Index termssynthetic aperture radar sar, ground mov ing target indication. But this implies that both doppler as well as range ambiguities occur. The performance of a ground moving target indicator gmti radar system. Theory of synthetic aperture radar imaging of a moving. Multipleinput multipleoutput mimo radar has been used for separating multipath returns in overthehorizon radar othr 3, 4 and ground moving target indicator gmti 5 67. Ground moving target indication gmti with synthetic.
Us9448304b2 ground moving target indicator gmti radar. Airborne groundmoving target indicator gmti is a radar mode that detects and. A principal radar metric to achieve this is the signaltonoise energy ratio snr in the gmti rangedoppler map. Radar mti may be specialized in terms of the type of clutter and environment. Here, there are 4 stripes corresponding to 4 transmitters.
A basic discussion of detection theory is given in an appendix of sandia report. Theory of synthetic aperture radar imaging of a moving target jen king jao, member, ieee abstract two novel image processing techniques have been developed to refocus a moving target image from its smeared response in the synthetic aperture radar sar image which is focused on the stationary ground. Optimum sargmti processing and its application to the. While other architectures are mentioned, we will focus on airborne pulsedoppler systems. In our simulations, we assume that the normalized power of the thermal noise is 1, the cnr is 30 db, and the snr is 30 db. It can be mathematically formulated by augmenting the conventional doppler. Synthetic aperture radar sar was originally designed as an airborne. The swerling 2 target model has the rcs exhibiting the same pdf as for the. We assume that the targets scattering objects are moving linearly, but we allow an arbitrary, known flight path for the antenna and allow it to transmit a sequence of.
Shengchou lin radar system design pulse doppler radar digital selection of digital approach for most modern pulsed doppler radar designs. A comprehensive analysis of the cost, reliability, and performance considerations for the complete techsat 21. Sar ground moving target indication based on relative. A principal performanceenabling, or performancelimiting, component of groundmoving targetindication gmti radar systems is the antenna. Ground moving target indicator gmti radar maps echo data to range and rangerate, which is a. We focus on the effect of doppler ambiguities on target tracking with airborne gmti radar.
Introduction this document describes a challenge problem whose scope is the detection, geolocation, tracking and id of moving vehicles from a set of xband sar data collected in an urban environment. A multiband airborne synthetic aperture radar and ground movingtarget indicating sar gmti radar system will be designed and developed that will utilize multiple frequency bands to improve the radar imaging and target detection performance in various clutter environments. Ground moving target indicator gmti radar that converts radar tracks to directed graphs dg, and creates weighted dgs aligned with superimposed with digital maps download pdf info publication number us9448304b2. Imaging underground objects using spatial sampling customization ru2537788c1 en 20910. Even after platform motion compensation by stap techniques, gmti tracking proves to be a challenging task. Spacetime adaptive processing for amti and gmti radar instructors. The principle of radar has been applied from frequencies of a few megahertz. Using constraining information, a theoretical way is presented to perform limited. Examples of radarlike principles are everywhere around us. In section 1, we give an overview of the theory behind mimo radar.
The standard radar operation is to resolve these ambiguities at the signal. Analysis of the experimental data is the principal focus of this report. Eee 554 or equivalent basic knowledge in random signals catalog course description. Blind velocities mitigation for mimo gmti radar with. Performance analysis of a spacebased gmti radar system using. To capture most of this traffic, even when it is moving almost tangentially to. Insight into adaptive mimo radar and mimo channel estimation is presented and techniques and illustrative examples are given. Gmti simulation framework for the radar plots generation, as well as the gmti tracker with grouping for tracking vehicles moving in convoys. Human data social media data source twitter feeds email traces coauthorship speech signals. For ground moving target indicator gmti radars, there are two.
Index termsantenna switching, ground movingtarget indication gmti, radar detection, radar position estimation, radar signal analysis, radar velocity measurement, spatial diversity, synthetic aperture radar sar. This chapter attempts to provide a comprehensive, indepth overview of the theory and the radar signalprocessing techniques required for spacebased sar gmti corroborated by real multichannel data from radarsat2. Doppler blind zone analysis for ground target tracking. Principles and applications of active and passive remote, focusing on methods, performance analysis, and applications of advanced rf. One type of data collected from these systems, known as ground moving target indicator gmti data, provides a wealth of information pertaining to the movement of those potential targets. Multiband airborne sargmti system development sbir. For modern synthetic aperture radar sar, it has much more urgent demands on ground moving target indication gmti, which includes not only the point moving targets like cars, truck or tanks but also the distributed moving targets like river or ocean surfaces. In principle, a sparse vector can be recovered from the least number of. Spacetimeadaptive processing stap is becoming an integral part of modern airborne and spacebased radars for performing airborne moving target indicator amti and ground moving target indicator gmti functions. Gmti show examples of common processing of multiple channel radar data into image and moving target products long coherent dwell e. James ward, stephen kogon, mit lincoln laboratory, usa synopsis. Microdoppler effect induced by micromotion dynamics the microdoppler effect induced by micromotions of a target or structures on the target can be derived from the theory of electromagnetic backscattering field. Mimo techniques can improve a radar s angle estimation and the minimum detectable velocity mdv for a target.
