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Space-Time Adaptive Processing (STAP) is used in Ground Moving Target Indication (GMTI) to improve the detection of slow or small targets and targets in the presence of jamming. It is used in a number of airborne radar surveillance systems. In order for STAP to be robustly used as part of a practical military sensor it must deliver robust detection performance
PAMIR, a multifunctional SAR\\/GMTI imaging radar, combines the tremendous research potential of an experimental active broadband phased array system with the wide area of imaging procedures of mono- and bistatic systems. With its two different reconfigurable antenna frontend configurations operating a very high simultaneous bandwidth of 1.8 GHz in X-band, a variety of controversal requirements can be investigated and experimentally
This report describes ground moving target indicator (GMTI) processing to be done for the PCA (polymorphism computing architecture) integrated radar-tracker application. GMTI processing of the raw radar data is done to extract targets; target reports are ...
This report describes ground moving target indicator (GMTI) processing to be done for the PCA (polymorphous computing architecture) integrated radar-tracker application. GMTI processing of the raw radar data is done to extract targets; target reports are ...
The performance of a Ground Moving Target Indicator (GMTI) radarsystem 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 GMTIradarsystem. 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'.
The application of MIMO (Multiple input multiple output) techniques to spaceborne multichannel radar offers a number of advantages, including target detection, parameter estimation, and so on. Based on two kinds of waveforms presented in MIMO radar, a concise definition of synthetical ISLR is proposed. Through analysis of synthetical ISLR for two kinds of waveforms, it concludes that compared with orthogonal frequency division waveform, the crosscorrelation of orthogonal code waveform badly weakens the performance of spaceborne MIMO radar in GMTI (Ground moving target indication). Thus, by adopting orthogonal frequency division waveform, the basic principle of space-time-frequency adaptive processing is studied. Simulation results demonstrate the superiority of frequency division orthogonal MIMO radar in improving clutter suppression and GMTI performance.
Synthetic aperture radar (SAR) and ground moving target indication (GMTI) systems from an airborne platform are in principle based on very simple concepts. The latter combines radar pulses over a short interval to extract Doppler information in order to detect ground moving targets against a clutter background. The former combines pulses over much longer intervals in a coherent manner to
M. Jahangir; D. Coe; A. P. Blake; P. G. Kealey; C. P. Moate
Multichannel radarsystems are of choice for ground moving target indication (GMTI) since they allow for a joint space-time processing of the received data that enables an efficient suppression of ground clutter returns. The design of the receiving sensor group is driven by the performance specifications of the intended GMTI modus, which usually requires the sensor array to consist of
Movement of a GMTIradar 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.
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
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.
Backprojection has long been applied to SAR image formation. It has equal utility in forming the range-velocity maps for Ground Moving Target Indicator (GMTI) radar processing. In particular, it overcomes the problem of targets migrating through range resolution cells.
A typical Ground Moving Target Indicator (GMTI) radar specification includes the parameters Probability of Detection (PD) - typically on the order of 0.85, and False Alarm Rate (FAR) - typically on the order of 0.1 Hz. The PD is normally associated with a particular target 'size', such as Radar Cross Section (RCS) with perhaps some statistical description (e.g. Swerling number). However, the concept of FAR is embodied at a fundamental level in the detection process, which traditionally employs a Constant-FAR (CFAR) detector to set thresholds for initial decisions on whether a target is present or not. While useful, such a metric for radar specification and system comparison is not without some serious shortcomings. In particular, when comparing FAR across various radarsystems, some degree of normalization needs to occur to account for perhaps swath width and scan rates. This in turn suggests some useful testing strategies.
Synthetic aperture radar (SAR) systems have become an important tool for fine-resolution mapping and other remote sensing operations. The multi-channel SAR ground moving-target indication (GMTI) must process its data to produce not only the image of surveillance area but also the information of the ground moving-targets. The topic of moving-target detection in clutter has been extensively studied, and there are
This paper analyzes the influence of typical target micromotions on synthetic aperture radar (SAR) images, azimuth resolution limit, SAR\\/ground moving target indication (GMTI), and MTI. According to the micromotion periods contained in the coherent processing interval, a new range model expansion and a generalized paired echo principle are proposed and applied to underlie the analysis. Several new kinds of image
Xiang Li; Bin Deng; Yuliang Qin; Hongqiang Wang; Yanpeng Li
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.
A large clear air radar with the sensitivity of an incoherent scatter radar for observing the whole equatorial atmosphere up to 1000 km altitude is now being designed in Japan. The radar, called the Equatorial Radar, will be built in Pontianak, Kalimantan Island, Indonesia (0.03 N, 109.3 E). The system is a 47 MHz monostatic Doppler radar with an active
A large clear air radar with the sensitivity of an incoherent scatter radar for observing the whole equatorial atmosphere up to 1000 km altitude is now being designed in Japan. The radar will be built in Pontianak, West Kalimantan, Indonesia (0.03 deg N, 109.29 deg E). The system is a 47-MHz monostatic Doppler radar with an active phased array configuration
A fire control radarsystem was developed, assembled, and modified. The baseline system and modified angle tracking system are described along with the performance characteristics of the baseline and modified systems. Proposed changes to provide additional techniques for radar evaluation are presented along with flight test data.
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 . 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
Research is reported relating to the weapons-location problem as it relates to Marine Corps Hostile Weapons Locating (HWL) radar and lightweight mortar locator requirements. Several technical system problems are discussed, including a review of the HWL system mechanical design. A detailed description is also given of the EES computer modeling program (ballistic trajectory model and radar operational simulation) that was
F. R. Williamson; R. R. Sheppard; C. E. Summers; E. K. Reedy
A large clear air radar with the sensitivity of an incoherent scatter radar for observing the whole equatorial atmosphere up to 1000 km altitude is now being designed in Japan. The radar, called the Equatorial Radar, will be built in Pontianak, Kalimantan Island, Indonesia (0.03 N, 109.3 E). The system is a 47 MHz monostatic Doppler radar with an active phased array configuration similar to that of the MU radar in Japan, which has been in successful operation since 1983. It will have a PA product of more than 5 x 10(9) sq. Wm (P = average transmitter power, A = effective antenna aperture) with sensitivity more than 10 times that of the MU radar. This system configuration enables pulse-to-pulse beam steering within 25 deg from the zenith. As is the case of the MU radar, a variety of sophisticated operations will be made feasible under the supervision of the radar controller. A brief description of the system configuration is presented.
A large clear air radar with the sensitivity of an incoherent scatter radar for observing the whole equatorial atmosphere up to 1000 km altitude is now being designed in Japan. The radar, called the Equatorial Radar, will be built in Pontianak, Kalimantan Island, Indonesia (0.03 N, 109.3 E). The system is a 47 MHz monostatic Doppler radar with an active phased array configuration similar to that of the MU radar in Japan, which has been in successful operation since 1983. It will have a PA product of more than 5 x 10(9) sq. Wm (P = average transmitter power, A = effective antenna aperture) with sensitivity more than 10 times that of the MU radar. This system configuration enables pulse-to-pulse beam steering within 25 deg from the zenith. As is the case of the MU radar, a variety of sophisticated operations will be made feasible under the supervision of the radar controller. A brief description of the system configuration is presented.
A large clear air radar with the sensitivity of an incoherent scatter radar for observing the whole equatorial atmosphere up to 1000 km altitude is now being designed in Japan. The radar will be built in Pontianak, West Kalimantan, Indonesia (0.03 deg N, 109.29 deg E). The system is a 47-MHz monostatic Doppler radar with an active phased array configuration similar to that of the MU radar in Japan, which has been in successful operation since 1983. It will have a PA product of about 3 x 10 to the 9th W sq m (P = average transmitter power, A = effective antenna aperture) with a sensitivity of approximately 10 times that of the MU radar. This system configuration enables pulse-to-pulse beam steering within 20 deg from the zenith. As is the case of the MU radar, a variety of operations will be made feasible under the supervision of the radar controller. A brief description of the system configuration is presented.
Improvement in our understanding of the radiative impact of clouds on the climate system requires a comprehensive view of clouds including their physical dimensions, dynamical generation processes, and detailed microphysical properties. To this end, millimeter vave radar is a powerful tool by which clouds can be remotely sensed. The NASA Goddard Space Flight Center has developed the Cloud RadarSystem (CRS). CRS is a highly sensitive 94 GHz (W-band) pulsed-Doppler polarimetric radar that is designed to fly on board the NASA high-altitude ER-2 aircraft. The instrument is currently the only millimeter wave radar capable of cloud and precipitation measurements from above most all clouds. Because it operates from high-altitude, the CRS provides a unique measurement perspective for cirrus cloud studies. The CRS emulates a satellite view of clouds and precipitation systems thus providing valuable measurements for the implementation and algorithm validation for the upcoming NASA CloudSat mission that is designed to measure ice cloud distributions on the global scale using a spaceborne 94 GHz radar. This paper describes the CRS instrument and preliminary data from the recent Cirrus Regional Study of Tropical Anvils and Cirrus Layers - Florida Area Cirrus Experiment (CRYSTAL-FACE). The radar design is discussed. Characteristics of the radar are given. A block diagram illustrating functional components of the radar is shown. The performance of the CRS during the CRYSTAL-FACE campaign is discussed.
Racette, Paul; Heymsfield, Gerald; Li, Lihua; Tian, Lin; Zenker, Ed
The main constituents of a largely automatic radar track-while-scan system are described. It contains a plot extractor, clutter map, stationary plot filter, and automatic tracking software. The system is designed to operate in high false alarm conditions without formation of false tracks. The clutter map is used to select the optimum video for processes by the plot extractor, which is
We have analyzed and experimentally tested the feasibility of thin wire detection using millimeter wave radar. The radarsystem includes a novel, fast scanning antenna and a transceiver\\/signal processor unit from BAE systems.
Lev S. Sadovnik; Vladimir A. Manasson; Robert M. Mino
The effect of the quality of components on the reliability of a radarsystem, measured as MTBF, is examined. It is shown that to achieve an MTBF of 1000 hr for radar used in ground mobile applications, only certain selective combinations of various professional grade components are permissible. A portion of the additional cost of these components is compensated in the form of a reduction in the number of likely repairs during the warranty period. The use of components, such as switches, semiconductor devices, and ICs, of commercial grade deteriorate the system MTBF to a considerable extent and therefore should be avoided. A proper choice of the type of soldering is also important in optimizing the system MTBF.
An airborne radar sensor operating in ground moving target indicator (GMTI) mode is able to distinguish between airborne targets and ground moving targets. Further it is possible to separate stationary from moving ground targets. For military radar applications, it is desirable that the GMTI mode be extended to allow classification of detected ground targets. In addition, such an extension should
A large clear air radar with the sensitivity of an incoherent scatter radar for observing the whole equatorial atmosphere up to 1000 km altitude is now being designed in Japan. The radar, called the Equatorial Radar, will be built in Pontianak, Kalimantan...
Radar polarimetry is a technology that overcomes the limitation between the radar resolution and the penetration depth of borehole radar. We have developed a stepped-frequency polarimetric borehole radarsystem. This is a polarimetric borehole radarsystem which measures the full-radar polarimetry in a borehole by changing the antenna arrangements. By using a network analyzer and an optical analog signal link,
This paper investigates the relationship between a ground moving target's kinematic state and its SAR image. While effects such as cross-range offset, defocus, and smearing appear well understood, their derivations in the literature typically employ simplifications of the radar/target geometry and assume point scattering targets. This study adopts a geometrical model for understanding target motion effects in SAR imagery, termed the target migration path, and focuses on experimental verification of predicted motion effects using both simulated and empirical datasets based on the Gotcha GMTI challenge dataset. Specifically, moving target imagery is generated from three data sources: first, simulated phase history for a moving point target; second, simulated phase history for a moving vehicle derived from a simulated Mazda MPV X-band signature; and third, empirical phase history from the Gotcha GMTI challenge dataset. Both simulated target trajectories match the truth GPS target position history from the Gotcha GMTI challenge dataset, allowing direct comparison between all three imagery sets and the predicted target migration path. This paper concludes with a discussion of the parallels between the target migration path and the measurement model within a Kalman filtering framework, followed by conclusions.
Ground moving target indicator (GMTI) tracking is often carried out using extended Kalman filters, as in the variable-structure interacting multiple-model (VS-IMM) filter. In some scenarios, however, this is considered to be inadequate. It has been shown that in this case, a particle filter can give better performance. Such a filter, the variable-structure multiple-model particle filter (VS-MMPF), is given in the
In this paper we present the simulation and design of a directional borehole radar. In addition we discuss an imaging method for the radarsystem. The antenna system contains an electric dipole which is in one direction shielded by a cylindrical perfectly conducting reflector. The radiation pattern of the reflected wavefield is computed by first solving the integral equation. This
Koen W. A. van Dongen; Ronald van Waard; Stefan van der Baan; Peter M. van den Berg; Jacob T. Fokkema
A coherent-on-receive MTI radar receiver system for use with cooperative or non-cooperative radar transmitters of either the coherent or noncoherent, simple magnatron type and scanning antennas is discussed. The receiver includes coherent digital signal processing with provision for normalizing or compensating phase variations in the transmitter carrier pulses.
A coherent-on-receive MTI radar receiver system for use with cooperative or non-cooperative radar transmitters of either the coherent or noncoherent, simple magnatron type and scanning antennas is discussed. The receiver includes coherent digital signal processing with provision for normalizing or compensating phase variations in the transmitter carrier pulses.
The Goldstone Solar SystemRadar (GSSR) has successfully collected radar echo data from Mars over the past 30 years. As such, the GSSR has played a role as a specific mission element within Mars exploration. The older data provided local elevation information for Mars, along with radar scattering information with global resolution. Since the upgrade to the 70-m Deep Space
A. F. C. Haldemann; R. F. Jurgens; K. W. Larsen; R. E. Arvidson; M. A. Slade
This paper presents a high performance 77 GHz FMCW radar sensor for automotive applications. Powerful automotive radarsystems are currently under development for various applications. Radar sensor based comfort systems like Adaptive Cruise Control (ACC) are already available on the market. The main objective from a radar sensor point of view is to detect all targets inside the observation area
At typical radar frequencies a wind turbine has a large radar-cross-section (RCS) and due to the movement of the blades, the wind turbine generates a Doppler spectrum. This scattering behaviour has caused concern with radar operators, particularly those working with safety critical radar and national defence. This paper presents results from a modelling tool developed by BAE systems, advanced technology
Signal strength information is a standard output of a modern radarsystem. Provided the amplitude of the target returns exceeds the false alarm background, the consideration of signal strength may lead to improved target estimates, depending on the scenario. In this paper a Bayesian tracking algorithm is presented which incorporates the signal strength information. In contrast to previous approaches, the
A performance analysis of the planetary radar data acquisition system is presented. These results extend previous computer simulation analysis and are facilitated by the development of a simple analytical model that predicts radarsystem performance over a wide range of operational parameters. The results of this study are useful to both the radarsystems designer and the science investigator in establishing operational radar data acquisition parameters which result in the best systems performance for a given set of input conditions.
An obstacle penetrating dynamic radar imaging system for the detection, tracking, and imaging of an individual, animal, or object comprising a multiplicity of low power ultra wideband radar units that produce a set of return radar signals from the individual, animal, or object, and a processing system for said set of return radar signals for detection, tracking, and imaging of the individual, animal, or object. The system provides a radar video system for detecting and tracking an individual, animal, or object by producing a set of return radar signals from the individual, animal, or object with a multiplicity of low power ultra wideband radar units, and processing said set of return radar signals for detecting and tracking of the individual, animal, or object.
Romero, Carlos E. (Livermore, CA); Zumstein, James E. (Livermore, CA); Chang, John T. (Danville, CA); Leach, Jr.. Richard R. (Castro Valley, CA)
A new design of a noise radarsystem is proposed with capabilities to measure and acquire the radar signature of various targets. The proposed system can cover a noise bandwidth of near DC to 30 GHz. The noise radar signature measurements were conducted for selective targets like spheres and carpenter squares with and without dielectric bodies for a noise band of 400MHz-3000MHz. The bandwidth of operation was limited by the multiplier and the antennae used. The measured results of the target signatures were verified with the simulation results.
Freundorfer, A. P.; Siddiqui, J. Y.; Antar, Y. M. M.; Thayaparan, T.
The middle and upper atmosphere (MU) radar of Japan is a unique mesosphere-stratosphere-troposphere type radar with an active phased array system. The MU radar has proved so reliable that continuous trouble-free operations over many days are possible. A brief description of new capabilities recently implemented and calibrations made to confirm the performance of the system are presented herein.
The middle and upper atmosphere (MU) radar of Japan is a unique mesosphere-stratosphere-troposphere type radar with an active phased array system. The MU radar has proved so reliable that continuous trouble-free operations over many days are possible. A brief description of new capabilities recently implemented and calibrations made to confirm the performance of the system are presented herein.
The Goldstone Solar SystemRadar (GSSR) has successfully collected radar echo data from Mars over the past 30 years. As such, the GSSR has played a role as a specific mission element within Mars exploration. The older data provided local elevation information for Mars, along with radar scattering information with global resolution. Since the upgrade to the 70-m Deep Space Network (DSN) antenna at Goldstone completed in 1986, Mars data has been collected during all but the 1997 Mars opposition. Radar data, and non-imaging delay-Doppler data in particular, requires significant data processing to extract elevation, reflectivity and roughness of the reflecting surface. The spatial resolution of these experiments is typically some 20 km in longitude by some 150 km in latitude. The interpretation of these parameters while limited by the complexities of electromagnetic scattering, do provide information directly relevant to geophysical and geomorphic analyses of Mars. The usefulness of radar data for Mars exploration has been demonstrated in the past. Radar data were critical in assessing the Viking Lander 1 site as well as, more recently, the Pathfinder landing site. In general, radar data have not been available to the Mars exploration community at large. A project funded initially by the Mars Exploration Directorate Science Office at the Jet Propulsion Laboratory (JPL), and later funded by NASA's Mars Data Analysis Program has reprocessed to a common format a decade's worth of raw GSSR Mars delay-Doppler data in aid of landing site characterization for the Mars Program. These data will soon be submitted to the Planetary Data System (PDS). The radar data used were obtained between 1988 and 1995 by the GSSR, and comprise some 63 delay-Doppler radar tracks. Of these, 15 have yet to be recovered from old 9-track tapes, and some of the data may be permanently lost.
Haldemann, A. F. C.; Jurgens, R. F.; Larsen, K. W.; Arvidson, R. E.; Slade, M. A.
Nowadays, radar technology represents a significant opportunity to collect useful information for the monitoring and conservation of critical infrastructures. Radarsystems 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 . 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 . 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  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.  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
An airborne weather radarsystem, the Enhanced Weather Radar (EWxR), with enhanced on-board weather radar data processing was developed and tested. The system features additional weather data that is uplinked from ground-based sources, specialized data processing, and limited automatic radar control to search for hazardous weather. National Weather Service (NWS) ground-based Next Generation Radar (NEXRAD) information is used by the EWxR system to augment the on-board weather radar information. The system will simultaneously display NEXRAD and on-board weather radar information in a split-view format. The on-board weather radar includes an automated or hands-free storm-finding feature that optimizes the radar returns by automatically adjusting the tilt and range settings for the current altitude above the terrain and searches for storm cells near the atmospheric 0-degree isotherm. A rule-based decision aid was developed to automatically characterize cells as hazardous, possibly-hazardous, or non-hazardous based upon attributes of that cell. Cell attributes are determined based on data from the on-board radar and from ground-based radars. A flight path impact prediction algorithm was developed to help pilots to avoid hazardous weather along their flight plan and their mission. During development the system was tested on the NASA B757 aircraft and final tests were conducted on the Rockwell Collins Sabreliner.
Knowing the statistical characteristics of a target's radar cross-section (RCS) is crucial to the success of radar target detection algorithms. A wide range of applications currently exist for dismount (i.e. human body) detection and monitoring using ground-moving target indication (GMTI) radarsystems. Dismounts are particularly challenging to detect. Their RCS is orders of magnitude lower than traditional GMTI targets, such as vehicles. Their velocity of about 0 to 1.5 m/s is also much slower than vehicular targets. Studies regarding the statistical nature of the RCS of dismounts focus primarily on simulations or very limited empirical data at specific frequencies. This paper seeks to enhance the existing body of work on dismount RCS statistics at Ku-band, which is currently lacking, and has become an important band for such remote sensing applications. We examine the RCS probability distributions of different sized humans in various stances, across aspect and elevation angle, for horizontal (HH) and vertical (VV) transmit/receive polarizations, and at diverse resolutions, using experimental data collected at Ku-band. We further fit Swerling target models to the RCS distributions and suggest appropriate detection thresholds for dismounts in this band.
Raynal, Ann Marie; Burns, Bryan L.; Verge, Tobias J.; Bickel, Douglas L.; Dunkel, Ralf; Doerry, Armin W.
Mine detection using active radarsystems is the subject of a number of research programs both in the US and in Europe. This paper considers the environmental and operational drivers that influence the design of such radarsystems. The prime system architectures are time domain and frequency domain configurations and each has its merits. The majority of the ground probing radars used at present are time-domain ultra- wideband radars and their characteristics are well established, while a smaller proportion of radars operate in the frequency domain, using FMCW, stepped frequency or noise modulation. The complexity and cost of the latter type of radar is at present greater than the time-domain radars but theoretically offers a better dynamic range. This paper considers the characteristics of these generic radarsystems and the factors that need to be considered in system design. The performance of the antenna significantly affects the overall system and the paper qualitatively discusses this aspect. For GPR, an important technical challenge is associated with achieving a well-defined antenna footprint to maximize the signal to clutter ratio and consideration will be given, in the paper, to time domain array antennas for mine detection. The results of studies carried out during EU funded programs will be reported in this paper. The radar image of the mine depends not only on its construction and on geometry but also on the local environment, hence prior assumptions about the radar spatial signature of the mine may be ill- founded.
This work addressed the development and application of neural models of multi-sensor, multi-modal data and information fusion at Levels 0, 1, 2, and 2+/3 according to the JDL Data Fusion Group Process Model. In order to support multisensor IMINT and GMTI ...
Weather radars are valuable instruments in monitoring explosive volcanic eruptions. Temporal variations in the eruption strength can be monitored as well as variations in plume and ash dispersal. Strength of the reflected radar signal of a volcanic plume is related to water content and droplet sizes as well as type, shape, amount and the grain size distribution of ash. The Icelandic Meteorological Office (IMO) owns and operates three radars and one more is planned for this radar volcano monitoring system. A fixed position 250 kW C-band weather radar was installed in 1991 in SW-Iceland close to Keflavík International Airport, and upgraded to a doppler radar in 2010. In cooperation with the International Civil Aviation Organization (ICAO), IMO has recently invested in two mobile X-band radars and one fixed position C-band radar. The fixed position 250 kW doppler C-band weather radar was installed in April 2012 at Fljótsdalsheiði, E-Iceland, and in June 2012 IMO received a mobile 65 kW dual-polarization doppler X-band radar. Early in 2013 IMO will acquire another mobile radar of the same type. Explosive volcanic eruptions in Iceland during the past 22 years were monitored by the Keflavík radar: Hekla 1991, Gjálp 1996, Grímsvötn 1998, Hekla 2000, Grímsvötn 2004, Eyjafjallajökull 2010 and Grímsvötn 2011. Additionally, the Grímsvötn 2011 eruption was mointored by a mobile X-band radar on loan from the Italian Civil Protection Authorities. Detailed technical information is presented on the four radars with examples of the information acquired during previous eruptions. This expanded network of radars is expected to give valuable information on future volcanic eruptions in Iceland.
Arason, Þórður; Yeo, Richard F.; Sigurðsson, Geirfinnur S.; Pálmason, Bolli; von Löwis, Sibylle; Nína Petersen, Guðrún; Bjornsson, Halldór
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 radarsystem is almost complete. This system, including the directional antennas, is fabricated into a tool to be used in a borehole.
Over 1,000,000 km2 of the equatorial surface of Mars west of the Arsia Mons volcano displays no 3.5-cm radar echo to the very low level of the radarsystem noise for the Very Large Array; the area displaying this unique property has been terms \\
This report summarizes the progress of the Borehole Directional Radar (BDR) System, which is a high-power, high-resolution tool that is being developed to locate lithologic layers or fractures away from a wellbore. The key to the tool's potential is its ability to accurately measure distance and direction of a lithologic discontinuity underground. The results of two field tests in 1988 are presented. The report also discusses the deficiencies of the current system, and a proposed upgrade. Finally, possible other applications of the BDR System are outlined, including (1) locating gas and oil reservoirs below a salt dome, (2) determining the integrity of underground structures (e.g., Strategic Petroleum Reserve, Nuclear Waste Repository Site), and (3) verifying underground nuclear tests. 25 refs., 14 figs.
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.
Thales Raytheon Systems' PC Simulation (PCS) tool allows a rapid simulated evaluation of Firefinder radar performance from a personal desktop computer. Firefinder radars are designed to track hostile rocket, artillery and mortar (RAM) projectiles in order to accurately estimate weapon ground location. The Firefinder tactical code is used within PCS. This design provides a low risk path to rapid prototyping
ISAT is the innovative space-based-radar antenna technology program of the Defense Advanced Research Projects Agency (DARPA). The goal of the ISAT program is to develop antenna technology to enable tactical grade space-based GMTI (ground moving target indicator) radar - particularly from higher (-10,000 km) orbits which facilitate constellations with fewer satellites.
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...
A novel multi-phase center reflector antenna is introduced for the Ground Moving Target Indicator (GMTI) applications. A single antenna is used to virtually make it more than one antenna by controlling the excitation modes of the dual-mode primary feed. First, the multi-mode primary feed is analytically modeled to study the concept in general. Then, the results are presented for the
An airborne ground looking radar sensor's performance may be enhanced by selecting algorithms adaptively as the environment changes. A short description of an airborne intelligent radarsystem (AIRS) is presented with a description of the knowledge based filter and detection portions. A second level of artificial intelligence (AI) processing is presented that monitors, tests, and learns how to improve and control the first level. This approach is based upon metacognition, a way forward for developing knowledge based systems.
We aid in a study of the solar system by means of ground-based radar. We have concentrated on (1) developing the ephemerides needed to acquire radar data at Arecibo Observatory and (2) analyzing the resultant data to: test fundamental laws of gravitation; determine the size, shape, topography, and spin vectors of the targets; and study the surface properties of these objects, through their scattering law and polarization characteristics.
The Lincoln Laboratory 35 GHz airborne SAR (synthetic aperture radar) imaging radarsystem consists of an instrumentation-quality Ka-band airborne radar plus a ground processing and archive system. This state-of-the-art radarsystem provides data collection in SAR and RAR (real aperture radar) modes, full polarization, high resolution (in both range and cross range), and archiving of fully calibrated data. The airborne
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 radarsystems 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 radarsystem 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.
A multstatic frequency-modulated continuous wave (FMCW) radarsystem is under development for use in the control system of autonomous vehicles. The aim of the system, named Colarado, is the 3D location of obstacles in the surrounding environment. In this paper a laboratory prototype system version, the demonstrator, is described and current results are presented.
P. J. F. Swart; J. Schier; A. J. C. van Gemund; W. F. van der Zwan; J. P. Karelse; G. L. Reijns; P. van Genderen; L. P. Ligthart; H. T. Steenstra
Coherent instrumentation radars have been developed at 35 and 94 GHz for use in radar cross section measurements at angles of incidence ranging from 0° to 60°. The systems are designed to measure the radar cross section of various targets, at like and cross-polarizations, in an effort to better understand their scattering characteristics. Both are dual antenna systems capable of
RICHARD T. LAWNER; PETER F. BLANCHARD; SIVA PRASAD GOGINENI
...RadarSystems, Navigational Aids, Mapping Systems and Related Software; Institution...radarsystems, navigational aids, mapping systems and related software by reason...radarsystems, navigational aids, mapping systems and related software by...
