Parametric Iterative Soft Thresholding Algorithm for Refocusing of Moving Targets in SAR Images

Abstract

As a classical sparse reconstruction algorithm, iterative soft thresholding (IST) is often used in SAR sparse imaging applications. However, for moving targets, the radar echo contains unknown phase error, so it is difficult to directly apply the IST algorithm to reconstruct the SAR moving target image. In this paper, a parametric iterative soft thresholding (P-IST) algorithm is proposed for refocusing of moving targets in synthetic aperture radar (SAR) images. In this algorithm, the echo phase error is modeled as a function of the phase compensation factor, and in the iteration process, a phase compensation factor optimization selection step based on residual energy minimization is added. Compared with the existing algorithms, the proposed P-IST algorithm can obtain the global optimal solution, and has better efficiency and robustness. Both simulated data and measured data are used to validate the effectiveness of the proposed algorithm.