Th e gmti data was collected using the drdc ottawas xband wideband experimental airborne radar xwear, 14, and numerical studies of the syntactic. Detection for a given range, angle, andor doppler, decide if a target is or is not present. Fmcw radar sensors data subject to change without notice. However, the raw data from the radar system also referred to as the sensor must first be changed to a form appropriate for transmission to a system. However, it was not until the early 20th century that systems able to use these principles were. For the love of physics walter lewin may 16, 2011 duration. Bliss, member, ieee abstractground movingtarget indication gmti provides both an opportunity and challenge for coherent multipleinput multipleoutput mimo radar. The ultimate aim of a gmti radar is to first detect, and then characterize, moving objects with a high probability of detection pd, while maintaining a low probability of false alarm pfa. Performance analysis of a spacebased gmti radar system. The book offers an introduction to optimum mimo radar and includes details about detection, clutter, and target id. Radar accuracy is a measure of the ability of a radar system to determine the correct range, bearing, and in some cases, altitude of an object.
The most capable of the current generation is the norden apg76, which is operationally deployed on the israeli air force f4e phantom ed. This possibility was suggested in james clerk maxwells seminal work on electromagnetism. Frequency modulated continuous wave radar basic operating principles and theory. Gmti data is derived from rangedoppler maps of the imaged scene, in which re. Mimo techniques have experienced great success in other radio frequency systems, most notably in wireless communications. Ground moving target indicator gmti utility analysis for. The rangedoppler image for a receiver is shown in fig. Ground movingtarget indication gmti provides both an opportunity and challenge for coherent multipleinput multipleoutput mimo radar. Ground moving target indication gmti radar 711 is an airborne radar tasked with. However, the challenge of clutter mitigation places significant constraints on mimo radar.
Introduction and basic gmti data processing, including basic detection theory. Applications for gmti radar, oth radar, maritime radar, and automotive radar are explained. A design study based on the spacebased gmti radar reference mission for. Performance limits for exoclutter ground moving target. Fast gmti algorithm for traffic monitoring based on a priori. Gmti tracking in the presence of doppler and range. Sensor stap radar lidar, wami acousticseismic software defined hf radar integration target model scattering model noiseclutter model covariance model graphical models. Undesired clutter leakage into antenna sidelobes can. Tracking and engagement radar, or forester, is an airborne radar system that provides standoff, persistent, widearea surveillance for situational awareness of foliage covered areas. With realtime onboard processing, the ground moving target indicator gmti radar uses ultrahigh frequency uhf to penetrate double. We develop a theory for waveformdiverse movingtarget syntheticaperture radar in the case in which a single moving antenna is used both on transmission and on reception. A radar system probes its environment with specially designed waveforms to identify and characterize targets of interest. A design study based on the spacebased gmti radar reference mission for the air forces techsat 21 program was conducted to identify viable system design configurations that satisfy specific radar performance requirements.
A scheme to combine these components provided by both parties is investigated and implemented as shown in figure 1. Spectral leakage uniformly weighted set of n samples other doppler shift high sidelobes in the same. Us8207887b2 computationally efficent radar processing. Airborne groundmoving target indicator gmti is a radar. All singlephasecenter radar airtoground gmti modes are characterized by a minimum detectable velocity. Applied radar s existing wideband digital receiverexciter drex. Synthetic aperture radar sar systems have become an important tool for fineresolution mapping and other remote sensing operations. Spacetime adaptive processing stap for airborne mti radar. Sar, sar change detection, gmti, radar, tracking 1. Ground moving target indicator gmti radar that converts radar tracks to directed graphs dg, and creates weighted dgs aligned with superimposed with digital maps us97393b2 en 20315. Nathanson, radar design principles, second edition, isbn 007046052 3. Targetindication gmti radar systems is the antenna. The multichannel sar ground movingtarget indication gmti must process its data to produce not only the image of surveillance area. Nathanson, radar design principles, second edition, isbn 0070460523.
Gmti ground moving target indicator an int type that detects and tracks moving surface objects in an area of interest detections can be associated to form tracks, or used for situational awareness traditionally radar based, but can be from other sources such as video and. The history of radar where radar stands for radio detection and ranging started with experiments by heinrich hertz in the late 19th century that showed that radio waves were reflected by metallic objects. A gmti radar must distinguish a moving target from ground clutter by using the targets doppler signature to detect the radial component of the targets velocity vector i. Unless appropriately handled, doppler blindness can cause serious problems, which seem to be even more difficult in the presence of doppler ambiguities producing multiple clutter notches. Essentially, as predicted by sampling theory, the spectrums of clutter and targets are.