We aid in study of the solar system by means of ground-based radar. We have concentrated on: (1) developing the ephemerides needed to acquire radar data at Arecibo Observatory and (2) analyzing the resultant data to: test fundamental laws of gravitation; determine the size , shape, topography, and spin vectors of the targets; and study the surface properties of these objects, through their scattering law and polarization characteristics. We are engaged in radar observations of asteroids and comets, both as systematically planned targets and as "targets of opportunity." In the course of the program, we have prepared ephemerides for about 80 asteroids and three comets, and the radar observations have been made or attempted at the Arecibo Observatory, in most cases successfully, and in some cases on more than one apparition. The results of these observations have included echo spectra for the targets and, in some cases, delay - Doppler images and measurements of the total round-trip delay to the targets. Perhaps the most dramatic of these results are the images obtained for asteroids (4179) Toutatis and 1989PB (Castalia), which were revealed to be double-lobed objects by the radar images. Besides these direct results, the radar observations have furnished information on the sizes and shapes of the targets through analysis of the Doppler width of the echoes as a function of time, and on the surface properties (such as composition, bulk density, and roughness) through analysis of the reflectivity and of the polarization state of the echoes. We have also refined the orbits of the observed asteroids as a result of the Doppler (and in some cases delay) measurements from the radar observations. Although the orbits of main-belt asteroids accessible to ground-based radar are quite well known from the available optical data, some near-Earth objects have been seen by radar very soon after their optical discovery (for example, 199OMF, just eight days after discovery). In such cases. the radar results ensure that the object in question can be anticipated and identified at the next apparition. We have also participated in radar studies of the terrestrial planets. The results of these studies have included both planetary topography profiles from the analysis of round-trip delays to points along the target Doppler equator and determinations of the target spin state. The latter is of special interest in the case of Venus, which is very close to, but not on, a multi-body spin-orbit resonance such that Venus rotates 12 times for every 8 Earth orbits and 13 Venus orbits. As a result, Venus presents nearly the same face toward Earth at each inferior conjunction. Our latest results confirm that the spin state of Venus is slightly off the resonance. The delay measurements from planetary 2 ranging have also been used in combination with other types of range data in testing general relativity with increasing accuracy. We have also been engaged in radar studies of planetary satellites. Using our ephemerides, Arecibo made radar observations of the Galilean satellites of Jupiter and of Mars' satellite Phobos during the favorable opposition seasons (1988-1992 for Jupiter and 1990 for Mars). An attempt was also made to observe Deimos, but without detecting an echo. In 1997, an attempt was made to observe Saturn's satellite Titan, using the newly upgraded Arecibo radarsystem for transmitting and the Goldstone radar for receiving, but no echo was detected. The study of satellites by radar is in many ways similar to that of asteroids. The results from these observations have included characterization of the surface properties from the reflectivity and polarization ratio, as well as (in the case of the large satellites of Jupiter) the variation of reflectivity with incidence angle.
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
Inspired by recent advances in multiple-input multiple-output (MIMO) communications, this paper introduces the statistical MIMO radar concept. The fundamental difference between statistical MIMO and other radar array systems is that the latter seek to maximize the coherent processing gain, while statistical MIMO radar capitalizes on the diversity of target scattering to improve radar performance. Coherent processing is made possible by
Eran Fishler; Alex Haimovich; Rick Blum; R. Cimini; Dmitry Chizhik; Reinaldo Valenzuela
This report describes the space position data processing system of the NASA Western Aeronautical Test Range. The system is installed at the Dryden Flight Research Facility of NASA Ames Research Center. This operational radar data system (RADATS) provides simultaneous data processing for multiple data inputs and tracking and antenna pointing outputs while performing real-time monitoring, control, and data enhancement functions.
This paper illustrates the application of mathematical methods used in software engineering to specification of radarsystems. Such methods are especially relevant to the design of safety critical systems comprising complex multi-processor architectures supporting distributed processing and a significant element of communications. The paper illustrates the use of Communicating Sequential Processes (CSP) and a new approach based on chronological and event logics. The use of CSP demonstrates the formalization of communication aspects while Chronologial Event Logic (CEL) demonstrates the formalization of timing requirements. The paper uses a ship-board phased array radarsystem as a case study.
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
The AN/APQ-153 fire control radar modified to provide angle tracking was evaluated for improved performance. The frequency agile modifications are discussed along with the range-rate improvement modifications, and the radar to computer interface. A parametric design and comparison of noncoherent and coherent radarsystems are presented. It is shown that the shuttle rendezvous range and range-rate requirements can be made by a Ku-Band noncoherent pulse radar.
The paper discusses influence of information technology (IT) on military radarsystems and how this impacts upon conducting military operations. Applications of new technologies in three basic areas of military radarsystems are considered: surveillance and automatic target recognition systems; tracking systems and data and signal processing. Some possible uses of radar data are shown along with how this will
Surface Acoustic Wave (SAW) oscillators are beginning to find growing applications for military radarsystems. This paper deals with the capability of SAW oscillators and the impact on system performance relative to meeting missile and radar requirements.
The EOS SAR mission under consideration as one element of the mission to planet earth, which will provide a long duration radar observing system with multipolarization and multifrequency capability, is presented. The payload consists of three synthetic aperture radarsystems; a C-band radar with dual polarization, an L-band radar with quadruple polarization, and an X-band radar with dual polarization. Each radarsystem will be of the phased-array type, will have variable resolutions and swath widths and will be capable of steering the beam electronically in elevation.
Wellman, John B.; Sander, Michael J.; Suggs, Eric E.; Way, Jobea
This document describes a challenge problem whose scope is the detection, geolocation, tracking and ID of moving vehicles from a set of X-band SAR data collected in an urban environment. The purpose of releasing this Gotcha GMTI Data Set is to provide the community with X-band SAR data that supports the development of new algorithms for SAR-based GMTI. To focus
Steven M. Scarborough; Curtis H. Casteel Jr.; Leroy Gorham; Michael J. Minardi; Uttam K. Majumder; Matthew G. Judge; Edmund Zelnio; Michael Bryant; Howard Nichols; Douglas Page
A complement to the local optical early warning system is described. The LS system (LS = optical early warning station) is suggested, using simple marine radars equipped with MTI circuits. It is possible for land based MTI-radar to separate moving target echoes from ground echoes. The LS-radar early warning system gives directly a warning to neighboring local command centers. Advantages
The signal phase histories at the transmitter, receiver, and radar signal processor in bistatic SAR systems are described. The fundamental problem of mismatches in the waveform generators for the illuminating and receiving radarsystems is analyzed. The effects of errors in carrier frequency and chirp slope are analyzed for bistatic radarsystems which use linear FM waveforms. It is shown
Carnegie Mellon University is automating the use of Ground Penetrating Radar (GPR) for cleanup of hazardous waste sites. The Site Investigation Robot (SIR) project at the Field Robotics Center is applying robotics and image processing technologies to the investigatory phase of these waste site cleanups. The current focus is on the development of an automated subsurface mapping system to locate
Robert Beck; Jay Cosentino; David W. Collier; Jim Osborn
Remote Sensing Solutions, Inc has received NASA funding to design a prototype millimeter-wave radarsystem that will lead to future generations of large aperture space-borne electronic scanning radars. A scanning millimeter-wave radar is critical tool for improving the remote sensing of the Earth and other bodies in our solar system. Low power solid-state scanning millimeter-wave radarsystems cannot provide the
A near real-time radar-based imaging system is developed in this dissertation. This system uses the combination of a spatially diverse antenna array, a high sensitivity range-gated frequency-modulated continuous wave (FMCW) radarsystem, and an airborne synthetic aperture radar (SAR) imaging algorithm to produce near real-time high resolution imagery of what is behind a dielectric wall. This system is capable of detecting and providing accurate imagery of target scenes made up of objects as small as 6 inch tall metallic rods and cylinders behind a 4 inch thick dielectric slab. A study is conducted of through-dielectric slab imaging by the development of a 2D model of a dielectric slab and cylinder. The SAR imaging algorithm is developed and tested on this model for a variety of simulated imaging scenarios and the results are then used to develop an unusually high sensitivity range-gated FMCW radar architecture. An S-band rail SAR imaging system is developed using this architecture and used to image through two different dielectric slabs as well as free-space. All results are in agreement with the simulations. It is found that free-space target scenes could be imaged using low transmit power, as low as 5 picowatts. From this result it was decided to develop an X-band front end which mounts directly on to the S-band rail SAR so that objects as small as groups of pushpins and aircraft models in free-space could be imaged. These results are compared to previous X-band direct conversion FMCW rail SAR work. It was found that groups of pushpins and models could be imaged at transmit powers as low as 10 nanowatts. A spatially diverse S-band antenna array will be shown to be developed for use with the S-band radar; thereby providing the ability for near real-time SAR imaging of objects behind dielectric slabs with the same performance characteristics of the S-band rail SAR. The research presented in this dissertation will show that near real-time radar imaging through lossy-dielectric slabs is accomplished when using a highly sensitive radarsystem located at a stand-off range from the slab using a free-space SAR imaging algorithm.
Due to distances and relative motions among the transmitter, target object, and receiver, the time-base between any transmitted and received signal will undergo distortion. Pre-distortion of the transmitted signal to compensate for this time-base distortion allows reception of an undistorted signal. In most radar applications, an arbitrary waveform generator (AWG) would be used to store the pre-calculated waveform and then play back this waveform during transmission. The Goldstone Solar SystemRadar (GSSR), however, has transmission durations that exceed the available memory storage of such a device. A waveform generator capable of real-time pre-distortion of a radar waveform to a given time-base distortion function is needed. To pre-distort the transmitted signal, both the baseband radar waveform and the RF carrier must be modified. In the GSSR, this occurs at the up-conversion mixing stage to an intermediate frequency (IF). A programmable oscillator (PO) is used to generate the IF along with a time-varying phase component that matches the time-base distortion of the RF carrier. This serves as the IF input to the waveform generator where it is mixed with a baseband radar waveform whose time-base has been distorted to match the given time-base distortion function producing the modulated IF output. An error control feedback loop is used to precisely control the time-base distortion of the baseband waveform, allowing its real-time generation. The waveform generator produces IF modulated radar waveforms whose time-base has been pre-distorted to match a given arbitrary function. The following waveforms are supported: continuous wave (CW), frequency hopped (FH), binary phase code (BPC), and linear frequency modulation (LFM). The waveform generator takes as input an IF with a time varying phase component that matches the time-base distortion of the carrier. The waveform generator supports interconnection with deep-space network (DSN) timing and frequency standards, and is controlled through a 1 Gb/s Ethernet UDP/IP interface. This real-time generation of a timebase distorted radar waveform for continuous transmission in a planetary radar is a unique capability.
The Lincoln Laboratory millimeter-wave synthetic aperture radar (SAR) imaging system is part of a DARPA-funded program that was established at Lincoln Laboratory to investigate the detection and classification of stationary targets using ultra-high resolution, fully polarimetric SAR and real aperture radar (RAR) data. The system consists of an airborne radar that operates at 33.56 GHz. The raw radar data are
John C. Henry; Thomas J. Murphy; Kathleen M. Carusone
SIR-C\\/X-SAR, a three-frequency radar to be flown on the Space Shuttle in September 1993, is described. The SIR-C system is a two-frequency radar operating at 1250 MHz (L-band) and 5300 MHz (C-band), and is designed to get four-polarization radar imagery at multiple surface angles. The X-SAR system is an X-band imaging radar operating at 9600 MHz. The discussion covers the
Rolando L. Jordan; Bryan L. Huneycutt; Marian Werner
Coherent instrumentation radars have been developed at 35 GHz and 94 GHz for use in radar-cross-section measurements at angles of incidence ranging from 0° to 60°. The systems are designed to measure the radar cross section of various targets, at like- and cross-polarizations, in an effort to better understand their scattering characteristics. Both are dual-antenna systems capable of operating in
A case study of the rain radarsystem for the Tropical Rainfall Measuring Mission has been conducted, considering pulse compression radar versus conventional type radar, active array radar with solid state power amplifiers versus passive array radar with TWTA, and various antenna types. The characteristic parameters, power consumptions, weights, and sizes of six different cases are presented. It is found that the most suitable candidate for the mission is the nonpulse compression active array radar with planar array.
An intelligent Synthetic Aperture Radar simulation system can be used to optimize the design of SAR system parameters and select optimum SAR data acquisition mode. Previous research mainly focused on simulating geometric characteristics of SAR image, lacking of radiometric consideration in flat areas because of the complexity of the problem. The popular geometric model of Range Doppler Equations cannot be applied to SAR sensor pre-launched as it relies on so many parameters contained in the original SAR data. In this paper we develop a new simulation system based on simplified geometric model and statistical radar scattering model for different thematic contents. It can generate simulated SAR image product at different bands, polarizations, incidence angles and resolutions, according to user's need. As an experiment, a simulation example of ENVISAT ASAR is compared with the real data collected, to demonstrate the utility and correctness of the system.
Coherent laser radarsystems at 10 micrometers have been studied in Europe for well over a decade. In the past few years, the level of activity has increased rapidly and work is now in progress on systems and components at a large number of research institutions and industrial firms. Some of the organizations have had specific involvement with wind and aerosol measuring lidars, while others are largely concerned with components. Some of the particular European strong points are reviewed in device physics and technology. In addition to wind measurement systems, much work has been done on other applications of coherent laser radar including ranging, imaging, and coherent DIAL studies. Some of these other applications are also outlined.
Two classes of coherent radar types are analyzed to ascertain whether any significant advantages exist for a given system. The classes compared are those coherent radars which transmit a phasecoherent pulse-to-pulse RF carrier as opposed to those which transmit randomly phased RF carriers but store the coherent information at the radar for Doppler extraction. Rigorous new analytical development is avoided
In this paper, moving target tracking performance in multiple input multiple output (MIMO) radarsystems with distributed antennas and non-coherent processing is studied. Due to the use of multiple, widely distributed antennas, MIMO radar architectures support both centralized and decentralized tracking techniques. Each receiving radar may contribute to central processing by providing either raw data or partially\\/fully processed data. Estimation
Hana Godrich; V. M. Chiriac; Alexander M. Haimovich; Rick S. Blum
New USA Navy missions and operating environments are driving radar requirements and technology needs for future surface combatants. Future Navy ships will likely have a suite of two (or possibly more) radars for providing defense against air targets and theater ballistic missile (TBM). Radar processors with open systems, COTS components, and portable software offer cost savings and the possibility of
Aspects of multidimensional radar processing are described. These include those related to adaptive beam forming, detection for multistatic radarsystems, polarimetric radar, time-frequency detection by Wigner transformation, and spotlight SAR processing by Radon transform. Benefits, in terms of new and/or computationally efficient processing schemes, are expected to come from a unified approach to multidimensional processing problems. In addition, the utility of transformation techniques not widely applied in radar science are discussed.
The Spaceborne Imaging Radar-C\\/X-Band Synthetic Aperture Radar (SIR-C\\/X-SAR) was a joint United States\\/German\\/Italian space agency imaging radarsystem successfully flown aboard the shuttle Endeavor in April 1994 and again in September\\/October 1994. The multifaceted SIR-C\\/X-SAR represents a major technological step forward in radar remote sensing and is the first spaceborne multifrequency, polarimetric SAR. The United States developed SIR-C operated at
The 94 GHz MMW airborne radarsystem 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.
This report describes the space position data processing system of the NASA Western Aeronautical Test Range. The system is installed at the Dryden Flight Research Facility of NASA Ames Research Center. This operational radar data system (RADATS) provides simultaneous data processing for multiple data inputs and tracking and antenna pointing outputs while performing real-time monitoring, control, and data enhancement functions. Experience in support of the space shuttle and aeronautical flight research missions is described, as well as the automated calibration and configuration functions of the system.
From October 8 th to 23 rd , 2000, a helicopter-borne radar measurement campaign has been carried out at the Careser Glacier in the Italian Alps. Main objectives were to provide radar profiles of the glacier and to obtain a comparison of the performances of a pulsed radarsystem and a novel stepped frequency radar. Since the weather conditions did
Methods and systems reduce clutter interference in a radar-responsive tag system. A radar transmits a series of linear-frequency-modulated pulses and receives echo pulses from nearby terrain and from radar-responsive tags that may be in the imaged scene. Tags in the vicinity of the radar are activated by the radar's pulses. The tags receive and remodulate the radar pulses. Tag processing
This report discusses the application and cost of two types of altimeter systems (spaceborne (satellite and shuttle) and airborne) to twelve user requirements. The overall design of the systems defined to meet these requirements is predicated on an unconstrained altimetry technology; that is, any level of altimeter or supporting equipment performance is possible.
Coherent Technologies, Inc. (CTI) was established in 1984 to engage in the development of coherent laser radarsystems and subsystems with applications in atmospheric remote sensing, and in target tracking, ranging and imaging. CTI focuses its capabilities in three major areas: (1) theoretical performance and design of coherent laser radarsystem; (2) development of coherent laser radarsystems for government agencies such as DoD and NASA; and (3) development of coherent laser radarsystems for commercial markets. The topics addressed are: (1) 1.06 micron solid-state coherent laser radarsystem; (2) wind measurement using 1.06 micron system; and flashlamp-pumped 2.09 micron solid-state coherent laser radarsystem.
It is well recognized that a wind turbine has a large radar cross-section (RCS) and, due to the movement of the blades, the wind turbine will generate a Doppler frequency shift. This scattering behavior may cause severe interferences on existing radarsystems including static ground-based radars and spaceborne or airborne radars. To resolve this problem, efficient techniques or algorithms should be developed to mitigate the effects of wind farms on radars. Herein, one transponder-based mitigation technique is presented. The transponder is not a new concept, which has been proposed for calibrating high-resolution imaging radars. It modulates the radar signal in a manner that the retransmitted signals can be separated from the scene echoes. As wind farms often occupy only a small area, mitigation processing in the whole radar operation will be redundant and cost inefficient. Hence, this paper uses a transponder to determine whether the radar is impacted by the wind farms. If so, the effects of wind farms are then mitigated with subsequent Kalman filtering or plot target extraction algorithms. Taking airborne synthetic aperture radar (SAR) and pulse Doppler radar as the examples, this paper provides the corresponding system configuration and processing algorithms. The effectiveness of the mitigation technique is validated by numerical simulation results. PMID:24385880
This paper presents a design for a new train control system, which we call the radarsystem for train tracking and control (RSTTC). The RSTTC is based on the communication-based train control (CBTC) system, and uses radar technology with a spread-spectrum scheme. The main advantage to using the CBTC system is that it allows (1) the headway between trains to
The state of the art determination was made for radar measurement of: soil moisture, snow, standing and flowing water, lake and river ice, determination of required spacecraft radar parameters, study of synthetic-aperture radarsystems to meet these parametric requirements, and study of techniques for on-board processing of the radar data. Significant new concepts developed include the following: scanning synthetic-aperture radar to achieve wide-swath coverage; single-sideband radar; and comb-filter range-sequential, range-offset SAR processing. The state of the art in radar measurement of water resources parameters is outlined. The feasibility for immediate development of a spacecraft water resources SAR was established. Numerous candidates for the on-board processor were examined.
Moore, R. K.; Claassen, J. P.; Erickson, R. L.; Fong, R. K. T.; Hanson, B. C.; Komen, M. J.; Mcmillan, S. B.; Parashar, S. K.
SIR-C/X-SAR, a three-frequency radar to be flown on the Space Shuttle in September 1993, is described. The SIR-C system is a two-frequency radar operating at 1250 MHz (L-band) and 5300 MHz (C-band), and is designed to get four-polarization radar imagery at multiple surface angles. The X-SAR system is an X-band imaging radar operating at 9600 MHz. The discussion covers the mission concept; system design; hardware; RF electronics; digital electronics; command, timing, and telemetry; and testing.
Jordan, Rolando L.; Huneycutt, Bryan L.; Werner, Marian
The investigations for a rendezvous radarsystem design and an integrated radar/communication system design are presented. Based on these investigations, system block diagrams are given and system parameters are optimized for the noncoherent pulse and coherent pulse Doppler radar modulation types. Both cooperative (transponder) and passive radar operation are examined including the optimization of the corresponding transponder design for the cooperative mode of operation.
Use of multiple-antenna radarsystems aboard moving high-altitude platforms has been proposed for measuring rainfall. The basic principle of the proposed systems is a variant of that of along-track interferometric synthetic-aperture radarsystems used previously to measure ocean waves and currents.
Millimeter-wave and terahertz radarsystems can play an important role in multimodal layered sensing systems targeted at measuring both physiological and behavioral biometric data for security and medical applications. We will describe a 228 GHz heterodyne radarsystem that is capable of measuring respiration rates at standoff distances of up to 50 meters and simultaneously measure respiration and heartbeat rates
Douglas T. Petkie; Erik Bryan; Carla Benton; Brian D. Rigling
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.
This paper describes a concept for a scalable RF sensor payload for small UAVs that can perform multiple RF functions such as synthetic aperture radar (SAR), ground-moving target indication (GMTI) and ESM. Essential to the scalable multifunction RF payload concept is the digitization of the antenna signals on transmit and receive at the antenne element level. The architecture of a
A. G. Huizing; M. P. G. Otten; W. L. van Rossum; R. van Dijk; A. P. M. Maas; E. H. van der Houwen; R. J. Bolt
A dual Ka-band radarsystem is developed by the Japan Aerospace Exploration Agency (JAXA) for the GPM DPR algorithm development. The dual Ka-radarsystem which consists of two identical Ka-band radars can measure both the specific attenuation and the equivalent radar reflectivity at Ka-band. Those parameters are important particularly for snow measurement. Using the dual Ka-radarsystem along with other instruments, such as a polarimetric precipitation radar, a windprofiler radar, ground-based rain measurement systems, the uncertainties of the parameters in the DPR algorithm can be reduced. The verification of improvement of rain retrieval with the DPR algorithm is also included as an objective. Observations using the dual Ka-radarsystem were performed in Okinawa Island, in Tsukuba, over the slope of Mt. Fuji, and in Nagaoka, Japan. In Okinawa Island, the performance of the measurement has been confirmed by rain observation. In Tsukuba, one radar was directed in vertical and the other was in slant direction. By this configuration, total attenuation in the melting layer was estimated. The objective of the Mt. Fuji experiment was to observe the melting layer. In Nagaoka, a lot of wet snow fell, and much data on the snow have been obtained. The main results are measured k-Ze relationships. For the rain, reasonable k-Ze relationship has been obtained. The feasibility of total attenuation in melting layer has been studied. Different k-Ze relationships have been obtained in snow observations.
...Notice to Manufacturers of Airport Avian RadarSystems AGENCY: Federal Aviation Administration...Notice to Manufacturers of Airport Avian RadarSystems...foreign manufacturers of airport avian radarsystems that meet the requirements of...
A frequency-modulated continuous wave radarsystem is under development in the Communications Systems Branch of the Information and Electronic Systems Laboratory at Marshall Space Flight Center. The radar unit is being designed for use on the teleoperator maneuvering system. Its function is to provide millimeter-level accuracy in range and range rate measurements out to a range of thirty meters. This will facilitate soft docking with accuracy. This report is an updating of previous developments reported on this system. An innovation in the system is the utilization of a standard reference signal generated by shunting a portion of the radar energy into a shorted coaxial delay line. The regular radar target return signal is constantly compared with the reference signal to provide internal error compensation. Within a five meter range, a limit imposed by present laboratory dimensions, the radarsystem exhibits reliable accuracy with range error less than 0.2%.
The application of synthetic aperture radar (SAR) in monitoring and managing earth resources is examined. Synthetic aperture radars form a class of side-looking airborne radar, often referred to as coherent SLAR, which permits fine-resolution radar imagery to be generated at long operating ranges by the use of signal processing techniques. By orienting the antenna beam orthogonal to the motion of the spacecraft carrying the radar, a one-dimensional imagery ray system is converted into a two-dimensional or terrain imaging system. The radar's ability to distinguish - or resolve - closely spaced transverse objects is determined by the length of the pulse. The transmitter components receivers, and the mixer are described in details.
Moore, R. K.; Claassen, J. P.; Erickson, R. L.; Fong, R. K. T.; Komen, M. J.; Mccauley, J.; Mcmillan, S. B.; Parashar, S. K.
The SEASAT, a synthetic aperture imaging radarsystem is the first radarsystem of its kind designed for the study of ocean wave patterns from orbit. The basic requirement of this system is to generate continuous radar imagery with a 100 km swath with 25m resolution from an orbital altitude of 800 km. These requirements impose unique system design problems. The end to end data system described including interactions of the spacecraft, antenna, sensor, telemetry link, and data processor. The synthetic aperture radarsystem generates a large quantity of data requiring the use of an analog link with stable local oscillator encoding. The problems associated in telemetering the radar information with sufficient fidelity to synthesize an image on the ground is described as well as the selected solutions to the problems.
The 305 m Arecibo telescope equipped with a 1 MW 2.38 GHz transmitter is used for studies of the terrestrial planets, planetary satellites including the Moon and small bodies in the solar system. Much of the recent program emphasis has been on astrometric and characterization observations of near-Earth objects for which the Arecibo radarsystem has capabilities not matched by
Donald B. Campbell; John K. Harmon; Michael C. Nolan
The Synthetic Aperture Radar (SAR) onboard the Seasat-A satellite will conduct a number of experiments involving deep ocean waves, coastal wave patterns, polar ice and land forms. The SAR will have a 25 m by 25 m resolution over a swath of 100 km width centered about 300 km to the right of the spacecraft track. The SAR's high data rate limits operations to times when Seasat-A is in view of a few ground stations with special SAR receiving equipment. However, the SAR will collect much useful data about deep ocean and coastal waves in the Atlantic and Pacific Oceans; about ice in the Northwest Atlantic, in the Great Lakes and off the coast of Alaska; and about land over much of the United States and Canada.
Modern phased-array radars are usually complex systems containing many hundreds or thousands of individual controllable, electronically steered, radiating and receiving elements. The usual definitions of system failure or success are given in terms of a discrete threshold of acceptability for a minimum number of operable elements out of the total simultaneously available. The availability, or readiness, of the phased-array radar
Ground Penetrating Radar (GPR) has been investigated as a non-destructive method for evaluating damage in concrete structures. However, the commercially available techniques are limited to detection of gross quantities of deterioration, due to the limited resolution of the system. The objective of this research is to evaluate a ground penetrating radarsystem with a novel Good Impedance Match Antenna (GIMA)
Dryver Huston; Jing Qiong Hu; Kenneth Maser; William Weedon; Chris Adam
The power requirements of a space-based radar (SBR) spacecraft are examined. Design considerations are discussed, and a baseline prime power system, generating about 30 kW, is described. The generic SBR and baseline power requirements have been derived from considerations of spacecraft payload power and the radar operating conditions and from a parametric model for sizing the power system. The proposed
Many microwave collision avoidance radars have been tested using FMCW (frequency modulated continuous wave) radar and pulsed radar working around 10, 35 and 60 GHz. The aim of this paper is to describe an efficient radarsystem, termed bimodal, obtained by the combination of these two systems. The FMCW sensor is used for close detection and easier speed calculation, and the pulsed one for large distances and multi-target separation. The bimodal system has been used to improve the performances of the two sensors by retaining the advantages of each. The new radar is able to detect obstacles between 2 and 150 m with low emitted power. The whole system is controlled by a decision program unit. An accuracy of 0957-0233/9/8/030/img8 m has been achieved.
Rivenq-Menhaj, A.; Rouvaen, J. M.; Assaad, J.; Heddebaut, M.; Bruneel, C.
