Clutter-Ridge Matched SR-STAP Technique for Non-stationary Clutter Suppression

Non-stationary clutter suppression is an attractive and challenging problem in space-time adaptive processing (STAP) algorithms. Although sparse recovery(SR) STAP can effectively alleviate strong clutter non-stationary characteristic with a few number of samples, there are still difficulties where the clutter components are not located on the discrete spacetime grid points of the dictionary, which results in significant performance loss. To overcome the off-grid problem, a clutter-ridge matched SR-STAP(CRM-SR-STAP) is proposed. In the proposed algorithm, clutter ridge is calculated at first according to prior knowledge including radar system parameters and modern inertial navigation system information. Then, the clutter-ridge matched dictionary is reconstructed to calibrate the uniformly discrete dictionary. Finally, the non-stationary clutter is suppressed by SR-STAP with this dictionary and the off-grid problem has been well-overcome. The proposed algorithm can effectively match the nonlinear characteristics of clutter under the non-side-looking array scenario, and the signal-to-interference-plus-noise ratio (SINR) loss also improves significantly. Simulations are given to verify the effectiveness of the proposed method.