An approach to compensate clutter range dependence for bistatic airborne radar

In a bistatic airborne geometry, snapshot statistics are range dependent. Straight averaging degrades the accuracy of clutter plus noise covariance matrix estimation. To mitigate the range dependence, a new method is presented in this paper. The method interpolates short range space-time steering vectors to the referenced range by using subspace fitting technique. And moving target steering vector restrictions are added to avoid ground moving target elimination. Compared to conventional sample matrix inverse (SMI) method, this approach can significantly improve the performance of ground moving target indication (GMTI). At last, simulated results are presented to verify the effectiveness of the proposed approach.