The Lincoln Laboratory millimeter-wave synthetic aperture radar (SAR) imaging system is part of a DARPA-funded program that was established at Lincoln Laboratory to investigate the detection and classification of stationary targets using ultra-high resolution, fully polarimetric SAR and real aperture radar (RAR) data. The system consists of an airborne radar that operates at 33.56 GHz. The raw radar data are recorded on high density digital tapes that are sent to the Radar Data Analysis Center, which is located at Lincoln Laboratory in Lexington, Mass. This center processes the data to create calibrated SAR and RAR images. The Radar Data Analysis Center consists of a number of major data processing elements: an image formation processor, an archival storage and retrieval system, and a cluster of computer systems used for data analysis. In order to accomplish the goals of the DARPA program, it is essential that the radar data be very carefully calibrated. The calibration process consists of three major steps: (1) an internally generated calibration pulse is inserted into the radar receiver at the front end; (2) calibration targets (dihedrals and trihedrals) deployed on the ground are measured by the radar from the air and; (3) special calibration processing software uses the measurements from (1) and (2) to achieve polarimetric calibration. This paper describes the airborne radar, the ground processing facility, and the calibration process. Recent SAR images, generated from airborne measurements, of ground clutter and selected urban areas are presented. The images were generated using the polarimetric whitening filter (PWF), a novel processing technique developed at Lincoln Laboratory. The PWF process exploits the polarimetric measurement capability of the radar to create imagery that is nearly optical in quality.
Henry, John C.; Murphy, Thomas J.; Carusone, Kathleen M.
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
Unobstructed, large RCS targets, similar radar targets surrounded by moving foliage, and small targets in severe clutter have been used as test cases for two pre-processing algorithms and several threshold levels in an experimental millimeter wave radarsystem. The rather conventional \\
A target recognition system is described using 3-D mathematical models which simulate radar images. The simulated radar images are created from radar cross section (RCS) responses of the 3-D models and compared with measured target radar images. The 3-D models consist of several thousands facets, and one facet size is less than the radar resolution. An RCS response of each facet in the models is calculated by the modified geometrical theory of diffraction (GTD) method using the information of the radar frequency and the target aspect angle. The RCS response of each facet is projected onto the 2-D plane based on target aspect angle to create the final simulation radar images. The system is verified to be able to simulate even a ship radar imagery, in spite of the difficulty in the simulation due to its structural complexity. Evaluations were made for this recognition system by comparing the simulated ship images created from the 3-D models with the real ship images obtained by an airborne MITSUBISHI-SAR which has the capability of obtaining the X-band 1m resolution SAR and ISAR images, and the system has been proved to have the classification accuracy of better than 90%.
The paper examines the overall system design for space-based radar and pertaining options, including the optimization of the power-aperture product, the definition of the beamwidths, and the use of multiple antenna beams. A distributed array architecture, made up of may coherently operating radar modules is recommended in a number of operational situations.
di Vito, Antonio; Pistoia, Daniela; Galati, Gaspare
The overall system design for space-based radar and pertaining options, including the optimization of the power-aperture product, the definition of the beamwidths and the use of multiple antenna beams are addressed. A distributed array architecture, made up by many radar modules coherently operating, is recommended in a number of operational situations.
After years of research effort, the Australian Government is now committed to build the Jindalee Over-The-Horizon Radar Network (JORN), which will enable a comprehensive and cost effective surveillance of the northern and western approaches of Australia. In order to realise the full potential of the technology embodied within the radarsystem, the Department of Defence is keen to incorporate the
The Goldstone Solar SystemRadar (GSSR) has successfully collected radar echo data from Mars over the past 30 years. The older data provided local elevation information for Mars, along with radar scattering information with global resolution. Since the upgrade to the 70-m DSN antenna at Goldstone completed in 1986, Mars data has been collected during all but the 1997 Mars opposition. Radar data, and non-imaging delay- Doppler data in particular, requires significant data processing to extract elevation, reflectivity and roughness of the reflecting surface. The spatial resolution of these experiments is typically some 10 km in longitude by some 150 km in latitude. The interpretation of these parameters while limited by the complexities of electromagnetic scattering, do provide information directly relevant to geophysical and geomorphic analyses of Mars.
Haldemann, A. F. C.; Jurgens, R. F.; Slade, M. A.; Larsen, K. W.
A marine tank gauging system based on the FMCW radar is introduced. The range measurement principle of this system is presented. The digital signal processing procedure based on the FFT is described. The experimental results are also reported
The objectives of the Apollo 17 Lunar Sounder Experiment (ALSE) were to detect subsurface geologic structures, to generate a continuous lunar profile, and to image the moon a radar wavelengths. The first objective is generally impossible on Earth, but is possible on the moon because of the very low EM attenuation found in lunar rocks. A three-wavelength synthetic-aperture radar (SAR)
LEONARD J. PORCELLO; R. L. Jordan; JERRY S. ZELENKA; GARY F. ADAMS; ROGER J. PHILLIPS; WALTER E. BROWN; S. H. Ward; P. L. Jackson
Pulse-compression is a technique used in radar to transmit a long pulse while retaining the range resolution of a short pulse. The echo from the target is compressed in the matched filter of the radar receiver and the range resolution becomes equal to the width of the central peak of the autocorrelation function of the transmitted signal. A range tracking
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. The radar would be housed primarily in a single large building on a site of approxim...
S. J. Everett W. A. Edson R. A. Shepherd L. N. Heynick T. H. Walklet
A real-time S-band radar imaging system will be shown in this paper that uses a spatially diverse antenna array connected to a highly sensitive linear FM radarsystem and uses a synthetic aperture radar (SAR) imaging algorithm to produce real-time radar imagery. The core of this radarsystem is a high-sensitivity, range gated, radar architecture. Previous work has demonstrated the
Gregory L. Charvat; Leo C. Kempel; Edward J. Rothwell
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 system. This processor system is designed to interface with the NASA Johnson Space Center in-house Extra Vehicular Activity (EVA) Retriever robot program and provide to it needed information so it can fetch and grasp targets in a space-type scenario.
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
This paper describes the waveform design space and signal processing system for dual-polarization Doppler weather radar operating at X band. The performance of the waveforms is presented with ground clutter suppression capability and mitigation of range velocity ambiguity. The operational waveform is designed based on operational requirements and system/hardware requirements. A dual Pulse Repetition Frequency (PRF) waveform was developed and implemented for the first generation X-band radars deployed by the Center for Collaborative Adaptive Sensing of the Atmosphere (CASA). This paper presents an evaluation of the performance of the waveforms based on simulations and data collected by the first-generation CASA radars during operations.
The report gives a description of a complement to the local optical early warning system. 'The LS-system' (LS = local optical early warning station) is suggested to use simple marine radars equipped with MTI circuits. It is possible for land based MTI-rad...
The patent application relates to automatically testing the operating characteristics of radar magnetrons by coupling the magnetron output through a plurality of filters to sample and hold circuits. The outputs from the sample and hold circuits provide a ...
Carnegie Mellon University is automating the use of Ground Penetrating Radar (GPR) for cleanup of hazardous waste sites. The Site Investigation Robot (SIR) project at the Field Robotics Center is applying robotics and image processing technologies to the ...
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. T...
S. J. Everett W. A. Edson L. N. Heynick S. R. Pierce R. A. Shepherd
The range information with Frequency Modulated Continuous Wave (FMCW) radarsystems is discrete within multiples of the modulation frequency. There is a correspondance between the spectral lines and discrete distance values. Even though the classical spec...
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...
The overall system design for space-based radar and pertaining options, including the optimization of the power-aperture product, the definition of the beamwidths and the use of multiple antenna beams are addressed. A distributed array architecture, made ...
Subsea laser radar has a potential for accurate 3-D imaging in water. A prototype system has been developed at Seatex A/S in Norway as a prestudy for the design of an underwater laser radar scanning system. Parallel to the experimental studies, a numerical radiometric model has been developed as an aid in the system design. This model simulates a raster scanning laser radarsystem for in-water use. Thus this parametric model allows for analysis and predictions of the performance of such a sensor system. Experiments have been conducted to test a prototype laser radarsystem. The experimental system tested uses a Q-switched, frequency doubled, Nd:YAG solid state laser operating at a wavelength of 532 nm, which is close to optimal for use in water due to the small light attenuation around this wavelength in seawater. The laser has an energy output of 6 (mu) J per pulse 1 kHz pulse repetition frequency (PRF) and the receiver aperture is approximately 17 cm2. The laser radar prototype was mounted onto an accurate pan and tilt unit in order to test the 3-D imaging capabilities. The ultimate goal of the development is to provide an optical 3-D imaging tool for distances comparable to high frequency sonars with a range capability of approximately 30 - 50 m. The results from these experiments are presented. The present implementation of the scanning laser radar model is described and some outputs from the simulation are shown.
Bjarnar, Morten L.; Klepsvik, John O.; Nilsen, Jan E.
The authors describe a 94 GHz bistatic FMCW (frequency-modulation continuous-wave) radar under development for an aircraft landing system. Using a narrow vertical fan beam antenna, the system scans the runaway rapidly in azimuth, processes the radar returns, and obtains a realistic real-time runway image with sufficient information and resolution to enable a pilot to operate in and out of the
The application of synthetic aperture radar (SAR) in monitoring and managing earth resources was examined. The function of spaceborne radar is to provide maps and map imagery to be used for earth resource and oceanographic applications. Spaceborne radar has the capability of mapping the entire United States regardless of inclement weather; however, the imagery must have a high degree of resolution to be meaningful. Attaining this resolution is possible with the SAR system. Imagery of the required quality must first meet mission parameters in the following areas: antenna patterns, azimuth and range ambiguities, coverage, and angle of incidence.
Moore, R. K.; Claassen, J. P.; Erickson, R. L.; Fong, R. K. T.; Hanson, B. C.; Komen, M. J.; Mcmillan, S. B.; Parashar, S. K.
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.
This document describes a challenge problem whose scope is the detection, geolocation, tracking and ID of moving vehicles from a set of X-band SAR data collected in an urban environment. The purpose of releasing this Gotcha GMTI Data Set is to provide the community with X-band SAR data that supports the development of new algorithms for SAR-based GMTI. To focus research onto specific areas of interest to AFRL, a number of challenge problems are defined. The data set provided is phase history from an AFRL airborne X-band SAR sensor. Some key features of this data set are two-pass, three phase center, one-foot range resolution, and one polarization (HH). In the scene observed, multiple vehicles are driving on roads near buildings. Ground truth is provided for one of the vehicles.
Scarborough, Steven M.; Casteel, Curtis H., Jr.; Gorham, Leroy; Minardi, Michael J.; Majumder, Uttam K.; Judge, Matthew G.; Zelnio, Edmund; Bryant, Michael; Nichols, Howard; Page, Douglas
For fully polarimetric wideband radarsystem, a novel method of radar target recognition using polarimetric feature is proposed. First, polarimetric scattering matrix is obtained from fully polarimetric high resolution range profiles(HRRPs). Then, two different kinds of polarimetric features are extracted by polarimetric target decomposition theorem. At last, K-Nearest Neighbors(KNN) classifier is applied to verify the recognition performance of these two
Remote measurement of the two-dimensional surface wave height spectrum of the ocean by the use of bistatic radar techniques was examined. Potential feasibility and experimental verification by field experiment are suggested. The required experimental hardware is defined along with the designing, assembling, and testing of several required experimental hardware components.
This paper presents first results of experimental amplitude comparison monopulse direction finder for harmonic radar. Aperture coupled patch antenna arrays are used for operation in 1.5 GHz band with 10% operation bandwidth. Antennas with leaf characteristic enable 50° sector of operation in azimuth. Problems with common (circular) polarisation are discussed.
Ivo Hertl; Michal Strycek; Vladimir Polacek; VTuo Brno
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.
An overview of modern radar is presented. The topics addressed include: functions and parameters of the radarsystem, the radar equation, targets and interfering signals, target echo information extraction, tracking radar, radar transmitters and microwave components, radar antennas, receivers and displays, radar signal processing, high resolution radar.
Millimeter-wave and terahertz radarsystems can play an important role in multimodal layered sensing systems targeted at measuring both physiological and behavioral biometric data for security and medical applications. We will describe a 228 GHz heterodyne radarsystem that is capable of measuring respiration rates at standoff distances of up to 50 meters and simultaneously measure respiration and heartbeat rates at a distance of 10 meters. We will discuss the latest hardware and signal processing developments and a wide range of studies aimed at optimizing the performance of the system under a variety of potential field applications.
Petkie, Douglas T.; Bryan, Erik; Benton, Carla; Rigling, Brian D.
AIRSAR has served as a test-bed for both imaging radar techniques and radar technologies for over a decade. In fact, the polarimetric, cross-track interferometric, and along-track interferometric radar techniques were all developed using AIRSAR. We present the up-to-date system configuration, the expected performance and data accuracy in the standard radar modes.
Data acquisition is generally a prerequisite condition to conducting practical radar researches such as radar signal detection, automatic target recognition and etc. Because the target returns hold a very short time interval within the radar pulse repetition period, the common data recording systems cannot acquire the target returns efficiently, especially on those radars running in a continuous scanning mode. In
Two improvements were made to the radarsystem in the last year, one was the addition of O/X mode capability to the full antenna array used in the real-time wind system, and the other was the development of a coherent receiver. The design of the transmitter antenna is examined. The proposed coherent real-time wind system is also discussed.
A PC-based system for the digital processing of radar echo signals is described. The proposed system, involving user-level interactive RSAS, is implemented on a PC-based digital processing system compatible with the IBM-XT. Both hardware and software features are considered.
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.
The next generation of radar (radio detection and ranging) systems needs to be based on software-defined radio to adapt to variable environments, with higher carrier frequencies for smaller antennas and broadened bandwidth for increased resolution. Today's digital microwave components (synthesizers and analogue-to-digital converters) suffer from limited bandwidth with high noise at increasing frequencies, so that fully digital radarsystems can work up to only a few gigahertz, and noisy analogue up- and downconversions are necessary for higher frequencies. In contrast, photonics provide high precision and ultrawide bandwidth, allowing both the flexible generation of extremely stable radio-frequency signals with arbitrary waveforms up to millimetre waves, and the detection of such signals and their precise direct digitization without downconversion. Until now, the photonics-based generation and detection of radio-frequency signals have been studied separately and have not been tested in a radarsystem. Here we present the development and the field trial results of a fully photonics-based coherent radar demonstrator carried out within the project PHODIR. The proposed architecture exploits a single pulsed laser for generating tunable radar signals and receiving their echoes, avoiding radio-frequency up- and downconversion and guaranteeing both the software-defined approach and high resolution. Its performance exceeds state-of-the-art electronics at carrier frequencies above two gigahertz, and the detection of non-cooperating aeroplanes confirms the effectiveness and expected precision of the system. PMID:24646997
This paper deals with mutual coupling, its effects and the compensation thereof in frequency-modulated continuous-wave (FMCW) multiple-input multiple-output (MIMO) array radarsystems. Starting with a signal model we introduce mutual coupling and its primary sources in FMCW MIMO systems. We also give a worst-case boundary of the effects that mutual coupling can have on the side lobe level of an array. A method of dealing with and compensating for these effects is covered in this paper and verified by measurements from a 77-GHz FMCW radarsystem.
Schmid, Christian M.; Feger, Reinhard; Wagner, Christoph; Stelzer, Andreas
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.
The THz impulse radar is an "RF-inspired" sensor system that has performed remarkably well since its initial development nearly six years ago. It was developed for ex vivo skin-burn imaging, and has since shown great promise in the sensitive detection of hydration levels in soft tissues of several types, such as in vivo corneal and burn samples. An intriguing aspect of the impulse radar is its hybrid architecture which combines the high-peak-power of photoconductive switches with the high-responsivity and -bandwidth (RF and video) of Schottky-diode rectifiers. The result is a very sensitive sensor system in which the post-detection signal-to-noise ratio depends super-linearly on average signal power up to a point where the diode is "turned on" in the forward direction, and then behaves quasi-linearly beyond that point. This paper reports the first nonlinear systems analysis done on the impulse radar using MATLAB.
Brown, E. R.; Sung, Shijun; Grundfest, W. S.; Taylor, Z. D.
This thesis presents the design of a 449 MHz radar for wind profiling, with a focus on modularity, antenna sidelobe reduction, and solid-state transmitter design. It is one of the first wind profiler radars to use low-cost LDMOS power amplifiers combined with spaced antennas. The system is portable and designed for 2-3 month deployments. The transmitter power amplifier consists of multiple 1-kW peak power modules which feed 54 antenna elements arranged in a hexagonal array, scalable directly to 126 elements. The power amplifier is operated in pulsed mode with a 10% duty cycle at 63% drain efficiency. The antenna array is designed to have low sidelobes, confirmed by measurements. The radar was operated in Boulder, Colorado and Salt Lake City, Utah. Atmospheric wind vertical and horizontal components at altitudes between 200m and 4km were calculated from the collected atmospheric return signals. Sidelobe reduction of the antenna array pattern is explored to reduce the effects of ground or sea clutter. Simulations are performed for various shapes of compact clutter fences for the 915-MHz beam-steering Doppler radar and the 449-MHz spaced antenna interferometric radar. It is shown that minimal low-cost hardware modifications to existing compact ground planes of 915-MHz beam-steering radar allow for reduction of sidelobes of up to 5dB. The results obtained on a single beam-steering array are extended to the 449 MHz triple hexagonal array spaced antenna interferometric radar. Cross-correlation, transmit beamwidth, and sidelobe levels are evaluated for various clutter fence configurations and array spacings. The resulting sidelobes are as much as 10 dB below those without a clutter fence and can be incorporated into existing and future 915 and 449 MHz wind profiler systems with minimal hardware modifications.
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.
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
The basic concept of the structure and properties of the ionosphere are discussed to explain how the performance of the over-the-horizon radar (OTHR) system is affected. An overview of the OTHR system characteristics and performance are presented along wi...
78. View of radarsystems 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
The concept of an Ultra Wideband (UWB) Monopulse Microwave RadarSystem for detection and location of breast cancer is described. The system uses a two-element Tapered Slot Antenna (TSA) array accompanied by a UWB 180° hybrid which scans the breast. When the breast tissue features symmetry with respect to the array axis and the hybrid enables the 180° out phase
Simulation of synthetic aperture radar (SAR) imagery may be approached in many different ways. One method treats a scene as a radar cross section (RCS) map and simply evaluates the radar equation, convolved with a system impulse response to generate simulated SAR imagery. Another approach treats a scene as a series of primitive geometric shapes, for which a closed form solution for the RCS exists (such as boxes, spheres and cylinders), and sums their contribution at the antenna level by again solving the radar equation. We present a ray-tracing approach to SAR image simulation that treats a scene as a series of arbitrarily shaped facetized objects, each facet potentially having a unique radio frequency optical property and time-varying location and orientation. A particle based approach, as compared to a wave based approach, presents a challenge for maintaining coherency of sampled scene points between pulses that allows the reconstruction of an exploitable image from the modeled complex phase history. We present a series of spatial sampling techniques and their relative success at producing accurate phase history data for simulations of spotlight, stripmap and SAR-GMTI collection scenarios.
Gartley, Michael; Goodenough, Adam; Brown, Scott; Kauffman, Russel P.
An optimum design study is carried out for synthetic aperture radarsystems intended for classifying randomly reflecting areas (such as agricultural fields) characterized by a reflectivity density spectral density. The problem solution is obtained, neglecting interfield interference and assuming areas of known configuration and location, as well as a certain Gaussian signal field property. The optimum processor is nonlinear, but includes conventional matched filter processing. A set of summary design curves is plotted, and is applied to the design of a satellite synthetic aperture radarsystem.
Practical application of multi-sensor fusion is critically dependent on the sensor system's registration in both time and space. A UK MOD study involving both Government agencies and industry has explored the practical issues of the field deployment of radar and EO (IRST) sensors and the subsequent fusion of their output data at both the track and plot level. The program used commercially available GPS units as the time and position sensor on both radar and EO sensors. The same system was used to record target position. The paper will use the data collected during the practical field trials to illustrate the impact of time and positional errors on the fusion process.
Charlwood, Eric C.; Griffiths, Roderick J.; Buttinger, Max R.
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
A viewgraph presentation on the design of a low cost unmanned aerial vehicle (UAV) doppler radar data system is presented. The topics include: 1) Science and Mission Background; 2) Radar Requirements and Specs; 3) Radar Realization: RF System; 4) Processing of RF Signal; 5) Data System Design Process; 6) Can We Remove the DSP? 7) Determining Approximate Speed Requirements; 8) Radar Realization: Data System; 9) Data System Operation; and 10) Results.
Range resolution enhancement techniques, or so called super-resolution ranging techniques, are a significant breakthrough in short-range radar imaging. Improving range resolution in a robust stable manner enables a target to be peeled in finer layers and/or the RF specifications of the radarsystem to be relaxed, which has clear effects on performance improvement and cost reduction. For a radarsystem using the frequency modulated continuous wave (FMCW) technique and traditional frequency domain techniques for reception, the range resolution is limited by the bandwidth of the transmitted wave. In this paper we propose and investigate a new super-resolution ranging technique. Multiple key performance characteristics including, minimum distinguishable distance between targets, accuracy in absolute positioning and stability in low SNR environments were evaluated using statistical simulations and real measured data. The presented results show that the proposed technique yields improved performance.
The paper presents a unified view of the tracking algorithms available for multistatic radarsystems. 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 errors are evaluated by means of Monte Carlo simulation for a number of typical target paths. The major topic considered in the paper refers to the derivation of a unique tracking filter structure for multistatic radarsystems. Particular attention is paid to the case of one transmitter and two noncolocated receivers; additionally, several combinations of multistatic measurements are considered. Furthermore, in this case, the tracking performance of the algorithms is evaluated by means of Monte Carlo simulation techniques. The closing section highlights the trends of the research towards multitarget tracking with distributed estimation techniques and the problem of data fusion.
Methods and systems reduce clutter interference in a radar-responsive tag system. A radar transmits a series of linear-frequency-modulated pulses and receives echo pulses from nearby terrain and from radar-responsive tags that may be in the imaged scene. Tags in the vicinity of the radar are activated by the radar's pulses. The tags receive and remodulate the radar pulses. Tag processing reverses the direction, in time, of the received waveform's linear frequency modulation. The tag retransmits the remodulated pulses. The radar uses a reversed-chirp de-ramp pulse to process the tag's echo. The invention applies to radarsystems compatible with coherent gain-block tags. The invention provides a marked reduction in the strength of residual clutter echoes on each and every echo pulse received by the radar. SAR receiver processing effectively whitens passive-clutter signatures across the range dimension. Clutter suppression of approximately 14 dB is achievable for a typical radarsystem.
Ormesher, Richard C. (Albuquerque, NM); Axline, Robert M. (Albuquerque, NM)
...that vehicular radarsystems operating at either the current or proposed limits would cause harmful interference to radio astronomy equipment. Accordingly, the Commission believes that there is no need to restrict vehicular radarsystems based on...
Early damage detection of bridge has been an important issue for modern civil engineering technique. Existing bridge inspection techniques used by State Department of Transportation (DOT) and County DOT include visual inspection, mechanical sounding, rebound hammer, cover meter, electrical potential measurements, and ultrasonics; other NDE techniques include ground penetrating radar (GPR), radiography, and some experimental types of sensors. Radar technology like GPR has been widely used for the bridge structure detection with a good penetration depth using microwave energy. The system to be presented in this paper is a different type of microwave sensing technology. It is focus on the subsurface detection and trying to find out detail information at subsurface (10 cm) with high resolution radar imaging from a flexible standoff distance. Our radar operating frequency is from 8-12 GHz, which is different from most of the current GPR systems. Scanning array antenna system is designed for adjustable beamwidth, preferable scanning area, and low sidelobe level. From the theoretical analysis and experimental results, it is found that the proposed technique can successfully capture the presence of the near-surface anomaly. This system is part of our Multi- Modal Remote Sensing System (MRSS) and provides good imaging correlations with other MRSS sensors.
Harmonic radarsystems provide an effective modality for tracking insect behavior. This letter presents a harmonic radarsystem 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 compact radar unit and a passive RF tag for mounting on the
Dimitris Psychoudakis; William Moulder; Chi-Chih Chen; Heping Zhu; John L. Volakis
In the future, headway control systems for consumer use must be cheap and capable of operating in all environmental conditions. To enable such systems to be built, a headway control system using dualmode millimeter-wave radar has been proposed. The radar would be able to operate in both radar mode, in which it would measure the distance to be leading vehicle,
The paper presents some recent developments in harmonic radar tracking systems. These are widely used for monitoring and tracking of low flying insects like honey bees, butterflies, snail and carabid beetles, and come under the category of individual marking techniques and use harmonic range detection or range finding for tracking insects tagged with harmonic transponders. In most cases the transponder
This paper examines the probability that any millimeter-wave radarsystems will interfere mutually by considering spatial, temporal, and operational frequency-related overlaps. It examines the nature and magnitude of the interference under different conditions and for different sensor types before concluding that in an overlapping frequency band, the probability that interference will occur is high. It goes on to demonstrate that,
A review is made of the application of sum-difference beam techniques to the ATC Radar Beacon System. A detailed error analysis is presented for the case of a monopulse azimuth measurement based on the existing beacon antenna with a modified feed network....
Integrated electronic techniques have been developed to the point where they can be applied to many types of military equipment. This paper discusses how these techniques are being used to increase the reliability and reduce the size and weight of three selected types of equipment used in military communications and radarsystems. Redundancy is used in the first of these
W. E. Montgomery; C. H. Wood; W. R. Olson; R. M. Frazier; G. R. Brainerd
The ability of a space-based radar surveillance system to obtain target information from a clutter corrupted radar echo signal is dependent on the clutter cancellation technique employed. To thoroughly understand the nature of clutter so as to efficiently...
SELEX Sistemi Integrati is now watching toward the future to reinforce its leadership in the state of the art of radarsystems. The strong position in the market has been achieved by delivering top radar performance in many fields of application and it has been based on the capability to manage the proper technology insertion in its radarsystems. For
In this paper, the infrared radiation model of phased array radar is studied. And the infrared radiation model of the object is created. The estimated equations of effect interval were given in infrared detect system to phased array radar. As an example, the effect interval in infrared detect system for some or other model phased array radar are appraised calculated
An instrumented test automobile equipped with an automatic/noncooperative radar brake system was used to gather and classify experimental data on radar false alarms as a function of various radarsystem parameters such as: detection range cut off (RCO), a...
R. E. Wong W. R. Faris W. O. Grierson W. C. Troll Y. M. Powell
In this paper, imaging method for moving target tracking by a multistatic ultra-wideband radarsystem is described. The task of moving target tracking consists in estimation of a target trajectory based on processing of raw radar data obtained from all receiving channels of a radarsystem. Then, the imaging method applied for target tracking consists of such signal processing phases
D. Kocur; J. Gamec; M. Svecova; M. Gamcova; J. Rovnakova
Optimal receivers are widely used in many applications and especially in military radars. In this paper, a correlation receiver connected to a pseudo-random sequence coded radar waveform is presented. This system is an original solution dedicated to a collision avoidance radarsystem for road vehicles. Experiments have been carried out at 10 GHz to show the efficiency of this method.
A. Menhaj; J. Assaad; J. M. Rouvaen; M. Heddebaut; C. Bruneel
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
An inexpensive frequency-modulated continuous-wave (FMCW) radarsystem is presented in this paper, which, nevertheless, meets all industrial requirements. The FMCW radar uses a low-cost nonlinear voltage-controlled oscillator (VCO), operating at an IF of 2.45 GHz to generate the frequency modulation of the radarsystem. This VCO signal is applied twice, first to generate the radar transmitter signal at 24 GHz,
Leonhard Reindl; Clemens C. W. Ruppel; Stefan Berek; Ulrich Knauer; Martin Vossiek; Patric Heide; Lutz Oréans
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.
This paper addresses the issue of interference suppression in noise radars. The proposed methods can be divided into non-parametric and parametric ones. The considered non-parametric methods are based on linear time-frequency (TF) tools, namely the short-time Fourier transform (STFT) and local polynomial Fourier transform (LPFT). The STFT is the simplest TF method, but, due to the resolution problem, it performs poorly with highly nonstationary interferences. The LPFT resolves the resolution problem, however at the cost of increased complexity. In parametric methods, the phase of interference is locally approximated by a polynomial, which is motivated by the Weierstrass's theorem. Using the phase approximation, the corrupted received signal is demodulated and successively filtered. Two methods for polynomial phase approximation are considered, the high-order ambiguity function (HAF) and product high-order ambiguity function (PHAF). The method based on the HAF is computationally efficient; however, it suffers from the identifiability problem when multicomponent signals are considered. The identifiability problem can be resolved using the PHAF.
