Topic
Moving target indication
About: Moving target indication is a research topic. Over the lifetime, 2653 publications have been published within this topic receiving 32435 citations.
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Papers
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10 May 2010TL;DR: This work examines ground target detection and characterization from radar data, which incorporates a modelbased optimization method called dynamic logic (DL) and applies it to a prototype airborne radar platform called Gotcha, developed by the Air Force Research Laboratory/Sensors Directorate/Automatic Target recognition Division in recent years.
Abstract: In this work, we examine ground target detection and characterization from radar data, which incorporates a modelbased optimization method called dynamic logic (DL). We apply our methodology to a prototype airborne radar platform called Gotcha, developed by the Air Force Research Laboratory/Sensors Directorate/Automatic Target Recognition Division in recent years. The aircraft traces out a circular path around an area of interest, and the onboard, side-looking radar transmits and receives energy at a constant pulse repetition frequency, while the main beam direction is maintained at a fixed aim point on the ground. Data collected during any appropriate length arc of the flight path can be used to create synthetic aperture radar (SAR) images of the ground. The data can also be used for ground moving target indication (GMTI) and provide Doppler/Range imagery of the same ground area. Our approach combines the computation of Range-Doppler surfaces and a variable target velocity backprojection SAR method. Potential targets are detected using multiple backprojection images and features are extracted using adaptive mixture models. We demonstrate the feasibility of our approach using target truth information provided with the Gotcha dataset. We outline the steps toward implementing a comprehensive automatic target tracking solution based on presented methodology.
11 citations
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01 Oct 2016TL;DR: A new processing method for moving target detection based on Keystone transform is proposed to solve above problem and the efficiency and the relevant conclusion are verified by the simulation results.
Abstract: For the linear frequency-modulated continuous wave radar, the coupling of fast time and slow time in the signal phase is occurred for the moving target detection, which results in migration through range cell in multi-cycle signal. A new processing method for moving target detection based on Keystone transform is proposed to solve above problem. Through the characteristics analysis of the received multi-cycle signal and utilizing the decoupling property of Keystone transform, a transform expression in the moving target detection processing, is derived which can be used for the range profiles alignment. Finally realization and performance of the proposed method is discussed. Compared with the direct motion compensation method, the efficiency of the proposed method and the relevant conclusion are verified by the simulation results.
11 citations
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30 Sep 1970
TL;DR: In this paper, an adaptive digital automatic gain control (DAGC) system was proposed for pulsed radar moving target indicator (MTI) systems to reduce the input dynamic range requirements of a data processing and display system by dividing each range sweep into a number of range elements of one or more range bins, and providing a digital error signal indicating whether or not the video signal is greater than the reference signal.
Abstract: An adaptive digital automatic gain control (DAGC) system is disclosed for pulsed radar moving target indicator (MTI) systems to reduce the input dynamic range requirements of a data processing and display system by dividing each range sweep into a number of range elements of one or more range bins, comparing the signal level in each range element to a selected reference level, and providing a digital error signal indicating whether or not the video signal is greater than the reference signal. The radar video signal is processed by an MTI filter, the output of which is compared with a selected reference level to similarly provide digital error signals for AGC control based on not only the raw radar video signal, but also the MTI video signal. These digital error signals are integrated separately for each range element, thereby developing for each range element an AGC signal in digital form based on the past history in the raw radar video signal and the MTI video signal over a continuous succession of range sweeps. After conversion into analog form, these digital AGC signals developed for all range bins of a given sweep are filtered by a low pass filter to provide an analog AGC signal which is smooth over approximately 16 range bins. A noise AGC signal is similarly developed and combined with the radar video and MTI video AGC, but at a much slower rate of one sample per azimuth scan.
11 citations
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TL;DR: A multichannel synthetic aperture radar (SAR) using waveform diversity, namely, multiple-input multiple-output (MIMO) SAR and distinct carrier frequency for GMTI applications and the proposed approach employs MIMO configuration with multiple antennas in azimuth and orthogonal wave form diversity.
Abstract: Ground moving target indication (GMTI) plays an important role in surveillance and reconnaissance applications, but it is a difficult problem due to the impacts of stationary clutter. This paper proposes a multichannel synthetic aperture radar (SAR) using waveform diversity, namely, multiple-input multiple-output (MIMO) SAR and distinct carrier frequency for GMTI applications. The proposed approach employs MIMO configuration with multiple antennas in azimuth and orthogonal waveform diversity. In doing so, multiple independent transmit-receive channels are formulated at the receiver. Since each antenna uses both waveform diversity and distinct carrier frequency, after clutter cancellation and noise suppression by the displaced phase center antenna (DPCA) and along-track interferometry (ATI) combined processing algorithm, the cross-track velocity is estimated through double-interferometry processing. Next, the Doppler parameters of moving targets are estimated with the fractional Fourier transform algorithm and then GMTI is obtained by a joint signal processing algorithm. Finally, the moving targets are focused with a general chirp scaling imaging algorithm. All the proposed methods are verified by simulation results.
11 citations
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07 Nov 2013TL;DR: In this paper, the Doppler shift of a moving target was measured using a two-dimensional complex valued matrix (CVM) whose spectral peak correspond to the position of the moving target.
Abstract: During the operation of an FMCW (frequency modulated continuous wave) maritime radar, the system transmits a continuous radio energy with a frequency modulated by a triangular or sawtooth-shaped signal. As a result, the frequency of the transmitted signal varies gradually with time. When the signal is reflected by an object, the received waveform will build up a delayed replica of the transmitted waveform, with the time delay as a measure of the target range. If the target is moving, the radar system will register a Doppler shift within the received signal. Compared to the frequency of the emitted signal, the received signal will show a higher frequency when the target is approaching and a lower frequency when the target is moving away from the radar location. Thus, the total Doppler shift may result from the superposition of both source and observer motions. Specifically, the amount of Doppler shift is directly proportional to the radial speed of the target. The Doppler shift can be determined after performing the range Fourier transform (range FFT) first. For a target of interest, we can repeat the range FFT until we have enough data to perform the second level of FFT. The result of this second FFT is a two dimensional complex valued matrix, whose spectral peak corresponds to the Doppler shift of the moving target. This method is known as Doppler FFT. Some results of the measurement of target speed using this method are presented in this paper.
11 citations