ISAR motion compensation using modified Doppler centroid tracking method

With regard to the phase compensation in inverse synthetic aperture radar (ISAR), the modified Doppler centroid tracking (MDCT) method is developed which applies the phase gradient autofocus (PGA) algorithm developed by Wahl (1994) to improve the Doppler centroid tracking (DCT) method. When the phase compensation is performed, the proposed approach smartly eliminates the effect of the rotational phase component (RPC) on the estimation of the translational phase component (TPC) by circular shifting, windowing and iteration steps. After several iterations, the maximum likelihood estimation and compensation of the TPC of the target can be realized more effectively. The processing results of live data show that the proposed method can improve the imaging quality of ISAR significantly.