The connection of the radar characteristics of cloud systems with the genetics of their formation, the microphysical structure, and the spatial extent of the clouds is examined. The relation of the probability of detecting clouds at various distances by their microphysical structure and the capabilities of the equipment are also considered. A method of discriminating cloud systems is proposed on the basis of obtained relations.
A 1.06 micron CW laser radarsystem was used to establish the feasibility of remotely measuring sea surface wind magnitude and direction. Simultaneous correlation of collected laser data with the environment was established by using meteorological instruments. The experimental system and methods of analysis are summarized. Results of the experiments, including wind magnitude and direction correlation, are reported. Results are compared with theoretical predictions.
This paper summarizes the results of a program directed to an assessment of the potential for interference to Georgia Power Company communications systems from the PAVE PAWS radar at Robins Air Force Base, GA. Susceptibility data were recorded on selected UHF and microwave receivers and compared to predicted PAVE PAWS field strength levels to identify potential interference problems. Several potential problems were identified which must be addressed to preclude PAVE PAWS related interference effects on communication system performance.
Donaldson, Ernest E., Jr.; Burdett, Robert P., Jr.
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 radarsystem and presents the results from the first experiment conducted.
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
In the active safety system, the object classification is important to decide the action for passenger's safety. Using microwave radar as a sensor, we can get the measure about the distance from the sensor, the azimuth angle, and also the signal power of the reflected signal. In this paper, we use these information from 24GHz microwave radar sensor and classify
A design for a physiological radar monitoring system (PRMS) that can be integrated with clinical sleep monitoring systems is presented. The PRMS uses two radarsystems at 2.45GHz and 24 GHz to achieve both high sensitivity and high resolution. The system can acquire data, perform digital processing and output appropriate conventional analog outputs with a latency of 130 ms, which can be recorded and displayed by a gold standard sleep monitoring system, along with other standard sensor measurements. PMID:24110139
In metal machining processes highly accurate distance sensors are indispensable. Due to the progressive development, radar technology could be used for this sensor application. In contrast to other highly accurate measurement systems, radar technology promises a low-cost solution with comparable performance. In this paper a FMCW radar sensor is used for an accurate position detection with micrometer accuracy. A signal
Mario Pauli; Serdal Ayhan; Steffen Scherr; Christian Rusch; Thomas Zwick
A radar based approach of range detection depends mainly on the utilized radar principle which allows either high accuracy or high unambiguous ranges. For the most widely used FMCW radar the entire distance is not restricted in the meter range whereas the achievable accuracy directly depends on the bandwidth. An improvement is only possible if system parameters are changed or
Serdal Ayhan; Mario Pauli; Thorsten Kayser; Steffen Scherr; Thomas Zwick
The FMCW radar is the most versatile radar principle used today. Depending on the system configuration, it is possible to use an FMCW radar to detect targets in the range from hundreds of kilometers down to a few centimeters. This paper describes an algorithm, which can be applied to improve the FMCW range accuracy down to a few mm. Numerical
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 radarsystem specifically designed for routine application in those enyironments.
Atmospheric remote sensing by Doppler radar is an increasingly used technique. An MST radar is an instrument that can be used for mesosphere, stratosphere and troposphere remote sensing. This paper describes a signal processing and control system for atmospheric sounding radars, with improved characteristics with respect to formerly used architectures. The authors refer especially to wind profiling as an important
Martin F. Sarango; Ronald F. Woodman; Enrico Ragaini; Edilberto H. Vasquez
An obstacle detection and warning system for civil helicopters is now being developed. An infrared camera and a 94 GHz millimeter wave (MMW) radar have been used as its sensor. Experimental MMW radars have been built to examine their propagation properties and obstacle detection performance. A 94 GHz Vivaldi antenna has been fabricated for a compact radar antenna. Measured results
K. Yamamoto; K. Yamadal; N. Yonemoto; H. Yasui; H. Nebiya; C. Migliaccio
The on-orbit alignment of the antenna beams of both the X-band and C-band radarsystems during operations of the shuttle radar topography mission/X-band synthetic aperture radar (SRTM/X-SAR)was a key requirement for achieving best interferometric performance.
A ground-borne detection radar and an air-borne synthetic aperture imaging radar are considered. The radar transmission equation for linear scatterers in free space is briefly reviewed, the free space harmonic radar transmission equation is derived, and an investigation of the planar earth effect is conducted. The characteristics of suitable near-ground detection systems are discussed. In a description of airborne imaging
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).
The FAA is currently developing the Discrete Address Beacon System (DABS) as an evolutionary upgrading of the Air Traffic Control Radar Beacon System (ATCRBS). DABS will provide improved surveillance and data link service to suitably equipped aircraft ope...
J. D. Welch W. H. Harman V. A. Orlando R. R. LaFrey
The NASA/JPL airborne SAR (AIRSAR) system operates in the fully polarimetric mode at P-, L- and C-band simultaneously or in the interferometric mode in both L- and C-band simultaneously. The system became operational in late 1987 and flew its first mission aboard a DC-8 aircraft operated by NASA's Ames Research Center in Mountain View, California. Since then, the AIRSAR has flown missions every year and acquired images in North, Central and South America, Europe and Australia. In this paper, we will briefly describe the instrument characteristics, the evolution of the various radar modes, the instrument performance, and improvement in the knowledge of the positioning and attitude information of the radar. In addition, we will summarize the progress of the data processing effort especially in the interferometry processing. Finally, we will address the issue of processing and calibrating the cross-track interferometry (XTI) data.
A novel low-power microwave sensor for level gaging in storage tanks has been developed. By using a PLL-controlled gated oscillator this FMCW radar can be operated in a standard 4-20 mA loop without additional supply power. The chosen system design features a fast settling time of the oscillators to achieve a quasi-continuous frequency sweep, resulting in a precise, stable and
A low-cost ultrawideband (UWB), 1.926-4.069 GHz, phased array radarsystem is developed that requires only one exciter and digital receiver that is time-division-multiplexed (TDM) across 8 receive elements and 13 transmit elements, synthesizing a fully populated 2.24 m long (?\\/2 element-to-element spacing) linear phased array. A 2.24 m linear phased array with a 3 GHz center frequency would require 44
Gregory L. Charvat; Leo C. Kempel; E. J. Rothwell; Christopher M. Coleman; Eric L. Mokole
For the US Navy's relocatable over-the-horizon radar (ROTHR) project, tradeoffs involve millions of dollars. This work describes the problems solved, work performed, and results achieved for the selection of ROTHR spare parts to optimally support mission availability at least cost. A reliability block diagram (RBD) describing the complete system-to-critical-part relationship was developed first. This RBD described 305 unique removable units
A primary scope of Mars exploration is the research of underground water. Knowledge of water and ice quantity and distribution has enourmous impacts on our understanding on gelogic, hydrologic and climate evolution of Mars and of its origin. To this aim, high resolution observations of geophysical parameters can address these items expecially when conducted by means of penetrating radarsystems orbiting around the planet, due to their intrinsic capabilities to detect underground water/ice. In this framework, SHARAD (SHAllow RADar) on-board NASA's Mars Reconnaissance Orbiter (MRO) assumes a key role within Mars exploration activities. SHARAD is a wideband radar sounder transmitting at a centre frequency of 20 MHz within 15-25 MHz spectral range. SHARAD has been launched on August '05 and will start its nominal observation phase from November '06. To guarantee its operations, commands and data analysis and processing, the SHARAD Ground Data System (GDS) has been designed and developped. SHARADA GDS is a ground system equipped with ad-hoc sw tools to allow instrument operations and data processing during the two-year mission duration. The present paper is focused on SHARAD GDS description of its architecture and of instrument planning, commanding and data processing sofwtare tools.
In the present communication, initial results from the allSKy interferometric METeor (SKiYMET) radar installed at Thumba (8.5°N, 77°E) are presented. The meteor radarsystem provides hourly zonal and meridional winds in the mesosphere lower thermosphere (MLT) region. The meteor radar measured zonal and meridional winds are compared with nearby MF radar at Tirunalveli (8.7°N, 77.8°E). The present study provided an
Karanam Kishore Kumar; Geetha Ramkumar; S. T. Shelbi
This paper takes focus on the detection of a single person from an elevated monitoring position using a compact two-channel 24 GHz FMCW radarsystem. The mountingpositionandadjustmentoftheradar system resemblesatypicalmotiondetector application, whereas the presented system delivers (x,y) coordinates of the target. The results presented demonstrate a precision in target localisation better than 30 cm for 1 GHz bandwidth at a distance
High resolution inverse synthetic aperture radar (ISAR) imaging is demonstrated by using a 0.22 THz stepped-frequency (SF) imaging radarsystem. The synthesis bandwidth of the terahertz (THz) SF radar is 12 GHz, which are beneficial for high resolution imaging. The resolution of ISAR image can reach centimeter-scale with the use of Range-Doppler algorithm (RDA). Results indicate that high resolution ISAR imaging is realized by using 0.22THz SF radar coupled with turntable scanning, which can provide foundations for further research on high-resolution radar image in the THz band.
Liang, Mei Yan; Zhang, Cun Lin; Zhao, Ran; Zhao, Yue Jin
This expert system automates and optimizes radar tracker selection for shuttle missions. The expert system is written in the FORTRAN and C languages on an HP9000. It is portable to any UNIX machine having both ANSI-77 FORTRAN and C language compilers. It is a rule based expert system that selects tracking stations from the S-band and C-band radar stations and the TDRSS east and TDRSS west satellites under a variety of conditions. The expert system was prototyped on the Symbolics in the Automated Reasoning Tool (ART) and ZetaLisp. After the prototype demonstrated an acceptable automation of the process of selecting tracking stations to support the orbit determination requirements of Shuttle missions, the basic ART rules of the prototype were ported to the HP9000 computer using the CLIPS language. CLIPS is a forward-chaining rule-based expert system language written in C. Prior to the development of this expert system the selection process was a tedious manual process and expensive in terms of human resources. Manual tracking station selection required from 1 to 2 man weeks per mission; whereas the expert system can complete the selection process in about 2 hours.
Optimal receivers are widely used in many applications and especially in military radars. In this paper, a correlation receiver connected to a pseudo-random sequence coded radar waveform is presented. This system is an original solution dedicated to a collision avoidance radarsystem for road vehicles. Experiments have been carried out at 10 GHz to show the efficiency of this method. The advantages of the system are its low cost, good resolution and low emitted peak power.
Menhaj, A.; Assaad, J.; Rouvaen, J. M.; Heddebaut, M.; Bruneel, C.
A ground-penetrating radar (GPR) technique was used to study the three-dimensional distribution of root systems of large (DBH = 14 to 35 cm) oak trees (Quercus petraea (Mattusch.) Liebl.) in relatively dry, luvisoil on loamy deluvium and weathered granodiorite. We used a pulse EKKO 1000 GPR system, a profile grid of 0.25 x 0.25 meters, at 0.05 m intervals, and a signal frequency of 450 MHz, to assure resolution of about 3 cm in both directions (further increases in resolution up to 1 cm are possible with the system). Coarse root density was 6.5 m m(-2) of stand area and 3.3 m m(-3) of soil volume. Maximum rooting depth of the experimental oaks was 2 m, and the root ground plan was significantly larger (about 1.5 times) than the crown ground plan. Based on earlier studies of Quercus robur L. from floodplain forests, where the extent of the root systems was much smaller (root ground plan:crown ground plan ratio of 0.6), we conclude that the high root ground plan:crown ground plan ratio indicates less favorable conditions of water supply at the experimental site than in the floodplain forest. The ground-penetrating radarsystem is noninvasive and allows relatively rapid and repeated measurements of the distribution of coarse root systems of trees. PMID:12651592
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.
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.
Sensor systems such as distributed sensor networks and radarsystems are potentially agile - they have parameters that can be adjusted in real-time to improve the quality of data obtained for state-estimation and decision-making. The integration of such sensors with cyber systems involving many users or agents permits greater flexibility in choosing measurement actions. This paper considers the problem of selecting radar waveforms to minimize uncertainty about the state of a tracked target. Past work gave a tractable method for optimizing the choice of measurements when an accurate dynamical model is available. However, prior knowledge about a system is often not precise, for example, if the target under observation is an adversary. A multiple agent system is proposed to solve the problem in the case of uncertain target dynamics. Each agent has a different target model and the agents compete to explain past data and select the parameters of future measurements. Collaboration or competition between these agents determines which obtains access to the limited physical sensing resources. This interaction produces a self-aware sensor that adapts to changing information requirements.
The U.S. Next-Generation Radar (NEXRAD) network provides operational precipitation products for the National Weather Service. However, the effective coverage of NEXRAD at low levels is restricted in complex terrain leading to insufficient surveillance of low-level portions of the atmosphere. This problem is especially most severe in the intermountain region of the western US. Quantitative precipitation estimation (QPE) based on radar measurements at high levels above the surface can be over- or underestimated, depending on if the radar beam intercepts or overshoots the melting layer. To mitigate this problem, researchers at the University of Oklahoma (OU) have proposed a VPR Identification and Enhancement (VPR-IE) approach to improve radar-based QPE near the surface. VPR-IE applies the VPR observed by Ku-band Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) to correct the S-band NEXRAD radar reflectivity contaminated by ice-related signals such as the bright band (BB) and dry snow signals. The real-time incorporation of TRMM-PR into the NEXRAD-based National Mosaic and Multi-sensor QPE (NMQ) system faces challenges because of their big difference in temporal resolution. The current study explores how to obtain representative VPRs for the real-time implementation of VPR-IE and investigates the potential error of VPR-IE attributed to the temporal variation of precipitation. The real-time VPR-IE is tested using the archived NMQ data collected in the mountainous West region of the U.S. (southern California, Arizona, and western New Mexico). Analysis results demonstrate the great potential of real-time VPR-IE in improving radar QPE in complex terrain.
Cao, Q.; Hong, Y.; Wen, Y.; Gourley, J. J.; Qi, Y.; Zhang, J.; Kirstetter, P.
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.
Stepped-frequency waveforms are being considered for inverse synthetic aperture radar (ISAR) imaging from ship and airborne platforms and for detailed radar cross section (RCS) measurements of ships and aircraft. These waveforms make it possible to achiev...
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...
The Multimode Airborne Radar Altimeter (MARA), a flexible airborne radar remote sensing facility developed by NASA's Goddard Space Flight Center, is discussed. This volume describes the scientific justification for the development of the instrument and the translation of these scientific requirements into instrument design goals. Values for key instrument parameters are derived to accommodate these goals, and simulations and analytical models are used to estimate the developed system's performance.
The Goldstone Solar SystemRadar (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 radarsystem 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.
This work presents a robust chaos radarsystem for collision detection and vehicular ranging in intelligent transportation systems (ITS). The robustness of the scheme lies in its multipath mitigation characteristics. By exploiting the spread spectrum (SS) nature of chaos, a high resolution radarsystem is designed. A cost effective receiver architecture for multipath mitigation in vehicular channel is proposed here.
Radar signal processing system is an important part of vessel traffic services. In order to overcome the shortcomings of traditional analog video system, this paper proposes a design solution for digital radar signal processing system based on DSP and a new method that is a constant false alarm rate algorithm based on wavelet transform. This method can suppress the interference
A survey was conducted to find out the system characteristics of commercially available and unclassified military radars suitable for deployment on a stationary platform. A total of ten domestic and eight foreign manufacturers of the radarsystems were identified. Questionnaires were sent to manufacturers requesting information concerning the system characteristics: frequency, power used, weight, volume, power radiated, antenna pattern, resolution,
Modern phased array radar has changed national defense and the battlefield. The agility of the antenna beam of phased array radar is the key characteristic that has facilitated this change, coupled with the growth in processing, communication and presentation of data for decision making. This paper describes the modern battlefield and airborne phased array radar that are manufactured by Northrop
Stepped-frequency radar has the ability of high range resolution. It normally adopts frequency time transformation (IDFT) processing to get the range profile of targets. Alternatively stepped frequency radar can also use time-frequency transformation (DFT) processing, with which it is regarded as a kind of Doppler (PD) radars. Through parametric design and signal processing methods, DFT method can achieve both unambiguous
Space based radar (SBR) applications impose challenging weight, volume, efficiency, reliability, environmental, performance and cost requirements on the radar power subsystem (RPS). To meet SBR requirements, the direct point of use (DPU) architecture was chosen. A 90% efficient, 100 watt power converter is demonstrated in a sub-panel that simulates a portion of the radar antenna. The power converter improves military
M. Brand; R. Thibodeaux; G. Fronista; J. Wilson; S. Levin
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)
The Deep Space Network (DSN) primarily uses the 70-m antenna at Goldstone — DSS -14 — for tracking, telemetry, and commanding National Aeronautics and Space Administration (NASA) spacecraft. However, for a small percentage of its time DSS-14 also provides NASA with the only fully steerable, high-power ground-based radar in the world. The Goldstone Solar SystemRadar (GSSR) has been used extensively for high-resolution radar ranging and imaging of planetary and small-body targets, including more than 160 asteroids, four comets, the Moon, Mercury, Venus, Mars, the Galilean satellites, Titan, and small orbital debris. The GSSR operates at a wavelength of 3.5 cm with a typical transmitter power of 450 kW, and provides radar imagery, surface topography, rotational information, and ice distribution on this wide variety of solar system objects. The bulk of current GSSR work centers on radar imaging, astrometry, and characterization of near-Earth asteroids (NEAs). GSSR has discovered binary and ternary NEAs (six to date); contact binary NEAs, and NEAs in non-principal axis rotation states. The GSSR has observed the following small-body mission targets: 4 Vesta (Dawn), 433 Eros (NEAR-Shoemaker), 25143 Itokawa (Hayabusa), 101955 1999 RQ36 (OSIRIS-REx), and 4179 Toutatis (Chang'e 2). Recently the highest range resolution improved by a factor of five from 18.75 meters to 3.75 meters. The first major application of this resolution increase was with imaging of 400-meter-diameter (308635) 2005 YU55 during the asteroid's 0.85 lunar distance flyby in November 2011. The images placed tens of thousands of pixels on the asteroid, and even revealed small surface boulders. The limitation to ~4-meter range resolution is driven by the bandwidth of the transmitter. However, by using chirp waveforms and klystrons with ~150 MHz bandwidth, the range resolution could be as fine as 1-meter. JPL is exploring methods of transmitting such wider bandwidths and potentially reaching 1-meter range resolution. The GSSR currently provides nearly encounter-quality imaging of NEAs a few times each year, and the potential exists for future imaging of even higher quality. Two main avenues exist to becoming a user of the GSSR. Successful proposers to the Research Opportunities in Space and Earth Sciences (ROSES) solicitations from the Planetary Science Division in the NASA Science Mission Directorate make up the majority of GSSR users. GSSR users also come via successful proposals to observing calls from the National Science Foundation for use of their Green Bank Telescope or the Extended Very Large Array that require 3.5-cm radar illumination of targets for primary science goals. In addition, any DSN-supported flight project can request GSSR observations that advance the goals of their mission. GSSR supports a wide community of scientists at many institutions. The research described above was carried out at the Jet Propulsion Laboratory, a division of the California Institute of Technology, under contract with the National Aeronautics and Space Administration. Government sponsorship acknowledged.
A computer simulation program was employed to evaluate the system cost-effectiveness of 36 automatic/ radar brake system configurations. The effects of changing system design parameters and operational differences within each system were examined. 1973 tr...
R. E. Wong W. R. Faris W. O. Grierson W. C. Troll Y. M. Powell
GeoSAR Geographic Synthetic Aperture Radar) is a new 3 year effort to build a unique, dual-frequency, airborne Interferometric SAR for mapping of terrain. This is being pursued via a Consortium of the Jet Propulsion Laboratory (JPL), Calgis, Inc., and the California Department of Conservation. The airborne portion of this system will operate on a Calgis Gulfstream-II aircraft outfitted with P- and X-band Interferometric SARs. The ground portions of this system will be a suite of Flight Planning Software, an IFSAR Processor and a Radar-GIS Workstation. The airborne P-band and X-band radars will be constructed by JPL with the goal of obtaining foliage penetration at the longer P-band wavelengths. The P-band and X-band radar will operate at frequencies of 350 Mhz and 9.71 Ghz with bandwidths of either 80 or 160 Mhz. The airborne radars will be complemented with airborne laser system for measuring antenna positions. Aircraft flight lines and radar operating instructions will be computed with the Flight Planning Software The ground processing will be a two-step step process. First, the raw radar data will be processed into radar images and interferometer derived Digital Elevation Models (DEMs). Second, these radar images and DEMs will be processed with a Radar GIS Workstation which performs processes such as Projection Transformations, Registration, Geometric Adjustment, Mosaicking, Merging and Database Management. JPL will construct the IFSAR Processor and Calgis, Inc. will construct the Radar GIS Workstation. The GeoSAR Project was underway in November 1996 with a goal of having the radars and laser systems fully integrated onto the Calgis Gulfstream-II aircraft in early 1999. Then, Engineering Checkout and Calibration-Characterization Flights will be conducted through November 1999. The system will be completed at the end of 1999 and ready for routine operations in the year 2000.
This paper describes the Canadian Meteor Orbit Radar (CMOR) that has been in operation since late 2001. CMOR is a 3 station meteor radar operating at a frequency of 29.85 MHz near Tavistock, Ont. To avoid bias against fragmenting meteoroids that is inherent in the traditional multi-station method of Gill and Davies (Mon. Not. R Astron. Soc. 116 (1955) 105), we use a completely geometrical method similar to that used in the AMOR system (Quart. J. R. Astron. Soc. 35 (1994) 293) based on the interferometric determination of the echo directions and the time delays of echoes from two remote stations to obtain the trajectories and speeds of meteoroids. We describe the hardware and some of the software and present some preliminary results that provide a good indication of present capabilities of the system. Typically, we can measure 1500 individual trajectories, and hence orbits, per day with a mean accuracy of 6° in direction and about 10% in speed. A small subset of these for which it is possible to measure the speeds using Hocking's (Radio. Sci. 35 (2000) 1205) method yield speeds with a precision of about 5%. The purpose of this paper is to show that the radiants and speeds necessary for the computation of orbits are well measured rather than to discuss any orbital surveys.
Jones, J.; Brown, P.; Ellis, K. J.; Webster, A. R.; Campbell-Brown, M.; Krzemenski, Z.; Weryk, R. J.
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 radarsystem 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
The on-orbit alignment of the antenna beams of both the X-band and C-band radarsystems during operations of the shuttle radar topography mission\\/X-band synthetic aperture radar (SRTM\\/X-SAR) was a key requirement for achieving best interferometric performance. In this paper, we consider the X-SAR antenna beam alignment in azimuth. For a single-pass cross-track SAR interferometer, we establish the relation between yaw
Dirk Geudtner; Manfred Zink; Christoph Gierull; Scott Shaffer
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.
Frequency modulated continuous wave (FMCW) radar have become common place in many roadside trac and on board vehicle safety systems. The accuracy in these systems is based on the underlying calibration of these sensors, which can be a time consuming and costly process. In our approach, using an uncalibrated commercial- o-the-shelf (COTS) radar sensor, vehicles were monitored along a roadside.
Two significant requirements in an FMCW radarsystem 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
The radar transmission equation for a harmonic radar operating over a planar, finite dielectric Earth through foliage is derived for an interesting class of nonlinear scatterers. The received power can typically depend on range to the (-14) power for small objects near the ground. The maximum detection range of a ground-based system is related to all major system parameters: it
This report addresses a problem of estimation of a constant false alarm rate (CFAR) processing loss for a high-resolution maritime radarsystem on an example of a generic radarsystem Anti-Submarine Warfare mode and discusses approaches to modelling of th...
A real-time high-performance and fault-tolerant FPGA-based hardware architecture for the processing of synthetic aperture radar (SAR) images has been developed for advanced spaceborne radar imaging systems. In this paper, we present the integrated design approach, from top-level algorithm specifications, system architectures, design methodology, functional verification, performance validation, down to hardware design and implementation.
ELTA Electronics Industries Ltd. has completed the assembly and the integration of two large ground-based radars (EL\\/M-2080) which are the search, aquisition and fire control radars of the ARROW anti-ballistic missile system. This paper describes the system concept and some of the hardware design
Tropical convection plays an important role in enhancing rainfall and also creates uncertainty in the model-based predictions of weather in tropics due to the latent heat released into the troposphere. Ground-based radarsystems are important tools available for the effective characterization of convective events. Availability of different radarsystems ideally suited to study tropical convection in an area popularly known
Lekshmi Vijayan; G. Viswanathan; R. Ranga Rao; A. R. Jain; D. Narayana Rao; V. K. Anandan; P. Rajesh Rao; S. Kalyana Sundaram; R. Suresh; S. B. Thampi
The Cloud Profiling RadarSystem (CPRS) is a single antenna, two frequency (33 GHz and 95 GHz) polarimetric radar which is currently under the development at the University of Massachusetts (UMASS). This system will be capable of making four dimensional Doppler and polarimetric measurements of clouds. This report gives details about the status of the various subsystems under development and discusses current research activities.
The NASA ER-2 high-altitude ( 20 km) aircraft that emulates a satellite view of precipitation systems carries a variety of passive and active ( lidar ) remote sensing instruments. A new Doppler weather radarsystem at X band ( 9.6 GHz ) called the ER-2 Doppler radar ( EDOP ) has been developed and flown on the ER-2 aircraft. EDOP
Gerald M. Heymsfield; Steven W. Bidwell; I. Jeff Caylor; Syed Ameen; Shaun Nicholson; Wayne Boncyk; Lee Miller; Doug Vandemark; Paul E. Racette; Louis R. Dod
Ground moving target indication (GMTI) for synthetic aperture radar (SAR) provides information on nonstatic objects in radar imagery of a static ground scene. An efficient approach for GMTI is the use of multichannel SAR systems for a space- and time-variant analysis of moving targets. This allows the indication, correction of position displacement, and estimation of radial velocity components of moving
Stepped frequency radarsystems 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
Ram M. Narayanan; Randall T. Becker; Michael B. Bashforth
The evolution of the Spaceborne Imaging Radar (SIR) has led to a multipolarization, multifrequency SAR with variable imaging geometry which will be ready for flight on the Space Station Earth Observing System (EOS). Nominally, this SAR will be a three-frequency (L-, C-, and X-band) system with quad polarization available for the L and C bands. It will be capable of acquiring multiincidence-angle data using electronic beam steering, and other imaging geometries by mechanically pitching, yawing, and rolling the antenna. The capabilities of the EOS SAR, particularly acquisition of cross-polarized and high-incidence-angle data, depend on the altitude of the platform on which the SAR flies and improve significantly at lower altitudes. The EOS SAR will provide a unique new data set and will play a key role in understanding the earth's global processes, alone and synergistically with other EOS instruments.
Progress to date and intended goals in the development of the Spaceborne Imaging Radar (SIR), a SAR remote sensing instrument targeted for carriage on one of the three polar orbiting earth observation system (EOS) platforms in the 1990s, are described. The Shuttle is the current testbed for the SIR, with spaceborne trials being used for testing continually upgraded versions of the three major components of the SIR: the electronics, the antenna and the digital data system. Experimentation is being performed in X-, K-, C- and P-bands in terms of the SNR, view angle, resolution and specific terrestrial features. The test flights are also serving to identify the most effective orbits, with consideration given to the capabilities of other instrumentation being developed for the EOS.
