基于改进混合坐标系的大斜视俯冲机动平台SAR快速时域成像算法  

A Fast Time-Domain Imaging Algorithm for High-Squint Diving Maneuvering Platform SAR Based on Modified Hybrid Coordinate System

作　　者：闫莉[1] 许高添 张廷豪 YAN Li;XU Gao-tian;ZHANG Ting-hao(Academy of Advanced Interdisciplinary Research,Xidian University,Xi’an,Shaanxi 710071,China;National Key Laboratory of Radar Signal Processing,Xidian University,Xi’an,Shaanxi 710071,China;School of Physics,Xidian University,Xi’an,Shaanxi 710071,China)

机构地区：[1]西安电子科技大学前沿交叉研究院,陕西西安710071 [2]西安电子科技大学雷达信号处理全国重点实验室,陕西西安710071 [3]西安电子科技大学物理学院,陕西西安710071

出　　处：《电子学报》2024年第10期3472-3481,共10页Acta Electronica Sinica

基　　金：国家自然科学基金(No.62171337);中央高校基本科研业务费专项资金(No.ZYTS24116)。

摘　　要：多级子图像融合是加速合成孔径雷达(Synthetic Aperture Radar,SAR)时域成像的关键手段.然而,机动平台SAR的大斜视采集增强了频谱支持区域的不规则特性,降低图像融合的效率和精度.针对这些问题,本文设计了一种改进的混合坐标系,在此基础上开发了大斜视俯冲机动平台SAR快速时域成像算法.得益于改进混合坐标系中建立的等效斜距模型,频谱对斜视角的敏感度降低,消除了频谱空变现象.因此,设计频谱预处理函数可以有效压缩和拼接频谱,提升图像融合的效率和精度.通过仿真和原始数据处理,验证了提出算法性能的优越性.The multi-stage sub-image merging is a key method to accelerate to synthetic aperture radar(SAR)imaging in the time domain.However,the high-squint acquisition in the maneuvering platform enhances the irregularity of the support region of the spectrum,which degrades the performance of image merging in efficiency and accuracy.Because of these issues,in this paper,a modified hybrid coordinate system is designed,based on which a fast time domain imaging algorithm is developed for high-squint diving maneuvering platform SAR.Benefiting from the equivalent slant range model in the modified hybrid coordinate system,the sensitivity of the spectrum to the squinted angle is reduced,and the space variation phenomenon of the spectrum is eliminated.Hence,the spectral preprocessing function can be easily designed to effectively compress and merge the spectrum,which improves the performance of the image merging in efficiency and accuracy.Both simulated and raw data are processed to validate the performance superiority of the proposed algorithm.

关 键 词：快速时域算法 大斜视俯冲机动平台 混合坐标系 等效斜距模型 频谱预处理 

分 类 号：TN957[电子电信—信号与信息处理]