New Solution to the Range-Dependence Problem in STAP Radar with HPRF

The primary differences in airborne radar clutter spectrum between non-sidelooking and sidelooking arrays are that its Doppler frequency of the clutter spectrum varies with the range and its clutter degrees of freedom (DOFs) are increased, so that the conventional STAP methods are not feasible. In this paper, the clutter distribution of airborne non-sidelooking arrays radar is analyzed and investigated in detail, then a new approach to non-sidelooking airborne radar with low pulse repetition frequency (LPRF) based on covariance matrix taper (CMT) is proposed, finally a novel ambiguous clutter suppression preprocessing method based on orthogonal projection technique is presented for non-sidelooking airborne radar with high pulse repetition frequency (HPRF). Using the preprocessing technique, clutter suppression improvement of 10 dB is achieved.