The basic configuration of the Wuhan MST (mesosphere-stratosphere-troposphere) radar, which was designed and constructed by the School of Electronic Information, Wuhan University, is preliminarily described in this paper. The Wuhan MST radar operates at very high frequency (VHF) band (53.8 MHz) by observing the real-time characteristics of turbulence and the wind field vector in the height range of 3.5-90 km (not including 25-60 km) with high temporal and height resolutions. This all-solid-state, all-coherent pulse Doppler radar is China's first independent development of an MST radar focusing on atmospheric observation. The subsystems of the Wuhan MST radar include an antenna system, a feeder line system, all-solid-state radar transmitters, digital receivers, a beam control system, a signal processing system, a data processing system, a product generation system, and a user terminal. Advanced radar technologies are used, including highly reliable all-solid-state transmitters, low-noise large dynamic range digital receivers, an active phased array, high-speed digital signal processing, and real-time graphic terminals. This paper describes the design and implementation of the radar. Preliminary online wind measurements and results of the comparison to simultaneous observations by a GPS rawinsonde are presented as well.
The CUTLASS Finland radar, which comprises 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 commenced operation, in February 1995, the mainland EISCAT UHF radar has been run in common programme 1 and 2 modes for a total duration exceeding 1000 h. Simultaneous and spatially coincident returns from these two radars over this period provide the basis for a comparison of irregularity drift velocity and F-region ion velocity. Initial comparison is limited to velocities from four intervals of simultaneous radar returns; intervals are selected such that they exhibit a variety of velocity signatures including that characteristic of the convection reversal and a rapidly fluctuating velocity feature. Subsequent comparison is on a statistical basis. The velocities measured by the two systems demonstrate reasonable correspondence over the velocity regime encountered during the simultaneous occurrence of coherent and incoherent scatter; differences between the EISCAT UHF measurements of F-region ion drift and the irregularity drift velocities from the Finland radar are explained in terms of a number of contributing factors including contamination of the latter by E-region echoes, a factor which is investigated further, and the potentially deleterious effect of discrepant volume and time sampling intervals.
Davies, J. A.; Lester, M.; Milan, S. E.; Yeoman, T. K.
Battelle and The Ohio State University ElectroScience Laboratory have built and demonstrated a ground-penetrating radar (GPR) system for locating buried unexploded ordnance (UXO), the system is ground based and towed by an autonomously controlled vehicle as part of the subsurface ordnance characterization system (SOCS). This paper presents the results of the synthetic aperture radar (SAR) processing of the radar data
Jennifer I. Halman; Keith A. Shubert; George T. Ruck
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
The design of an auxiliary signal processor for a multiparameter radar is described with emphasis on low cost, quick development, and minimum disruption of radar operations. The processor is based around a low-cost digital signal processor card and personal computer controller. With the use of such a concept, an auxiliary processor was implemented for the NCAR CP-2 radar during a 1991 summer field campaign and allowed measurement of additional polarimetric parameters, namely, the differential phase and the copolar cross correlation. Sample data are presented from both the auxiliary and existing radar signal processors.
A survey was conducted to find out the system characteristics of commercially available and unclassified military radars suitable for deployment on a stationary platform. A total of ten domestic and eight foreign manufacturers of the radarsystems were identified. Questionnaires were sent to manufacturers requesting information concerning the system characteristics: frequency, power used, weight, volume, power radiated, antenna pattern, resolution, display capabilities, pulse repetition frequency, and sensitivity. A literature search was also made to gather the system characteristics information. Results of the survey are documented and comparisons are made among available radarsystems.
In this paper, we design the signal processing module based on FPGA for vehicle FMCW radarsystems. We employ the detection algorithms based on two-step FFT (Fast Fourier Transform) using the several fast ramps in order to resolve radar range-velocity ambiguities. We implement the detection algorithms including the first FFT, DBF (Digital Beam Forming), the second FFT, and CFAR (Constant
Ground penetrating radar (GPR) is a well-known method for exploring the subsurface. Typically, the antenna system is located at the surface. This approach is not feasible if the target of interest is beyond the detection range of this surface equipment, for example because this target is located too far away or behind a highly conductive barrier. Directional borehole radar is
Ronald van Waard; Stefan van der Baan; K. W. A. van Dongen
This paper will examine the impact of discrete clutter on airborne adaptive radarsystems using a hi-fidelity radar cross section (RCS) model of buildings. A realistic model of the RCS for different building designs with respect to incidence angle and operating frequency has been developed that captures the phenomenology necessary to study the impact of discrete clutter on adaptive signal
Landing helicopters on rough unprepared terrain has always been considered hazardous, since the massive dust cloud generated by wind drafts from the helicopter's rotors completely obstructs the pilot's view of the landing area. This article presents a performance assessment of a proposed millimeter-wave (MMW) three-dimensional imaging radarsystem, specifically meant for helicopter assisted landing. The assessment includes simulation of radar
A controlled experiment was conducted at the Cold Region Research and Engineering Laboratory (CRREL) facilities for retrieving freshwater ice characteristics using a Frequency Modulated Continuous Wave (FM-CW) radarsystem. The purpose of this study is to quantify the interactions between a backscattered radar signal and ice cover characteristics such as thickness and air bubble content; and to provide a comprehensive
R. Leconte; S. Daly; Y. Gauthier; N. Yankielun; F. Bérubé; M. Bernier
Waveform design and ambiguity function are significant tools for the performance analysis of radarsystems. We first describe the principle of waveform design for ultrawideband (UWB) impulse waveforms and present the signal model and the advantages of a UWB-throb signal. The ambiguity function of the UWB-throb signal for monostatic radar is derived in detail and analyzed by computer simulation to
The paper describes the development of a new type of radarsystem called Chaotic Signal Radar (CSR), which utilises truly random signals for the modulation and a novel implicit sampling averaging algorithm in the receiver. The paper presents the results of simulation study in conjunction with the real measurements using a prototype CSR.
Yoshihisa Hara; Teruyuki Hara; Takashi Seo; Hajime Yanagisawa; Paul Ratliff; Wojciech Machowski
The present status of the project aimed at the realization of an innovative wearable system-on-chip UWB radar for the cardiopulmonary monitoring is presented. The overall 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 low-power radio interface. The principle of operation of the UWB radar for the monitoring of the heart wall is summarized. With respect to the prior art, this paper reports the results of the experimental characterization of the intra-body channel loss, which has been carried out successfully in order to validate the theoretical model employed for the radarsystem analysis. Moreover, the main building blocks of the radar have been manufactured in 90 nm CMOS technology by ST-Microelectronics and the relevant performance are resulted in excellent agreement with those expected by post-layout simulations. PMID:19163907
Zito, D; Pepe, D; Mincica, M; Zito, F; De Rossi, D; Lanata, A; Scilingo, E P; Tognetti, A
An operator-microprocessor interactive Operating System has been developed for the Time Domain Radar Laboratory (TDRL). The Operating System performs signal acquisition and averaging, real time and frequency domain computations and provides outputs in eas...
We developed the millimeter-wave radar that adopted both the FMpulse Doppler method and the Polarization-twisting Cassegrain antenna with mechanical scanning. Our radar features the following advantage: ? Wide target distance detection range with high distance accuray ? No “ghost” output for multiple target detection ? Superior accuracy of lateral position and excellent separation performance of vehicles running side by side
The Advanced Visual Technology System (AVTS) computer image generator was modified to produce highly accurate simulations of synthetic aperture radar (SAR) reflectively and elevation effects that can be precisely correlated with corresponding visual and infrared imagery. The resulting SAR snapshot is a plan view of the selected patch area with the field-of-view corresponding to a selected scale of 0.65, 1.3,
Robert L. Ferguson; John Ellis; Steven R. French; Jeanne Ball; Lisa Spencer; Herbert H. Bell; Peter M. Crane
For the successful design of low-cost and high-performance radarsystems accurate and efficient system simulation is a key requirement. In this paper we present a new versatile simulation environment for frequency-modulated continuous-wave radarsystems. Besides common hardware simulation it covers integrated system simulation and concept analysis from signal synthesis to baseband. It includes a flexible scenario generator, accurate noise modeling,
Stefan Scheiblhofer; Markus Treml; Stefan Schuster; Reinhard Feger; Andreas Stelzer
Compared with traditional microwave and millimeter wave radars, Terahertz radar has wide signal bandwidth and a very narrow antenna beam, which is beneficial to the realization of high resolution imaging. And as an instantaneous narrowband and synthetic wideband waveform, stepped frequency radar signal has been widely exploited in many applications, since it allows high range resolution with modest requirements of the system bandwidth. As an instantaneous narrowband and synthetic wideband waveform, stepped frequency radar signal has been widely exploited in many applications, since it allows high range resolution with modest requirements of the system bandwidth. This paper presents the design of a 0.2THz stepped frequency imaging radarsystem with operating bandwidth of 12 GHz, thus, a theoretical range resolution below 1.25 cm. The simulation of the system is implemented by using system design parameters. An experimental trial has been performed, and one-dimensional range profile of the stationary target is obtained by Imaging Experiment using THz radar. Results show that the THz radar imaging system could achieve the target detection and centimeter-level range resolution.
Described here is a software and hardware system for the real-time display of radar and video images for use in a measurement range. The main purpose is to give the reader a clear idea of the software and hardware design and its functions. This system is designed around a Tektronix XD88-30 graphics workstation, used to display radar images superimposed on video images of the actual target. The system's purpose is to provide a platform for tha analysis and documentation of radar images and their associated targets in a menu-driven, user oriented environment.
A DSP-based all-purpose radar parallel signal processing system (RPSPS) with high-speed real-time signal processing is implemented to fulfil the all-purpose radarsystem reconfiguration. High performance DSP chips are used as the kernel processing nodes. By means of local shared memory, a global distributed memory parallel system and the pipelined dataflow method, it can perform absolutely parallel data processing of multi
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 Research (NCAR), for the purpose of comparing these with observations from KSC's Lightning Detection and Ranging (LDAR) system. The NCAR radar was a special purpose dual-polarization system for studying the development of precipitation in storms and was at KSC for another project, the Small Cumulus Microphysics Study - SCMS. We used the radar on a non-interference basis to obtain the desired observations. In addition we recorded the electrostatic field change of the lightning discharges at two locations. Subsequent to the field observational period we compared the LDAR lightning observations with the storm structure as indicated by the radar. The results obtained to date are summarized briefly as follows: (1) The initial lightning sequence in a small developing storm was observed to occur in a region of the storm where supercooled raindrops had frozen within the previous few minutes. This is consistent with the idea that the storm electrification is produced by interactions between ice particles. (2) The lightning discharges tended to avoid regions of supercooled liquid raindrops, possibly indicating that corona from the drops reduces any electrification in the vicinity of the drops. (3) 'Bilevel' lightning discharges within storms have been confirmed to be between the level of negative charge at mid-levels in the storm and the upper storm level. This is consistent with and expands upon our understanding that storms have a basic dipolar charge structure. (4) The upward channels of the intracloud lightning discharges are often aligned with shafts of strong precipitation, and often begin just above the upper extent of 40 dBZ reflectivity in the precipitation shaft. This is consistent with a precipitation-based mechanism of electrification.
Measurements of lake ice thickness were made during March 1975 at the Straits of Mackinac by using a short-pulse radarsystem aboard an all-terrain vehicle. These measurements were compared with ice thicknesses determined with an auger. Over 25 sites were explored which had ice thicknesses in the range 29 to 60 cm. The maximum difference between radar and auger measurements was less than 9.8 percent. The magnitude of the error was less than + or - 3.5 cm. The NASA operating short-pulse radarsystem used in monitoring lake ice thickness from an aircraft is also described.
Unmanned Aircraft Systems (UAS) have become increasingly prevalent and will represent an increasing percentage of all aviation. These unmanned aircraft are available in a wide range of sizes and capabilities and can be used for a multitude of civilian and military applications. However, as the number of UAS increases so does the risk of mid-air collisions involving unmanned aircraft. This dissertation aims to present one possible solution for addressing the mid-air collision problem in addition to increasing the levels of autonomy of UAS beyond waypoint navigation to include preemptive sensor-based collision avoidance. The presented research goes beyond the current state of the art by demonstrating the feasibility and providing an example of a scalable, self-contained, RADAR-based, collision avoidance system. The technology described herein can be made suitable for use on a miniature (Maximum Takeoff Weight < 10kg) UAS platform. This is of paramount importance as the miniature UAS field has the lowest barriers to entry (acquisition and operating costs) and consequently represents the most rapidly increasing class of UAS.
This paper presents the basic concept and implementation of an 8 element DBF (digital beamforming) phased array radar. The real transmitting patterns with various frequencies, weights and nullings are shown. The receiving pattern is also given
In this scientific paper a versatile system simulation environment is introduced that enables investigations on millimeter-wave FMCW-radar sensors. With respect to the latest developments in automotive radar the simulator combines an RF-frontend simulation engine and a 3D ray-tracing tool to take the effects of the radar channel into account. Furthermore different antenna characteristics can be generated by the phased-array radar
Manuel Dudek; Ismail Nasr; Dietmar Kissinger; Robert Weigel; Georg Fischer
A report is presented on a preliminary design of a Synthetic Array Radar (SAR) intended for experimental use with the space shuttle program. The radar is called Earth Resources Shuttle Imaging Radar (ERSIR). Its primary purpose is to determine the usefulness of SAR in monitoring and managing earth resources. The design of the ERSIR, along with tradeoffs made during its evolution is discussed. The ERSIR consists of a flight sensor for collecting the raw radar data and a ground sensor used both for reducing these radar data to images and for extracting earth resources information from the data. The flight sensor consists of two high powered coherent, pulse radars, one that operates at L and the other at X-band. Radar data, recorded on tape can be either transmitted via a digital data link to a ground terminal or the tape can be delivered to the ground station after the shuttle lands. A description of data processing equipment and display devices is given.
7. CLOSE-UP FRONT VIEW OF RADARSYSTEM EMITTER/ANTENNA (TYPICAL DEVICE PHOTOGRAPH). - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA
This report provides details of a project in which two computer programs for systems studies of space-based radar, a pulse Doppler detection simulator (PDDS) and integrated surveillance simulator (ISS), were evaluated and upgraded. The validity and accura...
The transmitter and receiver of Bistatic RadarSystems are located at different positions. It is therefore possible simultaneously to transmit and receive. This opens up the possibility of using continuous wave (CW) signals. This report shows how traditio...
A theoretical and practical feasibility study for the development of an FMCW radar, combining features of FMCW and pulse radars was performed for application as SLAR for Earth observation. Design approaches were compared. Simulations with a network analyz...
In this paper a millimeter-wave radarsystem simulation environment for frequency-modulated continuous-wave (FMCW) radar using a 3D ray tracing channel simulator is presented. Therefore we use Agilents' RF design environment ADS® for system simulation and calculate the channel impulse response based on the data received from a 3D ray tracer in a Matlab® co-simulation. To reduce computing time the whole
Manuel Dudek; René Wahl; Dietmar Kissinger; Robert Weigel; Georg Fischer
The proliferation of mobile computing devices and local-area wireless networks has fostered a growing interest in location-aware systems and services. In this paper we present RADAR, a radio-frequency (RF) based system for locating and tracking users inside buildings. RADAR operates by recording and processing signal strength information at multiple base stations positioned to provide overlapping coverage in the area of
A general review of radar astronomy is given. Typical radarsystems are described and results cited. Methods of determining elements of orbits and rotation rates of planets are discussed. A proposed test of the Einstein theory of general relativity is des...
Radar Astronomy is a new and growing branch of Astronomy. Although it seems that radio echo studies must be confined to the solar system, they can play an important part in developing our understanding of the Sun and the planets. At the present time these objects are barely detectable by radar techniques and much of the work has been concerned
The presence of sea clutter in marine radar signals is sometimes not desired. So, efficient radar signal processing techniques are needed to reduce it. In this way, nonlinear signal processing techniques based on neural networks (NNs) are used in the proposed clutter reduction system. The developed experiments show promising results characterized by different subjective (visual analysis of the processed radar images) and objective (clutter reduction, target enhancement and signal-to-clutter ratio improvement) criteria. Moreover, a deep study of the NN structure is done, where the low computational cost and the high processing speed of the proposed NN structure are emphasized.
Vicen-Bueno, Raul; Carrasco-Alvarez, Ruben; Rosa-Zurera, Manuel; Nieto-Borge, Jose Carlos
Rockwell Collins France (RCF) radar department is currently developing, in close collaboration with TNO in The Hague, The Netherlands, a Frequency Modulated Continuous Wave (FMCW) radar sensor dedicated to Obstacle Warning function and potentially to air traffic detection. The sensor combines flood light illumination and digital beam forming to accommodate demanding detection and coverage requirements. Performances have been evaluated in flight tests and results prove that such a radar sensor is a good candidate for the Sense Function of Sense and Avoid Systems onboard UAV.
Itcia, Eric; Wasselin, Jean-Philippe; Mazuel, Sébastien; Otten, Matern; Huizing, Albert
The purpose of the field test program was to verify laboratory measurements of the effect of discrete address beacon system uplink signal formats on air traffic control radar beacon system transponders. The DABS interrogations tested were: (1) a combined ...
A computer analysis was conducted to investigate the effect of the proposed Discrete Address Beacon System (DABS) on the Air Traffic Control Radar Beacon System (ATCRBS) in a future (1982) Los Angeles, CA, air traffic environment. The performance of ATCRB...
Embedded training is a capability within an actual operational system, which provides sustainment training for system operators. It is invoked and used by the operator without instructor supervision. This paper describes Motorola's prototype embedded training system for the Army's Joint Surveillance and Target Attack RadarSystem (Joint STARS) groundstation. The embedded training capability is implemented entirely within the operational system
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
A fully integrated 77 GHz FMCW automotive radarsystem in 65 nm CMOS includes clock generation and chip-antenna assembly. Incorporating a full-rate fractional-N synthesizer and a high-performance RF front-end, the radar achieves a maximum detectable distance of 106 meters for a mid-size car while consuming 243 mW from a 1.2 V supply.
Yi-An Li; Meng-Hsiung Hung; Shih-Jou Huang; Jri Lee
This paper presents the digital signal processor design for constant-false-alarm-rate (CFAR) signal detection in a frequencymodulated-continuous-waveform (FMCW) radarsystem. 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
See-through-wall imaging radar is a unique application of ultra wideband communication that can provide soldiers and law enforcement officers with an enhanced situation awareness. We have developed an ultra-wideband high-resolution short pulse imaging radarsystem operating around 10 GHz, where two essential considerations are addressed: the effect of penetrating the walls; the pulse fidelity through the UWB components and antennas
This paper describes a radar-guided monocular vision system that detects, validates, and tracks the preceding vehicle and thus predicts its lane-change intentions. A vision-based lane tracking process is developed to create a stable motion model in order to map the radar targets to image coordinates and consequently generate the region of interest (ROI) to search for a potential preceding vehicle.
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
A frequency-agile C band Alpha K radarsystem was used to measure ocean surface currents during the SAXON-Chesapeake Light Tower experiment. Surface currents were measured with the radar approximately 80 percent of the time from September 20 to October 14, 1988. These measurements are compared with in situ current and wind probe measurements. The agreement between the radar and current probe measurements are found to be very good during periods when the wind- and wave-driven currents are negligible in the radar-viewing direction. During other times, the radar measurements are approximated by the Weber model.
The DOE ARM Program is deploying over $30M worth of scanning polarimetric Doppler radars at its four fixed and two mobile sites, with the object of advancing cloud lifecycle science, and cloud-aerosol-precipitation interaction science, by a quantum leap. As of 2011, there will be 13 scanning radarsystems to complement its existing array of profiling cloud radars: C-band for precipitation, X-band for drizzle and precipitation, and two-frequency radars for cloud droplets and drizzle. This will make ARM the world’s largest science user of, and largest provider of data from, ground-based cloud radars. The philosophy behind this leap is actually quite simple, to wit: dimensionality really does matter. Just as 2D turbulence is fundamentally different from 3D turbulence, so observing clouds only at zenith provides a dimensionally starved, and sometimes misleading, picture of real clouds. In particular, the zenith view can say little or nothing about cloud lifecycle and the second indirect effect, nor about aerosol-precipitation interactions. It is not even particularly good at retrieving the cloud fraction (no matter how that slippery quantity is defined). This talk will review the history that led to this development and then discuss the aspirations for how this will propel cloud-aerosol-precipitation science forward. The step by step plan for translating raw radar data into information that is useful to cloud and aerosol scientists and climate modelers will be laid out, with examples from ARM’s recent scanning cloud radar deployments in the Azores and Oklahoma . In the end, the new systems should allow cloud systems to be understood as 4D coherent entities rather than dimensionally crippled 2D or 3D entities such as observed by satellites and zenith-pointing radars.
The technological evolution in signal processing that has been made in last decades led to improvements in radar performances. Increasing the radar range by improving its sensitivity has been made by the designers of aircraft and other military systems to try to decrease the radar cross section of these types of equipment. The radar cross section is a matter of
An efficient microprocessor-based system has been implemented that permits real-time acquisition, stacking, and digital recording of data generated by a borehole radarsystem. 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
The spectral analysis of the low pass filtered echo signals of a stationary point target was carried out starting with the precise position of the transmit signal of a Frequency Modulated Continuous-Wave (FMCW) radar operated with sawtooth modulation and ...
The history of perimeter protection is based on building fences. That basic concept evolved into detecting activity along the fences using a variety of sensors. Today a wide variety of fiber and wire-based sensors are available to mount on a fence, as well as many different types of IR, radar, optical, seismic and acoustic sensors to place along the fence
A 'hybrid' radar waveform design technique is presented for improving slant range resolution in a synthetic aperture radarsystem which is processor-bandwidth limited. The hybrid waveform consists of K repetitions of L complementary phase coded pulses with linearly increasing carrier frequency from repetition to repetition. Processing of this frequency stepped, phase coded waveform consists of matched filtering on a pulse-by-pulse basis followed by amplitude weighting and coherent summation. The 'composite' ambiguity function is determined and illustrated for the hybrid waveform. A method for selecting optimum amplitude weights based on a cost function related to the integrated sidelobe ratio of the compressed waveform is also presented. This is contrasted with the usual method of choosing a window function with a low peak sidelobe ratio. The results of a computer study are summarized in terms of the cost function, peak and integrated sidelobe ratios, and mainlobe spread ratio as functions of selected waveform parameters. A numerical example is then given which illustrates the improvement factor to be expected by using the hybrid waveform technique.
The Goldstone Solar SystemRadar (GSSR) has collected a self-consistent set of delay-Doppler near-nadir radar echo data from Mars since 1988. Prior to the Mars Global Surveyor (MGS) Mars Orbiter Laser Altimeter (MOLA) global topography for Mars, these radar data provided local elevation information, along with radar scattering information with global coverage. Two kinds of GSSR Mars delay-Doppler data exist: low 5 km x 150 km resolution and, more recently, high (5 to 10 km) spatial resolution. Radar data, and non-imaging delay-Doppler data in particular, requires significant data processing to extract elevation, reflectivity and roughness of the reflecting surface. Interpretation of these parameters, while limited by the complexities of electromagnetic scattering, provide information directly relevant to geophysical and geomorphic analyses of Mars. In this presentation we want to demonstrate how to compare GSSR delay-Doppler data to other Mars datasets, including some idiosyncracies of the radar data. Additional information is included in the original extended abstract.
Haldemann, A. F. C.; Larsen, K. W.; Jurgens, R. F.; Slade, M. A.
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
The designer of the airborne defense missile system is interested in defining the fire control system (FCS) error, and the seeker detection probability to make the defense system more powerful. This paper develops one radar error statistical mathematics model for the airborne defense and determined the distribution of errors for each error, which can affect the probability of hit (PH).
Electromagnetic systems for imaging concealed objects at checkpoints typically employ radiation at millimetre and terahertz frequencies. These systems have been shown to be effective and provide a sufficiently high resolution image. However there are difficulties and current electromagnetic systems have limitations particularly in accurately differentiating between threat and innocuous objects based on shape, surface emissivity or reflectivity, which are indicative parameters. In addition, water has a high absorption coefficient at millimetre wavelength and terahertz frequencies, which makes it more difficult for these frequencies to image through thick damp clothing. This paper considers the potential of using ultra wideband (UWB) in the low gigahertz range. The application of this frequency band to security screening appears to be a relatively new field. The business case for implementing the UWB system has been made financially viable by the recent availability of low-cost integrated circuits operating at these frequencies. Although designed for the communication sector, these devices can perform the required UWB radar measurements as well. This paper reports the implementation of a 2 to 5 GHz bandwidth linear array scanner. The paper describes the design and fabrication of transmitter and receiver antenna arrays whose individual elements are a type of antipodal Vivaldi antenna. The antenna's frequency and angular response were simulated in CST Microwave Studio and compared with laboratory measurements. The data pre-processing methods of background subtraction and deconvolution are implemented to improve the image quality. The background subtraction method uses a reference dataset to remove antenna crosstalk and room reflections from the dataset. The deconvolution method uses a Wiener filter to "sharpen" the returned echoes which improves the resolution of the reconstructed image. The filter uses an impulse response reference dataset and a signal-to-noise parameter to determine how the frequencies contained in the echo dataset are normalised. The chosen image reconstruction algorithm is based on the back-projection method. The algorithm was implemented in MATLAB and uses a pre-calculated sensitivity matrix to increase the computation speed. The results include both 2D and 3D image datasets. The 3D datasets were obtained by scanning the dual sixteen element linear antenna array over the test object. The system has been tested on both humans and mannequin test objects. The front surface of an object placed on the human/mannequin torso is clearly visible, but its presence is also seen from a tell-tale imaging characteristic. This characteristic is caused by a reduction in the wave velocity as the electromagnetic radiation passes through the object, and manifests as an indentation in the reconstructed image that is readily identifiable. The prototype system has been shown to easily detect a 12 mm x 30 mm x70 mm plastic object concealed under clothing.
Podd, F. J. W.; David, M.; Iqbal, G.; Hussain, F.; Morris, D.; Osakue, E.; Yeow, Y.; Zahir, S.; Armitage, D. W.; Peyton, A. J.
We developed a novel non-contact monitoring system to measure the vital signs of casualties inside a moving ambulance. This system was designed to prevent exposure of patients to infectious organisms under biochemical hazard conditions. The system consists of two microwave radars: a 10-GHz respiratory-monitoring radar is positioned 20 cm away from the surface of the isolator. The 24-GHz cardiac-monitoring radar is positioned below the stretcher underneath the isolator. The subject (22.13 +/- 0.99 years) was placed inside the isolator on a stretcher in the simulated ambulance. While the ambulance was in motion at a speed of approximately 10 km/h, the heart rates determined by the cardiac-monitoring radar correlated significantly with those measured by ECG (r = 0.69, p < 0.01), and the respiratory rates derived from the respiratory-monitoring radar correlated with those measured by the respiration curves (r = 0.97, p < 0.0001). The proposed system appears promising for future on-ambulance monitoring of the vital sign of casualties exposed to toxins. PMID:18946695
Coherent and non-coherent radar detection of moving targets is analyzed and expressions relating the post-video-detection moving target signal-to-noise ratio to the pre-video-detection moving target signal-to-noise and clutter-to-noise ratios are obtained for non-coherent detection. The effect of processing this resulting real (non-coherent) signal with an FFT processor is then analyzed and compared to the FFT processing of a complex (coherent) signal.
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,
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 it provided valuable information during subsequent explosive events. We describe the capabilities of this new monitoring tool and present data that it captured during the Redoubt eruption. The volcano-monitoring Doppler radar operates in the C-band (5.36 cm) and has a 2.4-m parabolic antenna with a beam width of 1.6 degrees, a transmitter power of 330 watts, and a maximum effective range of 240 km. The entire disassembled system, including a radome, fits inside a 6-m-long steel shipping container that has been modified to serve as base for the antenna/radome, and as a field station for observers and other monitoring equipment. The radar was installed at the Kenai Municipal Airport, 82 km east of Redoubt and about 100 km southwest of Anchorage. In addition to an unobstructed view of the volcano, this secure site offered the support of the airport staff and the City of Kenai. A further advantage was the proximity of a NEXRAD Doppler radar operated by the Federal Aviation Administration. This permitted comparisons with an established weather-monitoring radarsystem. The new radarsystem first became functional on March 20, roughly a day before the first of nineteen explosive ash-producing events of Redoubt between March 21 and April 4. Despite inevitable start-up problems, nearly all of the events were observed by the radar, which was remotely operated from the Alaska Volcano Observatory office in Anchorage. The USGS and NEXRAD radars both detected the eruption columns and tracked the directions of drifting ash clouds. The USGS radar scanned a 45-degree sector centered on the volcano while NEXRAD scanned a full 360 degrees. The sector strategy scanned the volcano more frequently than the 360-degree strategy. Consequently, the USGS system detected event onset within less than a minute, while the NEXRAD required about 4 minutes. The observed column heights were as high as 20 km above sea level and compared favorably to those from NEXRAD. NEXRAD tracked ash clouds to greater distances than the USGS system. This experience shows that Doppler radar is a valuable complement to traditional seismic and satellite monitoring of explosive eruptions.
