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.

Spatially adaptive moving target indicator system for radar equipment

Abstract: A radar system is provided with first and second moving target indicator (MTI) systems. The first MTI system generally works better against ground clutter than against sky clutter. The second MTI system works well against sky clutter but generally requires a greater number of radar return echoes to discern targets in the sky clutter. A correlation estimation circuit is employed to calculate the correlation of clutter-like return echoes not suppressed by the first MTI system. If the return echoes are sufficiently correlated, the second MTI system is invoked against the clutter. If the return echoes are less well correlated, on the other hand, then electronic counter-counter measure systems may be invoked.

Optimum Processing of Unequally Spaced Radar Pulse Trains for Clutter Rejection

Abstract: A train of radar pulses from one resolution cell can be processed coherently to reject echoes from external clutter and detect targets moving radially with respect to the clutter. Optimum methods of signal processing are defined for systems in which the interpulse spacings are multiply staggered to avoid target blind speeds. Likelihood ratio tests are developed for systems in which the target Doppler frequency is known a priori and for systems employing a bank of filters to cover the target Doppler band. To implement such tests, the N pulses in the train are added with complex weights and the amplitude of the sum compared with a detection threshold. The set of weights which maximizes the average signal-to-clutter ratio is also computed for a single-filter system with unknown target Doppler frequency. When the clutter autocorrelation function is exponential, the clutter covariance matrix can be inverted analytically. This latter result is useful for comparing different interpulse-spacing codes for a particular system application.

Wall clutter mitigation and target detection using Discrete Prolate Spheroidal Sequences

Abstract: We present a new method for mitigating wall return and a new greedy algorithm for detecting stationary targets after wall clutter has been cancelled. Given limited measurements of a stepped-frequency radar signal consisting of both wall and target return, our objective is to detect and localize the potential targets. Modulated Discrete Prolate Spheroidal Sequences (DPSS's) form an efficient basis for sampled bandpass signals. We mitigate the wall clutter efficiently within the compressive measurements through the use of a bandpass modulated DPSS basis. Then, in each step of an iterative algorithm for detecting the target positions, we use a modulated DPSS basis to cancel nearly all of the target return corresponding to previously selected targets. With this basis, we improve upon the target detection sensitivity of a Fourier-based technique.

Localization and tracking with Multipath Exploitation Radar

Abstract: This paper illustrates the exquisite localization and tracking performance that is obtainable in urban areas with Multipath Exploitation Radar (MER). First, the MER concept is described. Next, Cramer-Rao Lower Bounds of the desired localization and tracking quantities are derived and evaluated with representative parameters. Measured data is then used to demonstrate that this performance can be achieved in practice. Finally, ideas for future MER research are discussed.

Moving target indicator system

Abstract: An improved moving target indicator system operable with antenna side lobe blanking, that substantially eliminates false target reports at the output of the moving target indicator so as to overcome a problem associated with radar systems using moving target indicator and side lobe blanking arrangements. The system provides one additional bit or an action bit in memory for each range bin in each canceller stage of the moving target indicator system. When side lobe blanking occurs, an associated bit is applied to the system and this bit is allowed to propagate through the second canceller as well as any subsequent cancellers. Thus, during each pulse repetition interval that would be affected by side lobe blanking action, a blanking gate is energized to inhibit the generation of false targets. For a radar system utilizing step transmission, a variable recirculating delay is provided to insure that regardless of the time of occurrence of the side lobe blanking condition, the output of the moving target indicator unit will be blanked the required number of periods.