Improvements of ROPE in ISAR Motion compensation

Motion compensation in inverse synthetic aperture radar (ISAR) usually consists of two parts: range alignment and phase compensation. In this paper, the rank one phase estimation (ROPE) algorithm is applied to the ISAR phase compensation. Its blind setting of zero Doppler frequency at the start is avoided greatly by circular shifting the poorly focused strongest scatterer in each range bin to the zero Doppler frequency. Moreover, the iteration is introduced to further increase the phase estimation precision of ROPE. Compared with PGA, a good phase compensation algorithm, the improved ROPE doesn ´t require a relatively focused image at the beginning, and can remove the high frequency phase errors and random phase errors effectively. The processing of ISAR real data verifies the good performance of the improved ROPE.