A Large Bandwidth Sliding Spotlight SAR Image Formation Based on Generalized Chirp Scaling and Moving Band Chirp-z Transform

This paper presents an efficient full-aperture imaging algorithm for sliding spotlight synthetic aperture radar (SAR) with a large bandwidth. The large bandwidth sliding spotlight SAR has serious phase coupling along the range and azimuth dimensions, which will considerably degrade the image quality. In this paper, we firstly analyze the effect of phase error on large bandwidth sliding spotlight SAR imaging theoretically. Then, based on the generalized chirp scaling (GCS) algorithm, a new image formation incorporating a moving band chirp-z transform (MBCZT) is proposed, which allows an effective processing of large bandwidth sliding spotlight SAR data. The proposed MBCZT-GCS algorithm can solve the phase coupling and azimuth aliasing problem successfully. Simulation results prove the validity of the proposed method and corresponding theoretical analysis.