Multichannel array processing in radar: state of the art, hot topics and way ahead

The space-time adaptive processing (STAP) technique was originally conceived to suppress clutter (and jamming) received by radar on board moving platforms such as aircraft; this was so because of the clutter ridge in the Doppler frequency and angle (spatial frequency) plane. In fact, the clutter echoes appear coupled in angle and Doppler frequency. When the platform is stationary this coupling does not exist any more. However, the STAP technique still seems valuable when clutter and jamming are present and their statistical features are not known a priori. This paper demonstrates concerning this statement by showing results concerning the processing of recorded live data. It also tackles the problem of selecting an algorithm to work in a nonstationary, nonhomogeneous environment.