Application of beam domain STAP techniques to space-based radars

This paper deals with beam-based space-time adaptive processing (STAP) algorithms for a low-earth-orbit (LEO) space-based radar (SBR). The performance of a subarray-based joint-domain-localized (JDL) algorithm is first examined for different parameters. Then, a combined beam-domain STAP algorithm approach that combines JDL with difference (Δ) beams is presented. It is shown that the combined JDL-Δ algorithms offer less system complexity and provide performance similar to that of the JDL with higher degrees of freedom. It is also shown that the earth´s rotation induces a crab angle, which makes the clutter range-Doppler spectrum range dependent. This paper shows that this crab angle severely degrades STAP performance.