Diagonal Loading Techniques to Relax Sample Support Requirement in Airborne Bistatic STAP

In this paper, we concentrate on the employment of diagonal loading to relax sample size requirement of airborne bistatic STAP. Due to the independent motion effects of the receiver and transmitter, bistatic clutter generally appears more severely nonstationary in the range dimension than the counterpart of monostatic system. This leads to the shortage of IID training data samples and inadequate estimation of the clutter-plus-noise covariance matrix for bistatic STAP, which greatly degrades the performance of bistatic STAP. In this work, we first make a comparison of sample support in different bistatic scenarios and then propose to further abate the required sample support by combining the diagonal loading techniques with the reduced-dimension STAP algorithm. Simulation results manifest that the satisfying performance of bistatic STAP can be obtained by using the proposed method in the bistatic geometries where the training data is extremely insufficient.