the signal-to-interference ratio improvement was better than 25 dB in the entire electronic scanning region. The present algorithm produced good nulls in the interference directions; however, it produced big sidelobes in the interference directions in some cases, especially when scanning to a large aiming angle.

Gong, Y. H.

48

Local motion feature aided ground moving target tracking with GMTI and HRR measurements  

Microsoft Academic Search

Tracking ground moving targets with ground moving target indicator (GMTI) measurements only could face a potential problem of losing tracks or track mingling, if the targets move together within the range of GMTI sensing uncertainty for an extended period of time. We propose a remedy for this problem by using local motion features extracted from high resolution range (HRR) profiles

Lang Hong; Ningzhou Cui; Mark Pronobis; Stephen Scott

2005-01-01

49

System capability of air traffic control radar beacon system  

Microsoft Academic Search

The air traffic control radar beacon system problems and solutions to these problems are discussed. Residual problems, their extent, and their impact on future systems are described. The results of a system model are related to the possible fixes.

N. K. Shaw; A. A. Simolunas

1970-01-01

50

Waveform Diversity and Design for Interoperating Radar Systems.  

National Technical Information Service (NTIS)

For many years, conventional radars transmitted, received, and processed the same waveform on every pulse or burst within a coherent processing interval (CPI), independently of the environment. Now, modern radar systems have considerable flexibility in th...

M. S. Greco

2013-01-01

51

The 94 GHz MMW imaging radar system  

NASA Astrophysics Data System (ADS)

The 94 GHz MMW airborne radar system that provides a runway image in adverse weather conditions is now undergoing tests at Wright-Patterson Air Force Base (WPAFB). This system, which consists of a solid state FMCW transceiver, antenna, and digital signal processor, has an update rate of 10 times per second, 0.35x azimuth resolution and up to 3.5 meter range resolution. The radar B scope (range versus azimuth) image, once converted to C scope (elevation versus azimuth), is compatible with the standard TV presentation and can be displayed on the Head Up Display (HUD) or Head Down Display (HDD) to aid the pilot during landing and takeoff in limited visibility conditions.

Alon, Yair; Ulmer, Lon

1993-12-01

52

System-level microwave design: radar-based laboratory projects  

Microsoft Academic Search

Two laboratory projects-a Doppler radar and a synthetic aperture radar (SAR)-designed to augment traditional electromagnetics education are proposed. The projects introduce students to component and system level design and expose them to modern computer-aided design (CAD) tools, microstrip and surface mount fabrication technologies, and industry standard test equipment and procedures. Additionally, because the projects result in a working radar system,

Michael A. Jensen; David V. Arnold; Donald E. Crockett

2000-01-01

53

47 CFR 15.515 - Technical requirements for vehicular radar systems.  

Code of Federal Regulations, 2010 CFR

...requirements for vehicular radar systems. 15.515...requirements for vehicular radar systems. (a) Operation...section is limited to UWB field disturbance...signal. (b) The UWB bandwidth of a vehicular radar system operating...

2009-10-01

54

47 CFR 15.515 - Technical requirements for vehicular radar systems.  

Code of Federal Regulations, 2010 CFR

...requirements for vehicular radar systems. 15.515...requirements for vehicular radar systems. (a) Operation...section is limited to UWB field disturbance...signal. (b) The UWB bandwidth of a vehicular radar system operating...

2010-10-01

55

Millimeter radar  

Microsoft Academic Search

The paper discusses some of the advantages offered by millimeter waves over microwaves, reviews possible and past millimeter radar applications, and looks at some future millimeter radar systems. The coming millimeter radars include radiometric seekers, radiometers, and high resolution radar for satellite identification. Important problems to be resolved before millimeter radars can be put into production include component capability; radar

S. L. Johnston

1977-01-01

56

Southwest PAVE PAWS radar system: Environmental assessment  

NASA Astrophysics Data System (ADS)

This document describes the probable environmental impacts of constructing and operating a new surveillance and tracking radar that would operate between 420 and 450 MHz. Four candidate sites in the vicinity of Goodfellow Air Force Base were considered. The impact analysis found that chronic exposure of humans to the radiofrequency radiation levels outside the exclusion fence is not likely to be harmful. No hazards would be associated with fuel handling or cardiac pacemakers at ground level beyond the exclusion fence. Interference with TV reception and other home electronic systems and with UHF land mobile and amateur radios is possible, depending on the site. Handling and use of electro-explosive devices (EEDs) would be safe beyond about 1.2 miles for the basic system and about 2.4 miles for the optional, higher power system. Electromagnetic interference with radar altimeters, air navigation, and air-ground communication is not likely except at two candidate sites, where interference and EED and pacemaker hazards may exist for aircraft operating into or out of a nearby landing strip. No significant adverse biophysical impacts are expected in any location.

Everett, S. J.; Edson, W. A.; Heynick, L. N.; Pierce, S. R.; Shepherd, R. A.; Wlaklet, T. H.

1983-03-01

57

Ultra-Wideband Multifunctional Communications\\/Radar System  

Microsoft Academic Search

We have designed, simulated, fabricated, and tested an ultra-wideband (UWB) multifunctional communication and radar system utilizing a single shared transmitting antenna aperture. Two surface acoustic wave bandpass chirp filters were used to modulate the radar and communications pulses, generating linear frequency modulation waveforms with opposite slope factors. The system operates at a center frequency of 750 MHz with 500 MHz

George N. Saddik; Rahul S. Singh; Elliott R. Brown

2007-01-01

58

Transform domain communication system as an ultra-wideband radar  

NASA Astrophysics Data System (ADS)

Traditionally, ultra-wideband radars increase bandwidth by using shorter pulses. However, by decreasing the pulse width, the power on target decreases and radar detection probabilities decrease. Therefore, new approaches to increase bandwidth are needed that still have adequate power on target. One radical new approach is to use a Transform Domain Communication System (TDCS) as an ultra-wideband radar. The primary advantage of this technique is that it has properties similar to Gaussian noise meaning that the radar would improve bandwidth similar to pseudo-noise (PN) sequences. Also, based on the number of carriers used to generate the TDCS code, multiple pulses can be made mutually orthogonal. This orthogonality can be exploited to effectively increase the maximum unambiguous range for pulse-Doppler radars up to the range of the horizon. In essence, TDCS radar possesses a high pulse repetition frequency (PRF) for velocity estimation and large unambiguous range.

Nunez, Abel S.; Caldwell, James T.

2005-05-01

59

Basic characteristics of FM-CW radar systems  

NASA Astrophysics Data System (ADS)

Due to rapid technological progress in real-time signal processing, FM-CW radar systems are expected to become a more serious competitor to pulse radar systems. This paper deals with basic radar principles such as modulating waveforms and ambiguity functions characteristics. Advantages and disadvantages of FM-CW radar systems are compared to pulse radar systems. The inherent signal processing used in FM-CW radar systems allows a flexible choice of system parameters. In this context aspects like sensitivity, range and velocity resolution are discussed. It is elucidated that the use of digital processors for signal processing (frequency determination, filtering, etc.) offers the possibility to exchange dedicated hardware solutions with software implementations. Attention is paid to equipment like the antennas, diplexer, transmitter and receiver, and to isolation problems between transmitter and receiver. Results of an experimental FM-CW research radar are shown. In addition, the future prospects of FM-CW radar, with the aerial and solid-state R.F. head-end integrated, are indicated.

Ligthart, L. P.; Nieuwkerk, L. R.; Vansinttruyen, J. S.

1986-07-01

60

Can OTH Radar Help Tsunami Warning Systems ?  

NASA Astrophysics Data System (ADS)

A series of ionospheric anomalies following the Sumatra tsunami has been reported in the scientific literature (e.g., Liu et al. 2006; DasGupta et al. 2006; Occhipinti et al. 2006). Similar anomalies were also observed after the tsunamigenic earthquake in Peru in 2001 (Artru et al., 2005) and after the recent earthquakes in Sumatra and Chile in 2007. All these anomalies show the signature in the ionosphere of tsunami-generated internal gravity waves (IGW) propagating in the neutral atmosphere over oceanic regions. Most of these ionospheric anomalies are deterministic and reproducible by numerical modeling (Occhipinti et al., 2006, 2008) via the ocean/neutral atmosphere/ionosphere coupling mechanism. In addition, the numerical modeling supplies useful helps in the estimation of expected anomalies to explore and identify new techniques to detect the tsunami signature in the ionosphere, other then GPS and altimeters. Here we present an overview of the physical coupling mechanism highlighting the advantage of OTH radar in the tsunami detection by ionospheric sounding. The large coverage of OTH radar and its sensitivity to plasma anomalies can open new perspectives in the future oceanic monitoring and tsunami warning system. [Artru et al., 2005] Geophys. J. Int., 160, 2005 [DasGupta et al., 2006] Earth Planet. Space, 35, 929-959. [Liu et al., 2006] J. Geophys. Res., 111, A05303. [Occhipinti et al., 2006] Geophys. Res. Lett., 33, L20104, 2006 [Occhipinti et al., 2008] Geophys. J. Int., 173, 3, 753-1135, 2008.

Coisson, P.; Occhipinti, G.; Roland, L.; Lognonné, P.

2008-12-01

61

Schedulability Envelope for Real-Time Radar Dwell Scheduling and Its Application to Multi-Ship Multi-Radar Systems  

Microsoft Academic Search

This paper presents novel techniques for scheduling radar dwells in phased array radar systems. In order to handle complex physical characteristics such as dwell interleaving, transmitting duty cycle constraint, and energy constraint, we propose a notion of schedulability envelope. The schedulability envelope designed offline hides the details of complex radar dwell scheduling and provides a simple measure for the schedulability

C.-G. Lee; P.-S. Kang; C.-S. Shih; M. Caccamo; L. Sha

2004-01-01

62

Tracking function in bistatic and multistatic radar systems  

Microsoft Academic Search

The paper presents a unified view of the tracking algorithms available for multistatic radar systems. The first topic considered is the derivation of tracking algorithms for bistatic radar. Different algorithms can be conceived according to different sets of measurements which may be processed (e.g., the range sum and one angle, or two angles). Mean and standard deviation values of tracking

A. Farina

1986-01-01

63

Integrated mobile radar-camera system in airport perimeter security  

Microsoft Academic Search

The paper presents the test results of a mobile system for the protection of large-area objects, which consists of a radar and thermal and visual cameras. Radar is used for early detection and localization of an intruder and the cameras with narrow field of view are used for identification and tracking of a moving object. The range evaluation of an

M. Zyczkowski; M. Szustakowski; W. Ciurapinski; R. Dulski; M. Kastek; P. Trzaskawka

2011-01-01

64

29. Perimeter acquisition radar building room #318, data processing system ...  

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

29. Perimeter acquisition radar building room #318, data processing system area; data processor maintenance and operations center, showing data processing consoles - Stanley R. Mickelsen Safeguard Complex, Perimeter Acquisition Radar Building, Limited Access Area, between Limited Access Patrol Road & Service Road A, Nekoma, Cavalier County, ND

65

Beam Steering Antenna Design for Low Altitude Radar Systems  

Microsoft Academic Search

A beam steering offset parabolic antenna with array feed is proposed for low altitude radar systems in order to minimize the undesired effect of irregular terrain obstacles between the radar and the target. This study provides information for the low altitude target located behind an obstacle. Focal region fields of the offset parabolic reflector are calculated in order to determine

B. Saka; E. Afacan; E. Yazgan

1997-01-01

66

Noninvasive biosignal detection radar system using circular polarization.  

PubMed

This paper proposes an integrated hypersensitive Doppler radar system through a circular polarization characteristic. Through the idea of a reverse sense of rotation when the reflecting surface is perfectly conducting, it is shown that the detecting property of the system can be effectively improved by using antennas that have a reverse polarization. This bistatic radar system can be used in noninvasively sensing biosignals such as respiration and heart rates with the periodic movement of skin and muscle near the heart. The operating frequency of the system is in the X-band and the radar size is 95 x50 x13 mm(3). PMID:19369168

Lee, Jee-Hoon; Hwang, Jung Man; Choi, Dong Hyuk; Park, Seong-Ook

2009-04-14

67

Portable Calibration System for Air Traffic Control Surveillance Radar  

Microsoft Academic Search

In this article, we design a portable calibration system for air traffic control surveillance radar. This system realizes the automatic flight calibration for Secondary Surveillance Radar (SSR), and also can provide a simple flight calibration capability for any aircraft without standard equipments onboard. On the basis of high-precision GPS technology, this system is composed of a portable dual-frequency & dual-antenna

Chen Zhu; Xiaofeng Shi

2010-01-01

68

Laser radar system for obstacle avoidance  

NASA Astrophysics Data System (ADS)

The threat of hostile surveillance and weapon systems require military aircraft to fly under extreme conditions such as low altitude, high speed, poor visibility and incomplete terrain information. The probability of collision with natural and man-made obstacles during such contour missions is high if detection capability is restricted to conventional vision aids. Forward-looking scanning laser radars which are build by the EADS company and presently being flight tested and evaluated at German proving grounds, provide a possible solution, having a large field of view, high angular and range resolution, a high pulse repetition rate, and sufficient pulse energy to register returns from objects at distances of military relevance with a high hit-and-detect probability. The development of advanced 3d-scene analysis algorithms had increased the recognition probability and reduced the false alarm rate by using more readily recognizable objects such as terrain, poles, pylons, trees, etc. to generate a parametric description of the terrain surface as well as the class, position, orientation, size and shape of all objects in the scene. The sensor system and the implemented algorithms can be used for other applications such as terrain following, autonomous obstacle avoidance, and automatic target recognition. This paper describes different 3D-imaging ladar sensors with unique system architecture but different components matched for different military application. Emphasis is laid on an obstacle warning system with a high probability of detection of thin wires, the real time processing of the measured range image data, obstacle classification und visualization.

Bers, Karlheinz; Schulz, Karl R.; Armbruster, Walter

2005-09-01

69

Prototype Fiber Optic System to Remote TRACALS Radars.  

National Technical Information Service (NTIS)

The transmission mediums currently used to remote Traffic Control and Landing Systems (TRACALS) radars are coaxial cables (coax) or a microwave link. Problems and limitations are encountered in using either medium. Coax is susceptible to electromagnetic i...

J. A. Radcliff K. E. Becker

1982-01-01

70

Radar Data Processing Using a Distributed Computational System.  

National Technical Information Service (NTIS)

This research specifies and validates a new concurrent decomposition scheme, called Confined Space Search Decomposition (CSSD), to exploit parallelism of Radar Data Processing algorithms using a Distributed Computational System. To formalize the specifica...

G. F. Mota

1992-01-01

71

Limited Characterization of the SPADS Radar System, Project 'START'.  

National Technical Information Service (NTIS)

The USAF Test Pilot School conducted flight tests to characterize the Weibel-manufactured Spaceport Arrival and Departure System (SPADS) radar functionality and performance for potential use as a single-station time-space- position information (TSPI) sour...

K. M. Roessig L. C. Kearl O. Carazo F. Ferreri

2005-01-01

72

Reconfigurable data acquisition system for weather radar applications  

Microsoft Academic Search

Tornado, hazardous weather and flood detection radars demand high-throughput, high-speed data acquisition and processing. Weather-processing systems need to be capable of implementing powerful signal processing algorithms on the raw data collected by the radars. Following processing, data is distributed to the end-user in real-time for timely and accurate detection of imminent weather disasters. Since physical accessibility to such systems is

Rishi Khasgiwale; Luko Krnan; Atchuthan Perinkulam; Russell Tessier

2005-01-01

73

Ultrawideband radar imaging system for biomedical applications  

SciTech Connect

Ultrawideband (UWB) (3-10 GHz) radar imaging systems offer much promise for biomedical applications such as cancer detection because of their good penetration and resolution characteristics. The underlying principle of UWB cancer detection is a significant contrast in dielectric properties, which is estimated to be greater than 2:1 between normal and cancerous tissue, compared to a few-percent contrast in radiographic density exploited by x rays. This article presents a feasibility study of the UWB imaging of liver cancer tumors, based on the frequency-dependent finite difference time domain method. The reflection, radiation, and scattering properties of UWB pulses as they propagate through the human body are studied. The reflected and back-scattered electromagnetic energies from cancer tumors inside the liver are also investigated. An optimized, ultrawideband antenna was designed for near field operation, allowing for the reduction of the air-skin interface. It will be placed on the fat-liver tissue phantom with a malignant tumor stimulant. By performing an incremental scan over the phantom and removing early time artifacts, including reflection from the antenna ends, images based on the back-scattered signal from the tumor can be constructed. This research is part of our effort to develop a UWB cancer detection system with good detection and localization properties.

Jafari, H.M.; Liu, W.; Hranilovic, S.; Deen, M.J. [ECE Department, McMaster University, Hamilton, Ontario L8S 4K1 (Canada)

2006-05-15

74

Networked weather radar system using coherent on receive technology  

NASA Astrophysics Data System (ADS)

The Engineering Research Center for Collaborative Adapting Sensing of the Atmosphere (CASA) was established to improve the coverage of the lowest portion of the atmosphere through coordinated scanning of low-power, short-range, networked radars (referred to as Distributed Collaborative Adaptive Sensing (DCAS)). The first DCAS technology demonstration test-bed has been deployed in south-west Oklahoma in early 2006: a network of four, low-power, short-range, dual polarization, Doppler radar units, referred to as IPI (after CASA's Integrated Project 1). This dissertation is devoted to documenting the IP1 system. Special emphasis is placed on the aspects that enable coordinated radar operation and on other features that provide substantial improvements over existing approaches. In particular, the IP1 radar network can sample the atmosphere with high spatio-temporal resolution and at low altitudes. The dual polarization capabilities and simultaneous multiple radar observations of weather phenomena enable the retrieval of enhanced data products including attenuation corrected reflectivity, dual polarization parameters, and vector wind fields. In addition, the modular radar control, data processing, and communications software architecture allows variations in the network topology, control, and weather information extraction, making the extension of the network easy through the addition of potentially heterogeneous radar nodes.

Junyent, Francesc

75

Adaptive space-time processing for interference suppression in phased array radar systems. I. Search radar  

Microsoft Academic Search

This paper presents an adaptive technique of filtering to suppress the interference in phased array search radar systems. This interference includes noise, clutter, and jamming signals. Unlike the time processing techniques, our filtering process is based upon the target Doppler shift as well as the interference spatial distribution to suppress adaptively the undesired signals. This can be achieved by estimating

H. H. M. Ghouz; F. I. A. Elghany; M. M. Qutb

2000-01-01

76

Scanning lidar with a coupled radar safety system.  

PubMed

A small scanning three-wavelength lidar system at NASA Langley Research Center in Hampton, Virginia, has been used since 1992 to make atmospheric measurements on stratospheric and upper tropospheric aerosols and on the evolution of aircraft exhaust plumes. Many of these measurements have been made away from the zenith, and, to reduce the hazard to air traffic produced by the laser beam, a radar safety device has been installed. The radar application is original in that the radar beam is made collinear with the laser beam by use of a dichroic mirror that transmits the laser radiation and reflects the microwaves. This mirror is inserted into the outgoing optical path prior to the radiation from both the radar and the laser passing through the independent scanning unit. Tests of the complete system show that the lidar and radar beams remain collocated as they are scanned and that the radar can be used to inhibit the laser prior to an aircraft passing through the beam. PMID:18324168

Kent, G S; Hansen, G M

1999-10-20

77

Ultrawideband imaging radar based on OFDM: system simulation analysis  

NASA Astrophysics Data System (ADS)

Orthogonal frequency division-multiplexing (OFDM) is rapidly emerging as a preferred method of UWB signaling in commercial applications aimed mainly at low-power, high data-rate communications. This paper explores the possibility of applying OFDM to use in imaging radar technology. Ultra-wideband nature of the signal provides for high resolution of the radar, whereas usage of multi-sub-carrier method of modulation allows for dynamic spectrum allocation. Robust multi-path performance of OFDM signals and heavy reliance of transceiver design on digital processors easily implemented in modern VLSI technology make a number of possible applications viable, e.g.: portable high-resolution indoor radar/movement monitoring system; through-the-wall/foliage synthetic aperture imaging radar with a capability of image transmission/broadcasting, etc. Our work is aimed to provide a proof-of-concept simulation scenario to explore numerous aspects of UWB-OFDM radar imaging through evaluating range and cross-range imaging performance of such a system with an eventual goal of software-defined radio (SDR) implementation. Stripmap SAR topology was chosen for modeling purposes. Range/cross-range profiles were obtained along with full 2-D images for multi-target in noise scenarios. Model set-up and results of UWB-OFDM radar imaging simulation study using Matlab/Simulink modeling are presented and discussed in this paper.

Garmatyuk, Dmitriy

2006-06-01

78

GMTI and IMINT data fusion for multiple target tracking and classification  

Microsoft Academic Search

In this paper, we propose a new approach to track multiple ground target with GMTI (Ground Moving Target Indicator) and IMINT (IMagery INtelligence) reports. This tracking algorithm takes into account road network information and is adapted to the out of sequence measurement problem. The scope of the paper is to fuse the attribute type information given by heterogeneous sensors with

Benjamin Pannetier; Jean Dezert

2009-01-01

79

Calibration of bistatic polarimetric radar systems  

Microsoft Academic Search

A calibration technique for laboratory type polarimetric, bistatic instrumentation radars is presented. It describes the errors induced by the standard radiation transfer approach (I-SRT) in a way similar to that for the monostatic case. A 12-term error correction and absolute polarimetric calibration is performed with two external reference targets. Only the polarimetric bistatic reference of the first target must be

Daniel Kaehny; Klaus Schmitt; Werner Wiesbeck

1992-01-01

80

47 CFR 15.509 - Technical requirements for ground penetrating radars and wall imaging systems.  

Code of Federal Regulations, 2010 CFR

...requirements for ground penetrating radars and wall imaging systems...requirements for ground penetrating radars and wall imaging systems. (a) The UWB bandwidth of an imaging system...paragraph (d) of this section, UWB transmitters operating...

2010-10-01

81

47 CFR 15.509 - Technical requirements for ground penetrating radars and wall imaging systems.  

Code of Federal Regulations, 2010 CFR

...requirements for ground penetrating radars and wall imaging systems...requirements for ground penetrating radars and wall imaging systems. (a) The UWB bandwidth of an imaging system...paragraph (d) of this section, UWB transmitters operating...

2009-10-01

82

Development of land based radar polarimeter processor system  

NASA Astrophysics Data System (ADS)

The processing subsystem of a land based radar polarimeter was designed and constructed. This subsystem is labeled the remote data acquisition and distribution system (RDADS). The radar polarimeter, an experimental remote sensor, incorporates the RDADS to control all operations of the sensor. The RDADS uses industrial standard components including an 8-bit microprocessor based single board computer, analog input/output boards, a dynamic random access memory board, and power supplis. A high-speed digital electronics board was specially designed and constructed to control range-gating for the radar. A complete system of software programs was developed to operate the RDADS. The software uses a powerful real time, multi-tasking, executive package as an operating system. The hardware and software used in the RDADS are detailed. Future system improvements are recommended.

Kronke, C. W.; Blanchard, A. J.

1983-09-01

83

Quantitative data quality metrics for 3D laser radar systems  

NASA Astrophysics Data System (ADS)

Several quantitative data quality metrics for three dimensional (3D) laser radar systems are presented, namely: X-Y contrast transfer function, Z noise, Z resolution, X-Y edge & line spread functions, 3D point spread function and data voids. These metrics are calculated from both raw and/or processed point cloud data, providing different information regarding the performance of 3D imaging laser radar systems and the perceptual quality attributes of 3D datasets. The discussion is presented within the context of 3D imaging laser radar systems employing arrays of Geiger-mode Avalanche Photodiode (GmAPD) detectors, but the metrics may generally be applied to linear mode systems as well. An example for the role of these metrics in comparison of noise removal algorithms is also provided.

Stevens, Jeffrey R.; Lopez, Norman A.; Burton, Robin R.

2011-05-01

84

An HF Radar Based Integrated Maritime Surveillance System  

Microsoft Academic Search

Abstract: - In this paper, the physics behind an Integrated Maritime Surveillance system based on HF surface wave,radars (HFSWR) is discussed. Due to the complexity of the system a comprehensive understanding of electromagnetic wave (EM) propagation, antenna design, EM wave – ocean wave interaction, target reflectivity, interference sources and their stochastic behaviours is essential. The success of the system depends,on

Levent Sevgi; Anthony M. Ponsford

85

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

Microsoft Academic Search

The CUTLASS Finland radar, which com- prises an integral part of the SuperDARN system of HF coherent radars, provides near continuous observations of high-latitude plasma irregularities within a field-of- view which extends over some four million square kilometres. Within the Finland radar field-of-view lie both the EISCAT mainland and EISCAT Svalbard incoherent scatter radar facilities. Since the CUTLASS Finland radar

J. A. Davies; M. Lester; S. E. Milan; T. K. Yeoman

1999-01-01

86

Fiber optic coherent laser radar 3d vision system  

SciTech Connect

Recent advances in fiber optic component technology and digital processing components have enabled the development of a new 3D vision system based upon a fiber optic FMCW coherent laser radar. The approach includes a compact scanner with no moving parts capable of randomly addressing all pixels. The system maintains the immunity to lighting and surface shading conditions which is characteristic of coherent laser radar. The random pixel addressability allows concentration of scanning and processing on the active areas of a scene, as is done by the human eye-brain system.

Sebastian, R.L.; Clark, R.B.; Simonson, D.L. [and others

1994-12-31

87

Data acquisition system for Doppler radar vital-sign monitor.  

PubMed

Automatic gain control (AGC) units increase the dynamic range of a system to compensate for the limited dynamic range of analog to digital converters. This problem is compounded in wireless systems in which large changes in signal strength are effects of a changing environment. These issues are evident in the direct-conversion Doppler radar vital-sign monitor. Utilizing microwave radar signals reflecting off a human subject, a two-channel quadrature receiver can detect periodic movement resulting from cardio-pulmonary activity. The quadrature signal is analyzed using an arctangent demodulation that extracts vital phase information. A data acquisition (DAQ) system is proposed to deal with issues inherent in arctangent demodulation of a quadrature radar signal. PMID:18002443

Vergara, Alexander M; Lubecke, Victor M

2007-01-01

88

Adaptive space-time processing for interference suppression in phased array radar systems. II. Tracking radar  

Microsoft Academic Search

For pt.I see ibid., p.B8\\/1-B8\\/8 (2000). In phased array radar systems, a tracking process is performed using an electronic scan of a predetermined sector to provide a continuous information about the detected targets. In practice, the presence of interference (noise, clutter, and jamming signals) either prevent or deceive the tracking circuit to follow the real targets, and consequently, the tracking

H. H. M. Ghouz; F. I. A. Elghany; M. M. Qutb

2000-01-01

89

78 FR 19063 - Airworthiness Approval for Aircraft Forward-Looking Windshear and Turbulence Radar Systems  

Federal Register 2010, 2011, 2012, 2013

...Aircraft Forward-Looking Windshear and Turbulence Radar Systems AGENCY: Federal Aviation...aircraft forward-looking windshear and turbulence radar systems. The planned advisory...Group and the generic issue papers on turbulence detection to publish an advisory...

2013-03-28

90

Radar data assimilation for the simulation of mesoscale convective systems  

NASA Astrophysics Data System (ADS)

A heavy rainfall case related to Mesoscale Convective Systems (MCSs) over the Korean Peninsula was selected to investigate the impact of radar data assimilation on a heavy rainfall forecast. The Weather Research and Forecasting (WRF) three-dimensional variational (3DVAR) data assimilation system with tuning of the length scale of the background error covariance and observation error parameters was used to assimilate radar radial velocity and reflectivity data. The radar data used in the assimilation experiments were preprocessed using quality-control procedures and interpolated/thinned into Cartesian coordinates by the SPRINT/CEDRIC packages. Sensitivity experiments were carried out in order to determine the optimal values of the assimilation window length and the update frequency used for the rapid update cycle and incremental analysis update experiments. The assimilation of radar data has a positive influence on the heavy rainfall forecast. Quantitative features of the heavy rainfall case, such as the maximum rainfall amount and Root Mean Squared Differences (RMSDs) of zonal/meridional wind components, were improved by tuning of the length scale and observation error parameters. Qualitative features of the case, such as the maximum rainfall position and time series of hourly rainfall, were enhanced by an incremental analysis update technique. The positive effects of the radar data assimilation and the tuning of the length scale and observation error parameters were clearly shown by the 3DVAR increment.

Lee, Jo-Han; Lee, Hyun-Ha; Choi, Yonghan; Kim, Hyung-Woo; Lee, Dong-Kyou

2010-09-01

91

Protecting digital avionics systems from high power radar interference  

Microsoft Academic Search

Protecting digital systems from high power radar interference is primarily a task of preventing unwanted RF energy from getting into sensitive semiconductor components. The degree of shielding or filtering required depends upon the RF field values, the sensitivity of the semiconductor components to the RF energy, and the degree of interference or upset that can be tolerated in the system.

J. M. Roe

1977-01-01

92

DC offset reduction in phase diversity heterodyne doppler radar system  

Microsoft Academic Search

Continuous wave Doppler radar systems have been used for non-contact detection of human cardiopulmonary activity, and these functions can be used in diverse applications including health care, emergency, military, or security. For reliable and robust sensing, several schemes are applied to overcome deleterious system sensitivity associated with the periodic phase relationship between the received signal and local oscillator. In previous

Byung-Kwon Park; Dragan Samardzija; Victor M. Lubecke; Olga Boric-Lubecke; Tod Sizer

2007-01-01

93

Real-time adaptive radiometric correction for imaging radars systems  

NASA Astrophysics Data System (ADS)

A new solution is given of a real time radiometric image correction that also minimizes the quantization and saturation noise introduced by the process of analog-to-digital conversion of raw data of coherent and noncoherent imaging radar systems. The implementation of this procedure was successfully performed with the experimental SAR System (E-SAR) of the DLR.

Moreira, Joao R.; Poetzsch, Winfried

1989-10-01

94

78. View of radar systems technical publication library, transmitter building ...  

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

78. View of radar systems technical publication library, transmitter building no. 102, second floor. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

95

A millimeter-wave Cloud Profiling Radar System (CPRS)  

Microsoft Academic Search

The Microwave Remote Sensing Laboratory (MIRSL) at the University of Massachusetts has developed a unique dual-frequency polarimetric Cloud Profiling Radar System (CPRS). This system, whose development was funded by the Atmospheric Radiation Measurement (ARM) program, was intended to fill the need for remote sensors capable of remotely sensing cloud properties such as partical phase and size. CPRS polarimetric and dual-wavelength

S. M. Sekelsky; R. E. McIntosh

1994-01-01

96

On the Perfomance of Air Traffic Control Radar Beacon System  

Microsoft Academic Search

The sidelobe suppression and improved sidelobe suppression mode performance of terminal and enroute air traffic control radar beacon systems using the existing antenna and a typical improved antenna in the presence of perfectly dielectric flat ground are investigated theoretically. Necessary analytical expressions for various quantities characterizing the system performance have been derived. A general purpose computer program has been developed

Dipak Sengupta; Jovan Zatkalik

1976-01-01

97

System aspects of a low-cost coherent radar system with AESA antenna for maritime applications  

Microsoft Academic Search

Motivated by new performance requirements and technological progress Fraunhofer FHR has initiated the development of a low-cost coherent radar system demonstrator with AESA antenna for maritime applications. The proposed system is expected to exhibit smaller operational costs and better performance than conventional shipborne navigation radar systems. In this contribution an overview of the total system was given. Emphasis was placed

T. Bertuchi; M. Pamiesi; C. Lo?cker; P. Knott; H. Erkens; R. Wunderlich; S. Heinen

2010-01-01

98

Affordable, Real-Time, 3-D Avian Radar Networks For Centralized North American Bird Advisory Systems  

Microsoft Academic Search

Affordable avian radar systems are being developed for Natural Resource Management (NRM) and bird aircraft strike hazard (BASH) applications. Recently (1), the authors have reported on mobile avian radar system requirements and on a system design that is state-of-the-art. In the present paper, the system design of a single avian radar is expanded in scope to address 3-D avian radar

Peter Weber; B. Eng; M. Eng; Tim J. Nohara; Sidney Gauthreaux Jr

99

Prototype fiber optic system to remote TRACALS radars  

NASA Astrophysics Data System (ADS)

The transmission mediums currently used to remote Traffic Control and Landing Systems (TRACALS) radars are coaxial cables (coax) or a microwave link. Problems and limitations are encountered in using either medium. Coax is susceptible to electromagnetic interference, moisture, ground loops, lightning and electromagnetic pulse (EMP). Microwave links are susceptible to electromagnetic interference, propagation anomaly, electronic warfare and EMP. The coax remoting system used on the Precision Approach Radar (PAR) is highly susceptible to interference from power lines for runway lights and has a maximum remoting distance of 12,000 ft. Remoting TRACALS radars via a fiber optic system appeared to be a complete solution to the problems listed above. The 1842 EEG conducted a feasiblity study of the use of a FO system to remote a PAR (AFCC Technical Report, 1842 EEG/EEIT-TR-80-9). The AN/FPN-62 radar was used in conducting the study. The study demonstrated that an analog FO system can handle the combined analog/digital, time and frequency multiplexed signals which are passed over the AN/FPN-62 remoting system. A FO system appeared to be a desirable alternative and warranted a full investigation.

Radcliff, J. A.; Becker, K. E.

1982-06-01

100

Multifunctional millimeter-wave radar system for helicopter safety  

NASA Astrophysics Data System (ADS)

A multi-featured sensor solution has been developed that enhances the operational safety and functionality of small airborne platforms, representing an invaluable stride toward enabling higher-risk, tactical missions. This paper demonstrates results from a recently developed multi-functional sensor system that integrates a high performance millimeter-wave radar front end, an evidence grid-based integration processing scheme, and the incorporation into a 3D Synthetic Vision System (SVS) display. The front end architecture consists of a w-band real-beam scanning radar that generates a high resolution real-time radar map and operates with an adaptable antenna architecture currently configured with an interferometric capability for target height estimation. The raw sensor data is further processed within an evidence grid-based integration functionality that results in high-resolution maps in the region surrounding the platform. Lastly, the accumulated radar results are displayed in a fully rendered 3D SVS environment integrated with local database information to provide the best representation of the surrounding environment. The integrated system concept will be discussed and initial results from an experimental flight test of this developmental system will be presented. Specifically, the forward-looking operation of the system demonstrates the system's ability to produce high precision terrain mapping with obstacle detection and avoidance capability, showcasing the system's versatility in a true operational environment.

Goshi, Darren S.; Case, Timothy J.; McKitterick, John B.; Bui, Long Q.

2012-05-01

101

Basic System Concept for Integrating a 2D and a 3D Radar and Designs of Automatic Detection Systems.  

National Technical Information Service (NTIS)

A basic system concept of digitally integrating any 2D radar and any frequency-scan 3D radar was applied to the SPS-12 and SPS-39 radars, giving a composite coverage with nulls greatly decreased from those of the SPS-12 pattern. Both radars operate in a s...

G. V. Trunk B. H. Cantrell D. F. Queen

1974-01-01

102

System Applications of Microwaves to Radars: Modern Trends  

Microsoft Academic Search

The impact of the microwave technology on the performance of modern radar systems is outlined, together with the resulting design implications. The most advanced characteristics of the main microwave components are pointed out and proper use of combined technologies in complex subsystems as electronically scanned antennas, is shown to be essential in order to reach advanced performance and capabilities for

Raffaele Esposito

1987-01-01

103

Prototype fiber optic system to remote TRACALS radars  

Microsoft Academic Search

The transmission mediums currently used to remote Traffic Control and Landing Systems (TRACALS) radars are coaxial cables (coax) or a microwave link. Problems and limitations are encountered in using either medium. Coax is susceptible to electromagnetic interference, moisture, ground loops, lightning and electromagnetic pulse (EMP). Microwave links are susceptible to electromagnetic interference, propagation anomaly, electronic warfare and EMP. The coax

J. A. Radcliff; K. E. Becker

1982-01-01

104

Feasibility study of a microwave radar system for agricultural inspection  

SciTech Connect

The feasibility of an impulse radar system for agricultural inspection is investigated. This system would be able to quickly determine the quality of foodstuffs that are passed through the system. A prototype was designed at the Lawrence Livermore National Laboratory and this report discusses it`s evaluation. A variety of apples were used to test the system and preliminary data suggests that this technology holds promise for successful application on a large scale in food processing plants.

Okelo-Odongo, S.

1994-10-03

105

Doppler radar sensor positioning in a fall detection system.  

