Airborne STAP with Unknown Mutual Coupling for Coprime Sampling Structure

In space-time adaptive processing (STAP) of airborne radar, the mutual coupling among array elements can lead to inaccurate estimation of the clutter covariance matrix (CCM), which makes the radar performance degradation. To solve this problem, a new STAP algorithm based on the coprime structure is developed. The proposed method uses the coprime structure and difference operation to construct the virtual space-time snapshots. Thus, the CCM is computed by utilizing these virtual snapshots obtained by using the low-rank matrix recovery technology. Finally, the virtual weight vector is built. The simulation results verify the effectiveness and superiority of the proposed method. The proposed algorithm can reduce the mutual coupling effect, accurately estimate CCM, and improve degrees of freedom (DOF).