基于椭球模型的斜视星载SAR距离模糊仿真  

RASR of Nonzero Squint Spaceborne SAR Based on Ellipsoid Model

作　　者：蔡佳睿 吕继宇 CAI Jiarui;LYU Jiyu(Aerospace Information Research Institute,Chinese Academy of Sciences,Beijing 100190,China;School of Electronic,Electrical and Communication Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院空天信息创新研究院,北京100190 [2]中国科学院大学电子电气与通信工程学院,北京100049

出　　处：《雷达科学与技术》2024年第4期434-442,453,共10页Radar Science and Technology

基　　金：国家重点研发计划(No.2021YFC3000405)。

摘　　要：距离模糊比是星载SAR图像的一项重要指标,与正侧视成像相比,大斜视成像星地几何关系更为复杂,传统距离模糊计算与仿真中将地球视为球体的假设会对计算结果造成较大偏差,不能准确评估SAR图像质量。本文采用更为准确的地球椭球模型代替球体模型,并提出了一种基于斜视天线坐标系的模糊区计算方法,利用此方法对距离模糊比沿距离向测绘带的变化进行仿真,同时对距离模糊比沿方位向的空变性也进行研究。本文研究成果对星载SAR系统设计具有重要参考价值。Range ambiguity signal ratio(RASR)is an important performance index of spaceborne SAR images.Compared with the zero squint SAR,the geometric relationship between the satellite and the earth in high squint SAR imaging is more complex.The assumption that the earth is regarded as a sphereintraditionalRASR calculationandsimu⁃lation will cause a large deviation in the calculation results,which will inaccurately estimate the SAR image quality.In this paper,a more accurate ellipsoid model of the earth is used to replace the sphere model,and an ambiguity region cal⁃culation method based on the squint antenna coordinate system is proposed.By using this method,the change of RASR along the range swath is simulated,and the spatial variability of RASR along the azimuth is also studied.The research results of this paper provide important reference value for the design of spaceborne SAR system.

关 键 词：大斜视星载SAR 距离模糊 椭球模型 

分 类 号：TN958[电子电信—信号与信息处理]