Robust STAP With Reduced Mutual Coupling and Enhanced DOF Based on Super Nested Sampling Structure

In practical airborne radar, mutual coupling between array elements usually leads to space-time steering vector distortion for space-time adaptive processing (STAP), which seriously degrades radar performance. In this paper, a robust STAP algorithm coupling the second order super nested arrays with pulses (2OSNAP) sampling structure is developed. The proposed method applies difference operation to construct virtual space-time snapshots in the virtual domain. To solve the clutter plus noise covariance matrix (CNCM) corresponding to the virtual space-time snapshots, the space-time smoothing method is used in this paper. Furthermore, the proposed method can directly give a set of virtual and robust STAP weight vector, which is convenient for the subsequent signal processing. Extensive numerical experiments were performed to verify the effectiveness and superiority of the proposed method. The test results also show that our proposed method provides more degrees of freedom (DOF), and eliminates the mutual coupling effect between array elements compared to most existing methods.