PubMed

Falling is a common health problem for more than a third of the United States population over 65. We are currently developing a Doppler radar based fall detection system that already has showed promising results. In this paper, we study the sensor positioning in the environment with respect to the subject. We investigate three sensor positions, floor, wall and ceiling of the room, in two experimental configurations. Within each system configuration, subjects performed falls towards or across the radar sensors. We collected 90 falls and 341 non falls for the first configuration and 126 falls and 817 non falls for the second one. Radar signature classification was performed using a SVM classifier. Fall detection performance was evaluated using the area under the ROC curves (AUCs) for each sensor deployment. We found that a fall is more likely to be detected if the subject is falling toward or away from the sensor and a ceiling Doppler radar is more reliable for fall detection than a wall mounted one. PMID:23365879

Liu, Liang; Popescu, Mihail; Ho, K C; Skubic, Marjorie; Rantz, Marilyn

2012-01-01

106

Time-domain compact range measurement system for radar targets  

NASA Astrophysics Data System (ADS)

Building scheme and developing procedures of a measuring system for radar targets were introduced. Theory of time domain measurement was studied. Sampling Oscilloscope was used for measurement in compact range for the first time. Structure of the system and operating flow for the measurement were presented. Programs for controlling of the oscilloscope and turntable as well as data processing were developed, based on which entire measuring software of UWB compact range was achieved, including measurement of radar cross-section, polarization scattering matrix and microwave imaging. FFT and windowing technique as well as digital filtering were used to transform data from time-domain to frequency-domain and to improve the accuracy. Idea of virtual instrument was used in the program. Finally, some data measured and processed by the system were presented, which proves performance of the system.

Li, Gaosheng; Liu, Jibin; Liu, Peiguo; He, Jianguo

2011-10-01

107

Radio Aurora Explorer: Mission science and radar system  

NASA Astrophysics Data System (ADS)

The Radio Aurora Explorer (RAX) satellite is the first of several satellites funded under the NSF CubeSat-based Space Weather and Atmospheric Research Program. RAX is a ground-to-space bi-static radar remote sensing experiment designed to measure and understand the causes of meter-scale ionospheric irregularities. Also known as field-aligned irregularities (FAI), such non-thermal, coherent fluctuations of electron density occur in response to strong ionospheric flows or plasma density gradients during geomagnetic disturbances and are considered a space weather concern due to disruption to communication and navigation signals. The RAX CubeSat was launched in November 2010 and conducted a single experiment in coordination with the Poker Flat Incoherent Scatter Radar. Due to geophysical inactivity, e.g., lack of strong ionospheric electric fields and low ionospheric densities, no FAI were expected or observed. However, the radar receiver payload operation was successfully demonstrated, including the capability to sense signals as low as -110 dBm, the capability of transmitter-receiver synchronization and accurate ranging, processing of 1.2 GB of raw radar data on board in less than 1 hour, and the downlink of the science results within three-four passes. Analysis of the payload data shows that the noise level is sufficiently low. Although the interference level is a concern, it does not appear to significantly limit the measurements. Toward the end of December 2010, the solar power system gradually degraded and the mission terminated in early February 2011 after prolonged loss of contact with the satellite. Meanwhile, RAX II was launched in October 2011 to a polar orbit. This paper describes the RAX science and radar system and presents the results from the first experiment conducted.

Bahcivan, H.; Cutler, J. W.

2012-04-01

108

Three-Dimensional Imaging via Wideband MIMO Radar System  

Microsoft Academic Search

The 3-D inverse synthetic aperture radar imaging fast maneuvering targets is an active research area in the past decades. Planar antenna arrays are used to avoid the motion compensation algorithms but at the cost of increasing the hardware complexity. In this letter, to reduce the hardware complexity of the imaging system, a wideband multiple-input multiple-output system with two perpendicular linear

Guang Qing Duan; Dang Wei Wang; Xiao Yan Ma; Yi Su

2010-01-01

109

The Interval Modulation System For The Ultra-Wideband Vehicular Radar  

Microsoft Academic Search

Since the (FCC) Federal Communications Commission approved the (UWB) Ultra-wideband application into the civilian areas, research on the UWB vehicular radar aroused much interest. Using of vehicular sensing radar is an important method in preventing the occurrence of traffic accidents, and enhance the radar's performance can directly improve the effectiveness of the collision prevention system. Ultra-wideband is a relatively new

Xi Li; Zhiguo Wang; Yuanchun Fei; Dechun Guo

2006-01-01

110

Radar Cross Section Measurements of the Improved BQM-34A Collocated Augmentation Scoring System.  

National Technical Information Service (NTIS)

Data were acquired to define the I-band radar cross section and glint characteristics of the Improved BQM-34A CAS (target drone equipped with Collocated active radar Augmentation Scoring System). Monostatic and bistatic radar measurements were made on a f...

M. R. Smith

1978-01-01

111

A borehole radar system for South African gold and platinum mines  

Microsoft Academic Search

Borehole radar is an electromagnetic tool that can be applied to assist in the delineation of orebody geometry, ideally using routinely drilled cover and exploration boreholes. Successful trials of borehole radar for delineating reef horizons on South African gold and platinum mines have led to the development of a borehole radar system specifically designed for routine application in those enyironments.

Declan Vogt

2006-01-01

112

System-on-chip based Doppler radar occupancy sensor.  

PubMed

System-on-Chip (SoC) based Doppler radar occupancy sensor is developed through non contact detection of respiratory signals. The radio was developed using off the shelf low power RF CC2530 SoC chip by Texas Instruments. In order to save power, the transmitter sends signal intermittently at 2.405 GHz. Reflected pulses are demodulated, and the baseband signals are processed to recover periodic motion. The system was tested both with mechanical target and a human subject. In both cases Doppler radar detected periodic motion closely matched the actual motion, and it has been shown that an SoC based system can be used for subject detection. PMID:22254705

Yavari, Ehsan; Song, Chenyan; Lubecke, Victor; Boric-Lubecke, Olga

2011-01-01

113

The Processing of Altimetric Data (PAD) System for Cassini RADAR.  

NASA Astrophysics Data System (ADS)

This paper describes the Cassini RADAR PAD System, which has been designed and developed in the frame of Cassini-Huygens, a joint NASA/ESA/ASI mission to Saturn and its moons, responding to ASI request to process the data collected by the Cassini RADAR Altimeter. The PAD System contains the HW and SW operational tools necessary to evaluate the instrument performances, to process the raw data, and finally to visualize digital maps of Titan's surface by using the data acquired by the Cassini RADAR during close flybys of Titan. Titan, the largest moon of Saturn, is the only satellite in the solar system to host an appreciable atmosphere. The smoggy haze that completely envelops the satellite is composed mostly of nitrogen, aerosols and a variety of hydrocarbons, produced as atmospheric methane is destroyed by sunlight. To date, many scientists have speculated that the surface could probably contain solid, liquid and muddy material creating features such as lakes, seas, or rivers, and it should be mostly coated with sticky brown organic condensate rained down from the atmosphere. The PAD System, actually installed and operated at Alcatel Alenia Space Italia premises in Rome will be able to grant the provision of altimetric data for at least the nominal 4-years mission lifetime (i.e. 45 envisaged flybys of Titan).

Alberti, G.; Catallo, C.; Festa, L.; Flamini, E.; Orosei, R.; Papa, C.; Picardi, G.; Seu, R.; Spataro, F.; Vingione, G.

114

The impact of technological evolution on radar systems  

NASA Astrophysics Data System (ADS)

It is possible to use surface acoustic wave devices having continually improving performance due to the possibilities of finer and finer engraving. In addition, the general evolution of silicon semiconductors has allowed the realization of efficient analog to digital encoding as well as the economic realization of dense digital memories which gave rise to digital solutions. Pulse compression was described before the end of WW II, but it was not truly developed in radar systems before the end of the 60's, due to the use of surface acoustic devices or of digital devices. Finally, radar systems will continue to benefit from new materials such as composites using carbon fiber, piezoelectric polymers, glass fibers, conductive polymers, PtSi, diamond thin films, compounds such as gallium arsenide, and possibly other materials such as high-temperature supraconducting materials.

Carpentier, Michel H.

115

Novel integrated system calibration method for impulse ground penetrating radar  

NASA Astrophysics Data System (ADS)

This paper proposes a new method of integrated system calibration that uses the transmitting and receiving signals from the impulse ground penetrating radar itself. In order to eliminate the influence from each subsystem or part including antenna, transmitter, receiver, signal processing circuits and transmission cables, two new calibration parameters that are different from the conventional S-parameters are introduced. The characteristic and influence of all parts in the transmitting and receiving channels are incorporated into the calibration equation through the new parameters. The calibration results of the radar detection data show that the new integrated system calibration can improve the quality of the data greatly in many aspects. It removes direct coupled waves, suppresses wave distortion and tail oscillation, and improves the quality of waveform and signal-clutter-ratios. It also compresses the pulse width and enhances resolution.

Huang, Chunlin; Lu, Min; Zhu, Shiping

2011-11-01

116

Hygienic standardization of electromagnetic fields of radar systems  

NASA Astrophysics Data System (ADS)

Radars operating in the frequency band above 300 MHz may represent a danger for the population. The applicability of the energy principle of standardization to regulation of electromagnetic fields in populated points is analyzed. Equations are derived for hygienic standardization of exposure to electromagnetic fields based on medical and biological research and the corresponding values of energy flux density created by weather systems. The equations confirm the correctness of the principle of differentiating electronic devices according to classes on the basis of the fields which they radiate. The energy approach to standardization in the millimeter decimeter waveband is generally incorrect, but can be useful in establishing the variation of maximum permissible level as a function of time for individual types of radars.

Dumanskiy, Y. D.; Ivanov, D. S.; Nikitina, N. G.; Tomashevskaya, L. A.

1985-03-01

117

Principals of Radar and Meteorological Radar Devices.  

National Technical Information Service (NTIS)

Three meteorological radar units are described: the Malachite radiotheodolite with rangefinder attachment, the Meteorite radar station, and the MRL radar station. The principles of operation of these systems are given along with circuit descriptions and e...

O. G. Korol R. D. Chernyak

1973-01-01

118

Space-fed lens phased array for advanced radar systems  

NASA Astrophysics Data System (ADS)

The completely overlapped subarray concept for use in airborne or spaceborne radar systems is discussed. The capability of this system for generating antenna patterns with low sidelobes, scannable over large angles and potentially usable with wideband signals is shown. It is shown how both mainlobe and sidelobe nulling can be achieved by processing applied at the output ports of a multibeam feed system. It is also shown how this concept lends itself to cancellation of clutter by means of the displace-phase-center technique.

Chan, K. K.; Faubert, D.; Martin, R.; Turner, R.

119

Signal Analysis Van - A radar system data acquisition and processing tool  

NASA Astrophysics Data System (ADS)

An advance in radar technology achieved in the U.S. Army Missile Command for the analysis of radar performance and the design of radar signal processors is discussed. It is noted that the concept is based on a Radar Technology Signal Analysis Van (SAV) which contains special purpose electronics and computer equipment. The unique system provides the first capability to analyze the exact performance of radars in the field by recording full-bandwidth, full-dynamic range video returns in a live environment. During optimization of radar designs, the real-world data are played into signal processor emulations in the laboratory. It is pointed out that these techniques for analyzing and designing high performance radars had not previously been possible.

Cash, T. W.; Owen, L. B.

120

Autonomous millimeter-wave radar guidance systems  

Microsoft Academic Search

Hercules Defense Electronics Systems, Incorporated has applied millimeter wave technologies to a variety of guidance and control problems. This presentation documents the development and integration of an autonomous millimeter wave seeker to the AGM-65(D) (Maverick) air- to-ground missile. The resulting system was successfully demonstrated to search a large area for potential targets, prioritize detections, and guide the missile to the

Kevin S. Schweiker

1992-01-01

121

The Space-Based Calibration of Optical Systems and HF Radars Using the Precision Expandable Radar Calibration Sphere  

NASA Astrophysics Data System (ADS)

The Precision Expandable Radar Calibration Sphere (PERCS) is designed to provide a relatively simple target in space that can be used to determine the operational parameters of both ground Imaging systems and HF radars. PERCS is a 10 meter diameter wire frame in low earth orbit with corner cube reflectors placed at 60 or more vertices around the wire frame. For optical system calibration, PERCS will provide precisely spaced reflection points on the vertices of a large polyhedron. For HF radar calibration, PERCS will have a known radar cross section that is independent of observation direction within 0.5 dB. Laser satellite tracking will provide accurate orbital position and velocity of PERCS. The PERCS will orbit at 600 km altitude in a high inclination. Because of the wire frame construction, atmospheric drag will be low and the large spherical structure is expected to be available for more than five years. The PERCS satellite will be launched in a stowed configuration that has less than one meter in diameter. After launch, the PERCS will expand to a diameter of almost 10 meters. Hoberman Sphere technology will be used to produce a stable wire-frame to act as a radar scatter target. The sphere is based on a truncated icosahedron commonly known in chemistry as a "buckyball". The 60 vertices (V60) are hinged to be joined to 90 rigid segments. Each segment is hinged so that the PERCS can be folded into a compact package for launch.

Bernhardt, P.

122

The Advanced Simulation System for MMW Imaging Radar Seeker onboard Air-to-air Missile  

Microsoft Academic Search

Millimeter wave (MMW) radar is booming in application to target seeker onboard the air-to-air missile (AAM), which has the capability to obtain all-weather radar images for auto target recognition (ATR) and intelligent active homing guidance. An advanced simulation system for MMW imaging radar seekers of AAM was introduced in this paper. The system is composed of parameter initialization module, signal

Sun Yumeng; C. Jie; G. Caihong; S. Bing; Z. Yinqing

2006-01-01

123

Integrated radar-camera security system: experimental results  

NASA Astrophysics Data System (ADS)

The nature of the recent military conflicts and terrorist attacks along with the necessity to protect bases, convoys and patrols have made a serious impact on the development of more effective security systems. Current widely-used perimeter protection systems with zone sensors will soon be replaced with multi-sensor systems. Multi-sensor systems can utilize day/night cameras, IR uncooled thermal cameras, and millimeter-wave radars which detect radiation reflected from targets. Ranges of detection, recognition and identification for all targets depend on the parameters of the sensors used and of the observed scene itself. In this paper two essential issues connected with multispectral systems are described. We will focus on describing the autonomous method of the system regarding object detection, tracking, identification, localization and alarm notifications. We will also present the possibility of configuring the system as a stationary, mobile or portable device as in our experimental results.

Zyczkowski, M.; Palka, N.; Trzcinski, T.; Dulski, R.; Kastek, M.; Trzaskawka, P.

2011-05-01

124

Resolution of a phase ambiguity in a calibration procedure for polarimetric radar systems  

SciTech Connect

In response to the remote sensing communities' interest in radar polarimetry, considerable effort has recently been devoted to the development of calibration techniques for polarimetric radar systems. A cross-pol/co-pol phase ambiguity in a previously published calibration procedure for polarimetric radar systems is discussed. The original procedure is modified to resolve the ambiguity while still retaining insensitivity to calibration target orientation. The modified form is then generalized and applied to an ultrawideband radar system for which the ambiguity in the original procedure is particularly evident.

Sletten, M.A. (Naval Research Lab., Washington, DC (United States). Radar Div.)

1994-01-01

125

The Goldstone solar system radar: A science instrument for planetary research  

NASA Astrophysics Data System (ADS)

The Goldstone Solar System Radar (GSSR) station at NASA's Deep Space Communications Complex in California's Mojave Desert is described. A short chronological account of the GSSR's technical development and scientific discoveries is given. This is followed by a basic discussion of how information is derived from the radar echo and how the raw information can be used to increase understanding of the solar system. A moderately detailed description of the radar system is given, and the engineering performance of the radar is discussed. The operating characteristics of the Arcibo Observatory in Puerto Rico are briefly described and compared with those of the GSSR. Planned and in-process improvements to the existing radar, as well as the performance of a hypothetical 128-m diameter antenna radar station, are described. A comprehensive bibliography of referred scientific and engineering articles presenting results that depended on data gathered by the instrument is provided.

Dvorsky, J. D.; Renzetti, N. A.; Fulton, D. E.

1992-12-01

126

Terrain and Weather Effects on Doppler Radar Navigation Systems.  

National Technical Information Service (NTIS)

The effects of terrain and weather conditions upon airborne doppler radar performance are described. The extensive flight test data compiled by military and commercial users of the doppler radar and theoretical knowledge of propagation and scattering theo...

E. Laskowski

1964-01-01

127

FPGA-based Radar Signal Processing for Automotive Driver Assistance System  

Microsoft Academic Search

Safety and comfort applications are addressed using driver assistance (DA) systems like adaptive cruise control (ACC) system using long range radar (LRR) or short range radar (SRR) or both. Novel waveforms and functionalities applied to next generation DA multi-sensor systems and their corresponding complex algorithms require advanced digital hardware supporting high computation rate and severe real-time constraints. In this paper,

Jean Saad; Amer Baghdadi; Frantz Bodereau

2009-01-01

128

Ocean radar for the planning and operational phase of off-shore renewable energy systems  

Microsoft Academic Search

The WERA system (WavE RAdar) is a shore based remote sensing system to monitor ocean surface currents, waves and wind direction. This long range, high resolution monitoring system is based on short radio wave radar technology. The vertically polarized electromagnetic wave is coupled to the conductive ocean surface and follows the curvature of the earth. This over the horizon oceanographic

Thomas Helzel; Oswaldo Lopez; Lucy Wyatt

2011-01-01

129

A Portable Low-Power Harmonic Radar System and Conformal Tag for Insect Tracking  

Technology Transfer Automated Retrieval System (TEKTRAN)

Harmonic radar systems provide an effective modality for tracking insect behavior. This paper presents a harmonic radar system proposed to track the migration of the Emerald Ash Borer (EAB). The system offers a unique combination of portability, low power and small tag design. It is comprised of a...

130

Fade: a vehicle detection and tracking system featuring monocular color vision and radar data fusion  

Microsoft Academic Search

This paper presents Fade, a vehicle detection and tracking system featuring monocular color vision and radar data fusion. Its main originality resides in its low-level fusion system. At each step and for each target, the fusion system fuses the results of four different image processing algorithms and radar information by automatically combining 12 different features and generating many possible target

B. Steux; C. Laurgeau; L. Salesse; D. Wautier

2002-01-01

131

Radar data processing using a distributed computational system  

NASA Astrophysics Data System (ADS)

This research specifies and validates a new concurrent decomposition scheme, called Confined Space Search Decomposition (CSSD), to exploit parallelism of Radar Data Processing algorithms using a Distributed Computational System. To formalize the specification, we propose and apply an object-oriented methodology called Decomposition Cost Evaluation Model (DCEM). To reduce the penalties of load imbalance, we propose a distributed dynamic load balance heuristic called Object Reincarnation (OR). To validate the research, we first compare our decomposition with an identified alternative using the proposed DCEM model and then develop a theoretical prediction of selected parameters. We also develop a simulation to check the Object Reincarnation Concept.

Mota, Gilberto F.

1992-06-01

132

Duell Mellan Brusradar i UCAV och Radarvarnare i Martkfordon (Duel Between Noise Radar for UCAV and Radar Warning Systems on Ground Vehicles).  

National Technical Information Service (NTIS)

In the project SUPREM, duel between noise radar for UCAV and radar warning systems on ground vehicles is investigated. Multi-sensor systems where SAR is a vital sensor, can be designed for UCAV-systems with respect to for instance low probability of inter...

M. Karlsson B. Andersson J. Svedin

2006-01-01

133

A Ka-Band Low Power Doppler Radar System for Remote Detection of Cardiopulmonary Motion  

Microsoft Academic Search

A low power Ka-band Doppler radar that can detect human heartbeat and respiration signals is demonstrated. This radar system achieves better than 80% detection accuracy at the distance of 2-m with 16-muW transmitted power. Indirect-conversion receiver architecture is chosen to reduce the DC offset and 1\\/f noise that can degrade signal-to-noise ratio and detection accuracy. In addition, the radar has

Yanming Xiao; Jenshan Lin; Olga Boric-Lubecke; Victor M. Lubecke

2005-01-01

134

A ka-band low power Doppler radar system for remote detection of cardiopulmonary motion.  

PubMed

A low power Ka-band Doppler radar that can detect human heartbeat and respiration signals is demonstrated. This radar system achieves better than 80% detection accuracy at the distance of 2-m with 16-?W transmitted power. Indirect-conversion receiver architecture is chosen to reduce the DC offset and 1/f noise that can degrade signal-to-noise ratio and detection accuracy. In addition, the radar has also demonstrated the capability of detecting acoustic signals. PMID:17281925

Xiao, Yanming; Lin, Jenshan; Boric-Lubecke, Olga; Lubecke, Victor

2005-01-01

135

Radar cross section measurements of the improved BQM-34A collocated augmentation scoring system  

Microsoft Academic Search

Data were acquired to define the I-band radar cross section and glint characteristics of the Improved BQM-34A CAS (target drone equipped with Collocated active radar Augmentation Scoring System). Monostatic and bistatic radar measurements were made on a flight worthy BQM-34A. This report provides a summary of the measurement conditions and reproductions of test plots obtained. Also included are reproductions of

M. R. Smith

1978-01-01

136

Fiber optic coherent laser radar 3D vision system  

SciTech Connect

This CLVS will provide a substantial advance in high speed computer vision performance to support robotic Environmental Management (EM) operations. This 3D system employs a compact fiber optic based scanner and operator at a 128 x 128 pixel frame at one frame per second with a range resolution of 1 mm over its 1.5 meter working range. Using acousto-optic deflectors, the scanner is completely randomly addressable. This can provide live 3D monitoring for situations where it is necessary to update once per second. This can be used for decontamination and decommissioning operations in which robotic systems are altering the scene such as in waste removal, surface scarafacing, or equipment disassembly and removal. The fiber- optic coherent laser radar based system is immune to variations in lighting, color, or surface shading, which have plagued the reliability of existing 3D vision systems, while providing substantially superior range resolution.

Clark, R.B.; Gallman, P.G.; Slotwinski, A.R. [Coleman Research Corp., Springfield, VA (United States); Wagner, K.; Weaver, S.; Xu, Jieping [Colorado Univ., Boulder, CO (United States)

1996-12-31

137

Radar system on a large autonomous vehicle for personnel avoidance  

NASA Astrophysics Data System (ADS)

The US Army Research Laboratory designed, developed and tested a novel switched beam radar system operating at 76 GHz for use in a large autonomous vehicle to detect and identify roadway obstructions including slowly-moving personnel. This paper discusses the performance requirements for the system to operate in an early collision avoidance mode to a range of 150 meters and at speeds of over 20 m/s. We report the measured capabilities of the system to operate in these modes under various conditions, such as rural and urban environments, and on various terrains, such as asphalt and grass. Finally, we discuss the range-Doppler map processing capabilities that were developed to correct for platform motion and identify roadway vehicles and personnel moving at 1 m/s or more along the path of the system.

Silvious, Jerry; Wellman, Ron; Tahmoush, Dave; Clark, John

2010-04-01

138

Goldstone Solar System Radar Observatory: Earth-Based Planetary Mission Support and Unique Science Results  

Microsoft Academic Search

The Goldstone Solar System Radar (GSSR) facility is the only fully steerable radar in the world for high-resolution ranging and imaging of planetary and small-body targets. These observations provide information on surface characteristics, orbits, rotations, and polar ices for a wide variety of solar system objects. The resulting data are used not just for scientific studies of these objects, but

Martin A. Slade; Lance A. M. Benner; Arnold Silva

2011-01-01

139

FPGA controlled DDS based frequency sweep generation of high linearity for FMCW radar systems  

Microsoft Academic Search

Two significant requirements in an FMCW radar system are linearity and low phase noise. Especially in range detection applications the achievable accuracy directly depends on the linearity of the modulated radar signal. In general PLL based systems with digital generated reference signals are used to meet this requirement. In this paper an FPGA controlled DDS based signal generator for highly

Serdal Ayhan; Viet Vu-Duy; Philipp Pahl; Steffen Scherr; Michael Hubner; Jurgen Becker; Thomas Zwick

2012-01-01

140

A low cost K-Band safety warning radar receiver system  

Microsoft Academic Search

A low cost K-band safety warning radar receiver system has been developed to receive highway hazard-warning messages transmitted from a newly developed Safety Warning System. This paper describes a radar detection scheme, which includes down converter, FM detector, microprocessor, and analog control circuits, intended for the K-band transmitter

M. C. Tsai; C. Autio; M. Batten; M. Gagne; T. Kvenvold; C. Papadopoulos; B. Ricker; S. Sarkar; A. Perlowski

1996-01-01

141

Comparisons between Canadian prairie MF radars, FPI (green and OH lines) and UARS HRDI systems  

NASA Astrophysics Data System (ADS)

Detailed comparisons have been completed between the MF radars (MFR) in the Canadian prairies and three other systems: two ground-based Fabry-Perot interferometers (FPI) and the UARS high resolution Doppler imager (HRDI) system. The radars were at Sylvan Lake (52°N, 114

Meek, C. E.; Manson, A. H.; Burrage, M. D.; Garbe, G.; Cogger, L. L.

1997-09-01

142

Estimation of a Constant False Alarm Rate Processing Loss for a High- Resolution Maritime Radar System.  

National Technical Information Service (NTIS)

This report addresses a problem of estimation of a constant false alarm rate (CFAR) processing loss for a high-resolution maritime radar system on an example of a generic radar system Anti-Submarine Warfare mode and discusses approaches to modelling of th...

I. Antipov J. Baldwinson

2008-01-01

143

Medium-high correlated Weibull-distributed clutter reduction by neural networks in coherent radar systems  

Microsoft Academic Search

This paper presents a clutter reduction system when medium-high correlated Weibull-distributed clutter governs the environment of a coherent radar system. This proposal is based on the capabilities of learning of some artificial intelligence techniques, such as the neural networks. This capability of learning of the neural networks is used to learn some statistical characteristics of the radar environment. The results

R. Vicen-Bueno; M. Rosa-Zurera; M. P. Jarabo-Amores; D. Mata-Moya

2009-01-01

144

Throughwall imaging of the objects scanned by M-sequence UWB radar system  

Microsoft Academic Search

UWB radar system facilitates us to estimate positions and shapes of objects behind the wall. We have made real through the wall SAR measurements with bistatic M-sequence UWB radar system. A metal plate, an aquarium filled with water and a wooden cupboard inside the room with concrete wall have been scanned. The simple and fast algorithm for compensation of different

Michal AFTANAS; Egor ZAIKOV; M. Drutarovsky; J. Sachs

2008-01-01

145

Data Collection and Analysis Techniques for a Planned Experimental Harbor Advisory Radar (Har) System.  

National Technical Information Service (NTIS)

In their continuing efforts to improve navigational aids for the maritime community, the U. S. Coast Guard is establishing an experimental Harbor Advisory Radar (HAR) system at the port of San Francisco, California. The system consists of an X-Band radar ...

1969-01-01

146

The RADOT Code System to Calculate the Radar Return from a Forested Area.  

National Technical Information Service (NTIS)

RADOT (Radar on Trees) is a system of FORTRAN computer codes designed to predict the radar return from a canopy of vegetation. The system combines a realistic simulation of the geometry of the trees of a forest with simple approximations as to the physics...

M. O. Cohen E. S. Troubetzkoy

1979-01-01

147

RAPTOR: radar plus thermal observation and recognition system  

NASA Astrophysics Data System (ADS)

Typical targets to be detected in ground surveillance scenarios have two common properties that are physically distinct, motion and radiation. This applies to pedestrians, vehicles, trucks and light aircraft. Infrared sensors can be used for the detection of radiating bodies through the application of image processing techniques and Doppler radar is an excellent detector of radial body motion. RAPTOR is a system whose aim is to produce a ground surveillance device with higher detection performance and lower false and nuisance alarm rates than possible with either or both sensor types operating alone. RAPTOR combines two complementary sensors, an infrared imager and a pulsed Doppler radar, which automatically detect targets using different physical phenomena and then uses data fusion techniques to enhance the automatic target detection performance. The fusion process includes alignment, correlation, association, target data processing and multisensor management. RAPTOR uses the two sensors in parallel, bore sighted on a single rotational platform. Both sensors concurrently scan the spatial volume and the individual target detection results, 'soft-targets,' are combined using data fusion algorithms to generate a confirmed set of targets, 'hard-targets.'

Charlesworth, Peter D.

1995-09-01

148

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

Code of Federal Regulations, 2013 CFR

...2013-01-01 false Doppler Radar and Inertial Navigation System (INS): Request...Appendix G to Part 121âDoppler Radar and Inertial Navigation System (INS): Request...for authority to use a Doppler Radar or Inertial Navigation System must submit a...

2013-01-01

149

Ground-based weather radar compatibility with digital radio-relay microwave systems  

NASA Astrophysics Data System (ADS)

The potential for ground-based weather radar (meteorological radar) interference to digital microwave systems in the common carrier bands of 3700 to 4200 MHz and 5925 to 6425 MHz is examined. Reported cases of interference to microwave common carrier systems from ground-based weather radar systems have increased due to the trend towards digital modulations. Because of this interference, the National Telecommunications and Information Administration, the Federal Communications Commission and the National Spectrum Managers Association formed an informal working group to investigate and document the potential problems. The existing and planned spectrum uses by ground-based weather radars and digital microwave systems are addressed as well as regulations and policy pertaining to their electromagnetic compatibility. Methods to mitigate the interference in both the radar transmitter and microwave receiver are also provided.

Gawthrop, P. E.; Patrick, G. M.

1990-03-01

150

Doppler Radar  

Microsoft Academic Search

This paper contains a discussion of the principle of operation of cw doppler search radar systems and an analysis of their performance capabilities, with particular emphasis on the elimination of fixed targets. A comparison of these systems and MTI pulse radar systems is made.

E. J. Barlow

1949-01-01

151

Design of the radar real-time simulation system joined with hardware  

Microsoft Academic Search

To improve the real-time property for typical Pulse Doppler radar simulation, an idea of signal-level simulation using hardware was proposed. The system framework and information flow was studied, then a host method of moving target echo simulation was given. Most of all, radar signal processing was realized by FPGA, which includes digital quadrature detection with IF sampling, pulse compression based

Yong Chen; Xinyu Yao; Wenbo Wu; Xiaofeng Tang

2011-01-01

152

77 FR 48097 - Operation of Radar Systems in the 76-77 GHz Band  

Federal Register 2010, 2011, 2012, 2013

...spectrum known as ``millimeter wave'' spectrum. The frequencies...are commonly called millimeter wave frequencies because of their...unlicensed use by vehicular radar technologies and by fixed radar systems limited...front of, beside, or behind a car to improve the driver's...

2012-08-13

153

MARSnet: Mission-aware Autonomous Radar Sensor Network for Future Combat Systems.  

National Technical Information Service (NTIS)

During the period of 1/1/2008 - 6/30/2008, we performed the following studies on radar sensor network: (1) favor weak fuzzy logic systems: theory and applications to threat assessment in disparate sensor networks; (2) cognitive radar sensor networks: a hu...

Q. Liang

2008-01-01

154

Precipitation Observed in Oklahoma Mesoscale Convective Systems with a Polarimetric Radar  

Microsoft Academic Search

In this paper, the fields of three radar polarimetric variables-differential reflectivity ZDR, specific differential phase KDP, and correlation coefficient between horizontally (H) and vertically (V) polarized echoes hv-along with radar reflectivity Zh, are examined within two Oklahoma mesoscale convective systems (MCSs). The analysis of the whole set of polarimetric variables reveals at least three types of hydrometeor populations in the

A. V. Ryzhkov; D. S. Zrni

1994-01-01

155

A generic video and radar data fusion system for improved target selection  

Microsoft Academic Search

This paper presents an automotive video and radar data fusion framework that can be used as a preliminary stage of an automatic cruise control or collision mitigation by braking system. The fusion framework finds the optimal assignment of radar and camera target reports and provides improved state estimates for the fused targets. A sophisticated critical path selection is presented and

Dennis Muller; Josef Pauli; Mirko Meuter; Lali Ghosh; Stefan Muller-Schneiders

2011-01-01

156

An experimental 210 GHz radar system for 3D stand-off detection  

Microsoft Academic Search

A 210 GHz radar system for studies of person scanning at stand-off distances is presented. The radar uses a mechanically scanned RX front-end based on an antenna-integrated MMIC. The TX part is based on an HBV quintupler. Image data formation is made using the FMCW and SAR principles.

J. Svedin; S. Rudner; G. Thordarsson; N. Wadefalk; S. E. Gunnarsson; M. Abbasi; H. Zirath; J. Stake; T. Bryllert; J. Vukusic

2010-01-01

157

Small battery operated unattended radar sensor for security systems  

NASA Astrophysics Data System (ADS)

McQ has developed, tested, and is supplying to Unattended Ground Sensor (UGS) customers a new radar sensor. This radar sensor is designed for short range target detection and classification. The design emphasis was to have low power consumption, totally automated operation, a very high probability of detection coupled with a very low false alarm rate, be able to locate and track targets, and have a price compatible with the UGS market. The radar sensor complements traditional UGS sensors by providing solutions for scenarios that are difficult for UGS. The design of this radar sensor and the testing are presented in this paper.

Plummer, Thomas J.; Brady, Stephen; Raines, Robert

2013-06-01

158

Features of ultrawideband radar projecting  

Microsoft Academic Search

The article presents a new approach to ultrawideband (UWB) radar projecting. Some advantages of such radars are shown in comparison with common narrowband radars and some features of UWB radars are considered, which do not allow the use of traditional methods. New methods of UWB radar characteristics calculation and radar systems projecting are suggested. It discusses the range equation, passive

Igor Immoreev; B. Vovshin

1995-01-01

159

Systems Analysis and Additional Instrumentation for Modified 'Porcupine' C-Band Pulse Doppler Radar.  

National Technical Information Service (NTIS)

Section one of the report contains the results of systems analysis of the Porcupine radar system and of several data processing techniques. Section two contains documentation for data processing instrumentation implemented during the period of the report....

D. S. Berg E. E. Cox H. L. Groginsky J. Misho J. C. Raymond

1966-01-01

160

Radar Seeker Based Autonomous Navigation Update System Using Topography Feature Matching Techniques.  

National Technical Information Service (NTIS)

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...

H. D. Lerche F. Tumbreagel

1992-01-01

161

Direct path interference suppression in bistatic system: DTV based radar  

Microsoft Academic Search

Over the past 20 years, bistatic radar has been an emerging technology. One of the major problems in continuous wave bistatic radar is the direct path interference (DPI). The reflected signal from the target is received at the background of this interference; the target would be buried under the sidelobes of the DPI in the receiver circuit. The conventional solution

Rajesh Saini; M. Cherniakov; V. Lenive

2003-01-01

162

Very Wide Frequency Band Pulsed/IF Radar System.  

National Technical Information Service (NTIS)

A pulsed/IF radar for compact range radar cross section measurements has been developed which converts RF returns to a fixed IF, so that amplification and grating may be performed at one frequency. This permits the use of components which have optimal per...

D. N. Jones W. D. Burnside

1988-01-01

163

Autonomous system for initializing synthetic aperture radar seeker acquisition  

Microsoft Academic Search

A method is described of guiding a missile having an active seeker including a synthetic aperture radar operating in a squint mode to a target aircraft having a search radar therein the maximum range of active seeker acquisition being within said missile's maneuver capability to intercept, and the maximum range of active seeker acquisition not exceeding the capability of the

1993-01-01

164

Comparative study of tracking performance in an airborne tracking radar simulator using global positioning system versus monopulse radar techniques  

NASA Astrophysics Data System (ADS)

This paper attempts to address the tracking accuracy between the two systems under test. A monopulse radar model was developed to theoretically calculate the would-be measured angle and angle variances. Essentially, measurements of the target's angle, angle variances, range and range rate from the monopulse radar receiver of an aircraft are assessed against the tracking performance of an airborne simulator which uses the time, space, position information (TSPI) delivered from a global positioning system (GPS) system. The accuracy of measurements from a monopulse radar primarily depends on the signal-to-noise ratio (SNR), distance from target in this case, but information received from the GPS Space Vehicle would be virtually jamfree, and independent of distance. Tracking using GPS data however requires good data link between airborne participants. The simulation fidelity becomes an issue when the target is in close range track. The monopulse random slope error and target glint become significant, while the resolution from GPS data links remains the same.

Nguyen, Joseph H.; Holley, William D.; Gagnon, Garry

1993-10-01

165

Shuttle Radar Topography Mission (SRTM) flight system design and operations overview  

Microsoft Academic Search

This paper provides an overview of the Shuttle Radar Topography Mission SRTM), with emphasis on flight system implementation and mission operations from systems engineering perspective. Successfully flown in February, 2000, the SRTM's primary payload consists of several subsystems to form the first spaceborne dual-frequency (C- band and X-band) fixed baseline interferometric synthetic aperture radar (InSAR0 system, with the mission objective

Yuhsyen Shen; Scott J. Shaffer; Rolando L. Jordan

2000-01-01

166

Development of an improved radar augmentation system for the BQM-34A target drone, volume 1  

Microsoft Academic Search

Data were acquired to define the radar cross section characteristics of the BQM-34A target drone equipped with an active radar augmentation system. The program resulted in an improved augmentation system for the BQM-34A target drone. Development of the improved I-Band augmentation system required the location and testing of a number of different antenna combinations and locations. After the determination of

C. J. Bishoff

1976-01-01

167

Ionospheric and auroral clutter models for HF surface wave and over-the-horizon radar systems  

NASA Astrophysics Data System (ADS)

The detection performance of high frequency surface wave radar (HFSWR) and high frequency over-the-horizon radar (OTHR) systems is heavily influenced by the presence of radar clutter. In HFSWR systems, the clutter has its origins in vertical-incidence ionospheric reflections, whereas in OTHR systems, the origin is Bragg backscatter from plasma structures in the auroral zone. This paper models the spreading of the radar clutter signal in the Doppler and angle-of-arrival domains that arises from forward-scattering effects as the radar pulse propagates through regions of ionospheric plasma irregularities. The models use a geometric optics approach to determine the power spectrum of the radar signal phase. This power spectrum is then used to simulate three-dimensional space-time-range radar data cubes. The accuracy of the models is tested by comparing the simulated data to measured data cubes. As an application, the data are then used to evaluate the performance of the newly developed fast fully adaptive (FFA) space-time adaptive processing (STAP) scheme to improve the extraction of target echoes from a clutter background.

