An improved imaging algorithm for spaceborne MAPs sliding spotlight SAR with high-resolution wide-swath capability

• Published in: Chinese journal of aeronautics Vol. 28; no. 4; pp. 1178 - 1188
• Main Authors: Kuang, Hui, Chen, Jie, Yang, Wei, Liu, Wei
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2015
• Subjects: High resolution; Imaging; Multiple-azimuth-phases; SAR系统; Sliding spotlight; Synthetic aperture radar; Wide swath; 地图; 宽测绘带; 成像算法; 星载; 滑动; 聚束SAR; 高分辨率; Multiple-azimuth-phases; High resolution; Wide swath; Imaging; Synthetic aperture radar; Sliding spotlight
• ISSN: 1000-9361; 2588-9230
• DOI: 10.1016/j.cja.2015.06.009

Conventional synthetic aperture radar（SAR） systems cannot achieve both highresolution and wide-swath imaging simultaneously.This problem can be mitigated by employing multiple-azimuth-phases（MAPs） technology for spaceborne sliding spotlight SAR systems.However, traditional imaging algorithms have met challenges to process the data accurately, due to range model error, MAPs data reconstruction problem, high-order cross-coupling phase error and variation of Doppler parameters along the azimuth direction.Therefore, an improved imaging algorithm is proposed for solving the above problems.Firstly, a modified hyperbolic range equation（MHRE） is proposed by introducing a cubic term into the traditional hyperbolic range equation（THRE）.And two curved orbit correction methods are derived based on the proposed range model.Then, a MAPs sliding spotlight data reconstruction method is introduced, which solves the spectral aliasing problem by a de-rotation operation.Finally, high-order cross-coupling phases and variation of Doppler parameters are analyzed and the corresponding compensation methods are proposed.Simulation results for point-target scene are provided to verify the effectiveness of the proposed algorithm.