Sparsity-Based Non-Stationary Clutter Suppression Technique for Airborne Radar

Conventional space-time adaptive processing (STAP) technique can achieve perfect performance when applied to side-looking airborne radar (SLAR), where the clutter is relatively stationary, whereas it suffers significant degradation for non-SLAR due to severe range dependence, especially when range ambiguity is present. In theory, the range-dependent clutter is mainly located at the near range and can be eliminated via elevation non-adaptive or adaptive beamforming. However, the pure near-range clutter portion utilized for calculating elevation adaptive weights cannot be obtained due to range ambiguity in practice. In this paper, a novel method to adaptive extract the near-range clutter via sparsity-based technique is presented and the non-stationary clutter potion can be effectively eliminated by elevation adaptive beamforming. With this technique, the residual clutter becomes stationary, and thus, the corresponding STAP performance will be significantly improved.