Ravan, M.; Riddolls, R. J.; Adve, R. S.

2012-01-01

168

HERMES: a high-speed radar imaging system for inspection of bridge decks.  

National Technical Information Service (NTIS)

Corrosion of rebar in concrete bridges causes subsurface cracks and is a major cause of structural degradation that necessitates repair or replacement. A ground-penetrating radar imaging system has been designed and developed that performs the nondestruct...

S. G. Azevedo

1996-01-01

169

7. CLOSEUP FRONT VIEW OF RADAR SYSTEM EMITTER/ANTENNA (TYPICAL DEVICE ...  

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

7. CLOSE-UP FRONT VIEW OF RADAR SYSTEM EMITTER/ANTENNA (TYPICAL DEVICE PHOTOGRAPH). - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

170

Performance Assessment of a Radar-Based Foreign Object Debris Detection System.  

National Technical Information Service (NTIS)

In 2004, the Federal Aviation Administration (FAA) Airport Technology Research and Development Team initiated a research program to conduct a performance assessment of the QinetiQ, Ltd. Tarsier Foreign Object Debris (FOD) detection radar system. The purpo...

E. Woodworth E. E. Herricks J. Patterson S. Majumdar

2011-01-01

171

Transmitter and Receiver Antenna Gain Analysis for Laser Radar and Communication Systems.  

National Technical Information Service (NTIS)

A comprehensive and fairly self-contained study of centrally obscured optical transmitting and receiving antennas is presented and is intended for use by the laser radar and communication systems designer. The material is presented in a format which allow...

B. J. Klein J. J. Degnan

1973-01-01

172

AN\\/SPY3: the navy's next-generation force protection radar system  

Microsoft Academic Search

This article provides a description of the functionality and design of the navy's first ship-board active array multifunction radar, the AN\\/SPY-3. The AN\\/SPY-3 radar principally provides detection, tracking, and illumination of low-flying antiship cruise missiles (ASCMs) as an integral part of advanced antiair warfare (AAW) systems including DD 21 and CVN 77. In order to provide the appropriate system context

W. J. Fontana; K. H. Krueger

2003-01-01

173

Minimum operational performance standards for airborne radar approach and beacon systems for helicopters  

NASA Astrophysics Data System (ADS)

Minimum operational performance standards are presented for airborne radar approach systems based on operational requirements of helicopters in the approach, missed approach, and departure modes, particularly during instrument flight rules, instrument meteorological conditions and at night. Included are those system characteristics pertinent to the airborne equipment and to the ground-based radar beacon for those operations requiring such equipment. Operational goals were established based on future requirements and technology, rather than merely repeating current state-of-the-art criteria.

1980-11-01

174

System concept for the next-generation spaceborne precipitation radars  

Microsoft Academic Search

The 13.8-GHz Precipitation Radar (PR) aboard the US\\/Japan Tropical Rainfall Measuring Mission (TRMM) satellite is the first rain profiling radar ever launched into space. A TRMM follow-on mission, called the Global Precipitation Mission (GPM), is currently planned to extend and to improve the TRMM acquired rainfall data set. One of the key components of the GPM science instrumentation is an

E. Im; S. L. Durden; G. Sadowy; A. Berkun; J. Huang; M. Lou; B. C. Lopez; Y. Rahmat-Samii; S. Rengarajan

2000-01-01

175

Mitigation of radar interference with WiMAX systems  

Microsoft Academic Search

In this paper, the effect of radar-induced electromagnetic interference (EMI) on a WiMAX base station receiver is investigated through the use of MATLAB models. The three types of radar pulses investigated include: a short, wideband, chirp pulse; a long, narrowband, chirp pulse; and a long, sinusoidal pulse. The benefits of superimposing these pulses in the guard interval and\\/or guard band

Lawrence Cohen; Erica Daly; Jean DeGraaf; Kim Scheff

2010-01-01

176

Active noise suppression in phased array radars using an antijamming optical beam-forming system  

NASA Astrophysics Data System (ADS)

We present the continuing development of an anti-jamming optical beamformer (AJOB) at Rome Laboratory's Photonics Division. Developments include live radar tests and new system designs. The purpose of the AJOB system is the cancellation of multipath jamming interference in advanced surveillance radars. AJOB is a multichannel adaptive optical system which performs cancellation of multiple wideband (10 MHz) interference sources in the presence of multipath. The live radar test consisted of using a downconverted 80 MHz received signal from the main and subarrays of a C-band radar to correlate jamming signals produced by stationary jammers. The correlation parameters fed a tapped delay line filter to form an estimate of the noise, which was subtracted from the main antenna signal. For the scenarios tested, the long integration time for the correlation data provided accurate estimates of the jammer delays, and therefore single-step convergence was achieved.

Turbyfill, Michael E.; Rudd, Mark A.; Mack, J. L.; Walge, Ernst K.; Lutsko, Jeffrey M.; Andrews, Harold G.; Berinato, Robert J.; Zari, Michael C.; Budge, Mervin C.; Williams, Kyle W.

1995-06-01

177

The development of two-dimensional target images from ultrawideband radar systems  

NASA Astrophysics Data System (ADS)

The development of ultrawideband radar systems has led to the production of echo waveforms with high resolution in range. The Valley Forge Research Center has studied the problem of extending this capability by adding the angular dimension to produce a 2-D image of the radar target. The system currently in use combines adaptive beamforming (ABF) phased array processing with a UWB radar to provide high resolution images of a variety of target configurations. The images were produced using the dominant scatterer ABF algorithm developed at VFRC over the past two decades. The tests were conducted at three frequencies (S, X and Ku bands) in order to allow diversity techniques to enhance the image quality. The formation of a monostatic synthetic aperture array with a 1 GHz bandwidth radar set allows the system to achieve a resolution of 15 cm. This permits fine detail to be observed on images of targets such as cars and trucks. Several examples are presented.

Carlson, Donald L.; Steinberg, Bernard D.

1992-05-01

178

System concept and analysis of an Artificial Ionospheric Mirror (AIM) radar  

NASA Astrophysics Data System (ADS)

Recognition of performance limitations associated with traditional skywave over-the-horizon (OTH) high frequency (HF) radars has led a number of investigators to propose the creation of an Artificial Ionospheric Mirror (AIM) in the upper atmosphere, in order to reflect ground-based radar signals for OTH surveillance. The AIM is produced by beaming sufficient electromagnetic power to the lower ionosphere (around 70 km) to enhance the in situ ionization level to 10(exp 7) to 10(exp 8) electrons/cu cm, thereby providing an ionized layer capable of reflecting radar frequencies of 30 to 90 MHz. This paper presents a baseline AIM system concept and an associated performance evaluation, based upon the relevant ionization and propagation physics and in the context of air surveillance for the cruise missile threat. Results of the subject study indicate that a system using this concept would both complement and enhance the performance of the existing skywave OTH radars.

Short, Robert D.; Stewart, Clayton V.; Wallace, Tom; Lallement, Pierre; Koert, Peter

1990-08-01

179

MultiSensor Microwave Soil Moisture Remote Sensing: NASA's Combined Radar\\/Radiometer (ComRAD) System  

Microsoft Academic Search

This paper describes the development of a ground-based radar\\/radiometer system called ComRAD. The system under development is an outgrowth of a network analyzer-based L, C, and X band polarimetric radar system developed jointly by NASA\\/GSFC and the George Washington University. The system is mounted on a 19-m hydraulic boom truck and has provided reliable calibrated radar data in soil moisture

Peggy E. O'Neill; Roger H. Lang; Mehmet Kurum; Cuneyt Utku; K. R. Carver

2006-01-01

180

Gray Wolf S-3B demonstration of podded Norden AN\\/APG76 radar system  

Microsoft Academic Search

In 1993, the US Navy's COMSEACONTROLWINGLANT (Cecil Field, FL.) agreed to support a proof of concept (POC) demonstration with Norden's AN\\/APG-76 multimode radar system, carried in a cargo pod aboard an S-3 Viking aircraft. Norden has modified an S-3 pod, including installation of an F-4 radome, to carry the radar. This modified pod has successfully flown in a non-operational demonstration.

J. Thoma; S. Dick

1994-01-01

181

Programmable AND-CFAR signal detector design and its FPGA prototyping for FMCW radar systems  

Microsoft Academic Search

This paper presents the digital signal processor design for constant-false-alarm-rate (CFAR) signal detection in a frequencymodulated-continuous-waveform (FMCW) radar system. It is capable of identifying the beat signal from the spectrum so as to calculate the distance between the radar and the ground. The proposed CFAR signal detection design is an enhancement of the basic AND-CFAR architecture, which combines the algorithms

Cheng-Ru Hong; Yin-Tsung Hwang; Wei-Chieh Hsu; Chi-Ho Chang; Jui-Chi Huang; Ho-En Liao

2011-01-01

182

Analysis of Radar System Performance and Interference in an Air Traffic Control Environment  

Microsoft Academic Search

In the Air Traffic Control (ATC) environment Secondary Surveillance Radar (SSR), Aircraft Dependent Surveillance Broadcast (ADS-B), Airborne Collision Avoidance Systems (ACAS) and military identification systems (IFF) are using the same frequencies. Technical or operational changes in one system have impact on self-interference within the same system as well as on the operation of the other systems. This paper gives an

Roland Mallwitz; Albert Walberer

2006-01-01

183

Standoff concealed weapon detection using a 350 GHz radar imaging system  

SciTech Connect

The Pacific Northwest National Laboratory is currently developing a 350 GHz, active, wideband, three-dimensional, radar imaging system to evaluate the feasibility of active sub-mm imaging for standoff concealed weapon detection. The prototype radar imaging system is based on a wideband, heterodyne, frequency-multiplier-based transceiver system coupled to a quasi-optical focusing system and high-speed rotating conical scanner. The wideband operation of this system provides accurate ranging information, and the images obtained are fully three-dimensional. Recent improvements to the system include increased imaging speed using improved balancing techniques, wider bandwidth, and image display techniques.

Sheen, David M.; Hall, Thomas E.; Severtsen, Ronald H.; McMakin, Douglas L.; Hatchell, Brian K.; Valdez, Patrick LJ

2010-04-01

184

High-resolution imaging using a wideband MIMO radar system with two distributed arrays.  

PubMed

Imaging a fast maneuvering target has been an active research area in past decades. Usually, an array antenna with multiple elements is implemented to avoid the motion compensations involved in the inverse synthetic aperture radar (ISAR) imaging. Nevertheless, there is a price dilemma due to the high level of hardware complexity compared to complex algorithm implemented in the ISAR imaging system with only one antenna. In this paper, a wideband multiple-input multiple-output (MIMO) radar system with two distributed arrays is proposed to reduce the hardware complexity of the system. Furthermore, the system model, the equivalent array production method and the imaging procedure are presented. As compared with the classical real aperture radar (RAR) imaging system, there is a very important contribution in our method that the lower hardware complexity can be involved in the imaging system since many additive virtual array elements can be obtained. Numerical simulations are provided for testing our system and imaging method. PMID:20051345

Wang, Dang-wei; Ma, Xiao-yan; Chen, A-Lei; Su, Yi

2009-12-31

185

Microprocessor-Based Data-Acquisition System for a Borehole Radar  

Microsoft Academic Search

An efficient microprocessor-based system has been implemented that permits real-time acquisition, stacking, and digital recording of data generated by a borehole radar system. Although the system digitizes, stacks, and records independently of a computer, it is interfaced to a desktop computer for program control over system parameters such as sampling interval, number of samples, number of times the data are

Jerry Bradley; David Wright

1987-01-01

186

Spaceborne Radar Study.  

National Technical Information Service (NTIS)

Three air-defense radar surveillance systems are described, each consisting of active radar satellites capable of operating at earth-synchronous orbit altitude with associated ground control stations. Systems 1 (three satellites) provides a detection fenc...

J. Greene R. Kaplan G. J. McNiff P. Nosal J. L. Schultz

1974-01-01

187

RAPTOR: radar plus thermal observation and recognition system  

Microsoft Academic Search

Typical targets to be detected in ground surveillance scenarios have two common properties that are physically distinct, motion and radiation. This applies to pedestrians, vehicles, trucks and light aircraft. Infrared sensors can be used for the detection of radiating bodies through the application of image processing techniques and Doppler radar is an excellent detector of radial body motion. RAPTOR is

Peter D. Charlesworth

1995-01-01

188

Extension of Synthetic Aperture Radar Seeker Systems to Circular Trajectories  

Microsoft Academic Search

Standard Synthetic Aperture Radars (SAR) have provided high resolution ground maps for the last 20 years. However, they require a horizontal linear trajectory which is a serious limitation in many applications. This dissertation is concerned with the extension of SAR to nonlinear trajectories. The limitations of the standard SAR are due to range walk and doppler bias. These problems are

Jong Gyu Kim

1989-01-01

189

Design considerations and technology assessment of phased-array antenna systems with RF MEMS for automotive radar applications  

Microsoft Academic Search

Planar array antennas are attractive for use in future automotive radar systems due to their flexibility in design and control of radar beams. The complexity and cost of a radar front-end phased array can be decreased by applying a beam-steering\\/switching concept, which reduces the number of parallel RF and baseband signal paths. RF-microelectromechanical systems (MEMS) subsystems are employed because of

Joerg Schoebel; Thomas Buck; Mathias Reimann; M. Ulm; M. Schneider; A. Jourdain; G. J. Carchon; H. A. C. Tilmans

2005-01-01

190

Ultrawideband radar echoes of land mine targets measured at oblique incidence using a 250-kW impulse radar system  

NASA Astrophysics Data System (ADS)

United Nations Peacekeeping forces around the world need to transport food, personnel and medical supplies through disputed regions were land mines are in active use as road blocks and terror weapons. A method of fast, effective land mine detection is needed to combat this threat to road transport. The technique must operate from a vehicle travelling at a reasonable velocity and give warning far enough ahead for the vehicle to stop in time to avoid the land mine. There is particular interest in detecting low- metallic content land mines. One possible solutionis the use of ultra-wide-band (UWB) radar. The Australian Defence Department is investigating the feasibility of using UWB radar for land mine detection from a vehicle. A 3 GHz UWB system has been used to collect target response from a series of inert land mines and mine-like objects placed on the ground and buried in the ground. The targets measured were a subset of those in the target set described in Wong et al. with the addition of inert land mines corresponding to some of the surrogate targets in this set. The results are encouraging for the detection of metallic land mines and the larger non-metallic land mines. Smaller low-metallic- content anti-personnel land mines are less likely to be detected.

Chant, Ian J.; Staines, Geoff

1997-07-01

191

Geometrical and signal processing aspects using a bistatic hitchhiking radar system  

Microsoft Academic Search

Bistatic hitchhiking radar system concepts have been object for extensive research both for military and civilian applications. Hitchhiking systems are in principle easy to construct and can be used without introducing any interference, or being seen by a possible enemy. This paper addresses how to handle the geometry such systems are faced together with using proper signal analysis strategies for

O. Overrein; Karl E. Olsen; S. Johnsrud; P. K. Sornes; T. Johnsen; J. Navarro; V. Sahajpal; R. O. Stemland

2005-01-01

192

Fusion of over-the-horizon radar and automatic identification systems for overall maritime picture  

Microsoft Academic Search

Over-the-horizon (OTH) radar and automatic identification system (AIS) are commonly used in the surveillance of maritime areas. This paper presents a method, which includes tracking and association algorithms, for fusing the information from these two types of systems into an overall maritime picture. Data to be fused consists of asynchronous track estimates from the OTH system and measurements obtained from

Daniel Danu; Abhijit Sinha; Thiagalingam Kirubarajan; Mohammad Farooq; Dan Brookes

2007-01-01

193

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

Microsoft Academic Search

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

H. D. Lerche; F. Tumbreagel

1992-01-01

194

Multiple-scattering in radar systems: A review  

Microsoft Academic Search

Although extensively studied within the lidar community, the multiple scattering phenomenon has always been considered a rare curiosity by radar meteorologists. Up to few years ago its appearance has only been associated with two- or three-body-scattering features (e.g. hail flares and mirror images) involving highly reflective surfaces.Recent atmospheric research aimed at better understanding of the water cycle and the role

Alessandro Battaglia; Simone Tanelli; Satoru Kobayashi; Dusan Zrnic; Robin J. Hogan; Clemens Simmer

2010-01-01

195

Design and Implementation of Ground Peneration Radar System using Coded Sequences and Improved Target Detection using Golay Codes  

Microsoft Academic Search

Ground penetration radar (GPR) is one of the non-destructive and non-intrusive data collecting technologies used in geophysical measurements. A GPR system operating at carrier frequency 500 MHz and a bandwidth of 250 MHz was designed and developed. The major problem in most of the existing Ground Penetration Radar systems is masking of the weaker returns by the strong sidelobes. This

Ana Vazquez Alejos; Dawood Muhammad; H. U. R. Mohammed

2008-01-01

196

An Analysis of 2D Target Positioning Accuracy for M-sequence UWB Radar System under Ideal Conditions  

Microsoft Academic Search

This paper describes analysis of target positioning accuracy for ultra wideband (UWB) maximum length binary sequence (M-sequence) radar system under ideal conditions in two dimensional space. In this case, it is shown that the target position estimation error is cased by quantization of time of arrival (TOA) measured by the radar system. The appropriate statistical quantities are suggested for describing

Michal AFTANAS; J. Rovnakova; M. Riskova; D. Kocur; M. Drutarovsky

2007-01-01

197

Modeling and performance of HF/OTH radar target classification systems  

NASA Astrophysics Data System (ADS)

The effects of a class of multipath propagation channels on the performance of a radar target classification system are considered. A Rician frequency-selective fading channel model is used to characterize the effects of the multipath propagation medium and evaluate the performances of radar target classification systems. The performances of classification algorithms that use relative amplitude, relative phase, and absolute amplitude measurements as features are investigated. Performance estimates of the various classification algorithms for interesting sets of channel parameters are obtained by means of Monte Carlo simulations.

Strausberger, Donald J.; Chamberlain, Neil F.; Garber, Frederick D.; Walton, Eric K.

198

Instrument-Based Noncontact Doppler Radar Vital Sign Detection System Using Heterodyne Digital Quadrature Demodulation Architecture  

Microsoft Academic Search

In this paper, we present a fast solution to build a Doppler radar system for noncontact vital sign detection (VSD) using instruments that are generally equipped in radio-frequency and communication laboratories. This paper demonstrates the feasibility of conducting research on VSD in ordinary radio-frequency laboratories. The system is designed with a heterodyne digital quadrature demodulation architecture that helps mitigate quadrature

Changzhan Gu; Changzhi Li; Jenshan Lin; Jiang Long; Jiangtao Huangfu; Lixin Ran

2010-01-01

199

Multiple electron beam helix TWT for the active phased array radar system  

Microsoft Academic Search

In order to apply the traveling wave tubes (TWTs) in the active phased array radar system, new mini-TWT, i.e., multiple electron beam helix TWT (MBTWT) is studied. It is made by putting 3 helixes and electron beams into one metal tube and one PPM focus system. They have common electron gun and collector. The electron gun has a common heater

Ming Hui Liu; Fu Jiang Liao; Xiaohan Sun; Wenxuan Qian; Mingfang Chen

2011-01-01

200

A Two-Frequency CW Radar System for Short-Range Distances Measurements  

Microsoft Academic Search

This paper discusses a new approach to measure distances between objects using two frequency Continuous waveforms and based on a K-band Doppler technology. The system's operation is performed using two-frequency radar to obtain expeditiously and highly accurate measurements for stationary and moving objects. Experiments have been conducted and a mathematical presentation of the system's model has been formulated along with

Takashi Araki; Tomoyuki Nagase; Makoto Araki; Hisao Ono

2008-01-01

201

Coherent uplink arraying techniques for next generation space communications and planetary radar systems  

Microsoft Academic Search

For several years, NASA has been pursuing demonstrations and development of coherent uplink arraying techniques for the next generation space communications and planetary radar systems. In addition radio science experiments would benefit with a 1000 times increase in signal to noise over current systems. I shall describe the three methods of uplink arraying NASA has pursued, all successful, and share

B. J. Geldzahler

2011-01-01

202

Space Shuttle thermal protection system inspection by 3D imaging laser radar  

Microsoft Academic Search

NASA has developed a sensor suite to inspect the Space Shuttle Thermal Protection System while the Shuttle is flying in orbit. When the Space Shuttle returns to flight, it will carry a 3D Imaging Laser Radar as part of the sensor suite to observe the Thermal Protection System and indicate any damages that may need to be repaired before return

James C. Lamoreux; James D. Siekierski; J. P. N. Carter

2004-01-01

203

Real-time procedures implemented within coastal HF radar system in the northern Adriatic  

Microsoft Academic Search

The paper overviews the performances of the HF radar network installed in the northern Adriatic Sea. The system architecture is designed to work in real-time and delayed modes, but the accent is given on the real-time data acquisition, processing, archiving and presenting on the web. Several minor and the major dropout of the system were reported in 2008, and the

I. Vilibic; V. Dadic; D. Ivankovic; S. Muslim; J. Sepic; H. Mihanovic

2009-01-01

204

Capability of patch antennas in a portable harmonic radar system to track insects  

Technology Transfer Automated Retrieval System (TEKTRAN)

Monitoring technologies are needed to track insects and gain a better understanding of their behavior, population, migration and movement. A portable microwave harmonic-radar tracking system that utilizes antenna miniaturization techniques was investigated to achieve this goal. The system mainly con...

205

A meteor echo detection and collection system for use on VHF radars  

Microsoft Academic Search

We have developed a meteor echo detection and collection system (MEDAC) that can be attached to many ST or MST radars operating in the VHF range. The system can be operated in parallel with the normal data collection of turbulent echoes. The use of the meteor echoes extends MST mesosphere observations into the night and extends ST capabilities into the

S. T. Wang; D. Tetenbaum; B. B. Balsley; R. L. Obert; S. K. Avery; J. P. Avery

1988-01-01

206

Measurement of parasite Doppler effect in radar systems using laser heterodyning techniques  

Microsoft Academic Search

The paper deals with development and realization of a heterodyne He-Ne laser Doppler system able to measure from distance the mechanical vibrations of a radar antenna. These vibrations, caused by wind and\\/or by proper system, could give false information concerning the velocity of a target. To measure the frequency and the amplitude of mechanical vibrations we used the optical heterodyne

Nicusor Iftimia; Mircea Mujat; Aurelian Stoica; Virgil Vasiliu; Ileana Iftimia

1996-01-01

207

Remote sensing of shelf sea currents using a high-frequency ocean surface current radar system  

NASA Astrophysics Data System (ADS)

In a deployment of an ocean surface current radar system made during May 1985, currents were measured in a region of sea to the northeast of Anglesey, Wales, and compared with data obtained from three current meters. The uppermost current meter was fixed at 5 m from the surface, in a water column of 40-m depth with tidal range of 9 m. In the east-west direction, close to the orientation of the major axis of the tidal ellipse, the radar and top current meter show good agreement to within an rms value of 0.16 m s-1, consistent with earlier comparative studies. For the weaker north-south components of the flow, however, differences between the radar results and those from the current meters are apparent. A larger-amplitude north-south signal is recorded by the radar. In terms of the M2 rotary (clockwise and anticlockwise) components of the flow, the radar data contain amplitude and phase anomalies with respect to a predicted surface behavior deduced from the current meter records and theory. In particular, anticlockwise phase at the surface is advanced considerably (by ? 20°). Further analysis shows that the flow field recorded by the radar has two components: the predicted tidal response, and an additional elliptical term of lower eccentricity than the main east-west tidal signal and with major axis directed close to north. Hourly synoptic maps of tidal circulation patterns derived from the radar show a smooth transition from near-westward flows on the ebb to near-eastward flows on the flood. The variation of north-south residual currents with height can be interpreted in terms of a "mean state" consistent with geostrophic shear and associated with the roughly east-west density gradient.

Matthews, J. P.; Simpson, J. H.; Brown, J.

1988-03-01

208

Aviation weather radar  

Microsoft Academic Search

The Federal Aviation Administration has established three ground-based weather radar programs. The terminal Doppler weather radar (TDWR) and weather system processor (WSP) provide wind shear detection capability for air traffic controllers in the terminal area. These systems also reduce weather related delays. The next generation weather radar (NEXRAD) is used by the FAA to improve safety and reduce weather related

D. H. Turnbull

1995-01-01

209

Indian MST radar 1. System description and sample vector wind measurements in ST mode  

NASA Astrophysics Data System (ADS)

An MST radar operating at 53 MHz with an average power aperture product of 7 × 108 W m2 has been established at Gadanki (13.5°N, 79.2°E), India. The radar development has been accomplished in two phases. In the first phase it was commissioned in ST mode using a partial system comprising one quarter (16 × 16)of the Yagi antenna array and 16 driver units of the transmitters providing an average power aperture product of 4.8 × 106 W m2. In this part we present the radar system description, including off-line data processing, and some sample high-resolution vector wind measurements made in ST mode operation.

Rao, P. B.; Jain, A. R.; Kishore, P.; Balamuralidhar, P.; Damle, S. H.; Viswanathan, G.

1995-07-01

210

Statistical evaluation of a radar rainfall system for sewer system management  

NASA Astrophysics Data System (ADS)

Urban areas are faced with mounting demands for managing waste and stormwater for a cleaner environment. Rainfall information is a critical component in efficient management of urban drainage systems. A major water quality impact affecting receiving waterbodies is the discharge of untreated waste and stormwater during precipitation, termed wet weather flow. Elimination or reduction of wet weather flow in metropolitan sewer districts is a major goal of environmental protection agencies and often requires considerable capital improvements. Design of these improvements requires accurate rainfall data in conjunction with monitored wastewater flow data. Characterizing the hydrologic/hydraulic performance of the sewer using distant rain gauges can cause oversizing and wasted expenditures. Advanced technology has improved our ability to measure accurately rainfall over large areas. Weather radar, when combined with rain gauge measurements, provides detailed information concerning rainfall intensities over specific watersheds. Knowing how much rain fell over contributing areas during specific periods aids in characterizing inflow and infiltration to sanitary and combined sewers, calibration of sewer system models, and in operation of predictive real-time control measures. Described herein is the design of a system for managing rainfall information for sewer system management, along with statistical analysis of 60 events from a large metropolitan sewer district. Analysis of the lower quartile rainfall events indicates that the expected average difference is 25.61%. Upper quartile rainfall events have an expected average difference of 17.25%. Rain gauge and radar accumulations are compared and evaluated in relation to specific needs of an urban application. Overall, the events analyzed agree to within ± 8% based on the median average difference between gauge and radar.

Vieux, B. E.; Vieux, J. E.

2005-09-01

211

Validation of the radiation pattern of the Middle Atmosphere Alomar Radar System (MAARSY)  

NASA Astrophysics Data System (ADS)

In 2009/2010 the Leibniz-Institute of Atmospheric Physics (IAP) installed a new powerful VHF radar on the island Andřya in Northern Norway (69.30° N, 16.04° E). The Middle Atmosphere Alomar Radar System (MAARSY) allows studies with high spatial and temporal resolution in the troposphere/lower stratosphere and in the mesosphere/lower thermosphere of the Arctic atmosphere. The monostatic radar is operated at 53.5 MHz with an active phased array antenna consisting of 433 Yagi antennas. Each individual antenna is connected to its own transceiver with independent phase control and a scalable power output of up to 2 kW, which implies high flexibility of beam forming and beam steering. During the design phase of MAARSY several model studies have been carried out in order to estimate the radiation pattern for various combinations of beam forming and steering. However, parameters like mutual coupling, active impedance and ground parameters have an impact on the radiation pattern, but can hardly be measured. Hence, experiments need to be designed to verify the model results. For this purpose, the radar has occasionally been used in passive mode, monitoring the noise power received from both distinct cosmic noise sources like e.g. Cassiopeia A and Cygnus A, and the diffuse cosmic background noise. The analysis of the collected dataset enables us to verify beam forming and steering attempts. These results document the current status of the radar during its development and provide valuable information for further improvement.

Renkwitz, T.; Singer, W.; Latteck, R.; Stober, G.; Rapp, M.

2012-09-01

212

Radar detection of NEA 33342 (1998 WT24) with Evpatoria => Medicina system at 6 cm  

NASA Astrophysics Data System (ADS)

We present the first radar detection of near-Earth asteroid 1998 WT24 that was performed with the bistatic system Evpatoria ? Medicina operating at 6 cm wavelength during WT24 close approaching to Earth at a distance of 0.0125 AU. Radar echo from WT24 was detected during both observational days on Dec. 16, 17, 2001. The maximum value of signal to noise level ratio was about 0.4 for filter, matched with echo bandwidth, which results in OC radar cross section of 0.02 km2. Doppler trend of spectrum center doesn't exceed 0.44 mHz/sec, the echo spectrum bandwidth varies from 6.2 to 6.7 Hz and the WT24's pole-on breadth is ~0.41 km, the estimation of radar albedo is ~0.1. Of most interest is the measurements result giving near-unity circular polarization ratio. Such combination of low radar albedo and near-unity circular polarization ratio may be interpreted as a property of comet-like surface.

Zaitsev, Alexander L.; di Martino, Mario; Konovalenko, Alexander A.; Montebugnoli, Stelio; Ignatov, Sergei P.; Kolyuka, Yuri F.; Nabatov, Alexander S.; Falkovich, Igor S.; Gavrik, Anatoly L.; Gavrik, Yuri A.; Bortolotti, Claudio; Cattani, Alessandro; Maccaferri, Andrea; Maccaferri, Giuseppe; Roma, Mauro; Delbo, Marco; Saba, Laura; Afanas'eva, Tatiana; Gridshina, Tatiana; Righini, Simona

2002-11-01

213

Identification of inner parameters in laser radar measuring system through system error analysis  

NASA Astrophysics Data System (ADS)

This paper concerns the study of error modeling and inner parameter identification of 3D laser radar measuring system (LRMS) equipped with 2D laser sensor and electric servo motor, for the potential application of on-site measurement of the heavy forging object with temperature as high as 1000°C Firstly the physical and geometric model of 3D laser radar measuring system is presented. Detail discussion about the deterministic error and random error of the measuring system is conducted. Consequently the discipline of the deterministic error and the variation laws of random errors are achieved by the nonlinear equations set through the coordinate transformation. Finally based on the above discuss the identification method of inner geometrical parameter of the measuring system is presented by using the local linearization for nonlinear equations with Tailor Series Expansion Formula and the Least Square Algorithm. Therefore its measuring accuracy has been improved significantly. The results show this calibration method is helpful to the similar application of other measuring systems.

Du, Zhengchun; Zhang, Shujie; Wei, Yongfei; Hong, Maisheng

2008-10-01

214

New experiments to validate the radiation pattern of the Middle Atmosphere Alomar Radar System (MAARSY)  

NASA Astrophysics Data System (ADS)

The Middle Atmosphere Alomar Radar System (MAARSY) is a monostatic radar with an active phased array antenna designed for studies of phenomena in the mesosphere and lower thermosphere. Its design in particular the flexible beam forming and steering capability makes it to a powerful instrument to perform observations with high angular and temporal resolution. The knowledge of the actual radiation pattern is crucial to configure and analyze experiments carried out with the radar. The simulated radiation pattern is evaluated by the observation of cosmic radio emissions which are compared to a Global Sky temperature Maps model consisting of the most recent, thorough and accurate radio astronomy surveys. Additionally to these passive receive-only experiments active two-way experiments are presented, which corroborate the findings of the passive experiments.

Renkwitz, T.; Stober, G.; Latteck, R.; Singer, W.; Rapp, M.

2013-07-01

215

GNSS-based passive radar sensing using hybrid-aperture system  

NASA Astrophysics Data System (ADS)

A hybrid-aperture radar system is being developed for passive, GNSS-based sensing and imaging missions. Different from previous work, the real aperture (RA) array has excellent cross-range resolution and electronic scanning capability, and synthetic aperture processing is applied for the dimension along the UAV/aircraft flight path. The hybrid aperture thus provides real-time, combined sensing capability and multiple functions. Multi-level signal synchronization and tracking is used to ensure the signal phase coherency and integrity. The advantages of covert radar sensing and reduced onboard computing complexity of this sensor are being demonstrated through experiments.

Silver, Randy; Zhang, Yan Rockee; Suarez, Hernan; Pan, Yu; Huang, Yih-Ru

2013-05-01

216

Addition of video to telemetry tracking system upgrades spatial data to radar quality  

NASA Astrophysics Data System (ADS)

A growing number of flight test operations require precision spatial position data in conjunction with telemetry data reception, in areas where no optical or radar support is available. Off-the-shelf technologies have accordingly been combined to upgrade the angle-output data accuracy of telemetry trackers to the level of precision radars. A TV boresight camera and video tracking-error detector, in conjunction with a microprocessor-based antenna control unit, are shown to furnish the means for automatic measurement and storage of all systematic bias errors inherent in a telemetry tracking system; the resulting error model is used to furnish real-time data correction for each error parameter.

Fournier, John; Sullivan, Arthur

217

EISCAT 3D - The Next Generation European Incoherent Scatter Radar System  

NASA Astrophysics Data System (ADS)

A major new research European infrastructure will be constructed in Northern Scandinavia, combining several very large phased-array transmitters/receivers with multiple receiver arrays. The new EISCAT 3D radar system has a design goal of ten times higher temporal and spatial resolution than the present radars, a volumetric radar imaging capability in an extended spatial area with simultaneous full-vector drift velocities, avoiding spatial and temporal ambiguities, having continuous operation modes, short baseline interferometry capability for imaging sub-beamwidth scales, real-time data access for applications and extensive data archiving facilities. Some arrays are very large, in the scale of 30 000 individual antenna elements. The receiver arrays will be located at 50-150 km distance from the illuminators, so that the total system will comprise in the order of 100 000 elements. These extremely large scale atmospheric and space environment radar arrays open up unprecedented science and technology application opportunities, well beyond the traditional ground-based ionospheric remote sensing role of the old incoherent scatter radars. EISCAT 3D was accepted on the European Roadmap for Research Infrastructures by the European Strategy Forum on Research Infrastructures in December 2008. The facility will be constructed as a modular concept by year 2015. The current status of the project is approaching the end of the first 4 MEUR design study, conducted during 2005-2009 by EISCAT Scientific Association, University of Tromsř, Luleĺ University of Technology, Swedish Institute of Space Physics, Rutherford Appleton Laboratory, and supported by EU FP6 funding. EISCAT Scientific Association operates currently three incoherent scatter radars in Northern Scandinavia on behalf of its associate members in Finland, China, Germany, Japan, Norway, Sweden and United Kingdom, as well as currently supporting partners in France and Russia.

Turunen, E.

2009-04-01

218

An autonomous, non-cooperative, wide-area traffic monitoring system using space-based radar (TRAMRAD)  

Microsoft Academic Search

To meet the challenges of ever increasing road traffic and the associated economic and sociological impacts, new techniques and technologies for better traffic management are needed. The TRAMRAD project (Traffic Monitoring with space-based Radar) aims to profit from research and development in earth observation and advances in radar remote sensing techniques to define a future space-based sensor system for the

D. Hounam; S. Baumgartner; K. H. Bethke; M. Gabele; E. Kemptner; D. Klement; G. Krieger; G. Rode; K. Wagel

2005-01-01

219

Antenna beamwidth and beamshape control techniques for satellite-borne synthetic aperture radar systems  

Microsoft Academic Search

The paper discusses methods of beamwidth and beamshape control suitable for a satellite-borne synthetic aperture radar (SAR) sensor system. The results of a parametric analysis which relates satellite orbital attitude, depression angle, beam width, and swath width are summarized. Attention is given to beam shaping techniques and their application to aperture configurations of interest to generate desired radiation patterns. Baseline

R. A. Kallas

1979-01-01

220

On the modified chirp z transform for synthetic aperture radar systems  

Microsoft Academic Search

A modified chirp z-transform (MCZT) algorithm which has been proposed by Lawton (1988) to replace the conventional polar format interpolation in synthetic aperture radar systems is discussed. The key assumption used in the MCZT approach is that the spatial-frequency samples can be obtained on a concentric squares (CS) grid. The CS grid is briefly reviewed. The conventional approach to processing

John W. Adams; Robert W. Bayma; Michael E. Lawrence; Leon Petrosian

1991-01-01

221

RF Systems in Space. Volume II. Space-Based Radar Analyses.  

National Technical Information Service (NTIS)

The main objective of this effort was to develop a computer based analytical capability for simulating the RF performance of large space-based radar (SBR) systems. The model is capable of simulating corporate and space fed aperture. The model also can sim...

A. V. Mrstik D. Beste P. M. Pazick R. J. Bartek

1983-01-01

222

System Analysis of Ultra-Wideband Instrumentation Radars: Impulse vs. Stepped-Chirp Approaches.  

National Technical Information Service (NTIS)

As part of an ongoing effort to determine the utility of ultra-wideband (UWB) radar systems for military application, an experimental program was developed and executed to collect terrain clutter data using high resolution waveforms in the ultra high freq...

