An FDA-MIMO-Based Range-Ambiguous Clutter Sensing Approach for STAP

Space-time adaptive processing (STAP) via dynamic clutter sensing can effectively suppress heterogeneous clutter, but the clutter suppression performance will be seriously degraded in scenarios with range ambiguities. To tackle this issue, this paper proposes a clutter sensing approach with airborne frequency diverse array (FDA) for multiple-input multiple-output (MIMO) radar. The proposed approach first uses FDA-MIMO radar to transmit sensing signals, which exploits the degree of freedom (DOF) in the range dimension. Then, a complete dictionary matrix in the range-angle-doppler domain is constructed. Finally, sparse recovery technology is used to reconstruct radar cross sections of clutter patches from sensing echoes, this prior information can assist STAP obtain better clutter suppression performance. Compared with the existing clutter sensing methods, the proposed method introduces the DOF in the range domain into the dictionary matrix, which can effectively improve the sensing performance of radar on range-ambiguous clutter, and then improve the suppression performance of STAP on heterogeneous clutter in the case of range ambiguity. Numerical experiments confirm the effectiveness of the proposed method.