Range-Ambiguous Sea Clutter Suppression for Multichannel Spaceborne Radar Applications Via Alternating APC Processing

In this article, a novel range ambiguous cluter suppression method, i.e., alternating azitmuth phase coding (AAPC), based on azimuth phase coding (APC) is proposed, where the blind areas of target detection are solved. Based on the motion model of spaceborne radar (SBR) system, the sea clutter motion property is analyzed, and a multichannel sea clutter signal model with the consideration of range ambiguity is established. After that, the novel method AAPC is proposed. Finally, a time-domain sliding window projection method with the consideration of clutter internal motions is proposed to realize the sea clutter rejection. Compared with the current range-ambiguous sea clutter suppression algorithms, the improvements of this method are: 1) the range-ambiguous clutter can be separated and most of the clutter components in the main-lobe region can be rejected; and 2) the repetitive detection blind regions can be avoided by applying the proposed AAPC technique. Simulation results are presented to validate the feasibility of the proposed algorithm.