J. Ralston

1993-01-01

223

Using radar tomography, tracer experiments and hydraulic data to characterize fractured rock flow systems  

Microsoft Academic Search

Among the most pressing problems in hydrogeology is describing heterogeneity in fractured rock, where data are typically local and sparse, and permeability varies by orders of magnitude over short distances. This dissertation presents new approaches to characterize fractured rock groundwater flow systems using cross-well radar, tracer, and hydraulic experiments. The methods are demonstrated using data from the U.S. Geological Survey

Frederick David Day-Lewis

2001-01-01

224

47 CFR 15.515 - Technical requirements for vehicular radar systems.  

Code of Federal Regulations, 2012 CFR

...engaging a turn signal. (b) The UWB bandwidth of a vehicular radar system operating...limits when measured using a resolution bandwidth of 1 MHz: Frequency in MHz EIRP...limits when measured using a resolution bandwidth of no less than 1 kHz: Frequency...

2012-10-01

225

Radar, Passive Microwave, and Lightning Characteristics of Precipitating Systems in the Tropics  

Microsoft Academic Search

The bulk radar reflectivity structures, 85- and 37-GHz brightness temperatures, and lightning characteristics of precipitating systems in tropical Africa, South America, the east Pacific, and west Pacific are documented using data from the Tropical Rainfall Measuring Mission (TRMM) satellite during August, September, and October of 1998. The particular focus is on precipitation features (defined as a contiguous area $75 km2

E. R. Toracinta; Daniel J. Cecil; Edward J. Zipser; Stephen W. Nesbitt

2002-01-01

226

CHIRP Doppler radar  

Microsoft Academic Search

The present investigation is concerned with the concept of a combination of the clinical procedure of reconstruction tomography with the radar processing for linear FM pulse compression. An approach based on such a combination is to be employed to map radar backscatter energy. Radar systems employing pulse compression of linear frequency modulated (CHIRP) pulses are considered along with the inversion

M. Bernfeld

1984-01-01

227

Flexible end-to-end system design for synthetic aperture radar applications  

NASA Astrophysics Data System (ADS)

This paper presents ARTEMIS, Inc.'s approach to development of end-to-end synthetic aperture radar systems for multiple applications and platforms. The flexible design of the radar and the image processing tools facilitates their inclusion in a variety of application-specific end-to-end systems. Any given application comes with certain requirements that must be met in order to achieve success. A concept of operation is defined which states how the technology is used to meet the requirements of the application. This drives the design decisions. Key to adapting our system to multiple applications is the flexible SlimSAR radar system, which is programmable on-the-fly to meet the imaging requirements of a wide range of altitudes, swath-widths, and platform velocities. The processing software can be used for real-time imagery production or post-flight processing. The ground station is adaptable, and the radar controls can be run by an operator on the ground, on-board the aircraft, or even automated as part of the aircraft autopilot controls. System integration takes the whole operation into account, seeking to flawlessly work with data links and on-board data storage, aircraft and payload control systems, mission planning, and image processing and exploitation. Examples of applications are presented including using a small unmanned aircraft at low altitude with a line of sight data link, a long-endurance UAV maritime surveillance mission with on-board processing, and a manned ground moving target indicator application with the radar using multiple receive channels.

Zaugg, Evan C.; Edwards, Matthew C.; Bradley, Joshua P.

2012-05-01

228

Comparison of Lightning Observations from the KSC LDAR System with Radar Observations from the NCAR CP-2 Radar.  

National Technical Information Service (NTIS)

This grant supported observations of thunderstorms at Kennedy Space Center during the summer of 1995. In particular, we obtained detailed observations of lightning-producing storms over KSC with the CP2 radar of the National Center for Atmospheric Researc...

P. Krehbiel W. Rison

1996-01-01

229

Preliminary Analysis of Army Aircrew Requirements for Joint Surveillance Target Attack Radar System (JSTARS): Human Performance Requirements and Job Demands.  

National Technical Information Service (NTIS)

In response to a request from Training and Doctrine Command (TRADOC) Systems Manager for the Joint Surveillance Target Attack Radar System (JSTARS), the U.S. Army Research Institute Field Office, now the Human Research and Engineering Directorate (HRED) o...

B. G. Knapp

1994-01-01

230

Air traffic control radar tester  

Microsoft Academic Search

Our aim is to develop a radar tester equipment for commercial and military services. The task is to create one (or more) target or clutter on the radar screen with given distance, velocity and fluctuation. This equipment is placed within few hundred meters from the radar, so it is able to analyze the whole radar system from the antenna, via

Péter KOVÁCS; Levente DUDÁS; Rudolf SELLER; József ORBÁN

2008-01-01

231

Air traffic control radar tester  

Microsoft Academic Search

Our aim had been to develop a radar tester equipment for commercial and military services. The task is to create one (or more) target or clutter on the radar screen with given distance, velocity and fluctuation. This equipment is placed within few hundred meters from the radar, so it is able to analyze the whole radar system from the antenna,

Levente DUDÁS; Rudolf SELLER; Péter RENNER; József ORBÁN

2009-01-01

232

Bistatic Radar In Space A New Dimension In Imaging Radar  

Microsoft Academic Search

Based on a set of examples, this paper shows that bistatic space radar systems can have important capabilities for special imaging radar applications. It explains' the different categories of bistatic space radars as there are single orbit systems, crossing orbit systems, tethered systems and systems with geostationary\\/ge osynchronous transmitters (GEO-BISAR). It discusses the ideas of mixed systems, where aircrafts are

Hans Martin Braun; Philipp Hartl

1989-01-01

233

Noise-induced outpulsing technique for energy efficiency improvement of laser radar systems  

NASA Astrophysics Data System (ADS)

There are stringent false alarm probability demands on laser radar systems systems, although their operation is often accompanied by a complex target environment, when the signal-to-noise ratio is low. New signal processing technique for laser radar systems is suggested. The technique provides detection of a backscattered signal from a target during an interval between a receiver noise bursts A pulse shoot is matched with a trailing edge of a noise burst, and the signal presence decision is made according to leading edge of the next burst. There is a contradiction between the impulse frequency and false alarm probability demands, that is why double-threshold processing is offered. The lower level induces outpulsing while the higher one determines target detection performance. Since duration of such sophisticated time intervals is random, statistic analysis was made via numerical model. The technique is aimed at providing low false alarm probability and energy efficiency of the system at the same time.

Serikova, Maria G.; Lebedko, Evgeny G.

2011-09-01

234

First Results Of The New Goldstone Delay-Doppler Radar Chirp Imaging System  

Microsoft Academic Search

We report the first results of a new delay-Doppler radar chirp waveform system at Goldstone, which improves the range resolution by a factor of five from 18.75-m to 3.75-m. We successfully tested the new system on near-Earth asteroids (NEAs) 2010 AL30 and 2009 UN3 in January and February 2010. 2010 AL30 was a target-of-opportunity observed only three days after its

Martin A. Slade; C. G. Lee; J. S. Jao; L. A. M. Benner; M. Brozovic; J. D. Giorgini; M. W. Busch

2010-01-01

235

A Novel Framework for Quality-Aware Resource Management in Phased Array Radar Systems  

Microsoft Academic Search

This paper addresses the problem of operating parameter assignment to multiple real-time tasks in a phased array radar system. The objective is to maximize the resulting system utility while ensuring the schedulability of all tasks with the assigned operating parameters. For this, we propose a novel framework by integrating the existing resource management framework called QRAM (QoS-based resource allocation model)

Chang-gun Lee

2005-01-01

236

A Single-Stage Target Tracking Algorithm for Multistatic DVB-T Passive Radar Systems  

Microsoft Academic Search

In this contribution, a particle filter (PF) is proposed for tracking a single target illuminated with a digital-video-broadcasting terrestrial (DVB-T) signal in a multistatic radar system. This algorithm utilizes a single-stage scheme, i.e. it estimates the target position trajectory in a Cartesian coordinate system directly from the signal reflected by this target. The multiple stages adopted in the conventional approaches

Xuefeng Yin; Troels Pedersen; Peter Blattnig; Alain Jaquier; Bernard H. Fleury

2009-01-01

237

24GHz Frequency-Modulation Continuous-Wave Radar Front-End System-on-Substrate  

Microsoft Academic Search

Design and implementation of a 24-GHz frequency-modulation continuous-wave radar front-end system is presented and discussed, and its hybrid planar and waveguide building blocks are fully integrated on one single substrate. A flexible and compact integration methodology on the basis of the substrate-integrated-circuits concept is deployed to design such a microwave front-end system-on-substrate. In this study, it is found that this

Zhaolong Li; Ke Wu

2008-01-01

238

A decision support system for locating weapon and radar positions in stationary point air defence  

Microsoft Academic Search

In this study, a decision support system (DSS) based on the interactive use of location models and geographical information\\u000a systems (GIS) was developed to determine the optimal positions for air defence weapons and radars. In the location model,\\u000a the fire units are considered as the facilities to be located and the possible approach routes of air vehicles are treated\\u000a as

Türker Tanergüçlü; Hakan Mara?; Cevriye Gencer; Haluk Aygüne?

239

Integration and demonstration of the STAR1 radar system with a real time soft copy display  

Microsoft Academic Search

This report describes three basic tasks. The first task is the definition and implementation of a real-time softcopy display to be used with STAR-1 real-time synthetic aperture radar system. The second task was the all-up system demonstration of the STAR-1, together with the real-time softcopy display. The third task is a data collection for targets of Army interest using the

P. Lumley; W. Wolters; B. Buchholz; H. McKenney; R. Motyka

1986-01-01

240

Passive coherent location radar demonstration  

Microsoft Academic Search

This paper describes a passive coherent location (PCL) radar system developed by Dynetics, Inc. This system uses commercial FM broadcast signals for the radar waveform. This paper presents a technical description of the system and performance data.

C. L. Zoeller; M. J. Moody

2002-01-01

241

MICROPROCESSOR-BASED DATA-ACQUISITION SYSTEM FOR A BOREHOLE RADAR.  

USGS Publications Warehouse

An efficient microprocessor-based system is described that permits real-time acquisition, stacking, and digital recording of data generated by a borehole radar system. Although the system digitizes, stacks, and records independently of a computer, it is interfaced to a desktop computer for program control over system parameters such as sampling interval, number of samples, number of times the data are stacked prior to recording on nine-track tape, and for graphics display of the digitized data. The data can be transferred to the desktop computer during recording, or it can be played back from a tape at a latter time. Using the desktop computer, the operator observes results while recording data and generates hard-copy graphics in the field. Thus, the radar operator can immediately evaluate the quality of data being obtained, modify system parameters, study the radar logs before leaving the field, and rerun borehole logs if necessary. The system has proven to be reliable in the field and has increased productivity both in the field and in the laboratory.

Bradley, Jerry, A.; Wright, David, L.

1987-01-01

242

Radar Antenna.  

National Technical Information Service (NTIS)

An antenna is described for range-gated, pulse doppler, radar systems. The antenna includes first and second, shortened, half-wave dipoles and first and second reflecting screens. One dipole is fed through a fixed 22 1/2 degree phase-shift network while t...

O. E. Rittenback

1978-01-01

243

Cloud and Precipitation Radar  

NASA Astrophysics Data System (ADS)

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

Hagen, Martin; Höller, Hartmut; Schmidt, Kersten

244

Phase locking of multiple optical fiber channels for a slow-light-enabled laser radar system.  

PubMed

Phase control is crucial to the operation of coherent beam combining systems, whether for laser radar or high-power beam combining. We have recently demonstrated a design for a multi-aperture, coherently combined, synchronized- and phased-array slow light laser radar (SLIDAR) that is capable of scanning in two dimensions with dynamic group delay compensation. Here we describe in detail the optical phase locking system used in the design. The phase locking system achieves an estimated Strehl ratio of 0.8, and signals from multiple emitting apertures are phase locked simultaneously to within ?/5 radians (1/10 wave) after propagation through 2.2 km of single-mode fiber per channel. Phase locking performance is maintained even as two independent slow light mechanisms are utilized simultaneously. PMID:23736563

Vornehm, Joseph E; Schweinsberg, Aaron; Shi, Zhimin; Gauthier, Daniel J; Boyd, Robert W

2013-06-01

245

General configuration and site specific surveys for the EISCAT_3D incoherent radar system  

NASA Astrophysics Data System (ADS)

EISCAT_3D a the next-generation incoherent scatter radar for the study of the atmosphere and geospace environment. It will be a distributed phased-array facility built in modular fashion from a few tens of thousands up to a hundred thousand individual antenna elements. The system will be located in northern Scandinavia and has a planned start of operations in 2015. Since EISCAT_3D is planned to be a multistatic system, the basic geometric configuration of the locations of the sites will have a certain impact on the quality of the measurements. Here we have studied the merit of different constellations of the transmitting and receiver stations of the radar system. We have also performed surveys of potential sites for the antenna arrays. We discuss the criteria for choosing specific locations of the sites, and show the results of the surveys in terms of factors such as the local geography, radio environment and access to infrastructure.

Tjulin, A.; Vanhainen, L.-G.; Mann, I.

2012-04-01

246

Three-Dimensional Radar and Total Lightning Characteristics of Mesoscale Convective Systems  

NASA Astrophysics Data System (ADS)

Preliminary analysis of three-dimensional radar and total lightning characteristics for two mesoscale convective systems (MCSs) occurring in the Dallas-Fort Worth, Texas area during 12-13 October 2001 and 7-8 April 2002 are presented. This study utilizes WSR-88D Level II radar (KFWS), Vaisala GAI Inc. Lightning Detection and Ranging II (LDAR II), and National Lightning Detection Network (NLDN) data to gain a better understanding of the structure and evolution of MCSs, with special emphasis on total lightning. More specifically, this research examines the following topics: 1) the characteristics and evolution of total lightning in MCS's, 2) the correlation between radar reflectivity and lightning flash origins in MCSs, 3) the evolution of the dominant cloud-to-ground (CG) lightning polarity and peak current in both the stratiform and convective regions of MCSs, and 4) the similarities and differences in mesoscale structure and lightning behavior between the two MCSs being studied. Results thus far are in good agreement with previous studies. For example, CG lightning polarity in both MCSs is predominately negative (~90%). Also, the storm cells within the MCSs that exhibit very strong updrafts, identified by high (> 50 dBZ) radar reflectivities, weak echo regions, hook echoes, and/or confirmed severe reports, have higher mean lightning flash origin heights than storm cells with weaker updrafts. Finally, a significant increase in total lightning production (from ~10 to ~18 flashes/min) followed by a significant decrease (from ~18 to ~12 to ~5 flashes/min) is evident approximately one-half hour and ten minutes, respectively, prior to tornado touchdown from a severe storm cell located behind the main convective squall line of the 12-13 October 2001 MCS. These preliminary results, as well as other total lightning and radar characteristics of two MCSs, will be presented.

McCormick, T. L.; Carey, L. D.; Murphy, M. J.; Demetriades, N. W.

2002-12-01

247

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

Code of Federal Regulations, 2010 CFR

Doppler Radar and Inertial Navigation System (INS): Request for Evaluation; Equipment and Equipment Installation; Training Program; Equipment Accuracy and Reliability; Evaluation Program G Appendix G to Part 121 Aeronautics and...

2010-01-01

248

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

Code of Federal Regulations, 2010 CFR

Doppler Radar and Inertial Navigation System (INS): Request for Evaluation; Equipment and Equipment Installation; Training Program; Equipment Accuracy and Reliability; Evaluation Program G Appendix G to Part 121 Aeronautics and...

2009-01-01

249

Improving Ground Penetrating Radar Imaging in High Loss Environments by Coordinated System Development, Data Processing, Numerical Modeling, & Visualization  

SciTech Connect

Improving Ground Penetrating Radar Imaging in High Loss Environments by Coordinated System Development, Data Processing, Numerical Modeling, and Visualization Methods with Applications to Site Characterization EMSP Project 86992 Progress Report as of 9/2004.

Wright, David L.

2004-12-01

250

Real-time Kinematics Global Positioning System (GPS) Operation and Setup Method for the Synchronous Impulse Reconstruction (SIRE) Radar.  

National Technical Information Service (NTIS)

The report provides a description of the Real-time Kinematics (RTK) global positioning system (GPS) operation and setup procedures to provide real- time position data for the Synchronous Impulse Reconstruction (SIRE) radar. These accurate position data al...

D. Wong F. Koenig

2010-01-01

251

Large dynamic range time-frequency signal analysis with application to helicopter Doppler radar data  

NASA Astrophysics Data System (ADS)

Despite the enhanced time-frequency analysis (TFA) detailing capability of quadratic TFAs like the Wigner and Cohen representations, their performance with signals of large dynamic range (DNR in excess of 40 dB) is not acceptable due to the inability to totally suppress the cross-term artifacts which typically are much stronger than the weakest signal components that they obscure. AMTI and GMTI radar targets exhibit such high dynamic range when microDoppler is present, with the aspects of interest being the weakest components. This paper presents one of two modifications of linear TFA to provide the enhanced detailing behavior of quadratic TFAs without introducing cross terms, making it possible to see the time-frequency detail of extremely weak signal components. The technique described here is based on subspace-enhanced linear predictive extrapolation of the data within each analysis window to create a longer data sequence for conventional STFT TFA. The other technique, based on formation of a special two-dimensional transformed data matrix analyzed by high-definition two-dimensional spectral analysis methods such as 2-D AR or 2-D minimum variance, is compared to the new technique using actual AMTI and GMTI radar data.

Marple, Stanley L., Jr.; Marino, Claudio S.; Strange, Shawn

2003-12-01

252

A high-resolution 3-D imaging algorithm with linear array antennas for UWB pulse radar systems  

Microsoft Academic Search

UWB pulse radar systems have a great potential for a high-resolution imaging in indoor environments. For a real-time imaging, we have already proposed a fast 3-dimensional imaging algorithm called SEABED based on a reversible transform BST (boundary scattering transform) between the received signals and the target shape. SEABED can be applied only to a mono-static radar system. Therefore, the resolution

Shouhei KIDERA; Takuya SAKAMOTO; Toru SATO

2006-01-01

253

Test results of an experimental autonomous aircraft landing system utilizing a 94 GHz FM-CW imaging radar  

Microsoft Academic Search

An experimental system capable of aiding a pilot during adverse weather landings, primarily dense fog, has been built and tested both on the ground and in flight. The system includes a 94-GHz FM-CW (frequency-modulation continuous-wave) radar as the front-end sensor and a back-end digital signal and image processor for image generation, enhancement, and transformation. The high-performance 94-GHz radar utilizes a

L. Q. Bui; D. Uecker; E. Loose; Y. Alon

1993-01-01

254

AN\\/TPS-73-a new tactical, solid-state air traffic control radar system with multi-emission capability  

Microsoft Academic Search

The AN\\/TPS-73 is a mobile, completely solid-state integrated primary surveillance S-band radar and L-band monopulse secondary surveillance radar system. Housed in a single shelter for rapid deployment, the system was designed to meet the air traffic control requirements of surveillance, detection, tracking, and identification in an adverse clutter and electronic countermeasures environment. The full band pulse-to-pulse frequency agility transmission of

D. Brosnihan; F. Scire; J. Perrotta; E. Giaccari; M. Di Lazzaro

1990-01-01

255

Standoff concealed weapon detection using a 350GHz radar imaging system  

Microsoft Academic Search

The sub-millimeter (sub-mm) wave frequency band from 300 - 1000 GHz is currently being developed for standoff concealed weapon detection imaging applications. This frequency band is of interest due to the unique combination of high resolution and clothing penetration. The Pacific Northwest National Laboratory (PNNL) is currently developing a 350 GHz, active, wideband, three-dimensional, radar imaging system to evaluate the

David M. Sheen; Thomas E. Hall; Ronald H. Severtsen; Douglas L. McMakin; Brian K. Hatchell; Patrick L. J. Valdez

2010-01-01

256

On the modifier chirp z transform for synthetic aperture radar systems  

Microsoft Academic Search

A modified chirp z-transform (MCZT) algorithm which has been proposed by W. Lawton (IEEE Trans. Acoust., Speech, Signal Processing, vol.ASSP-36, p.931-3, June 1988) to replace the conventional polar format interpolation in synthetic aperture radar (SAR) systems is discussed. The key assumption used in the MCZT approach is that the spatial-frequency samples can be obtained on a concentric squares (CS) grid.

John W. Adams; Robert W. Bayma; Michael E. Lawrence; Leon Petrosian

1991-01-01

257

On the modified chirp z transform for synthetic aperture radar systems  

NASA Astrophysics Data System (ADS)

A modified chirp z-transform (MCZT) algorithm which has been proposed by Lawton (1988) to replace the conventional polar format interpolation in synthetic aperture radar systems is discussed. The key assumption used in the MCZT approach is that the spatial-frequency samples can be obtained on a concentric squares (CS) grid. The CS grid is briefly reviewed. The conventional approach to processing CS grid data is described. The MCZT is discussed, and its disadvantages are emphasized.

Adams, John W.; Bayma, Robert W.; Lawrence, Michael E.; Petrosian, Leon

1991-04-01

258

Target Identification Method by Adaptive GO-CFAR Processor and DSP Implementation for Radar System  

Microsoft Academic Search

This paper presents a Greatest Of CFAR (GO-CFAR) detection scheme based on Censored Video Integration (CVI) that is increased detection probability of useful targets in noise environment and describes the Digital Signal Processor (DSP; ADSP-21160) implementation of adaptive GO-CFAR for radar system. Many signal processing algorithms are required high performance in real-time applications but it often means a high computational

Yang-Won Kwon; In-Kyu Kim; Bum-Soo Kim; Keun-Sup Shin

2007-01-01

259

A 77 GHz SiGe power amplifier for potential applications in automotive radar systems  

Microsoft Academic Search

We present the performance of a 77 GHz power amplifier for potential applications directed towards automotive radar systems. The circuit was fabricated in a SiGe bipolar preproduction technology. A balanced two-stage common emitter circuit topology was used to achieve 6.1 dB of power gain at 77 GHz and 11.6 dBm output power at 1dB compression. The power amplifier uses a

Ullrich R. Pfeiffer; Scott K. Reynolds; Brian A. Floyd

2004-01-01

260

A microjet array cooling system for thermal management of active radars and high-brightness LEDs  

Microsoft Academic Search

Advancement in high heat thermal management technology and its successful integration into emerging GaN-based amplifiers is imperative to meet the long-term requirement of future X-band radar systems. It is also known that the efficiency and reliability of light emitting diode (LED) strongly rely on successful thermal management due to its inherit low junction temperature in the LED chip. In this

Sheng Liu; Tim Lin; Xiaobing Luo; Mingxiang Chen; Xiaoping Jiang

2006-01-01

261

A frequency synthesis structure in radar target simulation system with high agility and resolution performance  

Microsoft Academic Search

In this paper, an approach of developing high agility and resolution x-band frequency synthesizer for radar target simulation system is proposed. Using the up-conversion of Direct Digital Synthesizer (DDS) output signal to provide the local oscillators and linearly frequency modulated (LFM) signal, with good frequency configuration and optimal utilization of DDS, and high-speed controlling of FPGA (Field Programming Gate Array),

Yuanwang Yang; Jingye Cai; Liu Lianfu

2011-01-01

262

Mapping of a major paleodrainage system in eastern Libya using orbital imaging radar: The Kufrah River  

NASA Astrophysics Data System (ADS)

Over the last few decades, remote sensing has revealed buried river channels in a number of regions worldwide, in many cases providing evidence of dramatic paleoenvironmental changes over Cenozoic time scales. Using orbital radar satellite imagery, we mapped a major paleodrainage system in eastern Libya, that could have linked the Kufrah Basin to the Mediterranean coast through the Sirt Basin, possibly as far back as the middle Miocene. Synthetic Aperture Radar images from the PALSAR sensor clearly reveal a 900 km-long river system, which starts with three main tributaries (north-eastern Tibesti, northern Uweinat and western Gilf Kebir/Abu Ras) that connect in the Kufrah oasis region. The river system then flows north through the Jebel Dalmah, and forms a large alluvial fan in the Sarir Dalmah. The sand dunes of the Calanscio Sand Sea prevent deep orbital radar penetration and preclude detailed reconstruction of any possible connection to the Mediterranean Sea, but a 300 km-long link to the Gulf of Sirt through the Wadi Sahabi paleochannel is likely. If this connection is confirmed, and its Miocene antiquity is established, then the Kufrah River, comparable in length to the Egyptian Nile, will have important implications for the understanding of the past environments and climates of northern Africa from the middle Miocene to the Holocene.

Paillou, Philippe; Schuster, Mathieu; Tooth, Stephen; Farr, Tom; Rosenqvist, Ake; Lopez, Sylvia; Malezieux, Jean-Marie

2009-01-01

263

The Total Lightning and Radar Characteristics of Two Mesoscale Convective Systems Over Houston  

NASA Astrophysics Data System (ADS)

The electrical and lightning properties of mesoscale convective systems (MCSs) have been the focus of many research studies, with much of the past attention focusing on cloud-to-ground (CG) lightning in relation to storm structure. With the recent deployment of the Texas A&M University (TAMU) Lightning Detection and Ranging (LDAR) network in Houston, Texas, the three-dimensional properties of total (i.e., CG and intracloud [IC]) lightning may be readily observed in a sub-tropical, coastal and urban environment. In our study, LDAR VHF lightning source data were used in conjunction with National Lightning Detection Network (NLDN) ground flash data and the Houston (KHGX) Weather Surveillance Radar - 1988 Doppler (WSR-88D) to provide insight into the electrical nature and lightning structure of a leading line trailing stratiform (LLTS) MCS on 31 October 2005 and a bow echo MCS on 21 April 2006 that passed within range of the Houston LDAR network. For example, contoured frequency by altitude diagrams (CFADs) of radar reflectivity and rain totals were calculated within selected stratiform and convective regions for each radar volume scan as the MCSs evolved over the course of two hours. The slope (i.e., height vs. line-normal distance) of the VHF source distribution rearward of the convective line evolved during the observed lifecycle of the LLTS MCS. During the early stages, flashes originating in the convective line or transition zone traveled horizontally backward into the developing stratiform region with little or no downward slope. As the system matured, these flashes propagated with a more pronounced downward slope into the stratiform region toward the radar bright band. Preliminary radar analysis suggests that the intensity of stratiform region precipitation, including the bright band, played an important role in the changing slope of the lightning and inferred charge structure. CFADs show an increase in the frequency of high dBZ values (>30 dBZ), mean reflectivity profile, and rain totals over the selected stratiform region as the lightning began to slope downward and backward. The bow echo case showed a similar increase in intensity of the stratiform precipitation with time. In our study, we will present a complete analysis of total lightning flash structure for both cases along with a corresponding investigation of radar properties, and NLDN CG flash location, rate, peak currents, and polarity.

Hodapp, C. L.; Carey, L. D.; Ely, B. L.; Orville, R. E.

2006-12-01

264

Radar Experiments Data Reduction, and Experimental Tests.  

National Technical Information Service (NTIS)

Work performed included software support for the evaluation and development of advanced radar antenna systems, development and maintenance of target identification databases, and the data reduction of raw radar data from field tests. Keywords: Radar anten...

W. O. Loescher

1990-01-01

265

A Two-Frequency CW Radar System for Short-Range Distances Measurements  

NASA Astrophysics Data System (ADS)

This paper discusses a new approach to measure distances between objects using two frequency Continuous waveforms and based on a K-band Doppler technology. The system's operation is performed using two-frequency radar to obtain expeditiously and highly accurate measurements for stationary and moving objects. Experiments have been conducted and a mathematical presentation of the system's model has been formulated along with computer-based simulations to study the performance and to validate the effectiveness of the proposed system's model. The obtained results demonstrate the capability of the system to adapt a short distance range.

Araki, Takashi; Nagase, Tomoyuki; Araki, Makoto; Ono, Hisao

266

Coherent uplink arraying techniques for next generation space communications and planetary radar systems  

NASA Astrophysics Data System (ADS)

For several years, NASA has been pursuing demonstrations and development of coherent uplink arraying techniques for the next generation space communications and planetary radar systems. In addition radio science experiments would benefit with a 1000 times increase in signal to noise over current systems. I shall describe the three methods of uplink arraying NASA has pursued, all successful, and share the vision for going forward from laboratory demonstrations to the proposed implementation and deployment of a dedicated multi-purpose facility to infuse an amalgam of these methods into a system that enhances NASA's missions.

Geldzahler, B. J.

2011-05-01

267

Shuttle orbiter Ku-band radar/communications system design evaluation  

NASA Astrophysics Data System (ADS)

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

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

1980-12-01

268

Adaptive system for detecting stationary targets with real-aperture radar  

NASA Astrophysics Data System (ADS)

Trained algorithms are required for detecting stationary targets with practical real-beam radars. The parameters of these algorithms are unique to each site or clutter class. A problem arises when an algorithm trained on one clutter class is applied, perhaps inadvertently, to another class. In this case, the performance of the system can degrade to an unacceptable level. We have developed a system that adapts, online, the parameters of the algorithm to the encountered clutter type. This system consists of two neural networks one for adapting the coefficients of the algorithm and the other for adapting the threshold level.

Khatri, Hiralal C.; Koenig, Francois; Innocenti, Roberto; Ranney, Kenneth I.

2003-08-01

269

Prospective Nuclear Reactor Power Systems for Space Based Radar Missions.  

National Technical Information Service (NTIS)

This document summarizes the characteristics of 10 kW(e) and 50 kW(e) space reactor power systems utilizing four types of power conversion systems. The Brayton, organic Rankine and thermoelectric systems represent near-to-intermediate term technologies. O...

1975-01-01

270

Radar-Based Highwall Rib-Thickness Monitoring System.  

National Technical Information Service (NTIS)

In addition to developing various types of coal-interface detection systems, the US Bureau of Mines is actively involved in developing a coal rib-thickness monitoring system for highwall mining applications. One particular system that shows promise uses a...

G. L. Mowrey C. W. Ganoe W. D. Monaghan

1995-01-01

271

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

NASA Astrophysics Data System (ADS)

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

Fang, N.; Bedient, P.

2009-12-01

272

MAARSY: The new MST radar on Andřya—System description and first results  

NASA Astrophysics Data System (ADS)

The Middle Atmosphere Alomar Radar System (MAARSY) on the North-Norwegian island Andřya is a 53.5 MHz monostatic radar with an active phased array antenna consisting of 433 Yagi antennas. The 3-element Yagi antennas are arranged in an equilateral triangle grid forming a circular aperture of approximately 6300 m2. Each individual antenna is connected to its own transceiver with independent phase control and a scalable power output up to 2 kW. This arrangement provides a very high flexibility of beam forming and beam steering with a symmetric radar beam of a minimum beam width of 3.6° allowing classical beam swinging operation as well as experiments with simultaneous multiple beams and the use of interferometric applications for improved studies of the Arctic atmosphere from the troposphere up to the lower thermosphere with high spatio-temporal resolution. The installation of the antenna array was completed in August 2009. The radar control and data acquisition hardware as well as an initial expansion stage of 196 transceiver modules was installed in spring 2010 and upgraded to 343 transceiver modules in November 2010. The final extension to 433 transceiver modules has recently been completed in May 2011. Beside standard observations of tropospheric winds and Polar Mesosphere Summer Echoes, the first multi-beam experiments using up to 97 quasi-simultaneous beams in the mesosphere have been carried out in 2010 and 2011. These results provide a first insight into the horizontal variability of polar mesosphere summer and winter echoes with time resolutions between 3 and 9 minutes. In addition, first meteor head echo observations were conducted during the Geminid meteor shower in December 2010.

Latteck, R.; Singer, W.; Rapp, M.; Vandepeer, B.; Renkwitz, T.; Zecha, M.; Stober, G.

2012-02-01

273

Determining the optimal parameters in a distant radar NDE technique for debonding detection of GFRP-concrete systems  

NASA Astrophysics Data System (ADS)

In the distant detection of debonding in glass fiber reinforced polymer (GFRP)-retrofitted concrete systems using radar NDE techniques, revealing the presence of debonding in reconstructed images is essential to the success of the techniques. An optimization scheme based on mathematical morphology is proposed for determining the optimal measurement and processing parameters in a distant radar NDE technique for debonding detection. Inverse synthetic aperture radar (ISAR) and backprojection algorithms are applied in the technique. Measurement (incident frequency and angle) and processing (frequency bandwidth and angular range) parameters are defined in this work. Performance of the optimization scheme is validated by laboratory ISAR measurements on GFRP-retrofitted concrete cylinders using radar signals in 8-18 GHz. From the results it is shown that better detection can be achieved by optimized measurements and processing.

Yu, Tzu-Yang

2009-03-01

274

Laser radar in robotics  

SciTech Connect

In this paper the authors describe the basic operating principles of laser radar sensors and the typical algorithms used to process laser radar imagery for robotic applications. The authors review 12 laser radar sensors to illustrate the variety of systems that have been applied to robotic applications wherein information extracted from the laser radar data is used to automatically control a mechanism or process. Next, they describe selected robotic applications in seven areas: autonomous vehicle navigation, walking machine foot placement, automated service vehicles, manufacturing and inspection, automotive, military, and agriculture. They conclude with a discussion of the status of laser radar technology and suggest trends seen in the application of laser radar sensors to robotics. Many new applications are expected as the maturity level progresses and system costs are reduced.

Carmer, D.C.; Peterson, L.M. [Environmental Research Inst. of Michigan, Ann Arbor, MI (United States)

1996-02-01

275

Radar in transition  

NASA Astrophysics Data System (ADS)

It is pointed out that radar engineers, at the end of 1984, find their field in transition between the conventional designs of the post War II era and the digitally controlled, solid-state systems which will be in place for the year 2000. The U.S. Navy has two major phased array radar systems in operation, including the rotating three-dimensional (3D) AN/SPS-48, and the phased-scanned AN/SPY-1 (Aegis) radars. The Aegis represents a major step beyond the conventional 3D and mechanical fire-control radars. However, it requires a special ship, dedicated to its use. Attention is given to questions regarding an extension of the application of Aegis technology to other U.S. Navy applications and to other navies, an ambitious solid-state radar program in the UK, and Army radars.

Barton, D. K.

1984-12-01

276

Establishment of a multiple-Doppler radar wind retrieval system and its application to the analysis of mesoscale convective systems  

NASA Astrophysics Data System (ADS)

A multiple-Doppler radar wind retrieval system is established by using a three dimensional variation method. The system consists of two parts. One is to interpolate reflectivities and radial velocities of nine Doppler radars of the Korea Meteorological Administration (KMA) into one analysis domain. The other is to retrieve three dimensional winds by minimizing a cost function that includes the following costs and constraints: the observed radial velocity cost, background wind cost, continuity constraint and smoothness constraint. In order to verify the performance of the system, retrieved winds are compared with observed winds obtained from five wind profilers of KMA. The performance of the system depends on the relative position to the baselines between Doppler radars. However, the performance of the system is enhanced when the number of overlaps among the radial velocities increases. The system is applied to the analysis of the evolution of a mesoscale convective system (MCS) on the Changma front on 1 July 2005. The analysis result shows that a new convective cell is developed by the convergence of the low troposphere winds at the organizing stage. The analysis of the vertical vorticity reveals that, among the two vorticity generation terms to be calculated utilizing the retrieved winds, tilting or twisting source dominates the divergence source in most convective regions. The strong downdrafts associated with the storm are produced on the downdraft branch of a meridional direction secondary circulation across the Changma front.

Lee, Seon-Yong; Chun, Hye-Yeong; Choi, Young-Jean

2012-11-01

277

Standoff concealed weapon detection using a 350-GHz radar imaging system  

NASA Astrophysics Data System (ADS)

The sub-millimeter (sub-mm) wave frequency band from 300 - 1000 GHz is currently being developed for standoff concealed weapon detection imaging applications. This frequency band is of interest due to the unique combination of high resolution and clothing penetration. The Pacific Northwest National Laboratory (PNNL) is currently developing a 350 GHz, active, wideband, three-dimensional, radar imaging system to evaluate the feasibility of active sub-mm imaging for standoff detection. Standoff concealed weapon and explosive detection is a pressing national and international need for both civilian and military security, as it may allow screening at safer distances than portal screening techniques. PNNL has developed a prototype active wideband 350 GHz radar imaging system based on a wideband, heterodyne, frequency-multiplier-based transceiver system coupled to a quasi-optical focusing system and high-speed rotating conical scanner. This prototype system operates at ranges up to 10+ meters, and can acquire an image in 10 - 20 seconds, which is fast enough to scan cooperative personnel for concealed weapons. The wideband operation of this system provides accurate ranging information, and the images obtained are fully three-dimensional. During the past year, several improvements to the system have been designed and implemented, including increased imaging speed using improved balancing techniques, wider bandwidth, and improved image processing techniques. In this paper, the imaging system is described in detail and numerous imaging results are presented.

Sheen, David M.; Hall, Thomas E.; Severtsen, Ronald H.; McMakin, Douglas L.; Hatchell, Brian K.; Valdez, Patrick L. J.

