Improvement of ISAR Autofocusing Performance Based on PGA

摘要

PGA(phase gradient autofocus) has been widely used to remove motion induced phase errors in the ISAR(inverse synthetic aperture radar) imaging. The critical process for the processing time and image quality is windowing stage in PGA. In this paper, the new method to determine window size based on polynomial least square approximation is proposed. Moreover, dominant range bins are selected for efficient phase error estimation, which improve image quality and speed up convergence. The simulation Results: show that the proposed algorithm provides high quality ISAR images while computational efficiency of inherent PGA is retained.