The use of dumpers is one of the main causes of accidents in construction sites, many of them with fatal consequences. These kinds of work machines have many blind angles that complicate the driving task due to their large size and volume. To guarantee safety conditions is necessary to use automatic aid systems that can detect and locate the different objects and people in a work area. One promising solution is a radar network based on low-cost radar transceivers aboard the dumper. The complete system is specified to operate with a very low false alarm rate to avoid unnecessary stops of the dumper that reduce its productivity. The main sources of false alarm are the heavy ground clutter, and the interferences between the radars of the network. This article analyses the clutter for LFM signaling and proposes the use of Offset Linear Frequency Modulated Continuous Wave (OLFM-CW) as radar signal. This kind of waveform can be optimized to reject clutter and self-interferences. Jointly, a data fusion chain could be used to reduce the false alarm rate of the complete radar network. A real experiment is shown to demonstrate the feasibility of the proposed system.
The use of dumpers is one of the main causes of accidents in construction sites, many of them with fatal consequences. These kinds of work machines have many blind angles that complicate the driving task due to their large size and volume. To guarantee safety conditions is necessary to use automatic aid systems that can detect and locate the different objects and people in a work area. One promising solution is a radar network based on low-cost radar transceivers aboard the dumper. The complete system is specified to operate with a very low false alarm rate to avoid unnecessary stops of the dumper that reduce its productivity. The main sources of false alarm are the heavy ground clutter, and the interferences between the radars of the network. This article analyses the clutter for LFM signaling and proposes the use of Offset Linear Frequency Modulated Continuous Wave (OLFM-CW) as radar signal. This kind of waveform can be optimized to reject clutter and self-interferences. Jointly, a data fusion chain could be used to reduce the false alarm rate of the complete radar network. A real experiment is shown to demonstrate the feasibility of the proposed system. PMID:24577521
Global rainfall is the primary distributor of latent heat through atmospheric circulation. The recently launched Tropical Rainfall Measuring Mission satellite is dedicated to advance our understanding of tropical precipitation patterns and their implications on global climate and its change. The Precipitation Radar (PR) aboard the satellite is the first radar ever flown in space and has provided. exciting, new data on the 3-D rain structures for a variety of scientific uses. However, due to the limited mission lifetime and the dynamical nature of precipitation, the TRMM PR data acquired cannot address all the issues associated with precipitation, its related processes, and the long-term climate variability. In fact, a number of new post-TRMM mission concepts have emerged in response to the recent NASA's request for new ideas on Earth science missions at the post 2002 era. This paper will discuss the system concepts for two advanced, spaceborne rainfall profiling radars. In the first portion of this paper, we will present a system concept for a second-generation spaceborne precipitation radar for operations at the Low Earth Orbit (LEO). The key PR-2 electronics system will possess the following capabilities: (1) A 13.6/35 GHz dual frequency radar electronics that has Doppler and dual-polarization capabilities. (2) A large but light weight, dual-frequency, wide-swath scanning, deployable antenna. (3) Digital chirp generation and the corresponding on-board pulse compression scheme. This will allow a significant improvement on rain signal detection without using the traditional, high-peak-power transmitters and without sacrificing the range resolution. (4) Radar electronics and algorithm to adaptively scan the antenna so that more time can be spent to observe rain rather than clear air. and (5) Built-in flexibility on the radar parameters and timing control such that the same radar can be used by different future rain missions. This will help to reduce the overall instrument development costs. In the second portion of this paper, we will present a system concept for a geostationary rainfall monitoring radar for operations at the geosynchronous Earth Orbit (GEO). In particular, the science requirements, the observational strategy, the instrument design, and the required technologies will be discussed.
This paper presents the design and implementation of a complete phase shifter system using vector (polar) modulation, suitable for solid-state phased array radar applications, providing a cost effective solution which overcomes the main constraints involved with traditional systems. The performance characteristics for three intermediate frequencies were measured. In addition, measurements at X- band were performed using frequency up-converters. Finally a
A directional borehole radarsystem using an array antenna connected to passive optical electric field sensors was developed and evaluated by laboratory and field experiments. This system uses a single dipole antenna for a transmitter and a four-dipole element circular array for a receiver. The received signals are transmitted through optical fibers from optical electric field sensors. The receiver array
Violating the privacy of individuals with sys- tems that measure daily human activities is unacceptable in our society. In this paper, the authors propose a system using ultrasonic radar embedded in the ceiling of a room to locate human individuals with a minimum violation of privacy. It is expected that this system will be used in the prevention of ac-
An operator-microprocessor interactive Operating System has been developed for the Time Domain Radar Laboratory (TDRL). The Operating System performs signal acquisition and averaging, real time and frequency domain computations and provides outputs in easily evaluated graphic displays. Target classification is made by analysis of either impulse, step or ramp responses. A noise-reduction signal optimization technique is implemented. Numerous measurements of
Foreign Objects and Debris (FODs) must be removed from runways. With the necessity of automatic continuous survey, we are investigating a new FOD detection system based on a millimeter wave radar network. This paper describes the concept of this FOD detection system and the Radio Frequency (RF) module for this application. In order to minimize cost and size, we installed
Naruto Yonemoto; Akiko Kohmura; Shunichi Futatsumori; Tetsuji Uebo; Alexandre Saillard
An orbital microwave imaging radarsystem suggested for use in conjunction with the space shuttle is presented. Several applications of the system are described, including agriculture, meteorology, terrain analysis, various types of mapping, petroleum and mineral exploration, oil spill detection and sea and lake ice monitoring. The design criteria, which are based on the requirements of the above applications, are discussed.
Satellite radar altimeter-derived sea surface heights (SSH) are in error in coastal regions due, in part, to the complex nature of echoes returned from rapidly varying land and sea surfaces. This paper presents improved altimeter-derived SSH results in Australian coastal regions using the waveform retracking technique, which reprocesses the waveform data through a “coastal retracking system”. The system, based upon
Satellite radar altimeter-derived sea surface heights (SSH) are in error in coastal regions due, in part, to the complex nature of echoes returned from rapidly varying land and sea surfaces. This paper presents improved altimeter-derived SSH results in Australian coastal regions using the waveform retracking technique, which reprocesses the waveform data through a ``coastal retracking system''. The system, based upon
In order to improve tracking ability, an adaptive fusion algorithm based on adaptive neuro-fuzzy inference system (ANFIS) for radar\\/infrared system is proposed, which combines the merits of fuzzy logic and neural network. Fuzzy adaptive fusion algorithm is a powerful tool to make the actual value of the residual covariance consistent with its theoretical value. To overcome the defect of the
Frequency modulated continuous wave (FMCW) radar have become common place in many roadside trac and on board vehicle safety systems. The accuracy in these systems is based on the underlying calibration of these sensors, which can be a time consuming and costly process. In our approach, using an uncalibrated commercial- o-the-shelf (COTS) radar sensor, vehicles were monitored along a roadside. A moving target indication (MTI) technique is used to reduce background clutter with thresholding and CFAR techniques used for signal detection. These detections are fed into an extended Kalman lter, and using dierent association approaches, the results are compared to GPS ground truth.
An orbit transfer mission concept has been studied for a Space-Based Radar (SBR) where 40 kW required for radar operation is assumed available for orbit transfer propulsion. Arcjet, pulsed electrothermal (PET), ion, and storable chemical systems are considered for the primary propulsion. Transferring two SBR per shuttle flight to 1112 km/60 deg using electrical propulsion systems offers an increased payload at the expense of increased trip time, up to 2000 kg each, which may be critical for survivability. Trade offs between payload mass, transfer time, launch site, inclination, and height of parking orbits are presented.
An orbit transfer mission concept has been studied for a Space-Based Radar (SBR) where 40 kW required for radar operation is assumed available for orbit transfer propulsion. Arcjet, pulsed electrothermal (PET), ion, and storable chemical systems are considered for the primary propulsion. Transferring two SBR per shuttle flight to 1112 km/60 deg using eiectrical propulsion systems offers an increased payload at the expense of increased trip time, up to 2000 kg each, which may be critical for survivability. Trade offs between payload mass, transfer time, launch site, inclination, and height of parking orbits are presented.
The scientific and engineering requirements for the Earth Observing System (EOS) imaging radar are provided. The radar is based on Shuttle Imaging Radar-C (SIR-C), and would include three frequencies: 1.25 GHz, 5.3 GHz, and 9.6 GHz; selectable polarizations for both transmit and receive channels; and selectable incidence angles from 15 to 55 deg. There would be three main viewing modes: a local high-resolution mode with typically 25 m resolution and 50 km swath width; a regional mapping mode with 100 m resolution and up to 200 km swath width; and a global mapping mode with typically 500 m resolution and up to 700 km swath width. The last mode allows global coverage in three days. The EOS SAR will be the first orbital imaging radar to provide multifrequency, multipolarization, multiple incidence angle observations of the entire Earth. Combined with Canadian and Japanese satellites, continuous radar observation capability will be possible. Major applications in the areas of glaciology, hydrology, vegetation science, oceanography, geology, and data and information systems are described.
A networked waveform system is developed to overcome the fundamental limitation of a single pulsed Doppler radar in re- solving ambiguities. The networked radarsystem uses the principle that the underlying intrinsic properties of the pre- cipitation medium remain consistent in a network. The am- biguity in range and velocity is resolved by jointly process- ing the measurements from all
This paper describes several alternative techniques for detecting and localizing slowly-moving targets in cultural clutter using synthetic aperture radar (SAR) data. Here, single-pass data is jointly processed from two or more receive channels which are spatially offset in the along-track direction. We concentrate on two clutter cancelation methods known as the displaced phase center antenna (DPCA) technique and along-track SAR interferometry (AT-InSAR). Unlike the commonly-used space-time adaptive processing (STAP) techniques, both DPCA and AT-InSAR tend to perform well in the presence of non-homogeneous urban or mountainous clutter. We show, mathematically, the striking similarities between DPCA and AT-InSAR. Furthermore, we demonstrate using experimental SAR data that these two techniques yield complementary information, which can be combined into a "hybrid" technique that incorporates the advantages of each for significantly better performance. Results are generated using the Gotcha challenge data, acquired using a three-channel X-band spotlight SAR system.
The traffic over Internet is constantly increasing; this is due in particular to social networks activities but also to the enormous exchange of data caused especially by the so-called "Internet of Things". With this term we refer to every device that has the capability of exchanging information with other devices on the web. In geoscience (and, in particular, in meteorology and climatology) there is a constantly increasing number of sensors that are used to obtain data from different sources (like weather radars, digital rain gauges, etc.). This information-gathering activity, frequently, must be followed by a complex data analysis phase, especially when we have large data sets that can be very difficult to analyze (very long historical series of large data sets, for example), like the so called big data. These activities are particularly intensive in resource consumption and they lead to new computational models (like cloud computing) and new methods for storing data (like object store, linked open data, NOSQL or NewSQL). The weather radarsystems can be seen as one of the sensors mentioned above: it transmit a large amount of raw data over the network (up to 40 megabytes every five minutes), with 24h/24h continuity and in any weather condition. Weather radar are often located in peaks and in wild areas where connectivity is poor. For this reason radar measurements are sometimes processed partially on site and reduced in size to adapt them to the limited bandwidth currently available by data transmission systems. With the aim to preserve the maximum flow of information, an innovative network connectivity paradigm for the large data produced by weather radarsystem is here presented. The study is focused on the Monte Settepani operational weather radarsystem, located over a wild peak summit in north-western Italy.
A dual Ka-band radarsystem was developed by the Japan Aerospace Exploration Agency (JAXA) for GPM/DPR (Dual-frequency Precipitation Radar) algorithm development. The system consists of two identical Ka-band radars. Both the equivalent radar reflectivity factor (Ze) and specific attenuation (k) can be measured at each range bin of the path. The measured k-Ze relations of rain, snow, and the melting layers can be used to develop the "scattering table" for the improvement of the GPM/DPR algorithm performance. Those measured parameters of snow are important because the measurements of snow at Ka-band were limited. Precipitation measurements were conducted using the dual Ka-band radarsystem in Nagaoka, Niigata, Japan. k-Ze relations of rain and snow were measured. A mobile precipitation observation system, which has a disdrometer, a 2DVD, several rain gauges and meteorological sensors, was placed at the middle of the path. Surface observation data are compared with Ze and k measured from the Ka radar. Among snow events, different tendencies of k-Ze plots appeared depending on surface temperature. When surface temperature was above 0 deg C during snow events, k-Ze plots were scattered and larger k values than those of rain appeared. On the other hand, when surface temperature was below 0 deg C during snow events, both the slight positive trend of k-Ze plots and small k and Ze values appeared. In the former (latter) cases, the wet (dry) snow was probably dominant. Thus, the difference of k-Ze relations of snow was attributed to the difference of the backscattering and attenuation characteristics between wet and dry snow. In the future, the k-Ze plots will be compared with the surface observation data such as snow size distributions and water mixing ratio of snow.
Nishikawa, M.; Nakamura, K.; Minda, H.; Nakagawa, K.; Hanado, H.; Komachi, K.; Nakai, S.; Kumakura, T.
A development history of radar technology is presented, with attention to the driving of radarsystem design advances by the emergence of such weapon systems as long range aircraft and cruise missiles in World War II and the range of current applications for state-of-the-art radar techniques. The applications noted encompass over-the-horizon backscatter radars for aircraft detection at 500-1800 nmi ranges, ultralow sidelobe antenna military radars, a long range, frequency scanning three-dimensional S-band radar, a shipborne phased array radar for the collection of exoatmospheric and endoatmospheric data on ballistic missile reentry vehicles, multimission/multimode X-band fighter aircraft radars, and phased array air defense radars.
We evaluated a radar-activated integrated hazing system for the protection of waterfowl at large contaminated ponds at a power plant. The hazing devices in the system included acoustic alarm calls, pyrotechnics and chemical repellents dispersed in the form of a bird tear-gas. Unlike, timed interval systems, or systems with random activation sequences, birds did not habituate to the demand-performance system
Gwen R. Stevens; Jamie Rogue; Richard Weber; Larry Clark
Because of the lack of dedicated frequency bands, the TD-LTE system is possibly deployed in the same band with other existed mobile systems. In this paper, the coexistence studies for the TD-LTE system with the radarsystem which has been widely deployed in the band 2300-2400 MHz, is presented. The dynamical system simulation methodology is utilized in the coexistence studies,
Wei Liu; Jian Fang; Haifeng Tan; Biao Huang; Wenbo Wang
The material presented covers the general topic of C-band radars and their use throughout the GEOS-2 C-band RadarSystem Project and has direct application to the general problem of gathering accurate radar tracking data. The material is hardware oriented and all analyses and evaluations described pertain to the gathering of accurate data rather than to the application of the gathered data. The radar oriented investigations formed a basic and necessary part of the overall C-band experiment. The successful completion of these efforts led to the definition of how the radars were to be operated and calibrated. These hardware decisions directly affected the quality of the radar data and therefore played a large part in the successful application of these data to geodetic research.
The detection of an ocean underneath Europa is one of the primary objectives of the Jupiter Icy Moons Orbiter (JIMO) mission. An orbiting surface penetrating radar has the potential of providing that measurement thus yielding information regarding the possibility of life support on Europa. Radars in the MHz range have successfully monitored the kilometer-deep ice shelves of Greenland and Antarctica, including the detection of Lake Vostok (and others) below an ice sheet thickness of about 4 km. The performance of a radarsystem orbiting Europa will be subject to several potential complications and unknowns. Besides ionospheric dispersion and the actual depth of the ocean, which is estimated between 2 and 30 km, major unknowns affecting radar performance are the temperature profile, the amount of salt and other impurities within the ice crust as well as the surface roughness. These impurities can in part be produced at the highly irradiated surface by magnetospheric interactions and transported downward into the ice crust by geologic processes. The ionospheric interference must also be modeled from effects of these interactions on production of the thin neutral atmosphere and subsequent ionization of the neutrals. We investigated these uncertainties through radar simulations using different surface and ice characteristics over a frequency range from 10 to 50 MHz. The talk will present results from these simulations discussing potential limitations.
In 2009/2010 the Leibniz-Institute of Atmospheric Physics (IAP) installed a new powerful VHF radar on the island Andøya in Northern Norway (69.30° N, 16.04° E). The Middle Atmosphere Alomar RadarSystem (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.
When we talk about for the ship detection, identification and its classification, we need to go for the wide area of monitoring and it may be possible only through satellite based monitoring approach which monitors and covers coastal as well as the oceanic zone. Synthetic aperture radar (SAR) has been widely used to detect targets of interest with the advantage of the operating capability in all weather and luminance free condition (Margarit and Tabasco, 2011). In EU waters, EMSA(European Maritime Safety Agency) is operating the SafeSeaNet and CleanSeaNet systems which provide the current positions of all ships and oil spill monitoring information in and around EU waters in a single picture to Member States using AIS, LRIT and SAR images. In many countries, a similar system has been developed and the key of the matter is to integrate all available data. This abstract describes the preliminary design concept for an integration system of RADAR, AIS and SAR data for vessel traffic monitoring. SAR sensors are used to acquire image data over large coverage area either through the space borne or airborne platforms in UTC. AIS reports should be also obtained on the same date as of the SAR acquisition for the purpose to perform integration test. Land-based RADAR can provide ships positions detected and tracked in near real time. In general, SAR are used to acquire image data over large coverage area, AIS reports are obtained from ship based transmitter, and RADAR can monitor continuously ships for a limited area. In this study, we developed individual ship monitoring algorithms using RADAR(FMCW and Pulse X-band), AIS and SAR(RADARSAT-2 Full-pol Mode). We conducted field experiments two times for displaying the RADAR, AIS and SAR integration over the Pyeongtaek Port, South Korea.
Yang, Chan-Su; Kim, Tae-Ho; Hong, Danbee; Ahn, Hyung-Wook
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.
The Middle Atmosphere Alomar RadarSystem (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.
Laser radar data acquisition systems have been utilized in conjunction with a light emitting diode to evaluate photomultipliers for laser radar use. Light pulses with an exponential decay rate of approximately one decade per sixty microseconds, as well as other pulse shapes, were used to drive the tubes. Properties studied in the analog mode include nonlinearity at high output currents, transient behavior upon gating, gate holdoff, dynamic range limitations because of light-induced noise, and the effect of dynode gating on tubes without a focus grid. Some of these properties were also studied in the photon counting mode, along with single photoelectron pulse shape and afterpulsing. A brief description of the laser radar technique of atmospheric measurements is included.
A new system-on-a-chip radar sensor for next-generation wearable wireless interface applied to the human health care and safeguard is presented. The system overview is provided and the feasibility study of the radar sensor is presented. In detail, the overall system consists of a radar sensor for detecting the heart and breath rates and a low-power IEEE 802.15.4 ZigBee radio interface, which provides a wireless data link with remote data acquisition and control units. In particular, the pulse radar exploits 3.1–10.6 GHz ultra-wideband signals which allow a significant reduction of the transceiver complexity and then of its power consumption. The operating principle of the radar for the cardiopulmonary monitoring is highlighted and the results of the system analysis are reported. Moreover, the results obtained from the building-blocks design, the channel measurement, and the ultra-wideband antenna realization are reported.
Zito, Domenico; Pepe, Domenico; Neri, Bruno; Zito, Fabio; De Rossi, Danilo; Lanata, Antonio
A new system-on-a-chip radar sensor for next-generation wearable wireless interface applied to the human health care and safeguard is presented. The system overview is provided and the feasibility study of the radar sensor is presented. In detail, the overall system consists of a radar sensor for detecting the heart and breath rates and a low-power IEEE 802.15.4 ZigBee radio interface, which provides a wireless data link with remote data acquisition and control units. In particular, the pulse radar exploits 3.1-10.6 GHz ultra-wideband signals which allow a significant reduction of the transceiver complexity and then of its power consumption. The operating principle of the radar for the cardiopulmonary monitoring is highlighted and the results of the system analysis are reported. Moreover, the results obtained from the building-blocks design, the channel measurement, and the ultra-wideband antenna realization are reported. PMID:18389068
Zito, Domenico; Pepe, Domenico; Neri, Bruno; Zito, Fabio; De Rossi, Danilo; Lanatà, Antonio
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 GMTIradar 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 GMTIradar data.
Marple, Stanley L., Jr.; Marino, Claudio S.; Strange, Shawn
In the frequency modulated continuous wave radarsystems, when the transmitter uses periodic linear symmetric triangular wave modulation, the received signal after processed by the mixer will have many harmonics. In the single target detection, this effect can be ignored. However, in the multi-target detection, targets with different ranges and velocities lead to overlapping of the harmonics. Using the peak
This paper deals with initial application of digital modulation techniques in the radarsystems utilizing non-linear junction detection (NLJD) principle. Various types of devices, such as handheld detectors for searching of hidden listening devices, have previously been developed and are commercially available. However, these devices transmit single frequency harmonic waveform which in general limits efficiency of energy transmission to nonlinear
This project is based on the previous research (0-1828 'Feasibility Study on Non-destructive Testing Technique to Measure PCC Pavement Thickness'), which provided information and a rudimentary radarsystem that may be able to be used to measure concrete p...
Large profile, high price, low efficiency in realization prevent phased array from being broadly used in automobile radar and communication systems, though phased array has high performance. The article puts forward a new kind of shifterless phased array based on coupled oscillators. The article studies the dynamics of nearest-neighbor coupled oscillators after reviewing the principles of electrical beam-scanning. According to
Tang Zhikai; Jiang Yonghua; Liu Longhe; Hao Yuan; Ling Xiang
The paper reports on current advances in the development of the Dornier Obstacle Warning System (OWS) for helicopters, with particular emphasis on the Obstacle Warning Ladar (OWL). Here both segments, development and application of the 1.5 micrometer imaging laser radar (LADAR) will be represented. It will be shown how advances in the eyesafe LADAR technology resulted in Obstacle Warning Ladar
The target tracking case, where radar and IRST contacts are fused at the central level fusion architecture, with special attention to the coordinate system, has been analyzed in this presentation. Tracking targets by fusing contacts from dissimilar sensors in a central level fusion process is acknowledged to be the most powerful tracking technique. This approach maximizes the synergy among the
Tracks from birds can form a significant component of the picture produced by a track processing system and are generally regarded as a nuisance. A knowledge of the feasible range of bird flight characteristics is a prerequisite to the successful development of discrimination techniques, but the information given in the standard radar references e.g. by Skolnik (1980) and by Barton
A new meteor radarsystem was installed at the Amundsen–Scott station South Pole in 2001 to further the understanding of the dynamics of the Antarctic region. The antenna array consists of four yagis pointed along the 0°, 90°, 180°, and 270° meridians and five folded crossed dipoles arranged in a cross configuration and operating as an interferometer to provide position
Elías M. Lau; Hiroyuki Iimura; Scott E. Palo; Susan K. Avery; James P. Avery; Chunmei Kang; Nikolai A. Makarov
A new meteor radarsystem was installed at the Amundsen Scott station South Pole in 2001 to further the understanding of the dynamics of the Antarctic region. The antenna array consists of four yagis pointed along the 0°, 90°, 180°, and 270° meridians and five folded crossed dipoles arranged in a cross configuration and operating as an interferometer to provide
Elías M. Lau; Hiroyuki Iimura; Scott E. Palo; Susan K. Avery; James P. Avery; Chunmei Kang; Nikolai A. Makarov
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 paper reports on the development of a hybrid optical\\/electronic signal processor for laser radar signals in fire control applications. The breadboard system being developed consists of three subsystems: (1) a signal generator producing target-representative signals, (2) the signal processor consisting of a radiometric channel and a Doppler channel, and (3) a data acquisition, analysis, and display subsystem. The radiometric
George B. Findley; Christopher S. Anderson; Sandi K. Tepper; Michael J. Pascale; Lee V. Watson; Howard A. Jenkinson
A nearest Gaussian approximation (NGA) is proposed to approximate any shape for a single mode laser beam by a Gaussian shape. The application considered is a determination of the system efficiency in heterodyne coherent laser radar (HCLR). For an actual beam its NGA is defined by three parameters: the waist spot size and location, and an amplitude coefficient. These parameters
Philippe Salamitou; Franck Darde; Pierre H. Flamant
The Ground Penetrating Radar (GPR) is a technique that utilizes the radio waves to map structure and features of objects buried in the ground. In this paper, we design a host control system (HCS) of GPR based on a maximum length binary sequence, abbreviation M-sequence, to implement the detecting of deep level objects on earth, and we realize the design
Wang Wenpeng; Ding Yipeng; Zhao Bo; Wang Wei; Fang Guangyou; Liu Xiao Jun
Tracking mobile agents with a Doppler radarsystem mounted on a moving vehicle is considered in this paper. Dopplers modulated from mobile agents on the single frequency continuous wave signals are analyzed in order to estimate the positions and velocities of multiple mobile agents. The measurement noise is assumed to be Gaussian and the maximum likelihood estimation is utilized to
This paper presents ARTEMIS, Inc.'s approach to development of end-to-end synthetic aperture radarsystems 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 radarsystem, 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.
A development history of radar technology is presented, with attention to the driving of radarsystem design advances by the emergence of such weapon systems as long range aircraft and cruise missiles in World War II and the range of current applications for state-of-the-art radar techniques. The applications noted encompass over-the-horizon backscatter radars for aircraft detection at 500-1800 nmi ranges,
The performance of frequency estimation procedures for sinusoidal signals in the presence of phase perturbations plays an important role in continuous-wave radarsystems for distance measurement, as it directly determines the ranging accuracy. For the most widely used frequency estimator, the fast Fourier transformation, the influence of deterministic deviations of the transmit signal from the ideal curve in FMCW\\/FSCW radars
Markus Pichler; Andreas Stelzer; Peter Gulden; Martin Vossiek
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
A three-channel data acquisition system was developed for the NASA Multi-Frequency Radar (MFR) system. The system is based on a commercial-off-the-shelf (COTS) industrial PC (personal computer) and two dual-channel 14-bit digital receiver cards. The decimated complex envelope representations of the three radar signals are passed to the host PC via the PCI bus, and then processed in parallel by multiple cores of the PC CPU (central processing unit). The innovation is this parallelization of the radar data processing using multiple cores of a standard COTS multi-core CPU. The data processing portion of the data acquisition software was built using autonomous program modules or threads, which can run simultaneously on different cores. A master program module calculates the optimal number of processing threads, launches them, and continually supplies each with data. The benefit of this new parallel software architecture is that COTS PCs can be used to implement increasingly complex processing algorithms on an increasing number of radar range gates and data rates. As new PCs become available with higher numbers of CPU cores, the software will automatically utilize the additional computational capacity.
An expanded introduction is presented which addresses the in-depth nature of the tasks and indicates continuity of the reported effort and results with previous work and related contracts, and the two major modes of operation which exist in the Ku-band system, namely, the radar mode and the communication mode, are described. The Ku-band radarsystem is designed to search for a target in a designated or undesignated mode, then track the detected target, which might be cooperative (active) or passive, providing accurate, estimates of the target range, range rate, angle and angle rate to enable the orbiter to rendezvous with this target. The radar mode is described along with a summary of its predicted performance. The principal sub-unit that implements the radar function is the electronics assembly 2(EA-2). The relationship of EA-2 to the remainder of the Ku-band system is shown. A block diagram of EA-2 is presented including the main command and status signals between EA-2 and the other Ku-band units.