2010-04-01

278

Radar cross section statistics of ground vehicles at Ku-band  

NASA Astrophysics Data System (ADS)

Knowing the statistical characteristics of a target's radar cross-section (RCS) is crucial to the success of radar target detection algorithms. Open literature studies regarding the statistical nature of the RCS of ground vehicles focus primarily on simulations, scale model chamber measurements, or limited experimental data analysis of specific vehicles at certain frequencies. This paper seeks to expand the existing body of work on ground vehicle RCS statistics at Ku-band for ground moving target indication (GMTI) applications. We examine the RCS probability distributions of civilian and military vehicles, across aspect and elevation angle, for HH and VV polarizations, and at diverse resolutions, using experimental data collected at Ku-band. We further fit Swerling target models to the distributions and suggest appropriate detection thresholds for ground vehicles in this band.

Raynal, Ann Marie; Bickel, Douglas L.; Denton, Michael M.; Bow, Wallace J.; Doerry, Armin W.

2011-05-01

279

A precrash system based on radar for automotive applications  

Microsoft Academic Search

In present-day cars, safety systems like airbag or seat belt pretensioner reduces accident consequences for passengers. Future generations of cars will support additional safety functions such as precrash, collision warning and broke assistant. For safety functions like precrash the timely deployment of seat belt pretensioner and some other safety systems is important, but is a very difficult problem. In this

M. Skutek; M. Mekhaiel; G. Wanielik

2003-01-01

280

29 CFR 1915.85 - Vessel radar and communication systems.  

Code of Federal Regulations, 2013 CFR

...shall ensure that: (1) There is no other work in progress aloft; and (2) No employee is closer to the system's antenna or transmitter than the manufacturer's specified safe minimum distance for the type, model, and power of the...

2013-07-01

281

Terahertz radar cross section measurements  

Microsoft Academic Search

We present the result of terahertz radar cross section measurements on various objects including models of aircraft fighters. Application of a time domain system provides both values of radar cross section and ranging information.

Krzysztof Iwaszczuk; Henning Heiselberg; Peter Uhd Jepsen

2010-01-01

282

CFAR detection for multistatic radar  

Microsoft Academic Search

A multistatic radar system with n transmitters and one receiver is modelled. Several CFAR algorithms for detection are introduced. The proposed CFAR detectors are simulated and the performances are compared with the performance of a monostatic radar of higher power.

Vahideh Amanipour; Ali Olfat

2008-01-01

283

MAARSY - The new MST radar on Andřya: System description and first results  

NASA Astrophysics Data System (ADS)

In 2011 the Leibniz-Institute of Atmospheric Physics in Kühlungsborn completed the installation of the Middle Atmosphere Alomar Radar System ({MAARSY}) on the North-Norwegian island Andřya. MAARSY is a 53.5 MHz monostatic radar with an active phased array antenna consisting of 433 Yagi antennas. The 3-element Yagi antennas are arranged in an equilateral triangular grid forming a circular aperture of approximately 6300 m^2. Each individual antenna is connected to its own transceiver with independent phase control and a scalable power output of up to 2 kW. This arrangement provides very high flexibility of beam forming and beam steering with a symmetric radar beam of a minimum beam width of 3.6°. The system allows classical beam swinging operation as well as experiments with simultaneous multiple beams and the use of interferometric applications for improved studies of the Arctic atmosphere from the troposphere up to the lower thermosphere with high spatio-temporal resolution. Standard observations of tropospheric winds and polar mesosphere summer echoes started immediately with an initial stage of expansion in spring 2010. Meteor head echo experiments and 3D observations of polar mesospheric winter echoes were conducted after an upgrade of the system in December 2010. Multi-beam experiments using up to 97 beams quasi-simultaneously in the mesosphere have been carried out during campaigns in summer 2011 with the completed system. We present a system description of MAARSY including beam pattern validation and show initial results from various campaigns obtained during the first 2 years of operation.

Latteck, Ralph; Zecha, Marius; Rapp, Markus; Stober, Gunter; Singer, Werner; Renkwitz, Toralf

2012-07-01

284

Millimeter Wave Cloud Radar (MMCR) Handbook  

SciTech Connect

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

KB Widener; K Johnson

2005-01-30

285

The Venus Radar Mapper mission  

Microsoft Academic Search

The Venus Radar Mapper (VRM) mission is sponsored by NASA to put a single spacecraft in orbit around Venus to map the surface using a synthetic aperture mapping radar. This paper describes the VRM mission at its present state of design. The science objectives and project constraints are described. Key features of the spacecraft system and radar system are discussed.

E. Cutting; J. H. Kwok; S. N. Mohan

1984-01-01

286

GEN-SYSTEM - A new experimental philosophy for EISCAT radars  

Microsoft Academic Search

GEN-SYSTEM is a code name for a new experimental design philosphy, a set of related correlator algorithms and an experiment library based on this philosophy. It is designed to obtain an easy way to develop powerful experiments having several different modulations in the same pattern or to have very powerful modulations in single channel experiments, needed sometimes in special applications.

Tauno Turunen

1986-01-01

287

Passive Radar.  

National Technical Information Service (NTIS)

The basic ideas and concepts of one of the newest branches of radar, that of passive radar, are discussed. A great deal of attention is devoted to questions of the use of passive radar by the armed forces. The physical fundamentals of passive radar, and t...

A. G. Nikolaev S. V. Pertsov

1975-01-01

288

Spatial-spectral processing for imaging systems: Multibeam RF imaging and radar systems using spectral hole burning materials  

NASA Astrophysics Data System (ADS)

Systems which form many spatial beams (beamformers) for the RF and microwave spectral bands output either a few simultaneous spatial beams across a wide bandwidth---using true-time-delay beamformers---or many simultaneous spatial beams across a moderate bandwidth---using digital aperture synthesis imagers. The simultaneous spatial beams in true-time-delay beamformers require parallel hardware while digital aperture synthesis imagers requires both high speed digitizers and huge digital processors. Moreover; each output beam is typically processed further by a spectrum analyzer or a radar processor. Simultaneous formation and processing of all spatial beams is intractable for wide bandwidths and many beams. This dissertation develops and demonstrates a new class of photonic processing architectures which form and process many simultaneous, wide bandwidth spatial beams. These photonic architectures modulate RF signals from an emulated array of antennas onto an array of coherent optical carriers. I show the theory, the methods, and the results for systems which use Fourier optics and spectral hole burning (SHB) crystals; the demonstrated applications are: wideband RF imaging, Doppler radar, and multi-static radar applications. Proof-of-concept results show 20-beam RF images across a 1 GHz bandwidth and 20-beam radar correlations across bandwidths up to 150 MHz, but these systems can be scaled to process antenna arrays with thousands of beams across bandwidths up to 20 GHz. While these systems can process wide bandwidths for large antenna arrays, I also show an analysis that claims these systems can offer sensitivity levels comparable to other digital or analog beamformers.

Braker, Benjamin M.

289

Phase correction system for automatic focusing of synthetic aperture radar  

DOEpatents

A phase gradient autofocus system for use in synthetic aperture imaging accurately compensates for arbitrary phase errors in each imaged frame by locating highlighted areas and determining the phase disturbance or image spread associated with each of these highlight areas. An estimate of the image spread for each highlighted area in a line in the case of one dimensional processing or in a sector, in the case of two-dimensional processing, is determined. The phase error is determined using phase gradient processing. The phase error is then removed from the uncorrected image and the process is iteratively performed to substantially eliminate phase errors which can degrade the image.

Eichel, Paul H. (Albuquerque, NM); Ghiglia, Dennis C. (Placitas, NM); Jakowatz, Jr., Charles V. (Albuquerque, NM)

1990-01-01

290

Classification and quantification of hydrometeors based on polarimetric radar measurements: Development of fuzzy logic and neuro-fuzzy systems and in situ verification  

Microsoft Academic Search

Fuzzy logic and Neuro-Fuzzy systems for the classification of hydrometeor type based on polarimetric radar measurements is developed. The hydrometeor classification system is implemented where the fuzzy logic is used to infer hydrometeor type, and the neural network learning algorithm is used for automatic adjustment of the parameters of the fuzzy sets in the fuzzy logic system. Five radar measurements,

Hongping Liu; V. Chandrasekar

2000-01-01

291

Virtual Drive: A Complete V2X Communication and Radar System Simulator for Optimization of Multiple Antenna Systems  

Microsoft Academic Search

Vehicle-to-X (V2X) communication as well as automotive radar are fast growing areas of consumer interest. This gives rise to a challenge to a well-working communication systems in handling the V2X radio channel. The two most important components influencing the channel are the an- tennas and the fast changing environment, resulting in a time- variant behavior of the channel. Therefore, finding

Lars Reichardt; Jürgen Maurer; Thomas Fugen; Thomas Zwick

2011-01-01

292

Recent results from a nested multi-static HF radar network for the NorthEast Observing System (NEOS)  

Microsoft Academic Search

Summary form only given. Anested HF radar network has been deployed along the New Jersey coast as part of the New Jersey Shelf Observing System (NJSOS) and the larger regional NorthEast Observing System (NEOS). A 25 MHz standard system (range about 50 km) setup for continuous operation since 1999 includes two sites in Brant Beach and Brigantine, New Jersey. A

J. T. Kohut; S. M. Glenn; H. J. Roarty

2003-01-01

293

A multi-agent system for meteorological radar data management and decision support  

Microsoft Academic Search

* Abstract: The Meteorological Service of Cyprus operates a Doppler radar at the mountainous region of the island. Data-streams recorded by the radar are used for weather forecasting and, especially, for identifying oncoming precipitation incidents and issuing (potential) warnings. However, the continuous processing and evaluation of radar data requires significant efforts by the meteorologists, both for data processing, storage, and

Ioannis N. Athanasiadis; Marios Milis; Pericles A. Mitkas; Silas C. Michaelides

2009-01-01

294

Destroyer Engineered Operating Cycle (DDEOC) System Maintenance Analysis DDC-37 Class Radar Data Display System SMA 37-303-411 Review of Experience.  

National Technical Information Service (NTIS)

This report, the Review of Experience, documents the historical maintenance experience for the DDG-37 Class Radar Data Display System. It has been developed for NAVSEA 934X, the sponsor of the Destroyer Engineered Operating Cycle (DDEOC) Program, under Co...

H. L. Mashaw

1977-01-01

295

Advanced ground-based ESCAN radars  

Microsoft Academic Search

Electronically scanned radars (ESCAN radars) are key system elements of ground based military systems being developed for air and missile defense against future threats including tactical ballistic missiles, high agile and low RCS targets like drones, ARMs, UAVs. The radar design is governed on the one hand by challenging requirements on ESCAN radar performance and on the other hand by

U. Fuchs; W. Sieprath

2005-01-01

296

HERMES: a high-speed radar imaging system for inspection of bridge decks  

SciTech Connect

Corrosion of rebar in concrete bridges causes subsurface cracks and is a major cause of structural degradation that necessitates repair or replacement. Early detection of corrosion effects can limit the location and extent of necessary repairs, while providing long-term information about the infrastructure status. Most current detection methods, however, are destructive of the road surface and require closing or restricting traffic while the tests are performed. A ground-penetrating radar imaging system has been designed and developed that will perform the nondestructive evaluation of road-bed cracking at traffic speeds; i.e., without the need to restrict traffic flow. The first-generation system (called the HERMES bridge inspector), consists of an offset-linear array of 64 impulse radar transceivers and associated electronics housed in a trailer. Computers in the trailer and in the towing vehicle control the data acquisition, processing, and display. Cross-road resolution is three centimeters at up to 30 cm in depth, while down-road resolution depends on speed; 3 cm below 20 mph up to 8 cm at 50 mph. A two-meter- wide path is inspected on each pass over the roadway. This paper, describes the design of this system, shows preliminary results, and lays out its deployment schedule.

Azevedo, S.G.

1996-10-26

297

UWB radars in medicine  

Microsoft Academic Search

Applied research on biomedical applications of UWB radar is targeted to the identification of the possible new devices made possible by the technology, to the design and development of those devices, and to the clinical testing of the systems obtained. Applications can be divided into two main sectors according to the frequency range used. For the conventional UWB radar microwave

Enrico M. Staderini

2002-01-01

298

Panchromatic and polypanchromatic radar  

Microsoft Academic Search

Application of broad-band (panchromatic) illumination in radar systems should permit improvement in image quality and reduction of tracking and detection problems due to fading. The effect of frequency averaging on radar return from a simple target array is demonstrated by numerical computation and on image quality by ultrasonic simulation. The required bandwidth for a slightly rough random surface is determined

RICHARD K. MOORE; WILLIAM P. WAITE

1969-01-01

299

Radar clutter classification  

Microsoft Academic Search

The problem of classifying radar clutter as found on air traffic control radar systems is studied, and an algorithm is developed to carry out this classification automatically. The basis for the algorithm is Bayes decision theory and the parametric maximum a posteriori probability (MAP) classifier. This classifier employs a quadratic discriminant function and is optimum for feature vectors that are

Wolfgang Stehwien

1990-01-01

300

Radar clutter classification  

Microsoft Academic Search

The problem of classifying radar clutter as found on air traffic control radar systems is studied. An algorithm based on Bayes decision theory and the parametric maximum a posteriori probability classifier is developed to perform this classification automatically. This classifier employs a quadratic discriminant function and is optimum for feature vectors that are distributed according to the multivariate normal density.

Wolfgang Stehwien

1989-01-01

301

Determination of the effectiveness of commercial-off-the-shelf radar in the cuing of unmanned aerial vehicle pan-tilt-zoom camera systems  

Microsoft Academic Search

This study examined the use of low-cost commercial-off-the-shelf (COTS) radar in support of the cuing of pan-tilt-zoom (PTZ) optical payload systems. Cancellation of the U.S. Navy's vertical take off and landing (VTOL) unmanned aerial vehicle (VTUAV) program left the Navy without a UAV with radar sensor capability. Using a UAV PTZ optical payload and a COTS radar, this study collected

Patrick Joseph Ford

2003-01-01

302

Measurement of electromagnetic fields generated by air traffic control radar systems with spectrum analysers.  

PubMed

Air traffic control (ATC) primary radars are 'classical' radars that use echoes of radiofrequency (RF) pulses from aircraft to determine their position. High-power RF pulses radiated from radar antennas may produce high electromagnetic field levels in the surrounding area. Measurement of electromagnetic fields produced by RF-pulsed radar by means of a swept-tuned spectrum analyser are investigated here. Measurements have been carried out both in the laboratory and in situ on signals generated by an ATC primary radar. PMID:19864331

Barellini, A; Bogi, L; Licitra, G; Silvi, A M; Zari, A

2009-10-28

303

Advances in Radar Technology for Bird Strike Risk Assessment  

Microsoft Academic Search

Since the 2001 BSC meeting in Calgary, Geo-Marine, Inc. has made dramatic advances in the development of avian radar systems. The Mobile Avian Radar System (MARS) has undergone major revisions. New radar processor cards provide the computer workstations with higher resolution data than was previously possible. The system now incorporates both horizontal- and vertical-scanning radars. The vertical scanning radar antenna

T. Adam Kelly; Ronald Merritt; Ronald L. White; Mark Howera; Timothy West

2002-01-01

304

Design and simulation of optical system based on microlens array for scannerless pulsed laser radar  

NASA Astrophysics Data System (ADS)

The transmitting and receiving optical system for the scannerless laser radar are designed and simulated in ZEMAX. In the transmitting optical system, in order to increase the operating distance, a beam expander telescope which is used for reducing divergent angle of laser beam is chosen. To make fully use of light, a micro lens array is used as a beam splitter. In the receiving optical system, in order to improve the filling factor of APD array, a micro lens array used to replace the previous usual lens is studied. The simulation shows that the density of the light spot after split was uniform, and demonstrates that the designed array illumination is feasible. In the part of receiving optical system, each beamspot through micro lens array can match perfectly with the APD unit cell, and the receiving efficiency is improved effectively.

Cai, Xiping; Leng, Xuelian; Liu, Jianbo; Han, Quan; Dai, Wenjiang

2011-11-01

305

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

ERIC Educational Resources Information Center

|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…

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

2013-01-01

306

Two-dimensional imaging via a narrowband MIMO radar system with two perpendicular linear arrays.  

PubMed

This paper presents a system model and method for the 2-D imaging application via a narrowband multiple-input multiple-output (MIMO) radar system with two perpendicular linear arrays. Furthermore, the imaging formulation for our method is developed through a Fourier integral processing, and the parameters of antenna array including the cross-range resolution, required size, and sampling interval are also examined. Different from the spatial sequential procedure sampling the scattered echoes during multiple snapshot illuminations in inverse synthetic aperture radar (ISAR) imaging, the proposed method utilizes a spatial parallel procedure to sample the scattered echoes during a single snapshot illumination. Consequently, the complex motion compensation in ISAR imaging can be avoided. Moreover, in our array configuration, multiple narrowband spectrum-shared waveforms coded with orthogonal polyphase sequences are employed. The mainlobes of the compressed echoes from the different filter band could be located in the same range bin, and thus, the range alignment in classical ISAR imaging is not necessary. Numerical simulations based on synthetic data are provided for testing our proposed method. PMID:20040416

Wang, Dang-wei; Ma, Xiao-yan; Su, Yi

2009-12-28

307

Performance metric development for a group state estimator in airborne UHF GMTI applications  

NASA Astrophysics Data System (ADS)

This paper describes the development and implementation of evaluation metrics for group state estimator (GSE, i.e. group tracking) algorithms. Key differences between group tracker metrics and individual tracker metrics are the method used for track-to-truth association and the characterization of group raid size. Another significant contribution of this work is the incorporation of measured radar performance in assessing tracker performance. The result of this work is a set of measures of performance derived from canonical individual target tracker metrics, extended to characterize the additional information provided by a group tracker. The paper discusses additional considerations in group tracker evaluation, including the definition of a group and group-to-group confusion. Metrics are computed on real field data to provide examples of real-world analysis, demonstrating an approach which provides characterization of group tracker performance, independent of the sensor's performance.

Elwell, Ryan A.

2013-05-01

308

A system for the real time exploitation of digital synthetic aperture radar data  

NASA Astrophysics Data System (ADS)

The Advanced Building Block for Large Area Exploitation (ABLE) is a system designed to demonstrate the feasibility of doing real time synthetic aperture radar exploitation. ABLE has four subsystems, which have the following functions: (1) reception and processing of the phase histories to produce an image; (2) automatic change detection; (3) two-stage exploitation function proper; and (4) production and management of cues, as well as the ancillary management necessary for efficient exploitation. ABLE's major components consist of the Synthetic Aperture Precision Processor High Reliability (SAPPHIRE) digital correlator, the automatic change detection subsystem, the exploitation subsystem, and the exploitation management system. Factors influencing the system engineering are discussed, and the resulting design features are described.

Withman, R. L.

309

Passive VHF radar for ionospheric physics  

Microsoft Academic Search

Recent technological advances enable a new class of passive radar instruments. These radars have no dedicated transmitter, observing serendipitous scatter of existing sources. Such radars may have very high performance and cost far less than conventional radars. The resulting equipment is essentially reduced to simple antennas, desktop computers, and Global Positioning System equipment. The safety hazards, interference problems, licensing issues,

J. D. Sahr; D. M. Gidner; Chucai Zhou; F. D. Lind

2001-01-01

310

High-level multifunction radar simulation for studying the performance of multisensor data fusion systems  

NASA Astrophysics Data System (ADS)

This paper presents the basic requirements for a simulation of the main capabilities of a shipborne MultiFunction Radar (MFR) that can be used in conjunction with other sensor simulations in scenarios for studying Multi Sensor Data Fusion (MSDF) systems. This simulation is being used to support an ongoing joint effort (Canada - The Netherlands) in the development of MSDF testbeds. This joint effort is referred as Joint-FACET (Fusion Algorithms & Concepts Exploration Testbed), a highly modular and flexible series of applications that is capable of processing both real and synthetic input data. The question raised here is how realistic should the sensor simulations be to trust the MSDF performance assessment? A partial answer to this question is that at least, the dominant perturbing effects on sensor detection (true or false) are sufficiently represented. Following this philosophy, the MFR model, presented here, takes into account sensor's design parameters and external environmental effects such as clutter, propagation and jamming. Previous radar simulations capture most of these dominant effects. In this paper the emphasis is on an MFR scheduler which is the key element that needs to be added to the previous simulations to represent the MFR capability to search and track a large number of targets and at the same time support a large number of (semi-active) surface-to-air missiles (SAM) for the engagement of multiple hostile targets.

Huizing, Albert; Bosse, Eloi

1998-07-01

311

Precipitation Observed in Oklahoma Mesoscale Convective Systems with a Polarimetric Radar.  

NASA Astrophysics Data System (ADS)

In this paper, the fields of three radar polarimetric variables-differential reflectivity ZDR, specific differential phase KDP, and correlation coefficient between horizontally (H) and vertically (V) polarized echoes hv-along with radar reflectivity Zh, are examined within two Oklahoma mesoscale convective systems (MCSs). The analysis of the whole set of polarimetric variables reveals at least three types of hydrometeor populations in the precipitation within thew MCSs. It seems to be possible to discriminate between pure liquid raindrops, drops with ice cores inside them, and mixed-phase precipitation containing rain and hail using joint analysis of all the polarimetric measurands available. Hail-bearing zones are characterized by significant reduction of ZDR and hv, as well as large values of Zh. Specific differential phase KDP is usually high in these zones, and sometimes a pronounced differential phase shift upon scattering is evident.Experimental data show that the differential phase DP and its derivative KDP are reliable indicators of liquid water in heavy precipitation. A negative bias of ZDR due to differential attenuation in precipitation could be significant in this type of storm. The validity of the correction scheme for ZDR estimates based on the DP evaluation proposed in earlier theoretical papers was examined. It was found that differential attenuation was underestimated at least twofold in the previous theoretical predictions.

Ryzhkov, A. V.; Zrni, D. S.

1994-04-01

312

Passive Radar.  

National Technical Information Service (NTIS)

This book sets forth in brief the physical principles of passive radar, describes the functional diagrams and circuit peculiarities of the apparatus, and offers recommendations for modifying radar receivers to adapt them for receiving natural radio-freque...

A. G. Nikolaev S. V. Pertsov

1975-01-01

313

Design and experimental validation of a robust-CFAR distributed multifrequency radar data fusion system  

NASA Astrophysics Data System (ADS)

A robust constant false alarm rate (CFAR) distributed detection system that operates in heavy clutter with unknown distribution is presented. The system is designed to provide CFARness under clutter power fluctuations and robustness under unknown clutter and noise distributions. The system is also designed to operate successfully under unbalanced power distributions among sensors, and exhibits fault-tolerance in the presence of sensor power fluctuations. The test statistic at each sensor is a robust (in terms of signal-to-noise ratio distribution across sensors) CFAR t-statistic. In addition to the primary binary decisions, confidence levels are generated with each decision and used in the fusion logic to robustify the fusion performance and eliminate weaknesses of the Boolean fusion logic. The test statistic and the fusion logic are analyzed theoretically for Weibull and lognormal clutter. The theoretical performance is compared against Monte-Carlo simulations that verify that the system exhibits the desired characteristics of CFARness, robustness, insensitivity to power fluctuations, and fault- tolerance. The system is tested with experimental target-in-clear and target-in-clutter data. The experimental performance agrees with the theoretically predicted behavior when the target is visible by all three radars. When the target is not visible in two out of the three radars, due to a possible undetected misalignment, the fusion performance is compromised. Robustification of the fusion performance against unpredictable and undetectable degradation of data quality in the majority of the sensors is then achieved using geometric filtering. Geometrical filtering is accomplished by using the Hough transform and additional information in the fusion design about the shape of the target trajectory(ies).

Thomopoulos, Stelios C.; Okello, Nickens N.

1995-07-01

314

Non-invasive respiration rate estimation using ultra-wideband distributed cognitive radar system.  

PubMed

It has been shown that remote monitoring of pulmonary activity can be achieved using ultra-wideband (UWB) systems, which shows promise in home healthcare, rescue, and security applications. In this paper, a geometry-based statistical channel model is developed for simulating the reception of UWB signals in the indoor propagation environment. This model enables replication of time-varying multipath profiles due to the displacement of a human chest. Subsequently, a UWB distributed cognitive radar system (UWB-DCRS) is developed for the robust detection of chest cavity motion and the accurate estimation of respiration rate. The analytical framework can serve as a basis in the planning and evaluation of future measurement programs. PMID:17945609

Chen, Yifan; Gunawan, Erry; Low, Kay Soon; Kim, Yongmin; Soh, Cheong Boon; Leyman, A Rahim; Thi, Lin Lin

2006-01-01

315

Spatial and diurnal variation of precipitation systems over Asia observed by the TRMM Precipitation Radar  

NASA Astrophysics Data System (ADS)

The spatial and diurnal variation of rainfall over Asia was investigated using the spaceborne radar data for four seasons during 1998-2003. The regional variation of the prevailing precipitation systems most closely associated with the maximum hourly rainfall was shown by examining the fine spatial distribution of rainfall amount and scale-based precipitation systems. Small precipitation systems (<102 km2) occurred most frequently around early afternoon over most land. The south facing slopes of the Himalayas, especially south of Mount Everest and the upper portion of the Brahmaputra valley, is the most obvious region of the daytime genesis of the convective systems over the Asian landmass. Over the Tibetan Plateau the occurrence of the small systems was larger than over inland India and the foothills. Large systems (>104 km2) developed mostly in the evening over nearly flat landmasses. Wide-spread systems with intense rain pixels developed over the foothills of the Himalayas in late night-early morning period, which was distinct from the daytime convection. Over ocean, in addition to the morning signature, spatially inhomogeneous and systematic characteristics were evident over the offshore region, for example, around the maritime continent. Large systems, which are strongly associated with terrain, have a great influence on the total number of rain pixels and the total amount of rainfall. For 86% of the region where large system is dominant the time of maximum rainfall is within 3 hours of the time of maximum rainfall for large systems.

Hirose, Masafumi; Nakamura, Kenji

2005-03-01

316

The effectiveness of adaptive PRF (Pulse Repetition Frequency) selection in minimizing range obscuration in the TDWR (Terminal Doppler Weather Radar) system  

Microsoft Academic Search

An adaptive procedure for selecting radar pulse repetition frequency (PRF) has been developed as the primary means of minimizing the occurrence of range aliased echoes within operationally significant coverage areas (e.g., airport runways) of the Terminal Doppler Weather Radar (TDWR) system. This procedure underwent extensive testing at the S-Band TDWR testbed while located in Denver, CO, where it was judged

S. C. Crocker

1989-01-01

317

Search and track coordination in multi-ship multi-radar systems using schedulability envelope  

Microsoft Academic Search

This paper addresses the search and track coordination problems of multiple shipboard radars. The proposed approach first\\u000a exploits the physical characteristics of a single phased array radar to improve its effective capacity. Its effective capacity\\u000a is abstracted by a closed-form equation called a schedulability envelope. Using the schedulability envelope for each radar, we deal with search and track coordination as

Phil-su Kang; Chang-gun Lee

2007-01-01

318

A system for high resolution 3D mapping using laser radar and requiring no beam scanning mechanisms  

Microsoft Academic Search

The inherently high angular and range resolution capabilities associated with radar systems operating at optical frequencies are at once a blessing and a curse. Standard implementations consist of very narrow field of view optical receivers operating in conjunction with laser transmitters or even narrower illumination beamwidth. While high angular resolution is thus achieved, mechanical scanning is required to gather data

Paul Rademacher

1988-01-01

319

Radar applications overview  

NASA Astrophysics Data System (ADS)

During the fifty years since its initial development as a means of providing early warning of airborne attacks against allied countries during World War II, radar systems have developed to the point of being highly mobile and versatile systems capable of supporting a wide variety of remote sensing applications. Instead of being tied to stationary land-based sites, radar systems have found their way into highly mobile land vehicles as well as into aircraft, missiles, and ships of all sizes. Of all these applications, however, the most exciting revolution has occurred in the airborne platform arena where advanced technology radars can be found in all shapes and sizes...ranging from the large AWACS and Joint STARS long range surveillance and targeting systems to small millimeter wave multi-spectral sensors on smart weapons that can detect and identify their targets through the use of highly sophisticated digital signal processing hardware and software. This paper presents an overview of these radar applications with the emphasis on modern airborne sensors that span the RF spectrum. It will identify and describe the factors that influence the parameters of low frequency and ultra wide band radars designed to penetrate ground and dense foliage environments and locate within them buried mines, enemy armor, and other concealed or camouflaged weapons of war. It will similarly examine the factors that lead to the development of airborne radar systems that support long range extended endurance airborne surveillance platforms designed to detect and precision-located both small high speed airborne threats as well as highly mobile time critical moving and stationary surface vehicles. The mission needs and associated radar design impacts will be contrasted with those of radar systems designed for high maneuverability rapid acquisition tactical strike warfare platforms, and shorter range cued air-to-surface weapons with integral smart radar sensors.

Greenspan, Marshall

1996-06-01

320

MAARSY -The Middle Atmosphere ALOMAR Radar System: Motivation, system description, observation strategies and first results  

NASA Astrophysics Data System (ADS)

The Leibniz-Institute of Atmospheric Physics is building a new MST-Radar (MAARSY) at the Andoya Rocket Range in Northern Norway. The scientific objective of MAARSY is the investigation of horizontal and vertical structures in the Troposphere/Lower Stratosphere and in the Mesosphere/Lower Thermosphere with a high vertical and horizontal resolution. The VHF radar operates at 53.5 MHz and reaches a peak power of 866 kW for the complete aperture. The complete aperture can be used to form a narrow (3.4° ) and freely steerable (<30° from zenith) radar beam or to create several independent steerable beams. This is achieved by connecting each of the 433 Yagi antennas to its own transceiver. Each transceiver provides a maximum power of 2kW and can be separately controlled in both phase and transmitted power. This flexibility allows us to perform a variety of experiments comprising classical Doppler-Beam-Swinging and Full Correlation Analysis, and more advanced methods such as interferometric techniques and different vertical and horizontal scanning modes with up to 50 beam positions. The installation of MAARSY started in 2009 and the full extension is scheduled for spring 2011. We present first results obtained with an initial expansion stage of MAARSY during spring and early summer 2010.

Latteck, Ralph; Singer, Werner; Stober, Gunter; Renkwitz, Toralf; Zecha, Marius; Rapp, Markus

321

Perspectives on Worldwide Spaceborne Radar Programs  

Microsoft Academic Search

Radar technology and techniques were originally developed for land-based, maritime, and airborne applications. Spaceborne radar systems development began in the 1960s in the USSR for military purposes, and in the 1970s in the United States for civilian scientific purposes. NASA launched the SeaSAT satellite in 1978, carrying a synthetic aperture radar, a radar altimeter, a radar scatterometer, and a radiometer,

P. A. Rosen; G. M. Buccolo

2007-01-01

322

A Multiband Passive Radar Demonstrator  

Microsoft Academic Search

Passive radar systems that exploit signals from the plethora of RF emissions that exist in the external environment offer a number of advantages over conventional active radar system, including procurement and operational cost saving. Each emitter has its own characteristics, including waveforms, which dictate system performance. BAE Systems Advanced Technology Centre has designed and built a demonstrator system to act

Dale Gould; Robert Pollard; Carlos Sarno; Paul Tittensor

2006-01-01

323

Bistatic auroral radar system and three-receiver-ionospheric-motions velocities: A comparison  

SciTech Connect

Observations of the NW-SE component of F region convection obtained with a scintillation drift experiment have been compared with power and Doppler velocity measurements of auroral E region coherent backscatter at 50 MHz made with the Bistatic Auroral Radar System (BARS), which is able to observe only at large magnetic aspect angles. It was found that E region backscatter was observed only when the NW-SE component of the F region drift was in the SE direction. This and other observations are shown to be consistent with a recently proposed explanation for these large aspect angle VHF backscatter observations, based on refraction through auroral ionization structures in the E region. In most cases the vector velocity derived from BARS observations had a magnitude substantially below that inferred from the scintillation measurements. Observations during one period were noticeably different from the others, with unusually small Doppler velocities.

MacDougall, J.W.; Hall, G.E.; Moorcroft, D.R. (Univ. of Western Ontario, London (Canada))

1990-09-01

324

Fast acquisition phase-locked loops for frequency agile pulsed radar systems  

NASA Astrophysics Data System (ADS)

The use of a phase-locked loop for the synchronisation of a varactor-controlled pulsed microwave solid-state source is described. The application is to radar systems and some forms of digital communication where locking must be established repetitively. Of particular importance is the speed of lock-up, and major attention is paid to the design of low group delay loop amplifiers so that maximum lock-in range is obtained with first-order characteristics. The locking performance of a 3 GHz source tunable over more than 10 percent bandwidth is described and it is shown that lock-up times in the region of 20 ns may be obtained. It is also shown that loop lock-up performance may be substantially influenced by exceedingly low-level leakage signals which can prime the source phase during the build-up of the pulse and either aid or hinder locking.

Ward, C. J.; Forrest, J. R.

1983-12-01

325

Terminal Doppler Weather Radar (TDWR) Low Level Wind Shear Alert System 3 (LLWAS 3) Integration Studies at Orlando International Airport in 1991 and 1992.  

National Technical Information Service (NTIS)

In 1993 the Federal Aviation Administration (FAA) began deploying two new wind shear detection systems: the Terminal Doppler Weather Radar (TDWR) and the third-generation Low Level Windshear Alert System (LLWAS 3). Currently, 9 airports are scheduled to r...

R. E. Cole R. F. Todd

1994-01-01

326

Multimode Radar Altimeter (MRA).  

National Technical Information Service (NTIS)

Multimode radar altimeter functions in the Comet Nucleus Sample Return mission are described. Range measurement gives distance information for navigation; angle tracking can be performed by optical systems. Velocity (three axes) can be obtained by Doppler...

G. Picardi C. Dai R. Seu A. Coradini

1988-01-01

327

Study of characteristics of a short-range multistatic radar system for diagnostics of the dynamic processes  

NASA Astrophysics Data System (ADS)

Based on the correlation and ranging methods, we developed an algorithm determining the coordinates of moving sources of wideband noise. The main advantage of this algorithm is the ability to eliminate the ambiguities of determining the target coordinates arising in the multistatic systems. To test the proposed algorithm, a laboratory passive multistatic radar system was designed and assembled. This paper describes the parameters of the experiment conducted using this system. The obtained results are discussed and analyzed.

Kanakov, V. A.; Gorda, V. V.

2013-07-01

328

Channel model estimation of OFDM for UWB radar in medical near-fall detection and warning system  

Microsoft Academic Search

A medical system for near-fall detection and warning based on UWB radar was proposed. This system for physiological activity monitoring can be considered as an application-specific short-distance wireless sensor network. The channel model estimation and performance analysis of multi-band orthogonal frequency division multiplexing (MB-OFDM) for this UWB system was described in this paper. In the end, the channel model simulation

Zaifeng Shi; Suying Yao; Hua Tian

2008-01-01

329

Nonlinear filtering for tracking large objects in radar imagery  

NASA Astrophysics Data System (ADS)

Detecting and tracking a moving ground target in radar imagery is a challenge intensified by clutter, sensor anomalies, and the substantial signature variations that occur when a target's aspect angle changes rapidly. In its GMTI mode, a radar produces range-Doppler images that contain both kinematic reports and shape features. An HRR signature, when formed as the Fourier transform of the range-Doppler image across its Doppler dimension, becomes a derived measurement and an alternative source of identity information. Although HRR signatures can vary enormously with even small changes in target aspect, such signatures were vital for associating kinematic reports to tracks in this work. This development started with video phase history (VPH) data recorded from a live experiment involving a GMTI radar viewing a single moving target. Since the target could appear anywhere in the range-Doppler image derived from the VPH data, the goal was to localize it in a small range-Doppler "chip" that could be extracted and used in subsequent research. Although the clutter in any given VPH frame generally caused false chips to be formed in the full range-Doppler image, at most one chip contained the target. The most effective approach for creating any chip is to ensure that the object is present in the return from each pulse that contributes to that chip, and to correct any phase distortions arising from range gate changes. Processing constraints dictated that the algorithm for target chip extraction be coded in MATLAB with a time budget of a few seconds per frame. Furthermore, templates and shape models to describe the target were prohibited. This paper describes the nonlinear filtering approach used to reason over multiple frames of VPH data. This nonlinear approach automatically detects and segments potential targets in the range-Doppler imagery, and then extracts kinematic and shape features that are tracked over multiple data frames to ensure that the real target is in the declared chip. The algorithm described was used successfully to process over 84,000 frames of real data without human assistance.

Greenewald, John H.; Musick, Stanton H.

2005-05-01

330

Radar techniques to study subsurfaces and interiors of the solar system objects  

Microsoft Academic Search

Over the past decades, a number of different Synthetic Aperture Radars (SAR) were developed for mapping the surface of the planets either from Earth or from orbiting spacecrafts. However, the idea to use radar to study the subsurface started to develop during the last 15 years. The ability of the radio waves to penetrate the ice, permafrost and arid surface

Wlodek Kofman

2012-01-01

331

Least Square Real Time Quality Control Routine for the North Warning Netted Radar System.  

National Technical Information Service (NTIS)

The ground surveillance radar group of the Radar and Space Division of DREO has a requirement to investigate the feasibility and propose a cost effective approach of correcting the Real Time Quality Control (RTQC) registration error problem of the North W...

