Showing papers on "Moving target indication published in 1991"

A localized adaptive MTD processor

Abstract: The problem of achieving the optimum moving target indicator (MTI) detection performance in strong clutter of unknown spectrum when the set of data available to the estimation of clutter statistics is small due to a severely nonhomogeneous environment is studied. A new adaptive implementation, called the Doppler domain localized generalized likelihood ratio processor (DDL-GLR), is proposed, and its detection performance is studied in detail. It is shown that the DDL-GLR is a data-efficient implementation of the high-order optimum detector and has several advantages of practical importance over the adaptive processors. >

Maneuvering target tracking using multiple maneuver model joint probabilistic data association

Abstract: The JDPA (joint probabilistic data association) algorithm has been reported to be suitable for tracking multiple targets in the presence of extraneous observations (i.e., clutter, thermal false alarms, other targets) and no reports (missed target detections). In the present work, a novel method for highly maneuvering target tracking is presented which is an extension of the JPDA. Computer simulation indicated that this method can track a highly maneuvering target (7 g) in the presence of extremely dense clutter (with a probability of a false alarm of 0.1) with a sampling interval of 0.5 s. >

Pilot-an example of advanced FMCW techniques

Abstract: 'Pilot' is an FMCW tactical navigational radar which uses the high time-bandwidth product of frequency modulated continuous wave (FMCW) to provide excellent low probability of intercept (LPI) characteristics It is shown that single antenna FMCW operation is feasible and practical and that FMCW MTI (moving target indication) can be implemented efficiently by using a correlation receiver< >

Radar signal processing device

Abstract: PURPOSE:To automatically discriminate and recognize the kind or the like of a moving target in a radar system of a radar signal processing device. CONSTITUTION:A radar signal processing device is provided with a frequency analyzing means 81 to obtain the frequency spectrum of the phase detection signal where phase detection of the radar received signal is made, a collating means 82 to collate the pattern of the frequency spectrum obtained by the frequency analyzing means 81 with the model pattern of various known frequency spectra of the moving target, and a recognizing means 83 to recognize the kind of the moving target on the basis of the collated result by the collating means 82.

Adaptive airborne MTI with two-dimensional motion compensation

Abstract: Clutter returns received by an airborne radar exhibit a Doppler bandwidth which depends on the platform speed, beamwidth and wavelength Echoes of slow targets may, therefore, be buried in the clutter band and are difficult to detect Perturbations of the flight path due to the flight dynamics of the aircraft and wind effects may cause further degradation of the MTI performance It has been shown in earlier papers of the author that space-time FIR filters applied to the output signals of a linear array antenna can be used to compensate adaptively for the flight path component of the platform motion so that a large improvement in signal-to-clutter-plus-noise ratio (SCNR) can be obtained Such filters are referred to as TASTE (techniques for airborne slow target extraction) methods In the paper these ideas are extended to the compensation of transversal velocity components by means of a planar array with horizontal orientation The influence of the system bandwidth is also investigated The results obtained can be generalised to compensate for three-dimensional perturbations of the flight path without using an inertial navigation device

Radar signal processing system

Abstract: PURPOSE:To detect a target with a high S/N by selecting a weight corresponding to a clutter level with respect to each range pin, and varying the characteristic of a fast Fourier transform (FFT) Doppler filter. CONSTITUTION:A radar signal is converted to a non-zero Doppler (NRZ) signal by a moving target indicator (MTI) 3 and is multiplied by the weight from a weight selecting circuit 8 by a weight multiplier 4 and is supplied to an FFT Doppler filter 5; and since several stages of weight are set in the circuit 8 and the weight corresponding to the detected clutter level of each range pin is selected and the output of the MTI 3 is multiplied by this weight by the multiplier 4, the characteristic of the filter 5 is varied for each range pin. Consequently, the Doppler frequency in each Doppler bank is selected by the filter 5 and has the S/N improved and is taken out. This output is compared with a threshold by constant forth alarm ratio (CFAR) fixing circuits 60 to 6n, and a target detecting and discriminating circuit 7 discriminates the NZD signal in the Doppler bank having a level exceeding the threshold as the target.

Optimum digital recursive filters for step scan phased array radars

Abstract: A design method for recursive filters with optimum clutter rejection is presented. The designed filters are suitable for MTI (moving target indication) systems in step scan phased array radars. The designed filters are optimized for a given clutter power spectrum and a finite number of samples without initialization. The performance of the designed filters was studied by considering their clutter rejection and pass-band characteristics. Finally, the superiority of these filters over conventional steady state filters was demonstrated. >

Missing radar pulse clutter processing

Abstract: The degradation incurred with a conventionally weighted moving target indication (MTI) or Doppler filter radar when one of the return pulses is missing is investigated. It is shown that, for conventional MTI and Doppler filter bank processor, the loss in performance can be large. For the single filter, such as an MTI filter, it is shown that the eigenvector methods for determining the weighting can result in large losses. However, the minimax log energy (MMLE) method is shown to give nearly optimal performance. It is shown that, using the MMLE design procedure, the number of filters could be substantially reduced without incurring a large degradation in performance. >

A programmable radar signal processor architecture

Abstract: A programmable radar signal processor architecture is described. It is designed to handle up to a 10-MHz analog/digital sample rate. The architecture consists of a front-end composed of a parallel array of programmable digital signal processing (DSP) devices, which performs the high-speed signal processing functions such as pulse compression, moving target indication, constant false alarm rate processing, etc., and outputs contact reports, to a back-end processor consisting of transputer microprocessors to perform post-detection processing. The processor is being developed to support the Point Defence Demonstration Radar. >

Moving targets SAR processing

Abstract: The main results of SAR (synthetic aperture radar) processing are reviewed, and a method for imaging fixed and moving targets, called MTI (moving target indicator) SAR, at the same time is presented. The advantages and limitations of this method are explained. This is done in the framework of a side-looking airborne SAR, as opposed to spaceborne SAR. >