Space-time adaptive processing for airborne radar

Advanced airborne radar systems are required to detect targets in the presence of both clutter and jamming. Ground clutter is extended in both angle and range, and is spread in Doppler frequency because of the platform motion. Space-time adaptive processing (STAP) refers to the simultaneous processing of the signals from an array antenna during a multiple pulse coherent waveform. STAP can provide improved detection of targets obscured by mainlobe clutter, sidelobe clutter, and jamming. This paper provides an overview of partially adaptive STAP approaches. Analysis of the clutter covariance matrix rank provides insight and conditions for preprocessor design. As the filters used for detection in a STAP radar depend on the background interference estimates, the approaches used for parameter estimation must be modified for a STAP radar. The effect of STAP on angle and Doppler accuracy is described, and an approach for joint angle and Doppler estimation in a STAP radar is described.