H. Leung M. Blanchette

1994-01-01

332

A new digital signal processor for Doppler radar cardiopulmonary monitoring system  

Microsoft Academic Search

Remote sensing and monitoring of cardiopulmonary activities based on direct conversion Doppler radar shows promise in medical and security applications. For accurate sensing, demodulation of the quadrature outputs of a direct-conversion Doppler radar is a great challenge. A digital signal processor based on Kalman filtering and principal component combining of quadrature channels is suggested. Rate detection ability and success ratio

Mohammad Shaifur Rahman; Byung-Jun Jang; Ki-Doo Kim

2008-01-01

333

Simultaneous measurement of duskside subauroral irregularities from the CUTLASS Finland radar and EISCAT UHF system  

Microsoft Academic Search

Dusk scatter event (DUSE) (first reported by Ruohoniemi et al. [1988]) is one of the most reproducible features among the SuperDARN radar backscatter within the subauroral ionosphere. Hosokawa et al. [2001] analyzed the scattering occurrence percentage of the Northern Hemisphere SuperDARN radars in a statistical fashion and pointed out that the region where the DUSE appears has a close relationship

K. Hosokawa; M. Sugino; M. Lester; N. Sato; A. S. Yukimatu; T. Iyemori

2002-01-01

334

Satellite and Radar Analysis of Mesoscale Weather Systems in the Tropics.  

National Technical Information Service (NTIS)

Gridded Miami WSR-57 radar PPI data during the summer of 1968 are used to study the coverages and frequencies of radar echoes typically associated with five convective regimes in South Florida. Three sets of maps are presented showing the average coverage...

H. P. Gerrish

1972-01-01

335

Theory of Adaptive Radar  

Microsoft Academic Search

This paper reviews the principles of adaptive radar in which both the spatial (antenna pattern) and temporal (Doppler filter) responses of the system are controlled adaptively. An adaptive system senses the angular-Doppler distribution of the external noise field and adjusts a set of radar parameters for maximum signal-to-interference ratio and optimum detection performance. A gradient technique for control of the

L. E. Brennan; L. S. Reed

1973-01-01

336

Radar in transition  

Microsoft Academic Search

It is pointed out that radar engineers, at the end of 1984, find their field in transition between the conventional designs of the post War II era and the digitally controlled, solid-state systems which will be in place for the year 2000. The U.S. Navy has two major phased array radar systems in operation, including the rotating three-dimensional (3D) AN\\/SPS-48,

D. K. Barton

1984-01-01

337

Meteor radar signal processing and error analysis  

Microsoft Academic Search

Meteor wind radar systems are a powerful tool for study of the horizontal wind field in the mesosphere and lower thermosphere (MLT). While such systems have been operated for many years, virtually no literature has focused on radar system error analysis. The instrumental error may prevent scientists from getting correct conclusions on geophysical variability. The radar system instrumental error comes

Chunmei Kang

2008-01-01

338

Radar Wind Profilers in the Colorado Network.  

National Technical Information Service (NTIS)

Radar systems used to measure vertical profiles of the horizontal wind in nearly all weather conditions can use frequencies between about 40 and 1000 MHz. This report describes three radar systems that measure wind profiles continuously and automatically....

R. G. Strauch D. A. Merritt K. P. Moran

1985-01-01

339

Active radar jamming  

NASA Astrophysics Data System (ADS)

Active radar jammers are described. In confusion jammers the perturbing action is produced by thermal noise which is intensified, or by a carrier wave modulated by a noise signal, or by a carrier wave which is frequency modulated with a lot of sine waves of different frequencies. There are jammers to be used once, which are fired to the spot or hang from a parachute. Deception jammers (misleading jammers) emit false radar echoes, one or several produced by a repetition system, requiring a certain form of memory. It is shown how to emit varying false distance or velocities, and how to disturb angles in a radar used to guide artillery fire.

Jernemalm, Veine

1988-09-01

340

Radar absorbing material (RAM) and shaping on radar cross section reduction of dihedral corners  

Microsoft Academic Search

How far can a radar system detect an object depends the radar cross section (RCS) of the target. Corner reflectors are the major scattering centers in the radar signatures of vehicles. The monostatic return from such structures can be reduced by ensuring that surfaces never meet at right angles and by application of radar absorbing materials (RAM). This paper deals

G. G. Peixoto; A. L. de Paula; L. A. Andrade; C. M. A. Lopes; M. C. Rezende

2005-01-01

341

Determination of the effectiveness of commercial-off-the-shelf radar in the cuing of unmanned aerial vehicle pan-tilt-zoom camera systems  

NASA Astrophysics Data System (ADS)

This study examined the use of low-cost commercial-off-the-shelf (COTS) radar in support of the cuing of pan-tilt-zoom (PTZ) optical payload systems. Cancellation of the U.S. Navy's vertical take off and landing (VTOL) unmanned aerial vehicle (VTUAV) program left the Navy without a UAV with radar sensor capability. Using a UAV PTZ optical payload and a COTS radar, this study collected specific time difference measurements between PTZ optical payload searches without radar cuing and searches with radar cuing. In every test run conducted, searches with radar cuing reduced PTZ optical payload detection time. The study showed that a low-cost COTS radar mounted on a small UAV can meet some of the radar requirements lost with cancellation of the VTUAV program. The study results could have a direct impact on myriad of U.S. Navy and other U.S. government surveillance requirements, especially the monitoring of U.S. coastal waters in support of homeland security goals and objectives.

Ford, Patrick Joseph

342

Polarimetric processing techniques for coherent stepped-frequency ground-penetrating radar systems: applications toward detection of buried utilities  

NASA Astrophysics Data System (ADS)

Stepped frequency radar systems are gaining popularity in ground penetrating radar applications since these can be designed to be phase coherent, thereby taking advantage of coherent processing techniques for target detection and clutter rejection. One such system is the GeoRadar model 1000B GPR system. This system operates over the 100 - 1000 MHz frequency range with a step size of 2 MHz and a modulation frequency of 500 kHz. The magnitudes of the in-phase (I) and the quadrature (Q) channels of the received radar return signal are combined vectorially to yield the amplitude, which is then fast Fourier transformed (FFT-ed) and displayed as the depth profile. The original design of the system used a pair of log-spiral antennas for transmit and receive functions. Although log-spiral antennas are broadband and frequency- independent, their polarization, although linear at each frequency, rotates as the frequency is stepped. The images acquired under these conditions are similar to those obtained by circularly polarized antennas, making it difficult to detect long slender objects, such as pipes and cables, which can be better detected by linearly polarized antennas oriented in the same direction. In order to enhance the performance of the system, a fully polarimetric processing technique has been implemented. A set of four wideband linearly polarized antennas is used, two for transmit and two for receive, each of the two being orthogonally polarized. The system sequentially transmits, orthogonal polarizations, while the receiver simultaneously measures both reflected polarizations. The transmit polarization switching rate is high enough to ensure that the successive pulses are correlated, thereby appearing as if taken from the same location. Reflected data from all four linear combinations of transmit and receive polarizations are then coherently processed to yield the polarimetric image of the target. Sandbox test results indicate that the system is better able to image pipes and utilities.

Narayanan, Ram M.; Becker, Randall T.; Bashforth, Michael B.

1999-10-01

343

A class of frequency hop codes with nearly ideal characteristics for use in multiple-access spread-spectrum communications and radar and sonar systems  

Microsoft Academic Search

The problem of constructing frequency hop codes for use in multiuser communication systems such as multiple-access spread-spectrum communications and multiuser radar and sonar systems is addressed. Previous frequency hopping techniques are reviewed. The construction of a new family of frequency hopping codes called hyperbolic frequency hop codes is given. The concepts of multiple-access spread-spectrum communication systems and multiuser radar and

Svetislav V. Maric; Edward L. Titlebaum

1992-01-01

344

Wearable System-on-a-Chip UWB Radar for Health Care and its Application to the Safety Improvement of Emergency Operators  

Microsoft Academic Search

A new wearable system-on-a-chip UWB radar for health care systems is presented. The idea and its applications to the safety improvement of emergency operators are discussed. The system consists of a wearable wireless interface including a fully integrated UWB radar for the detection of the heart beat and breath rates, and a IEEE 802.15.4 ZigBee radio interface. The principle of

Domenico Zito; Domenico Pepe; Bruno Neri; Danilo De Rossi; A. Lanata; A. Tognetti; E. P. Scilingo

2007-01-01

345

Extended-interaction klystron for the AN/TPS-43-E radar system  

NASA Astrophysics Data System (ADS)

This effort was directed at developing and demonstrating a form, fit, and functional extended-interaction klystron replacement for the VA-145E Twystron in the AN/TPS-43E radar system. A suitable extended-interaction output circuit had already been demonstrated under Contract F30602-78-C-0029. A total of three tubes were built and tested under this program. All performed to full specifications when tested under normal factory test conditions. However, none of the three tubes performed satisfactorily in a simulated AN/TPS-43-E system (a Westinghouse TPS-3 system). Unstable tube operation was caused by the rotary joint, which has a severe mismatch near the operating frequency band. After this condition was discovered with tube S/N 001, tubes S/N 002 and S/N 003 were built in an attempt to overcome this near-short-circuit condition by reducing the output resonator impedence near the problem frequencies. This solution was only partially successful. These later tubes operated satisfactorily at some orientations of the rotary joint but would become unstable at the worst mismatch points. The task of designing a special tube that would include novel features for overcoming the severe system mismatch problem was determined to be outside the scope of this contract and this effort was concluded.

1992-06-01

346

Development of a noncontact and long-term respiration monitoring system using microwave radar for hibernating black bear.  

PubMed

The aim of this study is to develop a prototype system for noncontact, noninvasive and unconstrained vital sign monitoring using microwave radar and to use the system to measure the respiratory rate of a Japanese black bear (Ursus thibetanus japonicus) during hibernation for ensuring the bear's safety. Ueno Zoological Gardens in Tokyo planned to help the Japanese black bear (female, approximately 2 years of age) going into hibernation. The prototype system has a microwave Doppler radar antenna (10-GHz frequency, approximately 7 mW output power) for measuring motion of the body surface caused by respiratory activity without making contact with the body. Monitoring using this system was conducted from December 2006 to April 2007. As a result, from December 18, 2006, to March 17, 2007, similar behaviors reported by earlier studies were observed, such as sleeping with curled up posture and not eating, urinating or defecating. During this hibernation period and also around the time of hibernation, the prototype system continuously measured cyclic oscillations. The presence of cyclic vibrations at 8-sec intervals (about 7 bpm) was confirmed by the system before she entered hibernation on December 3, 2006. The respiratory rate gradually decreased, and during the hibernation period the respiratory rate was extremely low at approximately 2 bpm with almost no change. The results show that motion on the body surface caused by respiratory activity can be measured without touching the animal's body. Thus, the microwave radar employed here can be utilized as an aid in observing vital signs of animals. PMID:19504598

Suzuki, Satoshi; Matsui, Takemi; Kawahara, Hiroshi; Gotoh, Shinji

2009-05-01

347

Radar observables  

NASA Astrophysics Data System (ADS)

A comprehensive account is given of missile design considerations relevant to the prediction, control, and measurement of airframe radar cross sections (RCSs), with a view to the minimization of missile observability. RCS reduction may proceed through airframe shaping to deflect incident radar emissions, as well as through the use of radar-absorbing surface materials and the devision of active radar signal-cancellation methods; some combination of these is often required, due to the deficiencies of any one method. The interaction of all RCS-reduction methods with airframe aerodynamic-design criteria are stressed.

Knott, Eugene F.

348

Terminal Doppler weather radar  

Microsoft Academic Search

The terminal Doppler weather radar (TDWR) system, now under development, will provide automatic detection of microbursts and low-level wind shear. This paper discusses the TDWR performance parameters and describes its structural elements, including the antenna subsystem, the transmitter, the receiver\\/exciter, the digital signal processor, and the radar product generator\\/remote monitoring subsystem. Attention is also given to the processes of the

M. Michelson; W. W. Shrader; J. G. Wieler

1990-01-01

349

Radar polarimetry for geoscience applications  

Microsoft Academic Search

The present volume on radar polarimetry for geoscience applications discusses wave properties and polarization, scattering matrix representation for simple targets, scattering models for point and distributed targets, polarimetric scatterometer systems and measurements, polarimetric radar system design, and polarimetric SAR applications. Attention is given to plane waves in a lossless homogeneous medium-wave polarization, polarization synthesis and response, and coordinate system transformations.

Fawwaz T. Ulaby; Charles Elachi; K. McDonald; K. Sarabandi; M. Whitt; H. Zebker; J. J. van Zyl

1990-01-01

350

Environment-adaptive radar techniques  

Microsoft Academic Search

This report describes the work performed in the first year of a contract to investigate the measurement and mitigation of environmental effects in a selected modern radar system. The baseline system is a mobile ground-based tactical radar system which performs wide-area surveillance for aircraft targets as well as multiple target tracking for eventual handover. The dominant technical problem is found

J. E. Howard; G. W. Lank; A. W. Rihaczek

1981-01-01

351

A microwave measurement system for metallic object detection using swept-frequency radar  

NASA Astrophysics Data System (ADS)

Guns and knives have become a significant threat to public safety. Recently, a variety of techniques based on Electromagnetics (EM) have been used for their detection. For example, walk-through metal detection has been used in airports; X-ray and THz detection systems have been used for luggage screening. Different EM frequencies for metallic object detection have demonstrated different merits. This paper reports on a 1-14 GHz swept-frequency radar system for metallic object detection using reflection configuration. The swept frequency response and resonant frequency behaviour of a number of metallic objects, in terms of position, object shape, rotation and multiple objects have been tested and analysed. The system working from 1 to 14 GHz has been set up to implement sensing of metal items at a standoff distance of more than 1 meter. Through a series of experimental investigations, it can be found that the optical depths derived from the Fourier Transform of the power spectrum profile is in close relation with the relative location of the metallic object. The cross correlation between coherence-polarisation and cross-polarisation RF returns can be used to distinguish different objects. Therefore the optical depth and the cross correlation can be used as useful features for metallic object detection and characterisation in this portion of the microwave frequency spectrum.

Li, Yong; Tian, Gui Y.; Bowring, Nicholas; Rezgui, Nacer

2008-10-01

352

Operational Problems of the Air Traffic Control Radar Beacon System. 1972 Seminar Held at the Shelburne Hotel, Atlantic City, New Jersey, on February 8 through 11, 1972.  

National Technical Information Service (NTIS)

The Air Traffic Control Radar Beacon System (ATCRBS) Seminar was the first of its kind dealing specifically with ATCRBS problems. Personnel attended the seminar from management, research, maintenance and operational organizations of the Federal Aviation A...

1973-01-01

353

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

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

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

354

A coherent FM laser radar based system for remote metrology in ITER  

SciTech Connect

The plasma facing surfaces in ITER must be aligned to millimeter accuracy with respect to the magnetic flux surfaces to prevent impurity influx into the plasma and to avoid component damage. Checking of in-vessel component alignment during initial assembly, operation, and subsequent maintenance is anticipated. A fully remote metrology system is necessary, particularly since major remote operations such as shield blanket exchange and divertor cassette replacement are planned. The metrology system must be compatible with the ITER in-vessel environment of high gamma radiation ({approximately} 10{sup 6} R/hr), super-clean ultra-high-vacuum ({approximately} 10{sup {minus}8} Torr), and elevated temperature ({approximately}200 C). A fast scanning rate is required since the plasma facing surface in ITER is very large ({approximately} 1,500 m{sup 2}). A coherent FM laser radar based metrology system, developed by Coleman Research Corporation, is being adopted to accomplish this task. Conceptually, this metrology system consists of a compact (few cm{sup 3}) remotely deployed laser transceiver optics module, linked through fiber optics to the laser source and imaging units that are located outside the biological shield. Range measurements conducted on a variety of surfaces using the system have yielded sub-millimeter accuracy. Therefore, the technique will easily meet the precision requirement for the ITER application. Computer simulations have been carried out to determine the optimum number of units required for complete mapping of the plasma facing surfaces. Most in-vessel components of the system appear to be radiation hardenable and vacuum compatible. Details of the system and developments required to make it fully compatible for ITER metrology application will be elaborated.

Barry, R.E.; Burgess, T.W.; Menon, M.M. [Oak Ridge National Lab., TN (United States). Robotics and Process Systems Div.; Slotwinski, A.; Sebastian, R. [Coleman Research Corp., Springfield, VA (United States)

1995-12-31

355

Structure and Dynamics of the Polar Mesosphere Investigated with the EISCAT Radar Systems (Absract Only).  

National Technical Information Service (NTIS)

The principle of incoherent backscatter of radar waves from the ionized part of the mesosphere, namely the D region of the ionosphere, is discussed. The coherent backscatter process, resulting from ionization irregularities due to clear air turbulence and...

J. Roettger

1991-01-01

356

Properties of Tropical Convection Observed by Millimeter-Wave Radar Systems  

Microsoft Academic Search

This paper describes the results of analysis of over 825 000 profiles of millimeter-wave radar (MWR) reflectivities primarily collected by zenith-pointing surface radars observing tropical convection associated with various phases of activity of the large-scale tropical circulation. The data principally analyzed in this paper come from surface observations obtained at the Atmospheric Radiation Measurement Manus site during active and break

Graeme L. Stephens; Norman B. Wood

2007-01-01

357

UWB radar imaging system with two-element receiving array antenna  

Microsoft Academic Search

UWB signals can propagate in cluttered environment and opaque media that enables exploring hidden homogeneities through registering and processing backscattered signals. One of such an application is UWB through-wall vision radar (UWBR), Sostanovsky (2004), Radar Vision (2005). A prototype of low-complexity and low-cost portable UWBR sensor with a small receiving antenna array is presented. Several key implementation issues are discussed

Dmitriy L. Sostanovsky; A. O. Boryssenko; E. S. Boryssenko

2005-01-01

358

Lunar Pole Illumination and Communications Maps Computed from Goldstone Solar System Radar Elevation Data  

NASA Astrophysics Data System (ADS)

The Goldstone Solar System Radar (GSSR) group at JPL produced a digital elevation model (DEM) of the lunar south pole using data obtained in 2006. This new DEM has 40-m horizontal resolution and about 5-m relative vertical accuracy. This article explains how this DEM was used to evaluate average solar illumination and Earth visibility near the lunar south pole. The elevation data were converted into local terrain horizon masks for the area within 100 km of the lunar south pole. These topocentric horizon masks were converted into selenographic latitude and longitude coordinates, then compared to regions bounding the maximum Sun and Earth motions relative to the Moon. Estimates of Earth visibility were computed by integrating the area of the region bounding the Earth's motion that was below the horizon mask. Solar illumination and other metrics were computed similarly. Proposed lunar south pole base sites are examined in detail, with the best site showing multiyear averages of solar power availability of 92 percent and direct-to-Earth (DTE) communication availability of 51 percent. Results are compared with a theoretical model and with actual Sun and Earth visibility averaged over the years 2009 to 2028. Peaks near the lunar south pole with continuous DTE communications are also presented. Results for the lunar north pole were computed using the GSSR DEM of the lunar north pole produced in 1997. The article also explores using a heliostat to reduce the photovoltaic power system mass and complexity.

Bryant, S.

2009-02-01

359

Design and test of a high power inverter for a ground based radar system for theater missile defense  

Microsoft Academic Search

A scaled prototype for a MW level inverter for the power supply of a new ground-based radar system for theater missile defense has been designed and tested. The full-scale inverter is specified to supply three-phase, 60 Hz AC power at 4160 V with a continuous power level of 1 MW. In order to achieve this high output voltage in an

M. Giesselmann; B. Crittenden; J. Fonseca

1997-01-01

360

TRMM Radar.  

National Technical Information Service (NTIS)

The results of a conceptual design study and the performance of key components of the Bread Board Model (BBM) of the Tropical Rainfall Measuring Mission (TRMM) radar are presented. The radar, which operates at 13.8 GHz and is designed to meet TRMM mission...

K. Okamoto

1993-01-01

361

Planetary Ephemerides Approximation for Radar Astronomy.  

National Technical Information Service (NTIS)

The planetary ephemerides approximation for radar astronomy is discussed, and, in particular, the effect of this approximation on the performance of the programmable local oscillator (PLO) used in Goldstone Solar System Radar is presented. Four different ...

R. Sadr M. Shahshahani

1991-01-01

362

Lidar-Radar Lower Atmospheric Observations.  

National Technical Information Service (NTIS)

Daytime observations of the vertical temperature and humidity structure in the atmosphere below 1000 meters made with a Cricketsonde rocket system are compared with simultaneous observations from a ruby lidar (laser radar) and a microwave K-band radar. Ob...

W. Viezee J. Oblanas

1968-01-01

363

46 CFR 121.404 - Radars.  

Code of Federal Regulations, 2012 CFR

...OVERNIGHT ACCOMMODATIONS FOR MORE THAN 49 PASSENGERS VESSEL CONTROL AND MISCELLANEOUS SYSTEMS AND EQUIPMENT Navigation Equipment...radar is not necessary due to the vessel's route and local weather conditions. (c) The radar and its installation must...

2012-10-01

364

Non-contact Screening System with Two Microwave Radars in the Diagnosis of Sleep Apnea-Hypopnea Syndrome.  

PubMed

There are two key problems in applying Doppler radar to a diagnosis system for sleep apnea-hypopnea syndrome. The first is noise associated with body movement and the second is the body position in bed and the change of the sleeping posture. We propose a new automatic gain control and a real-time radar-output channel selection method which is based on a spectrum shape analysis. There are three types of sleep apnea: central sleep apnea, obstructive sleep apnea and mixed sleep apnea. In this paper we paid attention to the obstructive sleep apnea and attempted to detect the disorder of corrugated shape compared with usual breathing or the paradoxical movement of the reversed phase with chest and abdominal radar signals. A prototype of the system was set up at a sleep disorder center in a hospital and field tests were carried out with eight subjects. Despite the subjects engaging in frequent body movements while sleeping, the system was quite effective in the diagnosis of sleep apnea-hypopnea syndrome (r=0.98). PMID:23920557

Kagawa, Masayuki; Ueki, Katsuhiko; Kurita, Akira; Tojima, Hirokazu; Matsui, Takemi

2013-01-01

365

COBRA meteor radar antenna designs  

Microsoft Academic Search

A meteor radar system is one of the effective remote sensing techniques in measuring atmospheric parameters such as wind velocities, temperature, pressure and density which are essential in understanding the atmospheric dynamics in the Mesosphere Lower Thermosphere (MLT) region. Previous studies of very high frequency (VHF) meteors radar systems suggest that the minimum error for the estimation of the horizontal

Mohamad Zainuddin

2009-01-01

366

Resolution independent radar target recognition  

Microsoft Academic Search

The value of Through the Wall Radar Imaging (TWRI) data collected with one system is limited when training the automatic target recognition classifier of a second system because of variation in the Point Spread Function (PSF). The target image is a function of both the scene reflectivity and the PSF, which is in turn a function of the imaging radar's

Graeme E. Smith; Bijan G. Mobasseri

2011-01-01

367

A Versatile C-Band Radar Transmitter.  

National Technical Information Service (NTIS)

The C-band transmitter is one of the four radar transmitters which are included in the Four-Frequency Radar System. The Four-Frequency Radar in its entirety is an airborne system capable of measuring target characteristics and terrain backscatter, and has...

W. T. Davis N. R. Mills J. A. Weston

1971-01-01

368

Australian Weather Watch Radar Home Page  

NSDL National Science Digital Library

The Commonwealth Bureau of Meteorology's Weather Watch Radar website provides up-to-date radar images of the locations of rain in Australia in relation to local features such as coast lines. The newly developed Loops provide four consecutive radar images so that users can view how the weather has been changing in the last forty to fifty minutes. The website provides radar images of past cyclone events as well as updates on severe weather throughout Australia. Those interested in radar systems can discover how the weather radars work and how to interpret the maps. [RME

369

Development of a passive VHF radar system using software-defined radio for equatorial plasma instability studies  

NASA Astrophysics Data System (ADS)

In this paper, a bistatic passive radar receiver system named "Coherent-scatter Atmospheric Passive Radar Imager (CAPRI)" is described. It is primarily designed to study the dynamics of the upper atmosphere by utilizing "transmitters of opportunity" as the RF target illuminators. CAPRI is constructed using the open source software-defined radio toolkit, GNU Radio, to meet the signal processing requirements in combination with the open source hardware, Universal Software Radio Peripheral 2, for data acquisition. The resultant system is highly flexible, and we present the details of the design as well as a performance analysis. CAPRI will be deployed in Peru, near the magnetic equator, for long-term operations in the area. FM stations near Lima, Peru, will be utilized with the targets of interest being the equatorial electrojet and the spread F. The results will then be compared to the Jicamarca Unattended Long-term investigations of the Ionosphere and Atmosphere (JULIA) radar data, and CAPRI will be used to improve the simultaneous time and spatial coverage in the region in a more cost-effective manner.

Tuysuz, B.; Urbina, J.; Lind, F. D.

2013-07-01

370

Assimilation of Doppler Radar Observations with a Regional 3DVAR System: Impact of Doppler Velocities on Forecasts of a Heavy Rainfall Case  

Microsoft Academic Search

In this paper, the impact of Doppler radar radial velocity on the prediction of a heavy rainfall event is examined. The three-dimensional variational data assimilation (3DVAR) system for use with the fifth-generation Pennsylvania State University-NCAR Mesoscale Model (MM5) is further developed to enable the assimilation of radial velocity observations. Doppler velocities from the Korean Jindo radar are assimilated into MM5

Qingnong Xiao; Ying-Hwa Kuo; Juanzhen Sun; Wen-Chau Lee; Eunha Lim; Yong-Run Guo; Dale M. Barker

2005-01-01

371

Coherent IR radar technology  

NASA Astrophysics Data System (ADS)

Recent progress in the development of coherent IR radar equipment is reviewed, focusing on the Firepond laser radar installation and the more compact systems derived for it. The design and capabilities of Firepond as a long-range satellite-tracking device are outlined. The technological improvements necessary to make laser radar mobile are discussed: a lightweight, stable 5-10-W transmitter laser for both CW and pulsed operation, a 12-element HgCdTe detector array, an eccentric-pupil Ritchey-Chretien telescope, and a combination of near-field phase modification and anamorphic expansion to produce a fan beam of relatively uniform intensity. Sample images obtained with a prototype system are shown, and the applicability of the mobile system to range-resolved coherent DIAL measurement is found to be similar to that of a baseline DIAL system.

Gschwendtner, A. B.; Harney, R. C.; Hull, R. J.

372

Laser Radar Development.  

National Technical Information Service (NTIS)

A range-gated imaging (RGI) laser radar system was constructed and field-tested at the Chesapeake Bay Division of the Naval Research Laboratories to evaluate the capability of RGI systems to provide extremely high contrast image displays. The system emplo...

J. A. Jenney

1968-01-01

373

Design and implementation of an experimental GSM based passive radar  

Microsoft Academic Search

Passive radar is a special kind of radar system that utilizes electromagnetic radiation already present in the environment to detect targets as well as estimate target parameters. This paper discusses the use of GSM base station as a non-cooperative illuminator for bistatic passive radar operation. The design and implementation of this novel passive radar system is introduced. Some initial experimental

Hongbo Sun; Danny K. P. Tan; Yilong Lu

2003-01-01

374

FM based passive bistatic radar target range improvement - Part II  

Microsoft Academic Search

The bistatic radar has been revitalized over the last few years through the rapid development of the passive bistatic radar technology. Passive bistatic radar systems have unique properties, especially is time on target high compared to traditional radar systems, as well as the freedom in choosing from the available transmitters of opportunity. This paper will focus on how to take

Karl Erik Olsen; Karl Woodbridge; Idar A. Andersen

2010-01-01

375

Proposed experiment to detect air showers with the Jicamarca radar system  

NASA Astrophysics Data System (ADS)

When an extremely high energy particle interacts in the atmosphere, the collision induces a multiplicative cascade of charged particles, which grows exponentially until the energy per secondary degrades enough to dissipate in ionization of the surrounding air. During this process the compact cloud of energetic secondary particles travels 10-20 km through the atmosphere, leaving a column of ionization behind it. This ionized column quickly recombines, but for a period of order 0.1 ms it is highly reflective at frequencies below 100 MHz. This ionization trail, which is comparable in ionization density to that of a micro-meteor, should be clearly detectable using standard radar methods. We propose radar measurements using the facilities operated by Cornell University and the Instituto Geofisico del Peru (IGP) at the Jicamarca Radio Observatory near Lima, Peru. This facility's primary instrument is 49.92 MHz incoherent scatter radar, transmitting up to 1.5 MW of pulse power. .

Vinogradova, T.; Chapin, E.; Gorham, P.; Saltzberg, D.

2001-07-01

376

Decorrelation in interferometric radar echoes  

Microsoft Academic Search

A radar interferometric technique for topographic mapping of surfaces, implemented utilizing a single synthetic aperture radar (SAR) system in a nearly repeating orbit, is discussed. The authors characterize the various sources contributing to the echo correlation statistics, and isolate the term which most closely describes surficial change. They then examine the application of this approach to topographic mapping of vegetated

Howard A. Zebker; John Villasensor

1992-01-01

377

Imaging Radars for Geoscience Use  

Microsoft Academic Search

Properties of a side-looking airborne radar (SLAR) designed for geoscience rather than military use are presented. The speckled nature of usual single-frequency radar images may be reduced by averaging in azimuth and by averaging in range or transmitting excess range bandwidth. With synthetic aperture systems, averaging is possible in both range and azimuth, but only range averaging (excess bandwidth) is

R. K. Moore; G. C. Thomann

1971-01-01

378

Radar sector blanker  

NASA Astrophysics Data System (ADS)

A radar sector blanker comprises in analog-to-digital converter and a sector controller unit. The analog-to-digital converter receives the analog synchro voltages describing the positioning of a radar antenna and changes these voltages into binary-coded decimal (BCD) information. The sector controller unit comprises a portable housing, a controller system, and a power supply. The controller system includes an OFF comparator circuit, an ON comparator circuit, an S-R latch, and a solid-state switch. Each comparator circuit comprises three cascaded transistor-transistor logic (TTL) integrated chips. The power supply gives a direct-current voltage to the solid-state switch and the TTL chips. The sector blanker blocks transmission for a predetermined rotational region or sector of a radar system.

Hall, Roger B.

1994-03-01

379

Microwave radar detection of gas pipeline leaks  

Microsoft Academic Search

We are developing a microwave radar sensing and imaging system to detect and locate gas leaks in natural gas pipelines. The underlying detection principle is radar backscattering from the index-of-refraction inhomogeneities introduced by the dispersion of methane in air. An essential first step in the development effort is modeling to estimate the radar cross section. This paper describes the modeling

N. Gopalsami; D. B. Kanareykin; V. D Asanov; S. Bakhtiari; A. C. Raptis

2002-01-01

380

Microwave Radar Detection of Gas Pipeline Leaks  

Microsoft Academic Search

We are developing a microwave radar sensing and imaging system to detect and locate gas leaks in natural gas pipelines. The underlying detection principle is radar backscattering from the index-of-refraction inhomogeneities introduced by the dispersion of methane in air. An essential first step in the development effort is modeling to estimate the radar cross section. This paper describes the modeling

N. Gopalsami; D. B. Kanareykin; V. Asanov; S. Bakhtiari; A. C. Raptis

2003-01-01

381

Doppler Radar Probing of the Clear Atmosphere  

Microsoft Academic Search

In the past few years, sensitive Doppler radars have been used to probe the clear atmosphere from the boundary layer up to stratospheric altitudes. Routine Doppler radar observations are now attainable over a wide range of frequencies at virtually all altitudes in this height range. Although a number of these systems operate at UHF (300-3000 MHz), sensitive Doppler radars have

K. S. Gage; B. B. Balsley

1978-01-01

382

a Satellite-Based Radar Wind Sounder  

Microsoft Academic Search

The objective of this study is to investigate the application of Doppler radar systems for global wind measurement. A model of the satellite-based radar wind sounder (RAWS) is discussed, and many critical problems in the designing, such as the antenna scan pattern, tracking the Doppler shift caused by satellite motion, and backscattering of radar signals from different types of clouds,

Weizhuang Xin

1991-01-01

383

Radar seekers for precision guided munitions  

Microsoft Academic Search

A general perspective is given on the evolution of radar guidance, utilizing the astonishing current advances in electronic technology, so as to overcome past disadvantages of radar guidance and to solve the problems of battlefield targets. Missile control, radar homing missiles, infrared detectors, and several types of missile systems are discussed.

D. A. Ramsay

1982-01-01

384

Compact programmable ground-penetrating radar system for roadway and bridge deck characterization  

NASA Astrophysics Data System (ADS)

A compact, high-performance, programmable Ground Penetrating Radar (GPR) system is described based on an impulse generator transmitter, a full waveform sampling single shot receiver, and high directivity antennas. The digital programmable pulse generator is developed for the transmitter circuit and both the pulse width and pulse shape are tunable to adjust for different modes of operation. It utilizes a step-recovery diode (SRD) and short-circuited microstrip lines to produce sub-nanosecond wide ultra-wideband (UWB) pulses. Sharp step signals are generated by periodic clock signals that are connected to the SRD's input node. Up to four variable width pulses (0.8, 1.0, 1.5, and 2.1 ns) are generated through a number of PIN switches controlling the selection of different microstrip lengths. A schottky diode is used as a rectifier at the output of the SRD in order to pass only the positive part of the Gaussian pulses while another group of short-circuit microstrips are used to generate amplitude-reversed Gaussian pulses. The addition of the two pulses results in a Gaussian monocycle pulse which is more energy efficient for emission. The pulse generator is connected to a number of UWB antennas. Primarily, a UWB Vivaldi antenna (500 MHz to 5 GHz) is used, but a number of other high-performance GPR-oriented antennas are investigated as well. All have linear phase characteristic, constant phase center, constant polarization and flat gain. A number of methods including resistive loading are used to decrease any resonances due to the antenna structure and unwanted reflections from the ground. The antennas exhibit good gain characteristics in the design bandwidth.

Busuioc, Dan; Xia, Tian; Venkatachalam, Anbu; Huston, Dryver; Birken, Ralf; Wang, Ming

2011-03-01

385

Radar analysis of the life cycle of Mesoscale Convective Systems during the 10 June 2000 event  

NASA Astrophysics Data System (ADS)

The 10 June 2000 event was the largest flash flood event that occurred in the Northeast of Spain in the late 20th century, both as regards its meteorological features and its considerable social impact. This paper focuses on analysis of the structures that produced the heavy rainfalls, especially from the point of view of meteorological radar. Due to the fact that this case is a good example of a Mediterranean flash flood event, a final objective of this paper is to undertake a description of the evolution of the rainfall structure that would be sufficiently clear to be understood at an interdisciplinary forum. Then, it could be useful not only to improve conceptual meteorological models, but also for application in downscaling models. The main precipitation structure was a Mesoscale Convective System (MCS) that crossed the region and that developed as a consequence of the merging of two previous squall lines. The paper analyses the main meteorological features that led to the development and triggering of the heavy rainfalls, with special emphasis on the features of this MCS, its life cycle and its dynamic features. To this end, 2-D and 3-D algorithms were applied to the imagery recorded over the complete life cycle of the structures, which lasted approximately 18 h. Mesoscale and synoptic information were also considered. Results show that it was an NS-MCS, quasi-stationary during its stage of maturity as a consequence of the formation of a convective train, the different displacement directions of the 2-D structures and the 3-D structures, including the propagation of new cells, and the slow movement of the convergence line associated with the Mediterranean mesoscale low.

Rigo, T.; Llasat, M. C.

2005-12-01

386

Doppler Radar Meteorological Observations. Part A. System Concepts, Responsibilities, and Procedures (Interim Version One).  

National Technical Information Service (NTIS)

The purpose of Federal Meteorological Handbook Number 11 (FMH No. 11) is to standardize, insofar as practical, the operation of the Weather Surveillance Radar - 1988, Doppler (WSR-88D) units and the procedures used by personnel of the Departments of Comme...

1991-01-01

387

Preliminary design of a space system operating a ground-penetrating radar  

Microsoft Academic Search

Ground-penetrating radars (GPR) are currently used only in ground campaigns or in few airborne installations. A feasibility analysis of a space mission operating a GPR for archaeological applications is presented in this work with emphasis on spacecraft critical aspects: antenna dimension and power required for achieving adequate depth and accuracy. Sensor parametric design is performed considering two operating altitudes (250

Marco D’Errico; Salvatore Ponte; Michele Grassi; Antonio Moccia

2005-01-01

388

In-bore chronograph--a laser radar for interior ballistics measurements, part 1: system design  

Microsoft Academic Search

An internal research and development program at Teledyne Brown Engineering has produced a laser radar device to measure velocities of projectiles as they travel through the barrel of a gun. The technique measures velocities directly via the Doppler shift imposed on a retro- reflected laser beam. The device, called the In-Bore Chronograph (IBC), is believed to be the first coherent

Greg Lawson; Stuart Fowler; Howard W. Halsey; Kerry B. Whittle; Gary W. Kamerman

1993-01-01

389

SCR584 radar and the Mark 56 naval gun fire control system  

Microsoft Academic Search

The pioneering World War II effort of marrying precision radar to antiaircraft fire-control computers is described. The people and organizations involved are discussed, and the new areas of application opened by the research are addressed. The technical problems that had to be solved are examined

1990-01-01

390

On the design of integrated HF radar systems for Homeland Security applications  

Microsoft Academic Search

In this paper, HCAC's research and development efforts on the development of integrated and low cost HF radar for coastal surveillance and other Homeland Security applications are summarized. The proposed design incorporates electrically small antenna for rapid deployment, supports operation on floating platforms by using enhanced DSP algorithms to mitigate clutter, incorporates improved propagation modeling to more accurately select optimum

James Baker; Nuri Celik; Nobutaka Omaki; Jill Kobashigawa; Hyoung-Sun Youn; Magdy F. Iskander

2010-01-01

391

Arctangent Demodulation With DC Offset Compensation in Quadrature Doppler Radar Receiver Systems  

Microsoft Academic Search

Direct-conversion microwave Doppler radar can be used to detect cardiopulmonary activity at a distance. One challenge for such detection in single channel receivers is demodulation sensitivity to target position, which can be overcome by using a quadrature receiver. This paper presents a mathematical analysis and experimental results demonstrating the effectiveness of arctangent demodulation in quadrature receivers. A particular challenge in

Byung-Kwon Park; Olga Boric-Lubecke; Victor M. Lubecke

2007-01-01

392

76 FR 35176 - Operation of Radar Systems in the 76-77 GHz Band  

Federal Register 2010, 2011, 2012, 2013

...Office of Engineering and Technology, (202) 418-2437...Office of Engineering and Technology, 445 12th Street...enhanced vehicular radar technologies in the 76-77 GHz band...beside, or behind a car to improve the driver's...limits for millimeter wave vehicular...

