Enhancing 3D SAR Imaging: A Near-Field Back Projection Algorithm for Addressing Geometric Distortion

This paper aims to address the issue of geometric distortion in traditional 2D SAR imaging under near-field conditions. To achieve this, the study explores the geometric model of MIMO SAR 3D imaging and derives the 3D back projection (BP) imaging algorithm based on it. The algorithm’s effectiveness is verified through the simulation of point targets and the collection of data using a sliding rail SAR system to image metal sheets in actual scenes. The simulation and actual imaging results confirm that our near-field BP algorithm has better imaging results compared to the BP algorithm which does not consider near-field effects while maintaining acceptable computational complexity.