This paper gives an overview of the European (EU) project RESOLUTION (reconfigurable systems for mobile local communication and positioning). RESOLUTION aims at developing a wireless three-dimensional (3-D) local positioning system with accuracy in the centimeter regime. A novel frequency modulated continuous wave (FMCW) radar principle is employed and co-designed together with common WLAN systems operating around 5 GHz. At 140
F. Ellinger; R. Eickhoff; A. Ziroff; J. Huttner; R. Gierlich; J. Carls; G. Bock
The Missile Defense Agency (MDA) Advanced Systems Directorate (MDA\\/DV) is developing the MicroSatellite Target System (MTS) to research and develop the technologies necessary to build relatively inexpensive microsatellites for calibration of terrestrial radar. MTS-1 is designed to simulate reentry vehicle (RV) dynamics using the spacecraft (SC) Attitude Control System (ACS). The Air Force Research Laboratory (AFRL) Space Vehicles Directorate is
Jason Guarnieri; Greg Hegemann; Greg Spanjers; James Winter; Martin Tolliver; Jeff Summers; Greg Cord
This paper investigates the effects of target acceleration on estimating the velocity vector of a ground moving target from single-pass dual-channel synthetic aperture radar data. Although vehicles traveling on roads and highways routinely experience acceleration, the majority of estimation algorithms assume a constant velocity scenario, which may result in erroneous estimates of target velocity. It is shown that under most
Jayanti J. Sharma; Christoph H. Gierull; Michael J. Collins
This paper investigates the relationship between a ground moving target's kinematic state and its SAR image. While effects such as cross-range offset, defocus, and smearing appear well understood, their derivations in the literature typically employ simplifications of the radar\\/target geometry and assume point scattering targets. This study adopts a geometrical model for understanding target motion effects in SAR imagery, termed
The present status of radar cross section (RCS) measurements is addressed. The fundamental considerations and definitions associated with RCS measurements are reviewed, including radar waveform, polarization requirements, far-field requirements, and target dimensional scaling. Different types of measurement facilities are examined, including their range geometries, target support systems, calibration standards, and facility evaluation. Instrumentation radar requirements and designs are reviewed, and
In this paper, a system for automatically recognizing radar waveforms is introduced. This type of techniques are needed in various spectrum management, surveillance and cognitive radio or radar applications. The intercepted radar signal is classified to eight classes based on the pulse compression waveform: linear frequency modulation (LFM), discrete frequency codes (Costas codes), binary phase, and Frank, P1, P2, P3,
Like much of the equipment used by the armed forces, both civil and military radarsystems may be allocated an identification resolved from a synonym, mnemonic, project name, number, application notation, or specialised nomenclature and sometimes may even be based upon the whims of an intelligence reporting service. Of these, mnemonics are very popular; whilst of designation systems used by
The MU (middle and upper atmosphere) radar of Japan uses an active phased array system. Each of 475 crossed three-subelement yagi antennas in a circular array is provided with a 2.4-kW peak power amplifier. This system configuration attains a very fast and almost continuous beam steerability at the total peak radiation power of 1 MW. A brief description of the
The MU (middle and upper atmosphere) radar of Japan uses an active phased array system. Each of 475 crossed three-subelement yagi antennas in a circular array is provided with a 2.4-kW peak power amplifier. This system configuration attains a very fast and almost continuous beam steerability at the total peak radiation power of 1 MW. A brief description of the in-house equipment is presented herein.
We describe a step-frequency radar (SFR) imaging system that is suitable for microwavenondestructive evaluation (NDE) applications. The system includes a computerautomatedmicrowave measurement apparatus, calibration software, and nonlinear inversescattering imaging algorithms. Through the use of an inverse Fourier transform, the rawSFR data is transformed into a synthetic time-domain pulse. A calibration procedure involvingthe use of calibration targets may then be used
A 35 GHz millimeter-wave radarsystem has been studied for space debris tracking. The objective is to track the particles ranging in size from 4 mm to 80 mm up to a range of 25 km. The system requires various state-of-the-art technologies including phased arrays, monopulse tracking, pulse compression, high power transmitters, low noise receivers, and pulse integration signal processing techniques.
Chang, Kai; Pollock, Michael A.; Skrehot, Michael K.; Arndt, G. Dickey; Suddath, Jerry
A 35 GHz millimeter-wave radarsystem has been studied for space debris tracking. The objective is to track the particles ranging in size from 4 mm to 80 mm up to a range of 25 km. The system requires various state-of-the-art technologies including phased arrays, monopulse tracking, pulse compression, high power transmitters, low noise receivers, and pulse integration signal processing
Kai Chang; Michael A. Pollock; Michael K. Skrehot; G. Dickey Arndt; Jerry Suddath
This paper presents the design of one real-time imaging system in airborne C-band Synthetic Aperture Radar. The real-time imaging algorithm based on subaperture-division is described in detail. In order to meet real-time signal processing the signal processing board with 8 ADSP-TS201S digital signal processors and 2GB SDRAM is designed. This system has excellent real-time processing ability and tremendous data throughput
This dissertation deals with the possibility of utilizing mid-infrared semiconductor lasers in systems of optical remote sensing with range resolution, called laser radar or lidar. The main subject investigated in this dissertation is two-fold: firstly, an analysis of the signal-to-noise ratio (SNR) and related maximum sensing range calculations in this type of lidar based on available system components, and---secondly---improvements in
The Santa Barbara Research Center has developed a variety of high speed HgCdTe photodetectors for use in CO2 laser radarsystems. These detectors have outstanding performance and can be made available in production quantities. Many of them have been employed in a variety of systems applications over the past ten years. In this paper, we briefly describe the detector technology, summarize the state-of-the-art, and indicate some practical applications.
Host plus multiple array processor architecture is demonstrated to yield a modular, fast, and cost-effective system for radar processing. Software methodology for programming such a system is developed. Parallel processing with pipelined data flow among the host, array processors, and discs is implemented. Theoretical analysis of performance is made and experimentally verified. The broad class of problems to which the architecture and methodology can be applied is indicated.
In a widely separated multiple-input multiple-out (MIMO) radarsystem with non-coherent receivers, the maximum likelihood estimator (MLE) of target location and the corresponding CRLB matrix are derived. Further, two interactive signal processing and tracking algorithms are developed based on the Kalman filter and the particle filter respectively. For a system with a small number of elements and a low SNR
Ruixin Niu; Rick S. Blum; Pramod K. Varshney; Andrew L. Drozd
Success is reported in the radar monitoring of such features of sea ice as concentration, floe size, leads and other water openings, drift, topographic features such as pressure ridges and hummocks, fractures, and a qualitative indication of age and thickness. Scatterometer measurements made north of Alaska show a good correlation with a scattering coefficient with apparent thickness as deduced from ice type analysis of stereo aerial photography. Indications are that frequencies from 9 GHz upward seem to be better for sea ice radar purposes than the information gathered at 0.4 GHz by a scatterometer. Some information indicates that 1 GHz is useful, but not as useful as higher frequencies. Either form of like-polarization can be used and it appears that cross-polarization may be more useful for thickness measurement. Resolution requirements have not been fully established, but most of the systems in use have had poorer resolution than 20 meters. The radar return from sea ice is found to be much different than that from lake ice. Methods to decrease side lobe levels of the Fresnel zone-plate processor and to decrease the memory requirements of a synthetic radar processor are discussed.
Moore, R. K.; Claassen, J. P.; Erickson, R. L.; Fong, R. K. T.; Hanson, B. C.; Komen, M. J.; Mcmillan, S. B.; Parashar, S. K.
An efficient microprocessor-based system is described that permits real-time acquisition, stacking, and digital recording of data generated by a borehole radarsystem. 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.
The design and operation of a switched phase modulation system for the Urbana RadarSystem are discussed. The system is implemented and demonstrated using a simple procedure. The radarsystem and circuits are described and analyzed.
The design and operation of a switched phase modulation system for the Urbana RadarSystem are discussed. The system is implemented and demonstrated using a simple procedure. The radarsystem and circuits are described and analyzed.
The MU (middle and upper atmosphere) radar of Japan, a 46.5 MHz pulse-modulated monostatic Doppler radar with an active phased array system, is described. The system's nominal beam width is 3.6 deg, and the peak radiation power is 1 MW with maximum average power of 50 kW. The system is composed of 475 crossed three-subelement Yagi antennas and an equivalent
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
This paper describes several alternative techniques for detecting and localizing slowly-moving targets in cultural clutter using synthetic aperture radar (SAR) data. Here, single-pass data is jointly processed from two or more receive channels which are spatially offset in the along-track direction. We concentrate on two clutter cancelation methods known as the displaced phase center antenna (DPCA) technique and along-track SAR
A limited comparison test was conducted to determine the improvement in surveillance capability between an existing Harbor Advisory Radar (HAR) and a prototype AN/FPS-109(XN-1) radar designed specifically for harbor surveillance. The FPS-109 radar is clea...
The basic operating principles, design, and applications of radars are discussed in an introductory text intended for first-year graduate students. Topics addressed include radar measurements, radar target cross sections, radar detection, ground effects, matched filters, ambiguity functions, coded radar signals, and radar measurement accuracy. Consideration is given to processing coherent pulse trains, moving-target indicators, CFAR, SAR, and monopulse antenna tracking.
The coherent radar technique is reviewed with special emphasis to mesosphere-stratosphere-troposphere (MST) radars operating in the VHF band. Some basic introduction to Doppler radar measurements and the radar equation is followed by an outline of the characteristics of atmospheric turbulence, viewed from the scattering and reflection processes of radar signals. Radar signal acquisition and preprocessing, namely coherent detection, digital sampling, pre-integration and coding, is briefly discussed. The data analysis is represented in terms of the correlation and spectrum analysis, yielding the essential parameters: power, signal-to-noise ratio, average and fluctuating velocity and persistency. The techniques to measure wind velocities, viz. the different modes of the Doppler method as well as the space antenna method are surveyed and the feasibilities of the MST radar interferometer technique are elucidated. A general view on the criteria to design phased array antennas is given. An outline of the hardware of a typical MST radarsystem is presented.
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.
Work performed on spectral analysis of data from the C-band radars tracking GEOS-2 and on the development of a data compaction method for the GEOS-2 C-band radar data is described. The purposes of the spectral analysis study were to determine the optimum data recording and sampling rates for C-band radar data and to determine the optimum method of filtering and smoothing the data. The optimum data recording and sampling rate is defined as the rate which includes an optimum compromise between serial correlation and the effects of frequency folding. The goal in development of a data compaction method was to reduce to a minimum the amount of data stored, while maintaining all of the statistical information content of the non-compacted data. A digital computer program for computing estimates of the power spectral density function of sampled data was used to perform the spectral analysis study.
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.
This study has as its objective the improvement of the protection provided by the military services to military personnel and members of the general public from the hazards of electromagnetic radiation (EMR) of military communications and radarsystems. T...
A new high-performance FMCW sensor system concept is presented. The approach is based on an adaptive signal processing scheme compensating phase errors caused by VCO phase noise as well as the non-linearity of the frequency modulation. The key component of the low-cost sensor is a SAW (surface acoustic wave) delay line representing a miniaturised high-precision radar reference path. A correction
The generation and recording of electromagnetic waves by ground-penetrating radar (GPR) systems are complex phenomena. To investigate the characteristics of typical surface GPR antennas operating in realistic environments, we have developed an antenna simulation tool based on a finite-difference time-domain (FDTD) approximation of Maxwell's equations in 3-D Cartesian coordinates. The accuracy of the algorithm is validated with respect to laboratory
K. Holliger; B. Lampe; U. Meier; M. Lambert; A. G. Green
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 radarsystem. Many signal processing algorithms are required high performance in real-time applications but it often means a high computational
A two-stage algorithm for landmine detection with a ground penetrating radar (GPR) system is described. First, 3-D data sets are processed using a computationally inexpensive pre-screening algorithm which flags potential locations of interest. These flagged locations are then passed to a feature-based processor which further discriminates target-like anomalies from naturally occurring clutter. Current field trial (over 6500 square meters) and
Peter A. Torrione; Chandra S. Throckmorton; Leslie M. Collins
In marine navigation systems, the three-dimensional (3D) visualization is often and often used. Echosonders and sonars working in hydroacustic systems can present pictures in three dimensions. Currently, vector maps also offer 3D presentation. This presentation is used in aviation and underwater navigation. In the nearest future three-dimensional presentation may be obligatory presentation in displays of navigation systems. A part of these systems work with radar and communicates with it transmitting data in a digital form. 3D presentation of radar picture require a new technology to develop. In the first step it is necessary to compile digital form of radar signal. The modern navigation radar do not present data in three-dimensional form. Progress in technology of digital signal processing make it possible to create multidimensional radar pictures. For instance, the RSC (Radar Scan Converter) - digital radar picture recording and transforming tool can be used to create new picture online. Using RSC and techniques of modern computer graphics multidimensional radar pictures can be generated. The radar pictures mentioned should be readable for ECDIS. The paper presents a method for generating multidimensional radar picture from original signal coming from radar receiver.
Accurate system simulations have proven to be a valuable aid during the development process and help to decrease the time-to-market and the amount of design iterations, thus keeping development costs at a moderate level. Therefore a frequency-modulated continuous-wave (FMCW) radarsystem simulation environment has been built up, enabling for performance analysis of millimeter-wave radar frontends for automotive applications. A key
M. Dudek; I. Nasr; D. Kissinger; R. Weigel; G. Fischer
Configuration comparisons and systems evaluation for the orbital radar mapping mission of the planet Venus are discussed. Designs are recommended which best satisfy the science objectives of the Venus radar mapping concept. Attention is given to the interaction and integration of those specific mission-systems recommendations with one another, and the final proposed designs are presented. The feasibility, cost, and scheduling of these configurations are evaluated against assumptions of reasonable state-of-the-art growth and space funding expectations.
We describe an experimental, model-based automatic target recognition (ATR) system, called XTRS, for recognizing tactical vehicles in real or synthetic laser-radar (LADAR) range and intensity images corresponding to a forwardlooking, CO2 laser radar (LADAR) that is carried either on a ground vehicle or on an airborne platform. Various aspects of the system's operation are illustrated through a variety of examples.
An antenna is described for range-gated, pulse doppler, radarsystems. 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...
Instrumentation radar has played a very significant role in testing and training for more than 50 years. Along with optics, it has been a major supplier of time space position information (TSPI). With the advent of the Global Positioning System (GPS), the...
The Jimsphere/Jimsonde system is described and some possible applications of the system for air-sea interface measurements are presented. As space vehicles became larger and more sophisticated, an improved method for obtaining wind profile data had to be found. To satisfy this need the FPS-16 radar/Jimsphere system was developed. The Jimsphere is an aluminized mylar spherical balloon, two meters in diameter. The balloon is under superpressure, and is tracked with a high precision radarsystem. The development of this detailed wind profile system was started in 1963, and the present design was established in 1964. To improve the system, a program was initiated in 1965 to obtain high resolution temperature data simultaneously with the wind profile data.
The NASA ER-2 high-altitude (20 km) aircraft that emulates a satellite view of precipitation systems carries a variety of passive and active (lidar) remote sensing instruments. A new Doppler weather radarsystem at X band (9.6 GHz) called the ER-2 Doppler radar (EDOP) has been developed and flown on the ER-2 aircraft. EDOP is a fully coherent Doppler weather radar with fixed nadir and forward pointing (33?? off nadir) beams that map out Doppler winds and reflectivities in the vertical plane along the aircraft motion vector. Doppler winds from the two beams can be used to derive vertical and along-track air motions. In addition, the forward beam provides linear depolarization measurements that are useful in discriminating microphysical characteristics of the precipitation. This paper deals with a general description of the EDOP instrument including the measurement concept, the system configuration and hardware, and recently obtained data examples from the instrument. The combined remote sensing package on the ER-2, along with EDOP, provides a unique platform for simulating spaceborne remote sensing of precipitation.
Heymsfield, G. M.; Bidwell, S. W.; Caylor, I. J.; Ameen, S.; Nicholson, S.; Boncyk, W.; Miller, L.; Vandemark, D.; Racette, P. E.; Dod, L. R.
Houston is facing flood problems of a serious nature. Until more permanent solutions are found accurate and timely, early warning flood systems are vitally needed to provide the early warnings that public and private entities are demanding. The current Rice University/TMC Flood Alert System (FAS2) began to utilize higher-resolutioned Level II NEXRAD radar data (1 x 1 km) that is calibrated against local rain gauges by the end of 2004, with the real-time hydrologic model (RTHEC-1) to provide important data for predicting flood levels along Brays Bayou. The finer resolution of Level II radar rainfall data provides significantly greater details with respect to the spatial variability of rainfall. FAS2 has been tested for more than 30 events including three recent events in 2006 season with excellent performance. It has been found from 2006 season that the average difference in peak flows is 8.76%; the average difference in terms of volumes is 13.70%. The floodplain map library (FPML) as a new hydraulic prediction tool has been developed based on the radar- based FAS2 and is being integrated into FAS2 to provide inundations maps in near real time. The development of FPML includes three stages: designing rainfall based on historical rainfall data over the watershed, delineating 99 maps based on design rainfalls, and designing algorithm to link real-time NEXRAD radar rainfall to appropriate maps. The enhance system can be a prototype for other flood-prone areas along the Gulf coast, and will improve emergency personnel's ability to initiate evacuation strategies at many levels.
We present studies of meteor head echo statistics at UHF frequencies using the megawatt-class Millstone Hill incoherent scatter radar facility during the November 1999 and November 2000 Leonid meteor shower periods. The majority of meteoroid particles observed have approximate radar cross-sections of 10-5 - 10-4m2 and masses in the 70 mg range. Diurnal count rates show expected sporadic meteor peaks at local dawn and minimum at local dusk during both shower periods. However, the lack of a significant increase in counts during periods when the Leonid radiant is visible implies that Leonid showers do not possess significant enhancement in milligram-class meteoroid particles. Altitude distributions from November 2000 show significant unusual enhancements in count rates at 118 km in addition to normal 105-110 km altitude peaks. We also describe upcoming enhancements to the Millstone Hill system which will allow improved statistics as well as advanced trajectory determinations.
Erickson, Philip J.; Lind, Frank D.; Wendelken, Suzanne M.; Faubert, Melissa A.
A data processing system for use with continuous-wave lidar is described in terms of its configuration and performance during the second survey mission of NASA'a Global Backscatter Experiment. The system is designed to estimate a complete lidar spectrum in real time, record the data from two lidars, and monitor variables related to the lidar operating environment. The PC-based system includes a transient capture board, a digital-signal processing (DSP) board, and a low-speed data-acquisition board. Both unprocessed and processed lidar spectrum data are monitored in real time, and the results are compared to those of a previous non-DSP-based system. Because the DSP-based system is digital it is slower than the surface-acoustic-wave signal processor and collects 2500 spectra/s. However, the DSP-based system provides complete data sets at two wavelengths from the continuous-wave lidars.
Hampton, Diana M.; Jones, William D.; Rothermel, Jeffry
Measurements of aircraft longitude, latitude, and velocity, and measurements of atmospheric pressure, temperature, and horizontal wind from the meteorological measurement system (MMS) on board the NASA ER-2 aircraft were compared with independent measurements of these quantities from radiosondes and radar tracking of both the ER-2 and radiosonde balloons. In general, the comparisons were good and within the expected measurement accuracy and natural variability of the meteorological parameters. Radar tracking of the ER-2 resolved the velocity and position drift of the inertial navigation system (INS). The rms errors in the horizontal velocity components of the ER-2, due to INS errors, were found to be 0.5 m/s. The magnitude of the drift in longitude and latitude depends on the sign and magnitude of the corresponding component velocity drift and can be a few hundredths of a degree. The radar altitudes of the ER-2 and radiosondes were used as the basis for comparing measurements of atmospheric pressure, temperature, and horizontal wind from these two platforms. The uncertainty in the MMS horizontal wind measurement is estimated to be +/- 2.5 m/s. The accuracy of the MMS pressure and temperature measurements were inferred to be +/- 0.3 hPa and +/- 0.3 K.
Gaines, Steven E.; Bowen, Stuart W.; Hipskind, R. S.; Bui, T. P.; Chan, K. R.
Polarimetric radars are now widely used for characterizing storm systems since they offer significant information for the improvement for atmospheric models and numerical weather prediction. Their observations allow a detailed insight into macro- and micro-physical processes during the spatial and temporal evolution of storm systems. In the frame of the initiative for High Definition Clouds and Precipitation for advancing Climate Prediction (HD(CP)2), which focuses on improving the accuracy of climate models in relation to cloud and precipitation processes, the HD(CP)2 Observational Prototype Experiment (HOPE) was designed to provide a critical model evaluation at scales covered by Large Eddy Simulation (LES) models, which in turn will be used to better understand sub-grid variability and microphysical properties and processes parameterized by larger scale models. Three X-band polarimetric radars deployed in Bonn (BoXPol) and in the vicinity of Juelich (JuXPol and KiXPol), Germany, were operated together with other instruments during the HOPE campaign, in order to obtain a holistic view of precipitation systems covering both macro- and microscopic processes. Given the variability of polarimetric moments observed by polarimetric radars, the corresponding microphysical processes occurring during the development of storm cells thus can be inferred accordingly. This study focuses on the microscopic processes of storm systems which were observed by RHI (range-height indicator) scans of the three X band radars. The two frequently observed microphysical processes during the HOPE campaign, coalescence and differential sedimentation, will be shown, and the evolution of droplet size distributions (DSDs) will be also analyzed. The associated DSDs which are retrieved using radar measured polarimetric moments are further verified by the polarimetric forward operator where the assumptions of non-spherical hydrometeors have been embedded. The results indicate that the estimated DSDs from the tested retrieval algorithms are in consistency with the identified microphysical processes although discrepancies still exist. Together with the analysis from the macroscopic perspective which quantifies macroscopic structures of storm cells like height, intensity and temporal change of brightband, a holistic view of the development of storm systems will be provided.
Xie, Xinxin; Evaristo, Raquel; Troemel, Silke; Simmer, Clemens
We address the problem of locating users inside buildings using a radio-frequency (RF) wireless LAN. A previous paper presented the basic design and a limited evaluation of a user-location system we have developed. In this paper, we analyze shortcomings of the basic system, and develop and evaluate solutions to address these shortcomings. Additionally, we describe several new enhancements, including a
An operator-microprocessor interactive Operating System has been developed for the Time Domain Radar Laboratory (TDRL). The Operating System performs signal acquisition and averaging, real time and frequency domain computations and provides outputs in easily evaluated graphic displays. Target classification is made by analysis of either impulse, step or ramp responses. A noise-reduction signal optimization technique is implemented. Numerous measurements of known and unknown targets are made using various antennas and results are compared to theory. Targets are classified. Antenna parameters are established. Algorithms using the specialized features of the host Graphic System are tailored to the requirements of the TDRL for a detailed graphic presentation of processed data.
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.
The Ku-band test equipment, known as the Deliverable System Test equipment (DSTE), is reviewed and evaluated. The DSTE is semiautomated and computer programs were generated for 14 communication mode tests and 17 radar mode tests. The 31 test modules provide a good cross section of tests with which to exercise the Ku-band system; however, it is very limited when being used to verify Ku-band system performance. More detailed test descriptions are needed, and a major area of concern is the DSTE sell-off procedure which is inadequate.
The listing and description of software routines which were used to analyze the analog data obtained from LIDAR - system are given. All routines are written in FORTRAN - IV on a HP - 1000/F minicomputer which serves as the heart of the data acquisition system for the LIDAR program. This particular system has 128 kilobytes of highspeed memory and is equipped with a Vector Instruction Set (VIS) firmware package, which is used in all the routines, to handle quick execution of different long loops. The system handles floating point arithmetic in hardware in order to enhance the speed of execution. This computer is a 2177 C/F series version of HP - 1000 RTE-IVB data acquisition computer system which is designed for real time data capture/analysis and disk/tape mass storage environment.
Laser radarsystems are required for various military applications including obstacle detection, target recognition, and terrain mapping. Each application requires different system parameters such as pulse energy, repetition rate, and field of view. This paper is the second in a series of papers describing the progress toward a multifunction laser radarsystem under construction for the Cooperative Eyesafe Laser Radar Program (CELRAP) of the U.S. Army CECOM Night Vision and Electronic Sensors Directorate.
Hutchinson, James A.; Trussell, Charlie W.; Allik, Toomas H.; Hamlin, Scott J.; McCarthy, John C.; Jack, Michael D.
The successful implementation of a linear frequency modulated continuous wave (FMCW) radar transmitter is presented, consisting of a 77-GHz voltage controlled oscillator (VCO) and a 19-GHz down-converter manufactured in a 200-GHz silicon germanium (SiGe) technology. The influence of phase noise and frequency sweep linearity on the radarsystem performance is briefly described, and measurement results of these parameters are compared
In this contribution a versatile system simulation environment for radar sensors being developed to operate in the automotive area is introduced. It combines a frontend simulation engine that is coupled in a co-simulation with a 3D ray-tracing tool to take the effects of the automotive radar channel into account, thus providing accurate and reliable results concerning the behavior of the
Manuel Dudek; Dietmar Kissinger; Robert Weigel; Georg Fischer
A frequency-agile C band DeltaK radarsystem was used to measure ocean surface currents during the SAXON-Chesapeake Light Tower experiment. Surface currents were measured with the radar approximately 80% of the time from September 20 to October 14, 1988. In this paper these measurements are compared with in situ current and wind probe measurements. We find the agreement between the
Laser radar based on gated viewing uses narrow laser pulses to illuminate a whole scene for direct (incoherent) detection. Due to the time of flight principle and a very fast shutter with precisely controlled delay time, only light reflected in the range R (range slice ?R) is detected by a camera. Scattered light which reaches the shutter outside a given exposure time (gate) is suppressed. Hence, it is possible to "look" along the optical axis through changing atmospheric transmissions (rain, haze, fog, snow). For each laser pulse, the grey value image ES(x,y) of the camera is captured by a framegrabber for subsequent evaluation. Image sequences from these laser radarsystems are ideally suited to recognize objects, because of the automatic contrast generation of the technology. Difficult object recognition problems, detection, target tracking, or obstacle avoidance at bad weather conditions are favorite applications. In this paper we discuss improvements in the system modelling and simulation of our laser radarsystem. Formerly the system performance was calculated for the whole system using the signal-to-noise ratio (SNR), leading to a general estimation of the maximum range of target detection. Changing to a pixel oriented approach, we are now able to study the system response for targets with arbitrary two and even three dimensional form. We take into account different kinds of target reflectivity and the Gaussian nature of the illuminating laser spot. Hence it is possible to simulate gray value images (range slices) and calculate range images. This will lead to a modulation transfer function for the system in future. Finally, the theoretical considerations are compared with experimental results from indoor measurements.
The history of perimeter protection is based on building fences. That basic concept evolved into detecting activity along fences using a variety of sensors. Today a wide variety of fiber and wire-based sensors are available to mount on a fence, and many different types of IR, radar, optical, seismic and acoustic sensors to place along the fence line. Generally some camera support is provided, with the cameras programmed to point to pre-set locations along the fence. A more robust perimeter protection would consist of wide area sensors with the capability to look out beyond the fence to detect potential intrusion and track intruders. In looking beyond the perimeter, wide area sensors can provide precious time to plan and initiate the appropriate response. In addition, because they sweep a 360-degree circle, the sensors can provide continued tracking of the intrusion, greatly enhancing the effectiveness and safety of the response team. The new wide-area concept consists of using modern radar technology for wide area detection of objects which are moving, and then using the precise location information from the radar to point a camera for assessment. Without having to continually stare at a bank of video monitors, the operator is presented with the location, direction of travel and identification and number of potential intruders, all in a matter of seconds. This paper presents the features of this new wide area system, followed by an overview of radar technology. It closes with a discussion on the benefits of the FMCW topology over Pulse Doppler in security and surveillance applications.