2011-06-16

393

MARSnet: Mission-aware Autonomous Radar Sensor Network for Future Combat Systems.  

National Technical Information Service (NTIS)

During the period of 7/1/2007-12/31/2007, we performed the following studies on radar sensor network: (1) Network-enabled Electronic Warfare (NEW) for Collaborative Automatic Target Recognition (CATR); (2) Foliage clutter modeling using narrowband and UWB...

2007-01-01

394

Investigations into an uwb microwave radar system for breast cancer detection  

Microsoft Academic Search

Recent years have shown a considerable interest in using a wideband microwave radar technique for detecting and locating breast cancer. The basis for microwaves to detect and locate tumour is the difference in the electrical properties of normal and malignant breast tissue. Normal breast tissue is largely transparent to microwaves while lesions, which contain more water and blood, scatter them

Wee Chang Khor; M. E. Bialkowski

2007-01-01

395

Comparison of radar polarimetric and lidar scattering matrix measurements and systems calibration methods  

Microsoft Academic Search

A systematic approach to the measurements of the four basic scattering matrices used in radar and also recently more frequently in lidar metrology of isolated scatterers and distributed scatter ensembles is considered. The pertinent scattering matrices in use are the 2×2 complex JONES propagation matrix [T] or the 2×2 complex Sinclair scattering matrix [S] for the coherent point scatter case;

H. Mott; Y. Yamaguchi; W.-M. Boerner

1993-01-01

396

Numerical study of a low permeability microporous heat sink for cooling phased-array radar systems  

Microsoft Academic Search

Microporous media is being used to develop an improved forced convection cold plate device for removing waste heat from high frequency phased-array radar apertures. The waste heat, generated by transmit and receive microwave functions mounted in separate electronic modules, is conducted to the surfaces of a thin rectangular enclosure (cold plate) through which coolant flows. The performance of the phased-array

R. M. Weber

1996-01-01

397

Terminal Doppler weather radar  

NASA Astrophysics Data System (ADS)

The terminal Doppler weather radar (TDWR) system, now under development, will provide automatic detection of microbursts and low-level wind shear. This paper discusses the TDWR performance parameters and describes its structural elements, including the antenna subsystem, the transmitter, the receiver/exciter, the digital signal processor, and the radar product generator/remote monitoring subsystem. Attention is also given to the processes of the base data formation, point target removal, signal-to-noise thresholding, and velocity de-aliasing and to the TDWR algorithms and displays. A schematic diagram of the TDWR system is presented.

Michelson, M.; Shrader, W. W.; Wieler, J. G.

1990-02-01

398

Extended Target Recognition in Cognitive Radar Networks  

PubMed Central

We address the problem of adaptive waveform design for extended target recognition in cognitive radar networks. A closed-loop active target recognition radar system is extended to the case of a centralized cognitive radar network, in which a generalized likelihood ratio (GLR) based sequential hypothesis testing (SHT) framework is employed. Using Doppler velocities measured by multiple radars, the target aspect angle for each radar is calculated. The joint probability of each target hypothesis is then updated using observations from different radar line of sights (LOS). Based on these probabilities, a minimum correlation algorithm is proposed to adaptively design the transmit waveform for each radar in an amplitude fluctuation situation. Simulation results demonstrate performance improvements due to the cognitive radar network and adaptive waveform design. Our minimum correlation algorithm outperforms the eigen-waveform solution and other non-cognitive waveform design approaches.

Wei, Yimin; Meng, Huadong; Liu, Yimin; Wang, Xiqin

2010-01-01

399

Extended target recognition in cognitive radar networks.  

PubMed

We address the problem of adaptive waveform design for extended target recognition in cognitive radar networks. A closed-loop active target recognition radar system is extended to the case of a centralized cognitive radar network, in which a generalized likelihood ratio (GLR) based sequential hypothesis testing (SHT) framework is employed. Using Doppler velocities measured by multiple radars, the target aspect angle for each radar is calculated. The joint probability of each target hypothesis is then updated using observations from different radar line of sights (LOS). Based on these probabilities, a minimum correlation algorithm is proposed to adaptively design the transmit waveform for each radar in an amplitude fluctuation situation. Simulation results demonstrate performance improvements due to the cognitive radar network and adaptive waveform design. Our minimum correlation algorithm outperforms the eigen-waveform solution and other non-cognitive waveform design approaches. PMID:22163464

Wei, Yimin; Meng, Huadong; Liu, Yimin; Wang, Xiqin

2010-11-11

400

Passive Radar Tracking Apparatus.  

National Technical Information Service (NTIS)

The radar system tracks a target whether it generates a signal of its own or not and may be used to sense noise energy radiated by the sun, other objects, or other celestial bodies. The system includes an antenna assembly of four horns arranged in a recta...

D. K. Barton W. J. Rose

1965-01-01

401

Propagation effects in tactical radars  

NASA Astrophysics Data System (ADS)

Tactical battlefield radars are employed in surveillance and target acquisition roles at ranges of approximately 1 to 20 km, their main targets being enemy ground vehicles and personnel. As with all types of radar the operating environment has a significant effect on the design and performance of these systems and propagation considerations are an important factor. The major propagation factors which limit the performance of tactical radars are the availability of line of sight, ground clutter, and effects of the weather. The ways in which propagation factors affect the choice of such radar parameters as frequency, polarisation, and RF waveform are discussed, and the ways in which propagation constraints can be minimised by the design of the signal processing system are considered. In an EW environment an important operational requirement is to minimize the probability of the location of the position of the radar by the enemy. Propagation effects such as multipath and diffraction are considered in broad terms in this context.

Prew, B. A.

1982-04-01

402

Observation of three-dimensional structures of quasi-periodic echoes associated with mid-latitude sporadic-E layers by MU radar ultra-multi-channel system  

NASA Astrophysics Data System (ADS)

Quasi-periodic (QP) backscatter observed by VHF radars associated with the mid-latitude Sporadic-E (Es) layers is characterized by distinct striations on range-time-intensity (RTI) plots. Two competing models claim to explain the structure of unstable regions that scatter the radar waves: horizontally drifting patches at an almost constant altitude and unstable regions elongated in altitude along the geomagnetic field line. We have conducted interferometric imaging observations of QP radar echoes to investigate spatial structures of QP echoes, precisely. Kyoto University's newly developed ultra-multi-channel receiving system of middle and upper atmosphere (MU) radar was used. We used 19 independent channels for the radar imaging, and determined the three-dimensional structure and the motion of the QP echoes. During the observation from 30 May to 02 June 2005, well-defined QP echoes were observed on the nights of 31 May, 01 June, and 02 June 2005. Some of QP echoes were found at altitudes higher than 120 km and appeared to descend in altitude as they approached the radar. This result suggests that backscatter regions are developed along the geomagnetic field line from Es layer altitudes to as high as 130 km and that the fluctuations in plasma density and electric field observed by Pfaff et al. (2005) using in-situ measurements form a part of QP echoes.

Saito, S.; Yamamoto, M.; Hashiguchi, H.; Maegawa, A.

2006-07-01

403

Development of a GPS-aided motion measurement, pointing, and stabilization system for a Synthetic Aperture Radar. [Global Positioning System (GPS)  

SciTech Connect

An advanced Synthetic Aperture Radar Motion Compensation System has been developed by Sandia National Laboratories (SNL). The system includes a miniaturized high accuracy ring laser gyro inertial measurement unit, a three axis gimbal pointing and stabilization assembly, a differential Global Positioning System (GPS) navigation aiding system, and a pilot guidance system. The system provides several improvements over previous SNL motion compensation systems and is capable of antenna stabilization to less than 0.01 degrees RMS and absolute position measurement to less than 5.0 meters RMS. These accuracies have been demonstrated in recent flight testing aboard a DHC-6-300 Twin Otter'' aircraft.

Fellerhoff, J.R.; Kohler, S.M.

1991-01-01

404

On the Design of Ultra Wideband FCC Compliant Integrated Radars  

Microsoft Academic Search

In this paper the design of a simple monostatic impulse radar is analyzed. The well known radar equations are revised accounting for the FCC rules. The required radar performances are quickly translated into the pulse parameters to obtain an FCC compliant radar. The effects of two major system weaknesses are also investigated: the effects of the ultra wideband channel and

Alessio Cacciatori; L. Colalongo; Z. Miklos; K. Vajna

2006-01-01

405

New Ornithological Radar Technologies for Bird & Bat Discrimination & Species Identification  

Microsoft Academic Search

Radars are more frequently being used to develop data on bird and bat activity at proposed wind turbine sites for determination of mortality risk. Radar provides superior data compared to traditional bird and bat survey techniques generating highly robust datasets to support the risk analysis. Most radar systems to date, however, have used marine radars and, while some are capable

Scott McLaughlin; Andreas Smith

406

Improvements of radar clutter classification in air traffic control environment  

Microsoft Academic Search

The use of adaptive technologies may prove useful in the processing of radar signals. The proposed radar clutter classificator is aimed to improve the detection of snow clutter presence in data acquired by a ground radar system in an air traffic control environment. Each plot detected in the radar image is processed in order to extract a series of features

L. Pierucci; L. Bocchi

2007-01-01

407

Rendezvous radar for orbital vehicles  

NASA Astrophysics Data System (ADS)

In this paper some of the factors which relate to the system design of rendezvous radars are discussed and the system design and the capabilities of the OMV Rendezvous Radar System (RRS) are described. The potential for transferring manufacturing technologies and methods which have been developed for high-volume-production commercial and military hardware systems into the relatively low volume world of hi-rel electronics hardware for space is discussed.

Locke, John W.; Casey, Larry D.

1992-03-01

408

Mapping of airborne Doppler radar data  

SciTech Connect

Two sets of equations are derived to (1) map airborne Doppler radar data from an aircraft-relative coordinate system to an earth-relative coordinate system, and (2) remove the platform motion from the observed Doppler velocities. These equations can be applied to data collected by the National Oceanic and Atmospheric Administration WP-3D system, the National Center for Atmospheric Research Electra Doppler Radar (ELDORA) system, and other airborne radar systems.

Lee, W.; Dodge, P.; Marks, F.D. Jr.; Hildebrand, P.H. (National Center for Atmospheric Research, Boulder, CO (United States) NOAA, Miami, FL (United States))

1994-04-01

409

First Results Of The New Goldstone Delay-Doppler Radar Chirp Imaging System  

NASA Astrophysics Data System (ADS)

We report the first results of a new delay-Doppler radar chirp waveform system at Goldstone, which improves the range resolution by a factor of five from 18.75-m to 3.75-m. We successfully tested the new system on near-Earth asteroids (NEAs) 2010 AL30 and 2009 UN3 in January and February 2010. 2010 AL30 was a target-of-opportunity observed only three days after its discovery by LINEAR on January 10. During 2.3 hours of observations, 2010 AL30 moved between 1.0 to 0.8 lunar distances from Earth en route to a close approach of only 0.34 lunar distances. Due to this short round-trip light-travel time, the observations were bistatic with transmissions at the 70-m DSS-14 antenna and reception at the 34-m DSS-13 antenna. 2010 AL30 has a very faint absolute magnitude of 27.2, suggesting a diameter of less than 20 meters. We imaged 2010 AL30 at resolutions as high as 3.75-m, which reveal a somewhat elongated shape roughly 15-m in diameter, making 2010 AL30 the smallest NEA spatially resolved at Goldstone to date. The sequence of images shows obvious rotation that is consistent with the period of about 9 minutes reported by W. Ryan. (pers. comm.). 2009 UN3 was discovered in October 2009 by the Siding Spring Survey and approached within 0.037 AU (14 lunar distances) on February 9. We observed 2009 UN3 monostatically at Goldstone on February 8 and 9. Due to its moderate SNRs, we used chirp imaging at 15-m and 30-m resolutions, and binary-phase-coded imaging with 37.5-m resolution. The images reveal an irregular, elongated object close to 700-m in diameter. For future research, the new 3.75-m-resolution capability at Goldstone offers significant scientific potential to reveal much more detailed surface features than previously possible, to yield more detailed 3D shapes, and to substantially improve NEA orbits and long-term orbit prediction.

Slade, Martin A.; Lee, C. G.; Jao, J. S.; Benner, L. A. M.; Brozovic, M.; Giorgini, J. D.; Busch, M. W.

2010-10-01

410

Radar polarimetry for geoscience applications  

SciTech Connect

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

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

1990-01-01

411

The RADAR Test Methodology: Evaluating a MultiTask Machine Learning System with Humans in the Loop  

Microsoft Academic Search

The RADAR project involves a collection of machine learning research thrusts that are integrated into a cognitive personal assistant. Progress is examined with a test developed to measure the impact of learning when used by a human user. Three conditions (conventional tools, Radar without learning, and Radar with learning) are evaluated in a large-scale, between- subjects study. This paper describes

Aaron Steinfeld; Rachael Bennett; Kyle Cunningham; Matt Lahut; Pablo-Alejandro Quinones; Django Wexler; Dan Siewiorek; Paul Cohen; Julie Fitzgerald; Othar Hansson; Jordan Hayes; Mike Pool; Mark Drummond

412

Radar SLAM using visual features  

NASA Astrophysics Data System (ADS)

A vessel navigating in a critical environment such as an archipelago requires very accurate movement estimates. Intentional or unintentional jamming makes GPS unreliable as the only source of information and an additional independent supporting navigation system should be used. In this paper, we suggest estimating the vessel movements using a sequence of radar images from the preexisting body-fixed radar. Island landmarks in the radar scans are tracked between multiple scans using visual features. This provides information not only about the position of the vessel but also of its course and velocity. We present here a navigation framework that requires no additional hardware than the already existing naval radar sensor. Experiments show that visual radar features can be used to accurately estimate the vessel trajectory over an extensive data set.

Callmer, Jonas; Törnqvist, David; Gustafsson, Fredrik; Svensson, Henrik; Carlbom, Pelle

2011-12-01

413

Airborne laser radar: systems and methods for reconnaissance and terrain modeling  

Microsoft Academic Search

Recently a number of airborne nadir scanning laser radars have been developed for both military and civilian applications. These have range resolutions on the order of 10 cm but relatively moderate area coverage rates, in the range 1000 - 10,000 m2\\/s (3.6 - 36 km2\\/h) when operating in a high resolution mode with 0.25 m spot distance. Technology development in

Ove K. Steinvall; Ulf Soederman; Simon Ahlberg; Martin Sandberg; Dietmar Letalick; Erland Jungert

1999-01-01

414

Salient features of radar nodes of the first generation NetRad System  

Microsoft Academic Search

The recently established National Science Foundation Engineering Research Center for Collaborative Adaptive Sensing of the Atmosphere (CASA) will be deploying the first generation of an automated network of four low-power, short-range, X-band, polarimetric, Doppler radars, known as NetRad, in central Oklahoma in late 2005. This network is developed with the goal of tracking tornadoes with high spatial and temporal resolution

Francesc Junyent; V. Chandrasekar; D. J. McLaughlin; S. Frasier; E. Insanic; R. Ahmed; N. Bharadwaj; E. Knapp; L. Krnan; R. Tessier

2005-01-01

415

Dynamic Experiment Design Regularization Approach to Adaptive Imaging with Array Radar/SAR Sensor Systems  

PubMed Central

We consider a problem of high-resolution array radar/SAR imaging formalized in terms of a nonlinear ill-posed inverse problem of nonparametric estimation of the power spatial spectrum pattern (SSP) of the random wavefield scattered from a remotely sensed scene observed through a kernel signal formation operator and contaminated with random Gaussian noise. First, the Sobolev-type solution space is constructed to specify the class of consistent kernel SSP estimators with the reproducing kernel structures adapted to the metrics in such the solution space. Next, the “model-free” variational analysis (VA)-based image enhancement approach and the “model-based” descriptive experiment design (DEED) regularization paradigm are unified into a new dynamic experiment design (DYED) regularization framework. Application of the proposed DYED framework to the adaptive array radar/SAR imaging problem leads to a class of two-level (DEED-VA) regularized SSP reconstruction techniques that aggregate the kernel adaptive anisotropic windowing with the projections onto convex sets to enforce the consistency and robustness of the overall iterative SSP estimators. We also show how the proposed DYED regularization method may be considered as a generalization of the MVDR, APES and other high-resolution nonparametric adaptive radar sensing techniques. A family of the DYED-related algorithms is constructed and their effectiveness is finally illustrated via numerical simulations.

Shkvarko, Yuriy; Tuxpan, Jose; Santos, Stewart

2011-01-01

416

Probing General Relativity with Radar Astrometry in the Inner Solar System  

NASA Astrophysics Data System (ADS)

We are engaged in a long-term program to obtain and interpret high-precision radar range measurements of a number of near-Earth objects (NEOs) that have trajectories reaching deep inside the gravitational well of the Sun. Objects in our sample have perihelion shift rates 1.5 to 2.5 times that of Icarus (10''/cy) and span a wide range of inclinations and semi-major axes, allowing for an unambiguous separation of general relativistic and solar oblateness effects. Four objects have been observed at Arecibo on at least two apparitions since 2000, with typical uncertainties of a few hundred meters. This program is expected to provide the first purely dynamical measurement of the oblateness of the Sun (J2 at the 10e-8 level) and to constrain the Eddington parameter beta at the 10e-4 level. Although our objects are selected to minimize Yarkovsky orbital drift, we also anticipate measuring Yarkovsky drift rates, which are orthogonal to the GR/J2 signatures. In addition to the asteroid data, we seek to re-analyze existing Mercury radar astrometry, which is warranted by the success of the MESSENGER mission. First, the flybys reveal a possible discrepancy of hundreds of meters between ephemeris predictions and the observed position of the planet. Second, new information about the topography of the planet can be used to reduce the impact of systematic errors in the analysis of radar ranges.

Margot, Jean-Luc; Giorgini, J. D.

2009-05-01

417

Dynamic experiment design regularization approach to adaptive imaging with array radar/SAR sensor systems.  

PubMed

We consider a problem of high-resolution array radar/SAR imaging formalized in terms of a nonlinear ill-posed inverse problem of nonparametric estimation of the power spatial spectrum pattern (SSP) of the random wavefield scattered from a remotely sensed scene observed through a kernel signal formation operator and contaminated with random Gaussian noise. First, the Sobolev-type solution space is constructed to specify the class of consistent kernel SSP estimators with the reproducing kernel structures adapted to the metrics in such the solution space. Next, the "model-free" variational analysis (VA)-based image enhancement approach and the "model-based" descriptive experiment design (DEED) regularization paradigm are unified into a new dynamic experiment design (DYED) regularization framework. Application of the proposed DYED framework to the adaptive array radar/SAR imaging problem leads to a class of two-level (DEED-VA) regularized SSP reconstruction techniques that aggregate the kernel adaptive anisotropic windowing with the projections onto convex sets to enforce the consistency and robustness of the overall iterative SSP estimators. We also show how the proposed DYED regularization method may be considered as a generalization of the MVDR, APES and other high-resolution nonparametric adaptive radar sensing techniques. A family of the DYED-related algorithms is constructed and their effectiveness is finally illustrated via numerical simulations. PMID:22163859

Shkvarko, Yuriy; Tuxpan, José; Santos, Stewart

2011-04-27

418

Pulse Doppler radar waveforms  

Microsoft Academic Search

Modern military airborne radars are highly sophisticated, multi-mode systems which are required to detect difficult targets in all aspects and over a large range\\/velocity detection space. There are particular difficulties associated with the airborne case such as the limited antenna aperture, high platform velocity and severe clutter levels which present difficult waveform design challenges. This tutorial will consider the design

C. M. Alabaster

2010-01-01

419

Radar cross-section analysis of wind turbine blades with radar absorbing materials  

Microsoft Academic Search

Wind turbines interfere with radar systems due to their large radar cross-section (RCS) and the rotation of the blades. Applying radar absorbing materials (RAM) is considered as a possible mitigation measure. This paper will present RCS modeling results of a generic 40 meters blade. The blade is segmented into 4 sections and the monostatic scattering from each section is modeled.

L. S. Rashid; A. K Brown

2011-01-01

420

Description and demonstration of the new Middle and Upper atmosphere Radar imaging system: 1-D, 2-D, and 3-D imaging of troposphere and stratosphere  

NASA Astrophysics Data System (ADS)

The Middle and Upper atmosphere Radar (MUR) was upgraded in March 2004 for radar imaging capability with 5 frequencies across a 1 MHz bandwidth and 25 digital receivers. Although digitization introduces problems of its own, the uniformity of digitization is a great benefit over the analogue system in place before. This increased reliability will help make the new system an important component of long-term atmospheric science programs. We demonstrate 3-D imaging with Capon's method, which can provide information about structure morphology. In addition, we demonstrate an experimental 0.5 ?s pulse mode and compare this to Capon method imaging results.

Hassenpflug, G.; Yamamoto, M.; Luce, H.; Fukao, S.

2008-04-01

421

Southern San Andreas-San Jacinto fault system slip rates estimated from earthquake cycle models constrained by GPS and interferometric synthetic aperture radar observations  

Microsoft Academic Search

We use ground geodetic and interferometric synthetic aperture radar satellite observations across the southern San Andreas (SAF)-San Jacinto (SJF) fault systems to constrain their slip rates and the viscosity structure of the lower crust and upper mantle on the basis of periodic earthquake cycle, Maxwell viscoelastic, finite element models. Key questions for this system are the SAF and SJF slip

Paul Lundgren; Eric A. Hetland; Zhen Liu; Eric J. Fielding

2009-01-01

422

Radar observations of the 2009 eruption of Redoubt Volcano, Alaska: Initial deployment of a transportable Doppler radar system for volcano-monitoring  

Microsoft Academic Search

The rapid detection of explosive volcanic eruptions and accurate determination of eruption-column altitude and ash-cloud movement are critical factors in the mitigation of volcanic risks to aviation and in the forecasting of ash fall on nearby communities. The U.S. Geological Survey (USGS) deployed a transportable Doppler radar during the precursory stage of the 2009 eruption of Redoubt Volcano, Alaska, and

R. P. Hoblitt; D. J. Schneider

2009-01-01

423

Phased array radar systems in support of the medium extended air defense system (MEADS)  

Microsoft Academic Search

MEADS, the medium extended air defense system program, is a tri-national program to fulfill the current and future air defense needs of German, Italian, and U.S. forces. As indicated in Figure 1, the program is developing a next-generation lower-tier air- and missile-defense system, to be effective against the anticipated future threat spectrum. It will be highly mobile, strategically and tactically

W. A. Kuhn; W. Sieprath; L. Timmoneri; A. Farina

2003-01-01

424

NASA Radar Images Asteroid Toutatis  

NASA Video Gallery

This 64-frame movie of asteroid Toutatis was generated from data by Goldstone's Solar System Radar on Dec. 12 and 13, 2012. In the movie clips, the rotation of the asteroid appears faster than it occurs in nature.

Anthony Greicius

2012-12-13

425

Mode S Baseline Radar Tracking.  

National Technical Information Service (NTIS)

Tests and evaluation were conducted to determine the baseline performance characteristics of the Moving Target Detector (MTD) and Radar Data Acquisition System (RDAS) as an integral part of the Mode S sensor. The MTD and RDAS were separately evaluated to ...

E. F. Mancus L. H. Baker

1982-01-01

426

Survey of Radar Signal Processing.  

National Technical Information Service (NTIS)

During the last decade, considerable progress has been made in radar signal processing, and this report states its present status. The three broad areas of coherent processing, noncoherent detection, and track-while-scan systems are discussed. Specificall...

G. V. Trunk

1977-01-01

427

Shipboard Radar.  

National Technical Information Service (NTIS)

The navigational radar 'Stvor' is designed for installation on ships of the shipping fleet and also on marine and river boats of low and medium tonnage. A 'Stvor' station enables ships to navigate in zero visibility -- in fog, at night, etc. Because of it...

1968-01-01

428

Antenna size, transmitter power, and solid state transmitter considerations in affordable radar design  

Microsoft Academic Search

Variant radar system configurations are explored in context of reducing radar production costs. The study baseline uses the Volume Surveillance Radar concept, a long range, 3-D shipboard air surveillance radar using pulsed Doppler processing techniques. The variants adjust the relative performance of the individual radar subsystems, primarily the antenna, transmitter, and number of receiver channels. When no deterioration in the

John Pavco; Max Michelson; David Alessio; Harold Ascher

1993-01-01

429

Statistical evaluation of a radar rainfall system for sewer system management  

Microsoft Academic Search

Urban areas are faced with mounting demands for managing waste and stormwater for a cleaner environment. Rainfall information is a critical component in efficient management of urban drainage systems. A major water quality impact affecting receiving waterbodies is the discharge of untreated waste and stormwater during precipitation, termed wet weather flow. Elimination or reduction of wet weather flow in metropolitan

B. E. Vieux; J. E. Vieux

2005-01-01

430

Methods for FMCW radar map georeferencing  

NASA Astrophysics Data System (ADS)

In a context of mobile environment mapping, a vehicle-based radar system, K2Pi, has been developed. A mapping of the environment is carried out from the radar datasets. Given the specificities of radar maps, the main problem at this stage is to find a method to georeference these maps. This article proposes three radar map georeferencing methods. The first method is a typical manual selection of a set of control point pairs. The second method consists of matching the relative trajectory computed by a specific radar algorithm with a trajectory recorded from absolute DGPS recording. Finally, the third method, inspired by the image-to-image approach, is based on Fourier-Mellin transform which automatically registers the radar map with respect to a georeferenced aerial photograph. Successfully tested on radar datasets, this method could be applied to many other types of data.

Jaud, Marion; Rouveure, Raphaël; Faure, Patrice; Monod, Marie-Odile

2013-10-01

431

Dual Super-Systolic Core for Real-Time Reconstructive Algorithms of High-Resolution Radar/SAR Imaging Systems  

PubMed Central

A high-speed dual super-systolic core for reconstructive signal processing (SP) operations consists of a double parallel systolic array (SA) machine in which each processing element of the array is also conceptualized as another SA in a bit-level fashion. In this study, we addressed the design of a high-speed dual super-systolic array (SSA) core for the enhancement/reconstruction of remote sensing (RS) imaging of radar/synthetic aperture radar (SAR) sensor systems. The selected reconstructive SP algorithms are efficiently transformed in their parallel representation and then, they are mapped into an efficient high performance embedded computing (HPEC) architecture in reconfigurable Xilinx field programmable gate array (FPGA) platforms. As an implementation test case, the proposed approach was aggregated in a HW/SW co-design scheme in order to solve the nonlinear ill-posed inverse problem of nonparametric estimation of the power spatial spectrum pattern (SSP) from a remotely sensed scene. We show how such dual SSA core, drastically reduces the computational load of complex RS regularization techniques achieving the required real-time operational mode.

Atoche, Alejandro Castillo; Castillo, Javier Vazquez

2012-01-01

432

Dual super-systolic core for real-time reconstructive algorithms of high-resolution radar/SAR imaging systems.  

PubMed

A high-speed dual super-systolic core for reconstructive signal processing (SP) operations consists of a double parallel systolic array (SA) machine in which each processing element of the array is also conceptualized as another SA in a bit-level fashion. In this study, we addressed the design of a high-speed dual super-systolic array (SSA) core for the enhancement/reconstruction of remote sensing (RS) imaging of radar/synthetic aperture radar (SAR) sensor systems. The selected reconstructive SP algorithms are efficiently transformed in their parallel representation and then, they are mapped into an efficient high performance embedded computing (HPEC) architecture in reconfigurable Xilinx field programmable gate array (FPGA) platforms. As an implementation test case, the proposed approach was aggregated in a HW/SW co-design scheme in order to solve the nonlinear ill-posed inverse problem of nonparametric estimation of the power spatial spectrum pattern (SSP) from a remotely sensed scene. We show how such dual SSA core, drastically reduces the computational load of complex RS regularization techniques achieving the required real-time operational mode. PMID:22736964

Atoche, Alejandro Castillo; Castillo, Javier Vázquez

2012-02-24

433

Multinomial pattern matching for high range resolution radar profiles  

NASA Astrophysics Data System (ADS)

Airborne ground moving-target indication (GMTI) radar can track moving vehicles at large standoff distances. Unfortunately, trajectories from multiple vehicles can become kinematically ambiguous, resulting in confusion between a target vehicle of interest and other vehicles. We propose the use of high range resolution (HRR) radar profiles and multinomial pattern matching (MPM) for target fingerprinting and track stitching to overcome kinematic ambiguities. Sandia's MPM algorithm is a robust template-based identification algorithm that has been applied successfully to various target recognition problems. MPM utilizes a quantile transformation to map target intensity samples to a small number of grayscale values, or quantiles. The algorithm relies on a statistical characterization of the multinomial distribution of the sample-by-sample intensity values for target profiles. The quantile transformation and statistical characterization procedures are extremely well suited to a robust representation of targets for HRR profiles: they are invariant to sensor calibration, robust to target signature variations, and lend themselves to efficient matching algorithms. In typical HRR tracking applications, target fingerprints must be initiated on the fly from a limited number of HRR profiles. Data may accumulate indefinitely as vehicles are tracked, and their templates must be continually updated without becoming unbounded in size or complexity. To address this need, an incrementally updated version of MPM has been developed. This implementation of MPM incorporates individual HRR profiles as they become available, and fuses data from multiple aspect angles for a given target to aid in track stitching. This paper provides a description of the incrementally updated version of MPM.

Koudelka, Melissa L.; Richards, John A.; Koch, Mark W.

2007-04-01

434

Debris flux comparisons from the Goldstone Radar, Haystack Radar, and Hax Radar prior, during, and after the last solar maximum  

NASA Astrophysics Data System (ADS)

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

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

2009-08-01

435

Automotive Radar and Lidar Systems for Next Generation Driver Assistance Functions  

NASA Astrophysics Data System (ADS)

Automotive radar and lidar sensors represent key components for next generation driver assistance functions (Jones, 2001). Today, their use is limited to comfort applications in premium segment vehicles although an evolution process towards more safety-oriented functions is taking place. Radar sensors available on the market today suffer from low angular resolution and poor target detection in medium ranges (30 to 60m) over azimuth angles larger than ±30°. In contrast, Lidar sensors show large sensitivity towards environmental influences (e.g. snow, fog, dirt). Both sensor technologies today have a rather high cost level, forbidding their wide-spread usage on mass markets. A common approach to overcome individual sensor drawbacks is the employment of data fusion techniques (Bar-Shalom, 2001). Raw data fusion requires a common, standardized data interface to easily integrate a variety of asynchronous sensor data into a fusion network. Moreover, next generation sensors should be able to dynamically adopt to new situations and should have the ability to work in cooperative sensor environments. As vehicular function development today is being shifted more and more towards virtual prototyping, mathematical sensor models should be available. These models should take into account the sensor's functional principle as well as all typical measurement errors generated by the sensor.

Rasshofer, R. H.; Gresser, K.

2005-05-01

436

Support Vector Clustering and Type-Entropy Based Joint De-interleaving\\/recognition System of Radar Pulse Sequence  

Microsoft Academic Search

Modern electronic warfare faces complex and dense pulses environments, which brings a severe challenge to radar signal sorting.\\u000a Support Vector Clustering (SVC) is used into the radar signal sorting and the notion of type-entropy is presented in this\\u000a paper. And combine the recognition technology based on type-entropy with the sorting technology based on SVC to constitute\\u000a a novel radar sequence

Qiang Guo; Zheng Li; Xingzhou Zhang

437

Theoretical Fundamentals of Radar.  

National Technical Information Service (NTIS)

The book examines the principles of radar, methods of coordinate measurement and scanning and circuits for radar stations of three types: with an operator, a continuous computer installation and a digital computer. It presents the characteristics of radar...

A. A. Korostelev A. V. Petrov N. I. Burenin V. E. Dulevich Y. A. Melnik

1967-01-01

438

Analysis of a Small, Vigorous Mesoscale Convective System in a Low-Shear Environment. Part I: Formation, Radar Echo Structure, and Lightning Behavior  

Microsoft Academic Search

The evolution of a small, vigorous mesoscale convective system (MCS) over northern Alabama is described using Doppler radar, GOES satellite, surface mesonet, lightning, and sounding data. The MCS formed near noon in a relatively unstable environment having weak synoptic forcing and weak shear. The initiation of separate lines and clusters of deep convection occurred in regions exhibiting cumulus cloud streets,

Kevin R. Knupp; Bart Geerts; Steven J. Goodman

1998-01-01

439

New law enforcement applications of millimeter-wave radar  

NASA Astrophysics Data System (ADS)

Recent advances in millimeter-wave (MMW) radar technologies provide new applications for law enforcement use over-and- above the venerable speed timing radar. These applications include the potential to detect weapons under clothing and to conduct surveillance through walls. Concealed Weapon Detection and covert surveillance are of high interest to both the Department of Defense in support of Small Unit Operations and the Justice Department for civilian law enforcement applications. MMW sensors are under development which should provide the needed capabilities including radiometric sensors at 95 GHz, active 95 GHz real aperture radars, active focal plane array (FPA) radars, and holographic radars. Radiometric sensors include 2D FPA systems, 1D FPA, scanned systems, and single element scanned sensors. Active FPA radars include illuminated radiometric systems and coherent radar systems. Real aperture MMW radar systems include raster scanned and conical scanned sensors. Holographic systems ruse mechanical scanners to collect coherent data over a significant solid angular sector.

Currie, Nicholas C.; Ferris, David D.; McMillan, Robert W.; Wicks, Michael C.

1997-06-01

440

An intership SATCOM versus radar electromagnetic interference prediction model  

Microsoft Academic Search

A model that analyzes the interactions of satellite communication (SATCOM) systems and radars operating on different ships is presented. Both the effects of the SATCOM system on the radar and the effects of the radar on the SATCOM system are considered. The model is statistical in nature and produces a measure of effect called the probability of degradation. Example calculations

Terry Foreman

1988-01-01

441

The developemnt of a power spectral density processor for C and L band airborne radar scatterometer sensor systems  

NASA Astrophysics Data System (ADS)

A real-time signal processor was developed for the NASA/JSC L-and C-band airborne radar scatterometer sensor systems. The purpose of the effort was to reduce ground data processing costs. Conversion of two quadrature channels of data (like and cross polarized) was made to obtain Power Spectral Density (PSD) values. A chirp-z transform (CZT) approach was used to filter the Doppler return signal and improved high frequency and angular resolution was realized. The processors have been tested with record signals and excellent results were obtained. CZT filtering can be readily applied to scatterometers operating at other wavelengths by altering the sample frequency. The design of the hardware and software and the results of the performance tests are described in detail.

Harrison, D. A., III; Chladek, J. T.

1983-02-01

442

An Integrated Navigation System using GPS Carrier Phase for Real-Time Airborne Synthetic Aperture Radar (SAR)  

SciTech Connect

A Synthetic Aperture Radar (SAR) requires accu- rate measurement of the motion of the imaging plat- form to produce well-focused images with minimal absolute position error. The motion measurement (MoMeas) system consists of a inertial measurement unit (IMU) and a P-code GPS receiver that outputs corrected ephemeris, L1 & L2 pseudoranges, and L1 & L2 carrier phase measurements. The unknown initial carrier phase biases to the GPS satellites are modeled as states in an extended Kalman filter and the resulting integrated navigation solution has po- sition errors that change slowly with time. Position error drifts less than 1- cm/sec have been measured from the SAR imagery for various length apertures.

Fellerhoff, J. Rick; Kim, Theodore J.; Kohler, Stewart M.

1999-06-24

443

Multivariable frequency response methods for optimal Kalman-Bucy filters with applications to radar tracking systems  

NASA Astrophysics Data System (ADS)

The problem of multi-output, infinite-time, linear time-invariant optimal Kalman-Bucy filter both in continuous and discrete-time cases in frequency domain is addressed. A simple new algorithm is given for the analytical solution to the steady-state gain of the optimum filter based on a transfer function approach. The algorithm is based on spectral factorization of observed spectral density matrix of the filter which generates directly the return-difference matrix of the optimal filter. The method is more direct than by algebraic Riccati equation solution and can easily be implemented on digital computer. The design procedure is illustrated by examples and closed-form solution of ECV and ECA radar tracking filters are considered as an application of the method.

Arcasoy, C. C.

1992-11-01

444

Preliminary design of a space system operating a ground-penetrating radar  

NASA Astrophysics Data System (ADS)

Ground-penetrating radars (GPR) are currently used only in ground campaigns or in few airborne installations. A feasibility analysis of a space mission operating a GPR for archaeological applications is presented in this work with emphasis on spacecraft critical aspects: antenna dimension and power required for achieving adequate depth and accuracy. Sensor parametric design is performed considering two operating altitudes (250 and 500 km) and user requirements, such as minimum skin depth, vertical and horizontal resolution. A 500-km altitude, 6 a.m.-6 p.m. sun-synchronous orbit is an adequate compromise between atmospheric drag and payload transmitted average power (12 kW) to achieve a 3-m penetration depth. The satellite bus preliminary design is then performed, with focus on critical subsystems and technologies. The payload average power requirement can be kept within feasible limits (1 kW) by using NiH2 batteries to supply the radar transmitter, and with a strong reduction of the mission duty cycle ( 40km×1100km are observed per orbit). As for the electric power subsystem, a dual-voltage strategy is adopted, with the battery charge regulator supplied at 126 V and the bus loads at 50 V. The overall average power (1.9 kW), accounting for both payload and bus needs, can be supplied by a 20m2 GaAs solar panel for a three-year lifetime. Finally, the satellite mass is kept within reasonable limits (1.6 tons) using inflatable-rigidisable structure for both the payload antenna and the solar panels.

D'Errico, Marco; Ponte, Salvatore; Grassi, Michele; Moccia, Antonio

2005-12-01

445

Instruments and Methods Sub-ice topography in Patriot Hills, West Antarctica: first results of a newly developed high-resolution FM-CW radar system  

Microsoft Academic Search

We present a newly developed high-resolution frequency-modulated continuous-wave (FM- CW) radar system for sounding the sub-ice topography. The system, working in the frequency range from 200 to 400 MHz, was developed to measure thickness and internal layers in cold ice with a resolution better than 1 m. This system has the potential to measure accumulation rates, an important input for

Carlos A. CARDENAS MANSILLA; Martin JENETT; Klaus SCHUNEMANN; Jurgen WINKELMANN

2010-01-01

446

Radar and sensor netting - Present and future  

NASA Astrophysics Data System (ADS)

It is pointed out that a natural evolution of radar systems leads to the netting of radars dispersed on a certain portion of the surveillance space. The motivation for this evolution was provided by the possibility of fusing a great amount of data taken by radars operating independently. Multiradar tracking (MRT) represents a well-known system employed in civilian and military applications. The multistatic radar system is another well known netting concept. The present paper has the objective to provide some information regarding the potential of the netted system concepts. The netting of sensors other than radars is also promising, taking into account lasers, TV, radiometer, and acoustic devices. Attention is given to details concerning the multiradar system concept (the present), the multistatic system concept, wideband netting (the future), the multisensor system concept (the future), and artificial intelligence.

Farina, A.; Studer, F. A.

1986-01-01

447

A system for high resolution 3D mapping using laser radar and requiring no beam scanning mechanisms  

NASA Astrophysics Data System (ADS)

The inherently high angular and range resolution capabilities associated with radar systems operating at optical frequencies are at once a blessing and a curse. Standard implementations consist of very narrow field of view optical receivers operating in conjunction with laser transmitters or even narrower illumination beamwidth. While high angular resolution is thus achieved, mechanical scanning is required to gather data over extended fields of view. The many laser pulse transmissions necessary to cover the entire field of view increase the detectability of the system by enemy sensors. A system concept is proposed which, through the use of a single laser transmitter and multiple optical receivers, largely eliminate these deficiencies. Complete 3D data over a broad angular field of view and depth of field can be gathered based upon the reflections from a single transmitted laser pulse. Covert operation is enhanced as a result of the sparse laser transmissions required. The eye safety characteristics of the system are also enhanced. Proprietary coding of optical shutters in each of the multiple optical receivers permits the number of such receivers to be reduced to a very practical few. An alternative configuration of the system reduces the number of receivers required to one, at the expense of increased data acquisition time. The multiple receiver configuration is simply a parallel processing implementation of the single receiver approach. While data rate is reduced by the single receiver configuration, it still greatly exceeds that of scanning systems, and hardware complexity is also reduced significantly.

Rademacher, Paul

1988-06-01

448

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

PubMed

Merging of radar rainfall data with rain gauge measurements is a common approach to overcome problems in deriving rain intensities from radar measurements. We extend an existing approach for adjustment of C-band radar data using state-space models and use the resulting rainfall intensities as input for forecasting outflow from two catchments in the Copenhagen area. Stochastic grey-box models are applied to create the runoff forecasts, providing us with not only a point forecast but also a quantification of the forecast uncertainty. Evaluating the results, we can show that using the adjusted radar data improves runoff forecasts compared with using the original radar data and that rain gauge measurements as forecast input are also outperformed. Combining the data merging approach with short-term rainfall forecasting algorithms may result in further improved runoff forecasts that can be used in real time control. PMID:23925186

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

2013-01-01

449

Geologic Studies of Planetary Surfaces Using Radar Polarimetric Imaging.  

National Technical Information Service (NTIS)

Radar is a useful remote sensing tool for studying planetary geology because it is sensitive to the composition, structure, and roughness of the surface and can penetrate some materials to reveal buried terrain. The Arecibo Observatory radar system transm...

B. A. Campbell D. B. Campbell L. M. Carter

2010-01-01

450

Radar techniques program  

Microsoft Academic Search

This is the fifth Quarterly Technical Summary covering the development of an airborne Multiple-Antenna Moving-Target Surveillance Radar (MASR) which employs special antenna and signal-processing techniques to provide continuous, wide-area surveillance of moving targets on or near the ground. Such a sensor, equipped with an appropriate data-reduction facility, can provide useful real-time information to a Tactical Air Control System. A DeHavilland

C. E. Muehe

1974-01-01

451

High-resolution vertical imaging of the troposphere and lower stratosphere using the new MU radar system  

NASA Astrophysics Data System (ADS)

In the present paper, a new application of the range imaging technique called Frequency Interferometry Imaging (FII) or Range Imaging (RIM), performed in April 2005, is shown using the new 46.5-MHz Middle and Upper (MU) atmosphere radar system (Shigaraki, Japan). Height-time images of brightness distribution have been computed at the highest resolution ever obtained for imaging with VHF radars in the troposphere and, for the very first time, in the lower stratosphere, up to about 22 km. The images were produced by processing signals obtained with an initial range-resolution of ?r=150 m and five equally-spaced frequencies within ?f=1.0 MHz, with the adaptive Capon method. These values represent an improvement of a factor 2 over all the previous published experiments at VHF, which were performed with ?r=300 m and ?f=0.5 MHz. The Capon images present realistic and self-consistent features, and reveal many more organized structures than the height-time SNR plots at the initial range-resolution. For example, the Capon images show persistent enhanced brightness layers significantly thinner than 150 m in the stratosphere, which are impossible to track with the standard single-frequency mode owing to a lack of range resolution. These observations thus support the idea of strong stratification even at vertical scales much smaller than 100 m, as suggested by recent high-resolution temperature observations by balloons (Dalaudier et al., 1994). We also present comparisons of Capon images with patterns obtained from the dual-FDI technique and two parametric methods (the MUSIC algorithm and the newly-introduced Maximum Entropy Method based on an auto-regressive (AR) model). The comparisons confirm the insufficiencies of the dual-FDI technique and indicate that parametric methods such as MEM and the MUSIC algorithm can help to validate the Capon images when the parametric methods provide similar patterns.

Luce, H.; Hassenpflug, G.; Yamamoto, M.; Fukao, S.

2006-05-01

452

Lightning activity related to satellite and radar observations of a mesoscale convective system over Texas on 7 8 April 2002  

NASA Astrophysics Data System (ADS)

A multi-sensor study of the leading-line, trailing-stratiform (LLTS) mesoscale convective system (MCS) that developed over Texas in the afternoon of 7 April 2002 is presented. The analysis relies mainly on operationally available data sources such as GOES East satellite imagery, WSR-88D radar data and NLDN cloud-to-ground flash data. In addition, total lightning information in three dimensions from the LDAR II network in the Dallas Ft. Worth region is used. GOES East satellite imagery revealed several ring-like cloud top structures with a diameter of about 100 km during MCS formation. The Throckmorton tornadic supercell, which had formed just ahead of the developing linear MCS, was characterized by a high CG+ percentage below a V-shaped cloud top overshoot north of the tornado swath. There were indications of the presence of a tilted electrical dipole in this storm. Also this supercell had low average CG- first stroke currents and flash multiplicities. Interestingly, especially the average CG+ flash multiplicity in the Throckmorton storm showed oscillations with an estimated period of about 15 min. Later on, in the mature LLTS MCS, the radar versus lightning activity comparison revealed two dominant discharge regions at the back of the convective leading edge and a gentle descent of the upper intracloud lightning region into the trailing stratiform region, apparently coupled to hydrometeor sedimentation. There was evidence for an inverted dipole in the stratiform region of the LLTS MCS, and CG+ flashes from the stratiform region had high first return stroke peak currents.

Dotzek, Nikolai; Rabin, Robert M.; Carey, Lawrence D.; Macgorman, Donald R.; McCormick, Tracy L.; Demetriades, Nicholas W.; Murphy, Martin J.; Holle, Ronald L.

2005-07-01

453

GSM passive radar for medium range surveillance  

Microsoft Academic Search

This paper presents a passive radar system using GSM as illuminator of opportunity. The new feature is the used high performance uniform linear antenna (ULA) for extracting both the reference and the echo signal in a software defined radar. The signal processing steps used by the proposed scheme are detailed and the feasibility of the whole system is proved by

Reda Zemmari; Ulrich Nickel; Wulf-Dieter Wirth

2009-01-01

454

Feasibility analysis of GSM signal for passive radar  

Microsoft Academic Search

Passive radar makes use of an 'illuminator of opportunity' already present in the environment for other purposes (TV transmission, broadcast systems, etc) to detect targets as well as estimating target parameters. This radar has the merit of being a completely covert radar system, which does not advertise the presence of either the receivers or transmitting stations. One such existing radio

Danny K. P. Tan; Hongbo Sun; Yilong Lu; Weixian Liu

2003-01-01

455

Classification of radar clutter in an air traffic control environment  

Microsoft Academic Search

The results of an experimental study aimed at the classification of radar clutter encountered on ground-based coherent scanning radar systems used for air traffic control are presented. The clutter signals of interest are primarily those due to birds and to clouds and weather systems. A historical perspective on the radar clutter classification problem is given, and related issues are discussed.

SIMON HAYKIN; WOLFGANG STEHWIEN; CONG DENG; PETER WEBER; RICHARD MANN

1991-01-01

456

Radar data processing. Volume 2 - Advanced topics and applications  

Microsoft Academic Search

The design and implementation of the radar data processing (RDP) theory are discussed. Data processing for netted monostatic and bistatic radar systems and technical problems such as the misalignment between radars and target altitude uncertainty are examined. The organization and display of the data on a computer system are studied. The computer simulation of tracking algorithms for RDP performance evaluation

A. Farina; F. A. Studer

1986-01-01

457

Detection and tracking systems - An historical overview  

Microsoft Academic Search

Major branches of Raytheon radar and sonar activity since World War II are: sonar equipment, navigation and surveillance radar, special purpose radar, weapon control and guidance, and seekers. Major systems developed in these areas are charted. The development of certain navigational and surveillance radars (military and commercial), special purpose radars (e.g., weather radars, bombing radar, and missile-range radar), and missile

F. A. Gross; D. K. Barton; W. M. Hall

1974-01-01

458

CFAR: The principles of automatic radar detection in clutter  

Microsoft Academic Search

The basic design of constant-false-alarm-rate (CFAR) processors for automatic-detection radar systems is examined theoretically, in an introduction for advanced engineering students and practicing radar engineers. Chapters are devoted to the elements of probability and statistics; automatic radar detection; radar system architectures; and Rayleigh-envelope clutter, Weibull and log-normal envelope clutter, and nonparametric CFAR techniques. Extensive graphs and diagrams are included.

G. Minkler; J. Minkler

1990-01-01

459

UWB Array-Based Radar for Landmine Detection  

Microsoft Academic Search

In this paper, the development of an UWB array-based time-domain radar sensor is described. The radar sensor is designed to be used within a vehicle-mounted multi-sensor system for humanitarian demining. The main novelty of the radar lies in the modular approach, design of the antenna system and waveform of the transmit antenna feeding pulse. The radar has focusing capability via

Alexander Yarovoy; Pascal Aubry; Pidio Lys; Leo Ligthart

2006-01-01

460

CFAR: The principles of automatic radar detection in clutter  

NASA Astrophysics Data System (ADS)

The basic design of constant-false-alarm-rate (CFAR) processors for automatic-detection radar systems is examined theoretically, in an introduction for advanced engineering students and practicing radar engineers. Chapters are devoted to the elements of probability and statistics; automatic radar detection; radar system architectures; and Rayleigh-envelope clutter, Weibull and log-normal envelope clutter, and nonparametric CFAR techniques. Extensive graphs and diagrams are included.

Minkler, G.; Minkler, J.

461

Microwave radar detection of gas pipeline leaks.  

SciTech Connect

We are developing a microwave radar sensing and imaging system to detect and locate gas leaks in natural gas pipelines. The underlying detection principle is radar backscattering from the index-of-refraction inhomogeneities introduced by the dispersion of methane in air. An essential first step in the development effort is modeling to estimate the radar cross section. This paper describes the modeling results and the experimental efforts underway to validate the model. For the case of leaks from small holes in a pressurized gas pipeline, we modeled the gas dynamics of the leak jet to determine the plume geometry and the variation of methane concentration in air as a function of distance from the leak source. From the static and dynamic changes in the index of refraction in the turbulent plume, the radar backscatter cross sections were calculated. The results show that the radar cross sections of the leak plumes should be detectable by special-purpose radars.

Gopalsami, N.; Kanareykin, D. B.; Asanov, V. D; Bakhtiari, S.; Raptis, A. C.

2002-10-02

462

Meso-?-scale convective systems observed by a 443MHz wind-profiling radar with RASS in the Okinawa subtropical region  

Microsoft Academic Search

We observed a meso-?-scale convective system in July 2007 using a 443-MHz wind profiler radar (WPR) with a radio acoustic sounding system (RASS) at the NICT Ogimi observatory in Okinawa, Japan. We analyzed the virtual temperature, Tv, the Brunt–Vaisala frequency squared, N2, and three components of wind velocity profiles from the WPR-RASS data. We also employed a non-hydrostatic meso-scale (NHM)

Aya Mikami; Takuya Kawabata; Shinsuke Satoh; Jun-Ichi Furumoto; Seiji Nagai; Yasuhiro Murayama; Toshitaka Tsuda

2011-01-01

463

Meso-gamma-scale convective systems observed by a 443MHz wind-profiling radar with RASS in the Okinawa subtropical region  

Microsoft Academic Search

We observed a meso-gamma-scale convective system in July 2007 using a 443-MHz wind profiler radar (WPR) with a radio acoustic sounding system (RASS) at the NICT Ogimi observatory in Okinawa, Japan. We analyzed the virtual temperature, Tv, the Brunt-Vaisala frequency squared, N2, and three components of wind velocity profiles from the WPR-RASS data. We also employed a non-hydrostatic meso-scale (NHM)

Aya Mikami; Takuya Kawabata; Shinsuke Satoh; Jun-Ichi Furumoto; Seiji Nagai; Yasuhiro Murayama; Toshitaka Tsuda

2011-01-01

464

Lightning, radar reflectivity, infrared brightness temperature, and surface rainfall during the 2–4 July 2004 severe convective system over Taiwan area  

Microsoft Academic Search

On 2–4 July 2004, unusually severe convective systems developed over Taiwan area, following the passage of Typhoon Mindulle (10W, T0407). During the lifetime of these storms, total lightning was detected by the TPC SAFIR total lightning detection system, infrared cloud-top temperatures were measured by the NOAA GOES-9 satellite, radar reflectivity was observed by the CWB Doppler network, and hourly surface

Kuo-Ying Wang; Shun-An Liao

2006-01-01

465

Lightning, radar reflectivity, infrared brightness temperature, and surface rainfall during the 2-4 July 2004 severe convective system over Taiwan area  

Microsoft Academic Search

On 2-4 July 2004, unusually severe convective systems developed over Taiwan area, following the passage of Typhoon Mindulle (10W, T0407). During the lifetime of these storms, total lightning was detected by the TPC SAFIR total lightning detection system, infrared cloud-top temperatures were measured by the NOAA GOES-9 satellite, radar reflectivity was observed by the CWB Doppler network, and hourly surface

Kuo-Ying Wang; Shun-An Liao

2006-01-01

466

Feasibility study of a low-cost system-on-a-chip UWB pulse radar on silicon for the heart monitoring  

Microsoft Academic Search

In February 2002 the FCC authorized the marketing of a new class of radiofrequency devices: the ultra-wide-band (UWB) systems. One of the most interesting applications for which the UWB systems are addressed is related to the medical imaging. This paper addresses the feasibility study of a novel fully integrated 3.1-10.6 GHz UWB radar on a standard silicon technology for the

Domenico Zito; Domenico Pepe; Bruno Neri; Danilo De Rossi

2007-01-01

467

Solar Radar Astronomy with LOFAR  

NASA Astrophysics Data System (ADS)

A new approach to the study of the Sun's corona and its dynamical processes is possible with radar investigations in the frequency range of about 10-50 MHz. The range of electron densities of the solar corona is such that radio waves at these frequencies can provide diagnostic radar echoes of large scale phenomena such as coronal mass ejections (CMEs). We expect that the frequency shift imposed on the echo signal by an earthward-moving CME will provide a direct measurement of the velocity, thereby providing a good estimate of the arrival time at Earth. It is known that CMEs are responsible for the largest geomagnetic storms at Earth, which are capable of causing power grid blackouts, satellite electronic upsets, and degradation of radio communications circuits. Thus, having accurate forecasts of potential CME-initiated geomagnetic storms is of practical space weather interest. New high power transmitting arrays are becoming available, along with proposed modifications to existing research facilities, that will allow the use of radio waves to study the solar corona by the radar echo technique. Of particular interest for such solar radar investigations is the bistatic configuration with the Low Frequency Array (LOFAR). The LOFAR facility will have an effective receiving area of about 1 square km at solar radar frequencies. Such large effective area will provide the receiving antenna gain needed for detailed investigations of solar coronal dynamics. Conservative estimates of the signal-to-noise ratio for solar radar echoes as a function of the integration time required to achieve a specified detection level (e.g., ~ 5 dB) indicate that time resolutions of 10s of seconds can be achieved. Thus, we are able to resolve variations in the solar radar cross section on time scales which will provide new information on the plasma dynamical processes associated with the solar corona, such as CMEs. It is the combination of high transmitted power and large effective receiving area that makes possible the significant performance indicated. We will review early and current solar radar investigations and proposed approaches to future radar studies of the solar corona. Solar radar experiments were done almost from the beginning of the modern era of space physics research and has a very interesting history. In addition to re-opening the solar radar window, LOFAR will also be able to open new studies of planetary hard surfaces (e.g., the Moon and asteroids), and solar system plasmas (solar wind, magnetosphere, dusty plasmas, comets).

Rodriguez, P.

2003-04-01

468

Radar observations in low earth orbit  

NASA Astrophysics Data System (ADS)

This paper presents an overview on radar techniques for the observation of space debris in low Earth orbits which were developed at FGAN in the frame of DARA and ESA/ESOC study contracts for the employment of the Tracking and Imaging Radar (TIRA) system in the past five years. For space debris observations TIRA is mainly operated in two different modes: In a tracking mode and in a beam-park mode of operation. Methods and algorithms were developed to analyse raw radar data, to compute radar images, and to estimate physical characteristics of space objects like size, shape, attitude, orbit, orbital lifetime, ballistic coefficient, mass, and material composition.

Mehrholz, Dieter

1997-05-01

469

Comparison of precipitation observations from a prototype space-based cloud radar and ground-based radars  

NASA Astrophysics Data System (ADS)

A prototype space-based cloud radar has been developed and was installed on an airplane to observe a precipitation system over Tianjin, China in July 2010. Ground-based S-band and Ka-band radars were used to examine the observational capability of the prototype. A cross-comparison algorithm between different wavelengths, spatial resolutions and platform radars is presented. The reflectivity biases, correlation coefficients and standard deviations between the radars are analyzed. The equivalent reflectivity bias between the S- and Ka-band radars were simulated with a given raindrop size distribution. The results indicated that reflectivity bias between the S- and Ka-band radars due to scattering properties was less than 5 dB, and for weak precipitation the bias was negligible. The prototype space-based cloud radar was able to measure a reasonable vertical profile of reflectivity, but the reflectivity below an altitude of 1.5 km above ground level was obscured by ground clutter. The measured reflectivity by the prototype space-based cloud radar was approximately 10.9 dB stronger than that by the S-band Doppler radar (SA radar), and 13.7 dB stronger than that by the ground-based cloud radar. The reflectivity measured by the SA radar was 0.4 dB stronger than that by the ground-based cloud radar. This study could provide a method for the quantitative examination of the observation ability for space-based radars.

Liu, Liping; Zhang, Zhiqiang; Yu, Danru; Yang, Hu; Zhao, Chonghui; Zhong, Lingzhi

2012-11-01

470

Radar Ionospheric Impact Mitigation  

Microsoft Academic Search

New ionospheric modeling technology is being developed to improve correction of ionospheric impacts on the performance of ground-based space-surveillance radars (SSRs) in near-real-time. These radars, which detect and track space objects, can experience significant target location errors due to ionospheric delay and refraction of the radar signals. Since these radars must detect and track targets essentially to the radar horizon,

G. Bishop; D. Decker; C. Baker

2006-01-01

471

Radar detection of Iapetus  

NASA Astrophysics Data System (ADS)

We have obtained echoes from the bright, trailing hemisphere of Iapetus using the Arecibo Observatory's 13-cm radar system on three dates in January 2002. A circularly polarized signal was transmitted and an echo in the opposite circular (OC) sense to that transmitted was clearly received along with a much weaker detection of echo power in the same circular (SC) sense. Prior to this experiment, one expectation may have been that the radar scattering properties of Iapetus may behave like the similar atmosphere-less, icy surfaces of the Galilean satellites which, due to an efficient multiple scattering mechanism, are strong backscatterers with SC reflections stronger than their OC reflections. Instead we find that Iapetus' radar cross section and polarization properties are very different from those of the icy Galilean satellites, and more reminiscent of less efficient and less exotic scattering mechanisms such as dominate the echoes from inner Solar System targets. Thus these observations indicate that there is a significant difference between the surface properties of Iapetus and the icy Galileans despite their overall classification as low temperature, water ice surfaces. A plausible explanation for Iapetus' inefficient scattering is that contaminants in the water ice increase the absorption of the signal and suppress any multiple scattering. Likely contaminants on Iapetus are ammonia and the dark material from Cassini Regio embedded below the surface. Proposed observations will seek to measure Iapetus' radar scattering law and to detect the dark, leading side which was not targeted during this observing session. The Arecibo Observatory is part of the National Astronomy and Ionosphere Center, which is operated by Cornell University under a cooperative agreement with the National Science Foundation.

Black, G. J.; Campbell, D. B.; Carter, L. M.; Ostro, S. J.

2002-09-01

472

Classification and quantification of hydrometeors based on polarimetric radar measurements: Development of fuzzy logic and neuro-fuzzy systems and in situ verification  

NASA Astrophysics Data System (ADS)

Fuzzy logic and Neuro-Fuzzy systems for the classification of hydrometeor type based on polarimetric radar measurements is developed. The hydrometeor classification system is implemented where the fuzzy logic is used to infer hydrometeor type, and the neural network learning algorithm is used for automatic adjustment of the parameters of the fuzzy sets in the fuzzy logic system. Five radar measurements, namely, horizontal reflectivity (ZH ), differential reflectivity (ZDR), differential propagation phase shift (KDP), correlation coefficient (?HV(0)), and linear depolarization ratio (LDR), and corresponding altitude have been used as input variables to the hydrometeor classifier. The output is one of the many possible hydrometeor types, namely (1)drizzle, (2)rain, (3)dry and low density snow, (4)dry and high density crystals, (5)wet and melting snow, (6)dry graupel, (7)wet graupel, (8)small hail, (9)large hail, and (10)mixture of rain and hail. The Neuro-Fuzzy classifier is more advantageous than a simple Neural Network or a fuzzy logic classifier because it is transparent rather than a ``black box'' (unlike a neural network), and can learn the parameters of the system from the past data (unlike a fuzzy logic system). The Neuro-Fuzzy hydrometeor classifier has been applied to several case studies and the results are compared against in-situ observations. A novel scheme of adaptively updating the structure and parameters of the neural network for rainfall estimation is presented. This adaptive neural network scheme enables the network to implement the nonstationary relationship between radar measurements and precipitation estimation with change of season and other environment conditions, and also can incorporate new information, without re- training the complete network from the beginning. It was shown that the adaptive neural network is much faster, more efficient and convenient for real time rainfall estimation to be used with WSR-88D. Another important issue for the application of radar rainfall algorithm is the detection of rain/no-rain conditions on the ground. Vertical reflectivity profiles of radar observations are used as input variables to the rain/no-rain determination. Radar data and ground raingage measurements are used to train the neural network. Results indicate that rain/no-rain conditions on the ground can be inferred from the procedure developed in this paper fairly accurately. It is shown that by using rain/no-rain classification scheme the accuracy of rainfall accumulation estimates can be improved greatly. (Abstract shortened by UMI.)

Liu, Hongping

473

A Theory for the Determination of Wind and Precipitation Velocities with Doppler Radars  

Microsoft Academic Search

The feasibility of determining components of wind velocity and precipitation particle terminal fallspeeds from the equation of continuity for air and precipitation velocity data collected by Doppler radars is investigated. The investigation is carded out for a system which utilizes two Doppler radars as well as for a system which utilizes three Doppler radars. When only two Doppler radars are

L. Armijo

1969-01-01

474

Analysis of the performance of a multiband passive bistatic radar processing scheme  

Microsoft Academic Search

The bistatic radar has been revitalized over the last few years through the rapid development of the passive bistatic radar technology. Passive bistatic radar systems have unique properties, especially is time on target high compared to traditional radar systems, as well as the freedom in choosing from the available transmitters of opportunity. This paper will focus on how to take

Karl Erik Olsen; Karl Woodbridge

2010-01-01

475

Virtual Prototyping and Performance Analysis of RapidIO-Based System Architectures for Space-Based Radar.  

National Technical Information Service (NTIS)

Space-Based Radar (SBR) processing is a processor- and communication- intensive HPEC application that presents unique design challenges. This talk will concentrate on the presentation of simulation results of mapping a parallel Ground Moving Target Indica...

D. Bueno C. Conger A. Leko I. Troxel A. D. George

2004-01-01

476

Radar clutter classification  

NASA Astrophysics Data System (ADS)

The problem of classifying radar clutter as found on air traffic control radar systems is studied. An algorithm based on Bayes decision theory and the parametric maximum a posteriori probability classifier is developed to perform this classification automatically. This classifier employs a quadratic discriminant function and is optimum for feature vectors that are distributed according to the multivariate normal density. Separable clutter classes are most likely to arise from the analysis of the Doppler spectrum. Specifically, a feature set based on the complex reflection coefficients of the lattice prediction error filter is proposed. The classifier is tested using data recorded from L-band air traffic control radars. The Doppler spectra of these data are examined; the properties of the feature set computed using these data are studied in terms of both the marginal and multivariate statistics. Several strategies involving different numbers of features, class assignments, and data set pretesting according to Doppler frequency and signal to noise ratio were evaluated before settling on a workable algorithm. Final results are presented in terms of experimental misclassification rates and simulated and classified plane position indicator displays.

Stehwien, Wolfgang

1989-11-01

477

Radar Pulse Shape Versus Ocean Wave Height.  

National Technical Information Service (NTIS)

The radar height distribution of the vertical ocean surface structure has been measured with a 1 ns radar system from a tower platform. It is shown that the reflecting properties of the ocean biases the mean sea level by about 5% of the significant wave h...

A. Shapiro E. A. Uliana B. S. Yaplee

1972-01-01

478

Terrestrial Quadstatic Interferometric Radar Observations of Mars  

Microsoft Academic Search

A new technique for resolving the ambiguity inherent in delay-Doppler radar observations of Mars has been developed and implemented using a suite of data collected during 2001, 2003, and 2005 oppositions. New recording systems, processing techniques, and, most importantly, the addition of a fourth receiving telescope allow for the high-resolution mapping of Mars' radar properties. In this paper, we develop

Kristopher W. Larsen; Raymond F. Jurgens; Albert F. C. Haldemann; Martin A. Slade; Howard C. Rumsey

2010-01-01

479

The Magellan Venus radar mapping mission  

Microsoft Academic Search

The NASA Magellan Venus Radar Mapper spacecraft, which will be placed into orbit around Venus on August 10, 1990, is described and its mission is discussed. The orbiter's 12-cm wavelength, multimode radar system is examined and the applications of its modes are addressed. In the SAR mode, it can image most of the Venus surface at a resolution of better

R. S. Saunders; G. H. Pettengill; R. E. Arvidson; W. L. Sjogren; W. T. K. Johnson; L. Pieri

1990-01-01

480

GSFC Short Pulse Radar, JONSWAP-75.  

National Technical Information Service (NTIS)

In September 1975, the Goddard Space Flight Center operated a short pulse radar during ocean wave measuring experiments off the coast of West Germany in the North Sea. The experiment was part of JONSWAP-75. The radar system and operations during the exper...

D. M. Levine W. T. Walton J. Eckerman R. L. Kutz M. Dombrowski

1977-01-01

481

Adaptive Multipath Cancellation Algorithm in Passive Radar  

Microsoft Academic Search

In passive radar system, multipath components including direct wave heavily degrades the performance of target detecting. This paper is focused on adaptive multipath cancellation algorithm in passive radar. In order to evaluate the level of cancellation required, the self-ambiguity of FM is analyzed, and the necessary minimum ratio of interference suppressed is brought forward. According to the similarity of multipath

Kui Wang; Ran Tao; Yongfeng Ma; Tao Shan

2006-01-01

482

Standard Electronic Module Radar Cost Analysis.  

National Technical Information Service (NTIS)

The standard electronic module radar (SEMR) is a redesigned AN/APN-59b weather, navigation, beacon radar system using standard electronic modules wherever possible. Two configurations of SEMR have been developed to permit use in C-130 and C-135 or in C-14...

R. Archbald R. Hoefle R. Lipeles

1977-01-01

483

A general radar surface target echo simulator  

Microsoft Academic Search

A general radar echo simulator system proposed in this paper is to satisfy the various needs of the radar signal processor testing. This simulator is based on the type of echo data playback device, the surface target echo data is pre-calculated and stored in the device at first, then according to the external timing PRI signal, echo data is read

Chengfa Xu; Jingliang Bai; Ronggang Wu; Yongbin Hong

2010-01-01

484

Roadrunner: A novel radar guidance concept  

Microsoft Academic Search

An exploratory development program aimed at demonstrating a novel radar navigation\\/guidance scheme which enables a small unmanned aircraft (drone) to follow roads is presented. Since vehicles on the road can be easily detected, this aircraft could be used as either a strike vehicle itself or as a reconnaissance adjunct to another strike system. The guidance scheme involves onboard radar measurements

J. R. Kelsey

1979-01-01

485

Programmable Radar Signal Processing Using the Rap  

Microsoft Academic Search

This paper describes the architecture of the Raytheon Associative\\/Array Processor (RAP) and its application to real-time radar signal processing. The nature of radar computations is analyzed and parallel processing requirements are characterized. The effects of these requirements upon the design of the RAP are described. Features of the operational RAP system are discussed. Finally, an implementation of a Constant False

George R. Couranz; Mark S. Gerhardt; Charles J. Young

1974-01-01

486

Radar Dwell Scheduling Considering Physical Characteristics of Phased Array Antenna  

Microsoft Academic Search

This paper proposes novel techniques for scheduling radar dwells in phased array radar systems. In order to handle complex physical characteristics such as dwell inter- leaving, transmitting duty cycle constraint, and energy con- straint, we propose a notion of schedulability envelope. The schedulability envelope designed offline hides the details of complex radar dwell scheduling and provides a simple mea- sure

Chang-gun Lee; Phil-su Kang; Chi-sheng Shih; Lui Sha

2003-01-01

487

Schedulability Envelope for Real-Time Radar Dwell Scheduling  

Microsoft Academic Search

This paper proposes novel techniques for scheduling radar dwells in phased array radar systems. In order to handle complex physical characteristics such as dwell interleaving, transmitting duty cycle constraint, and energy constraint, we propose a notion of schedulability envelope. The schedulability envelope designed offline hides the details of complex radar dwell scheduling and provides a simple measure for the schedulability

Chang-Gung Lee; Phil-su Kang; Chi-sheng Shih; Lui Sha

2006-01-01

488

Assimilation of Doppler radar current data into numerical ocean models  

Microsoft Academic Search

A technique is presented for the assimilation of ocean surface currents determined from Doppler radar systems into numerical ocean models. An approach is taken in which the Doppler radar current data act as if there were an additional layer of water overlying the ocean surface. A pseudo-shearing stress resulting from the difference between the model-predicted velocity and the Doppler radar

James K. Lewis; Igor Shulman; Alan F. Blumberg

1998-01-01

489

Radar sensors for automotive collision warning and avoidance  

Microsoft Academic Search

Many different sensors and systems, from sonar to machine vision, have been installed on ground vehicles and automobiles. This paper describes the use of radar to improve driving safety and convenience. Radars are valuable sensors for all weather operation and experiments with automotive radar sensors have been conducted for over 40 years. This paper shows the advantages and disadvantages of

Theodore O. Grosch

1995-01-01

490

High power ultra wideband radar exotic material response  

Microsoft Academic Search

This paper is the first of two that present analytical and numerical analysis of high power and ultra wide band radars interacting with EMI and radar suppression materials. Magnetic materials are often used in isolators, thin film EMI materials and\\/or appliques. Such magnetic composites may be exposed to wide band and\\/or high power signals in operational radar systems. We describe

Rick L. Moore; John Meadors; Robert Rice

2008-01-01

491

EMP (electro-magnetic pulse) hardening of a relocatable radar  

Microsoft Academic Search

The problem of ensuring radar survivability in a HEMP (high-altitude electromagnetic pulse) environment is examined with particular reference to experimental results obtained for the relocatable TRS 22XX radar. The approach used here is global hardening, whereby the whole system except the antenna is enclosed in a Faraday cage. Every penetration of the radar station is protected, the energy input is

G. J. Deville

1987-01-01

492

The detection of clear air turbulence by radar  

Microsoft Academic Search

Considers the relationship between clear air turbulence (CAT) and the associated scattering of radio waves, and shows that radar detection is possible using extremely sensitive microwave systems. Successful measurements with such radars support the view that CAT is due to Kelvin-Helmholtz instability which results from a breakdown of highly sheared airflow. Using current radar technology it would be possible to

C. D. Watkins; K. A. Browning

1973-01-01

493

Coherent Dual Point Sources Deceive Semiactive Monopulse Radar Seeker Technology  

Microsoft Academic Search

The technology of coherent dual point sources is used widely in jamming monopulse passive and active radar. The azimuth of enemies' radar need be measured precisely when coherent dual point source interfere with the semiactive monopulse radar. Analyzing the azimuth value detected by monopulse phase-comparison angle measurement system and the direction value of amplitude-phase distorted area formed by coherent dual

Xiaohui Qi; Tao Jin; Ming Jin; Xiaolin Qiao

2006-01-01

494

CFAR processing for airborne pulse-Doppler radars  

Microsoft Academic Search

Constant false alarm rate (CFAR) processors which may be used in airborne pulse-Doppler radar systems are described. Using radar parameters selected for an aircraft flying at Mach 1 and at up to 10 km altitude, a simulation using the ABRSIM airborne radar simulator reveals that a 70 dB clutter peak appears across all of the range gates and many of

G. Vrckovnik; D. Faubert

1991-01-01

495

W-band ARM Cloud Radar (WACR) Handbook.  

National Technical Information Service (NTIS)

The W-band Atmospheric Radiation Measurement (ARM) Program Cloud Radar (WACR) systems are zenith pointing Doppler radars that probe the extent and composition of clouds at 95.04 GHz. The main purpose of this radar is to determine cloud boundaries (e.g., c...

K. Johnson K. B. Widener

2006-01-01

496

New techniques applied to air-traffic control radars  

Microsoft Academic Search

During the past two years a program has been carried out to show how new techniques can greatly improve the performance of radars used for air-traffic control. A survey of problems associated with presently used radars was undertaken. This survey indicates that primary radar in an automated air-traffic control system can be made significantly more effective by the use of

CHARLES E. MUEHE; LINCOLN CARTLEDGE; WILLIAM H. DRURY; EDWARD M. HOFSTETTER; MELVIN LABITT; PETER B. McCORISON; VINCENT J. SFERRINO

1974-01-01

497