During the last 10 years, CNES has taken a great interest in radar imagery. The development of VARAN airborne SAR and the implementation of a complete tool (aircraft + ground processing means) devoted to thematic and technological SAR campaigns, were important milestones of this effort. Taking advantage of this SAR know-how and of the SPOT actual experience, CNES is now moving on toward introducing a radar imaging system to be operated in parallel with the optical SPOT family around the 2000s. The studies are still in preliminary phase (B phase to be started in 1992) but the goals are: (1) to begin a microwave subfamily within the SPOT family, the first satellite being already operated on commercial basis. This is a reasonable challenge since SPOT background will be reused (s/c bus, receiving stations network, commercial facilities, etc.). Therefore, efforts can focus on specific radar aspects such as the study and the development of an advanced X-band SAR payload and the validation of valuable applications. (2) To take advantage of the active antenna concept which allows the design of a highly versatile and efficient SAR sensor with many imaging modes. The resolution may range from 2 to 50 m while the instantaneously steerable swath may range from 20 to 200 km. (3) To select applications according to their economical potential and thematic maturity. This includes complementation of optical imagery in cloud covered areas (cartography) as well as specific radar applications in the large field of renewable resources (agriculture, water, forests) and sensitive surveillance applications (catastrophe, media, public works, etc.).
The European Defence Agency (EDA) engages countermeasures against Improvised Explosive Devices (IEDs) by funding several scientific programs on threat awareness, countermeasures IEDs or land-mine detection, in which this work is only one of numerous projects. The program, denoted as Surveillance in an urban environment using mobile sensors (SUM), covers the idea of equipping one or more vehicles of a patrol or a convoy with a set of sensors exploiting different physical principles in order to gain detailed insights of the road situation ahead. In order to give an added value to a conventional visual camera system, measurement data from an infra-red (IR) camera, a radiometer and a millimetre-wave radar are fused with data from an optical image and are displayed on a human-machine-interface (HMI) which shall assist the vehicle's co-driver to identify suspect objects or persons on or next to the road without forcing the vehicle to stop its cruise. This paper shall especially cover the role of the millimetre-wave radar sensor and its different operational modes. Measurement results are discussed. It is possible to alter the antenna mechanically which gives two choices for a field of view and angular resolution trade-off. Furthermore a synthetic aperture radar mode is possible and has been tested successfully. MIMO radar principles like orthogonal signal design were exploited tofrom a virtual array by 4 transmitters and 4 receivers. In joint evaluation, it was possible to detect e.g. grenade shells under cardboard boxes or covered metal barrels which were invisible for optical or infra-red detection.
Kirschner, A. J.; Guetlein, J.; Bertl, S.; Detlefsen, J.
Accurate measurement of flow in the San Joaquin River at Vernalis, California, is vital to a wide range of Federal and State agencies, environmental interests, and water contractors. The U.S. Geological Survey uses a conventional stage-discharge rating technique to determine flows at Vernalis. Since the flood of January 1997, the channel has scoured and filled as much as 20 feet in some sections near the measurement site resulting in an unstable stage-discharge rating. In response to recent advances in measurement techniques and the need for more accurate measurement methods, the Geological Survey has undertaken a technology demonstration project to develop and deploy a radar-based streamflow measuring system on the bank of the San Joaquin River at Vernalis, California. The proposed flow-measurement system consists of a ground-penetrating radarsystem for mapping channel geometries, a microwave radarsystem for measuring surface velocities, and other necessary infrastructure. Cross-section information derived from ground penetrating radar provided depths similar to those measured by other instruments during the study. Likewise, surface-velocity patterns and magnitudes measured by the pulsed Doppler radarsystem are consistent with near surface current measurements derived from acoustic velocity instruments. Since the ratio of surface velocity to mean velocity falls to within a small range of theoretical value, using surface velocity as an index velocity to compute river discharge is feasable. Ultimately, the non-contact radarsystem may be used to make continuous, near-real-time flow measurements during high and medium flows. This report documents the data collected between April 14, 2002 and May 17, 2002 for the purposes of testing this radar based system. Further analyses of the data collected during this field effort will lead to further development and improvement of the system.
Cheng, Ralph T.; Gartner, Jeffrey W.; Mason, Robert R., Jr.; Costa, John E.; Plant, William J.; Spicer, Kurt R.; Haeni, F. Peter; Melcher, Nick B.; Keller, William C.; Hayes, Ken
A short historical review is given of the development of ultrasonics. Uses in the low-amplitude range are sonar systems, dispersive and nondispersive delay lines, ultrasonic inspectoscopes, and crystal and mechanical filters. In all of these applications, the very low internal friction of metals and fused silica provides very low losses, while the guided wave properties of various shaped transmission paths
In the South-Eastern part of the North Sea, known as the German Bight, the Helmholz-Zentrum Geesthacht (HZG, former GKSS Research Center) is currently realizing the experimental observation Network COSYNA for: Coastal Observing System for Northern and Arctic Seas. The observation area underlies extensive industrial use like oil and gas production, wind farming, transportation of all kind of goods, fishery, tourism
Jorg Seemann; Friedwart Ziemer; Marius Cysewski; Stylianos Flampouris; Klaus-Werner Gurgel; Thomas Schlick
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.
In May 1978, when the U.S. Air Force requested the National Research Council to assess certain aspects of its newest missile defense warning system then under construction at the Otis Air Force Base on Cape Cod, Massachusetts, the facility was the subject...
From August 2003 to December 2006, In-Service Evaluations (ISE) of the Turbulence Auto-PIREP System (TAPS) and Enhanced Turbulence (E-Turb) Radar, technologies developed in NASA's Turbulence Prediction and Warning System (TPAWS) element of its Aviation Safety and Security Program (AvSSP), were conducted. NASA and AeroTech Research established an industry team comprising AeroTech, Delta Air Lines, Rockwell Collins, and ARINC to conduct the ISEs. The technologies were installed on Delta aircraft and their effectiveness was evaluated in day-to-day operations. This report documents the establishment and conduct of the ISEs and presents results and feedback from various users.
Prince, Jason B.; Buck, Bill K.; Robinson, Paul A.; Ryan, Tim
This paper describes a digital processing algorithm and its associated system design for producing images from Synthetic Aperture Radar (SAR) data. The proposed system uses the Fast Fourier Transform (FFT) approach to perform the two-dimensional correlation process. The range migration problem, which is often a major obstacle to efficient processing, can be alleviated by approximating the locus of echoes from a point target by several linear segments. SAR data corresponding to each segment is correlated separately, and the results are coherently summed to produce full-resolution images. This processing approach exhibits greatly improved computation efficiency relative to conventional digital processing methods.
A highly successful Earth orbiting synthetic antenna aperture radar (SAR) system, known as the SIR-C mission, was carried into orbit in 1994 on a U.S. Shuttle (Space Transportation System) mission. The radarsystem was mounted in the cargo bay with no need to fold, or in any other way reduce the size of the antennas for launch. Weight and size were not limited for the L-Band, C-Band, and X-Band radarsystems of the SIR-C radar imaging mission; the set of antennas weighed 10,500 kg, the L-Band antenna having the major share of the weight. This paper treats designing an L-Band antenna functionally similar to that used for SIR-C, but at a fraction of the cost and at a weight in the order of 250 kg. Further, the antenna must be folded to fit into the small payload shroud of low cost booster rocket systems. Over 31 square meters of antenna area is required. This low weight, foldable, electronic scanning antenna is for the proposed LightSAR radarsystem which is to be placed in Earth orbit on a small, dedicated space craft at the lowest possible cost for an efficient L- Band radar imaging system. This LightSAR spacecraft radar is to be continuously available for at least five operational years, and have the ability to map or repeat-map any area on earth within a few days of any request. A microstrip patch array, with microstrip transmission lines heavily employed in the aperture and in the corporate feed network, was chosen as the low cost approach for this active dual-polarization, 80 MHz (6.4%) bandwidth antenna design.
A highly successful Earth orbiting synthetic antenna aperture radar (SAR) system, known as the SIR-C mission, was carried into orbit in 1994 on a U.S. Shuttle (Space Transportation System) mission. The radarsystem was mounted in the cargo bay with no need to fold, or in any other way reduce the size of the antennas for launch. Weight and size were not limited for the L-Band, C-Band, and X-Band radarsystems of the SIR-C radar imaging mission; the set of antennas weighed 10,500 kg, the L-Band antenna having the major share of the weight. This paper treats designing an L-Band antenna functionally similar to that used for SIR-C, but at a fraction of the cost and at a weight in the order of 250 kg. Further, the antenna must be folded to fit into the small payload shroud of low cost booster rocket systems. Over 31 square meters of antenna area is required. This low weight, foldable, electronic scanning antenna is for the proposed LightSAR radarsystem which is to be placed in Earth orbit on a small, dedicated space craft at the lowest possible cost for an efficient L-Band radar imaging system. This LightSAR spacecraft radar is to be continuously available for at least five operational years, and have the ability to map or repeat-map any area on earth within a few days of any request. A microstrip patch array, with microstrip transmission lines heavily employed in the aperture and in the corporate feed network, was chosen as the low cost approach for this active dual-polarization, 80 MHz (6.4%) bandwidth antenna design.
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.
Ground penetrating radars (GPR's) have been often applied to underground object imaging. However, conventional radarsystems do not work sufficiently to detect anti-personnel plastic landmines. We propose a novel radar imaging system, which processes adaptively interferometric front-end data obtained at multiple-frequency points. The system deals with interferometric images using complex-valued self-organizing map (C-SOM). We demonstrate a successful visualization of a plastic mine buried near the ground surface. PMID:15555861
This paper describes a perspective of military radar development. The foreseen configuration of radarsystems in the first part of the 21 st century is proposed. The avenues of radar evolution and the expected occurrence of technological breakthrough are discussed
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)
The basic operating principles, design, and applications of radars are discussed in an introductory text intended for first-year graduate students. Topics addressed include radar measurements, radar target cross sections, radar detection, ground effects, matched filters, ambiguity functions, coded radar signals, and radar measurement accuracy. Consideration is given to processing coherent pulse trains, moving-target indicators, CFAR, SAR, and monopulse antenna tracking. Extensive diagrams and graphs are provided.
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, radarsystems 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, radarsystems have
This dissertation discusses integration architectures using digital terrain elevation data (DTED) with an inertial navigation system (INS), a global positioning system (GPS) and a radar altimeter. Two integration architectures are considered: DTED with INS, GPS and radar altimeter for aircraft vertical accuracy improvement during the final approach; and DTED with kinematic GPS (KGPS) and a radar altimeter for enhanced aircraft
The Ibiza Channel located between the East Coast of the Iberian Peninsula, and the West Coast of Ibiza, at the Balearic Islands, is a well-known biodiversity hot spot. This area is relevant due to the interaction of water masses coming from the Atlantic Ocean - ascending through the Iberian Peninsula coast - with the older Atlantic waters descending from the Gulf of Lion. In 2012, the installation of Coastal HF Radar in the area provides valuable information for the study of the surface transport along the channel. The Coastal HF Radar operates since June 2012, and provides hourly surface current maps with a spatial resolution of approximately 3 km and a range reaching up to 70 km offshore. The instrument forms part of a monitoring multi-platform system, which is completed with satellite-derived data, gliders, modelling and fixed and lagrangian buoys. All HF Radar data are processed with standard quality control methods. Drifter velocity obtained from lagrangian buoys for two oceanographic campaigns, satellite-derived data and currentmeter data from a fixed buoy in the Ibiza Channel are used to validate the HF Radar data. All surface current data are used to perform a spectrum analysis in order to show the physical processes, at the main temporal periods. The contribution of the different temporal scales to the total Kinetic Energy has been analysed for the first time at different seasonal intervals. This served to evaluate the energetic importance of the different components of the surface currents. The inertial currents have a lower contribution to the total KE during winter, compared with the summer period. Besides, the spatial distribution of the inertial component to the total KE varies seasonally, and according to the bathymetry of the area. The low-pass (sub-inertial) filtered HF Radar currents show a predominant northern current during the summer months in the channel, and a mean southern current during the winter period. These results are discussed and related with the external forcing, and bathymetry distribution, according to coastal or open ocean data.
The MU (middle and upper atmosphere) radar of Japan, a 46.5 MHz pulse-modulated monostatic Doppler radar with an active phased array system, is described. The system's nominal beam width is 3.6 deg, and the peak radiation power is 1 MW with maximum average power of 50 kW. The system is composed of 475 crossed three-subelement Yagi antennas and an equivalent number of solid state power amplifiers. Each Yagi antenna is driven by a transmitter-receiver module with peak output power of 2.4 kW. This configuration enables very fast and almost continuous beam steering that has not been realized by other mesosphere-stratosphere-troposphere radars. The system's antenna and power amplifiers are described, as is the in-house equipment related to transmission reception, on-line data processing, and system control.
Fukao, S.; Sato, T.; Tsuda, T.; Kato, S.; Wakasugi, K.
The paper discusses an SAR problem based on actual requirements set forth by NASA for a spaceborne application. The requirements for high resolution and high quality necessitate a data sampling rate of 7.5 MHz. For each data value 1,025 4-bit complex multiply + add operations are needed, which is equivalent to 7.7 GHz complex multiply + add operation rate. Since this rate is much too high for general purpose systems, a special-purpose device was sought. This paper discusses two architectures based on parallel operation of 1,025 identical cells, each of which is capable of performing arithmetic, storage, and several control operations. The operation rate in each device is only 7.5 MHz, which is quite manageable, especially with the help of a substantial degree of pipelining. A computational-mathematical analysis is used as a primary tool for evaluating the design and some of its tradeoffs. Two different approaches are discussed and compared; both are based on having 1,025 identical cells working in parallel, but differ in their dual approaches to the flow of data.
The feasibility of using a wind power system on an aerostat (tethered baloon) was studied. The system would be used by the US Air Force North Warning Program to provide power for a radar carried on the aerostat. Upper atmosphere wind data for a potential site were collected and probability functions for wind speed and wind power density calculated. Information was collected on aerostats, tethers, telemetry transmitters, and auxiliary equipment. Important design considerations were identified and useful mathematical expressions, e.g., wind reliability, derived. A first-cut wind power system was designed and system performance and aerodynamic loads were calculated. The benefits and risks of a wind power system were enumerated. The study concluded that a wind system is feasible for this application.
Synthetic aperture radarsystems that use the polar format algorithm are subject to a focused scene size limit inherent to the polar format algorithm. The classic focused scene size limit is determined from the dominant residual range phase error term. Given the many sources of phase error in a synthetic aperture radar, a system designer is interested in how much phase error results from the assumptions made with the polar format algorithm. Autofocus algorithms have limits to the amount and type of phase error that can be corrected. Current methods correct only one or a few terms of the residual phase error. A system designer needs to be able to evaluate the contribution of the residual or uncorrected phase error terms to determine the new focused scene size limit. This paper describes a method to estimate the complete residual phase error, not just one or a few of the dominant residual terms. This method is demonstrated with polar format image formation, but is equally applicable to other image formation algorithms. A benefit for the system designer is that additional correction terms can be added or deleted from the analysis as necessary to evaluate the resulting effect upon image quality.
The design, development, and first observations of a high power meteor-radarsystem located near Urbana, Illinois are described. The roughly five-fold increase in usable echo rate compared to other facilities, along with automated digital data processing and interferometry measurement of echo arrival angles, permits unsurpassed observations of tidal structure and shorter period waves. Such observations are discussed. The technique of using echo decay rates to infer density and scale height and the method of inferring wind shear from radial acceleration are examined. An original experiment to test a theory of the Delta-region winter anomaly is presented.
This paper describes the implementation of digital radar range-rate filters on a microprocessor-based system. A range-rate filter processes a digitized noisy range signal to recover smoothed range data and its derivative, range rate. Two filter designs are implemented. Considerations aiding their efficient operation on an 8-bit microprocessor are discussed. The filters are subjected to a noisy range input signal of known variance, and the associated output signals are statistically analysed to determine noise-rejection characteristics. These results are compared to analytical predictions.
The report describes the calculation of the monostatic radar return from a target consisting of an assembly of discrete reflectors illuminated by a radar antenna. In order to keep the description of the scattering numerically manageable, it is assumed tha...
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)
We conducted a ground penetrating radar (GPR) survey of several fault traces from the Warm Springs Valley fault system in western Nevada. Several trenches have been excavated along the southern part of the fault system, in an ideal setting to experiment with GPR. Our survey was conducted with a pulseEKKO 100 GPR system, using a 1000v transmitter, at an antenna frequency of 200 MHz, with an antenna separation of 0.5 m and a step spacing of 0.1 m. With a wavelength of 0.5 m, this frequency of energy penetrated up to 6 m into the sediments we explored, with the potential to resolve the upper and lower surfaces of stratigraphic units that were 12.5 cm or thicker. We used a limited two-way travel time window of 150-200 ns, to allow imaging of our desired target depth with minimal unwanted reflections (recording instrument, truck, wire fences, etc.). We ran surveys immediately adjacent to two fault trenches (Trenches WSVFS T1 and WSVFS T3) to compare them with established trench logs, and additional surveys over other parts of the fault (WSVFS T2) with a 30 m setback to avoid the noise effects from trenches (trench walls, bottoms, fencing, etc.). The latter survey was run as a series of seven trench-parallel lines, with two perpendicular tie lines to evaluate profile-to-profile features. The results from the approximately 400 meters of radar data collected in this experiment are encouraging. Nearly all mapped faults had fault-type signatures on the radar profiles, and the general stratigraphic features of the upper 1 to 3 m of sediments were imaged fairly well. Major faults were easily recognized as offset reflections, abrupt lateral changes in amplitudes of reflections and overall unit characteristics, and offset groundwater barriers. Numerous secondary faults were also recognizably imaged, although they were more difficult to discern from natural variations in the sediments (textural and structural), and from noise inherent in the GPR method. Liquefied units were found to correspond to chaotic radar reflections. Further research will include experimentation with varying antenna frequencies and orientation, step spacing, and more closely spaced 3-D grid data collection.
The preliminary investigation of peat bog is facilitated by the use of radar. The continuous radar profiles make it possible to calculate the thickness of peat. An area of 240 ha has been investigated in less than 2 days by means of radar profiles 100 m a...
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.
A multistatic radarsystem 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.
Primary radarsystems in the United Kingdom that recently entered service or are at an advanced stage of development are presented. Naval, airborne, and land-based types and civil and military radars, especially airborne equipment, are discussed.
Primary radarsystems in the United Kingdom that recently entered service or are at an advanced stage of development are presented. Naval, airborne, and land-based types and civil and military radars, especially airborne equipment, are discussed.
A digital signal processing system was studied for the determination of the spectral frequency distribution of echo signals from a teleoperator radarsystem. The system consisted of a sample and hold circuit, an analog to digital converter, a digital filter, and a Fast Fourier Transform. The system is interfaced to a 16 bit microprocessor. The microprocessor is programmed to control the complete digital signal processing. The digital filtering and Fast Fourier Transform functions are implemented by a S2815 digital filter/utility peripheral chip and a S2814A Fast Fourier Transform chip. The S2815 initially simulates a low-pass Butterworth filter with later expansion to complete filter circuit (bandpass and highpass) synthesizing.
As part of our continental defense system, the United States Air Force has operated a radarsystem, known generally by the label PAVE PAWS, off of Cape Cod, MA since 1978. Some populated areas in the vicinity of the system are subject to a low level of background radiofrequency radiation from the system, and local citizens' groups have expressed concern that this radiofrequency radiation may affect their health. These concerns have been fueled by presentations and letters by Dr. R. A. Albanese, an applied mathematician at the Air Force Research Laboratory, who has proposed standards by which that PAVE PAWS radiofrequency radiation which is incident on populations should be judged. I discuss those standards that are sufficiently well defined to be subject to analysis and show that they are not based on sound quantitative reasoning. PMID:12492377
The results of a conceptual design study and the performance of key components of the Bread Board Model (BBM) of the Tropical Rainfall Measuring Mission (TRMM) radar are presented. The radar, which operates at 13.8 GHz and is designed to meet TRMM mission objectives, has a minimum measurable rain rate of 0.5 mm/h with a range resolution of 250 m, a horizontal resolution of about 4 km, and a swath width of 220 km. A 128-element active phased array system is adopted to achieve contiguous scanning within the swath. The basic characteristics of BBM were confirmed by experiments. The development of EM started with the cooperation of NASDA and CRL.
The results of a conceptual design study and the performance of key components of the Bread Board Model (BBM) of the Tropical Rainfall Measuring Mission (TRMM) radar are presented. The radar, which operates at 13.8 GHz and is designed to meet TRMM mission objectives, has a minimum measurable rain rate of 0.5 mm/h with a range resolution of 250 m, a horizontal resolution of about 4 km, and a swath width of 220 km. A 128-element active phased array system is adopted to achieve contiguous scanning within the swath. The basic characteristics of BBM were confirmed by experiments. The development of EM started with the cooperation of NASDA and CRL.
The U.S. Navy has been interested in applying neural network processing architectures to automatically determine the naval class of ships from an inverse synthetic aperture radar (ISAR) on-board an airborne surveillance platform. Currently an operator identifies the target based on an ISAR display. The emergence of the littoral warfare scenario, coupled with the addition of multiple sensors on the platform, threatens to impair the ability of the operator to identify and track targets in a timely manner. Thus, on-board automation is quickly becoming a necessity. Over the past four years the Opto-RadarSystem Group at MIT Lincoln Laboratory has developed and fielded a neural network based automatic ship classification (ASC) system for ISAR imagery. This system utilizes imagery from the APS-137 ISAR. Previous related work with ASC systems processed either simulated or real ISAR imagery under highly controlled conditions. The focus of this work was to develop a ship classification system capability of providing real-time identification from imagery acquired during an actual mission. The ship classification system described in this report uses both neural network and conventional processing techniques to determine the naval class of a ship from a range- Doppler (ISAR) image. The `learning' capability of the neural network classifier allows a single naval class to be distributed across many categories such that a degree of invariance to ship motion is developed. The ASC system was evaluated on 30 ship class database that had also been used for an operational readiness evaluation of ISAR crews. The results of the evaluation indicate that the ASC system has a performance level comparable to ISAR operators and typically provides a significant improvement in throughput.
The study of the Solar System allowed to discover the population of asteroids crossing the Earth orbit (NEA) and realized the problem named Asteroid Impact Hazard. The impacts from such bodies could cause local, regional or global catastrophes. The initial step in any prevention or mitigation scheme of impacts must involve a comprehensive NEA search and detailed analysis of their orbits. The most details about specific NEA were achieved by the radar technique used in USA with Goldstone (the group of S. Ostro) and Arecibo. There is another opportunity for such investigation with Evpatoria RT-70 planetary radar in Crimea of Ukraine. The RT- 70 has the 200 kW continuous power transmitter at 6-cm wavelength, which is used for radio location of planets usually, and twice the radio signals of Evpatoria were reflected from asteroids - 4179 Toutatis in 1992 and 1998 WT24 in 2001. The international program for research of the Solar system bodies with Evpatoria radar was started in 1999. The program envisages the development of VLBR method in order to broaden the capability of Evpatoria RT-70 to perform the radar measurements. The method combines the advantages of radar and very long baseline interferometry (VLBI) techniques, when the echo-signals are received with array of radio telescopes and recorded on VLBI terminals. The classic radar measurements provides the data on range and radial velocity and VLBI - on angle and angular rate. The use of differential VLBI technique for NEA trajectory determination (the echo-signals are received alternately with signals of close reference ICRF quasars) allows to obtain the coordinate precision more than 0.01". The combination of radar map and VLBI image can result the "radio holography" picture of NEA. The first trial VLBR experiments are described in this report.
Ground Penetrating Radar (GPR) systems are worth to be considered as in situ non invasive diagnostic tools capable of assessing stability and integrity of transport infrastructures. As a matter of fact, by exploiting the interactions among probing electromagnetic waves and hidden objects, they provide images of the inner status of the spatial region under test from which infer risk factors, such as deformations and oxidization of the reinforcement bars as well as water infiltrations, crack and air gaps. With respect to the assessment of concrete infrastructures integrity, the reconstruction capabilities of GPR systems have been widely investigated [1,2]. However, the demand for diagnostic tools capable of providing detailed and real time information motivates the design and the performance evaluation of novel technologies and data processing methodologies aimed not only to effectively detect hidden anomalies but also to estimate their geometrical features. In this framework, this communication aims at investigating the advantages offered by the joint use of two GPR systems both of them equipped with a specific tomographic imaging approach. The first considered system is a time domain GPR equipped with a 1.5GHz shielded antenna, which is suitable for quick and good resolution surveys of the shallower layers of the structure. As second system, the holographic radar Rascan-4/4000 [3,4] is taken into account, due to its capability of providing holograms of hidden targets from the amplitude of the interference signal arising between the backscattered field and a reference signal. The imaging capabilities of both the GPR tools are enhanced by means of model based data processing approaches, which afford the imaging as a linear inverse scattering problem. Mathematical details on the inversion strategies will be provided at the conference. The combined use of the above GPR systems allows to perform multi-resolution surveys of the region under test, whose aim is, first of all, to detect hidden anomalies and then to provide a high resolution image of their geometrical features. Therefore, reliable and efficient diagnostic surveys devoted to state the healthy state of a structure can be scheduled. Numerical examples and on field validations assessing the achievable reconstruction capabilities will be provided at the conference.  D. J. Daniels, Ground Penetrating Radar, in IEE Radar, Sonar and Navigation Series 15, London, U.K.: IEE, 2004.  M. Proto, M. Bavusi, R. Bernini et al., Transport Infrastructure Surveillance and Monitoring by Electromagnetic Sensing: The ISTIMES Project, Sensors, vol.10, n.12, pp.10620-10639, 2010.  S. Ivashov, I. A. Vasiliev, T. D. Bechtel, C. Snapp, Comparison between impulse and holographic subsurface radar for NDT of space vehicle structural materials, Progress In Electromagnetic Research, vol.3, pp.658-661, 2004.  I. Catapano. L. Crocco, A. F. Morabito, F. Soldovieri, Tomographic imaging of holographic GPR data for non-invasive structural assessment: the Musmeci Bridge investigation, submitted to Nondestructive Testing and Evaluation Acknowledgement The research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement no 225663.
Catapano, I.; Bavusi, M.; Loperte, A.; Crocco, L.; Soldovieri, F.
High energy laser systems with highly accurate measurements as target tracking sensors use a conical scan process to obtain a target capture and tracking within the narrow beamwidth. This searching process and the target tracking algorithm are major factors in the performance of the laser radar/target tracking system. Previous research results use information-theoretic concepts in establishing a laser radar/target tracking performance bound independent of the filtering algorithm. A computer program was developed to calculate the lower bound of the estimation error due to the non-linear Gaussian glint measurement process. Applying the Extended Kalman filter to the angle estimation problem for a Gaussian glint measurement process, the resulting filter is found to have a structure consisting of a series of demodulations with gains adaptively determined by the resulting angle estimate. The optimal performance of this estimation process is shown to be dependent on the angle and a bound on the performance as well as a numerical algorithm is presented.
The use of a scanning antenna beam for a synthetic aperture system was examined. When the resolution required was modest, the radar did not use all the time the beam was passing a given point on the ground to build a synthetic aperture, so time was available to scan the beam to other positions and build several images at different ranges. The scanning synthetic-aperture radar (SCANSAR) could achieve swathwidths of well over 100 km with modest antenna size. Design considerations for a SCANSAR for hydrologic parameter observation are presented. Because of the high sensitivity to soil moisture at angles of incidence near vertical, a 7 to 22 deg swath was considered for that application. For snow and ice monitoring, a 22 to 37 deg scan was used. Frequencies from X-band to L-band were used in the design studies, but the proposed system operated in C-band at 4.75 GHz. It achieved an azimuth resolution of about 50 meters at all angles, with a range resolution varying