星载SAR全方位模糊特性及计算方法  

Research on omnidirectional ambiguity characteristics and calculation method of spaceborne SAR

作　　者：陶满意[1] 胡广清[1] 黄源宝[1] 陈国忠[1] 苏小明 TAO Manyi;HU Guangqing;HUANG Yuanbao;CHEN Guozhong;SU Xiaoming(Shanghai Institute of Satellite Engineering,Shanghai 200240,China;Shanghai Academy of Spaceflight Technology,Shanghai 201109,China)

机构地区：[1]上海卫星工程研究所,上海200240 [2]上海航天技术研究院,上海201109

出　　处：《中国空间科学技术》2022年第1期92-98,共7页Chinese Space Science and Technology

基　　金：国家自然科学青年基金(61801294).

摘　　要：常规的星载SAR模糊度计算方法是基于距离向一维方向图和方位向一维方向图,独立进行距离向模糊度和方位向模糊度分析。由于星载SAR对地观测是二维的,因此距离模糊度是全方位的,且真实的模糊能量仅来自于距离向模糊信号,方位向模糊是基于距离向模糊信号的基础上由于成像处理导致的模糊信号重组。为解决系统设计时预估分析的距离向模糊度值与实际成像效果不一致的问题和还原方位向模糊度本质,提出了星载SAR模糊度分析和计算的新方法。该方法首先从模糊特性机理出发,分析了距离和方位模糊产生的原因和两者之间的关系;然后建立了方向图任意指向角度与对地实际观测之间的角度转换模型,同时以二维方向图为基础给出了全方位模糊度计算的方法和步骤;最后进行了仿真设计验证,仿真结果表明,全方位模糊度计算方法更加符合实际成像效果,且为后续高分辨率星载SAR系统设计和模糊度抑制提供了参考依据。The conventional ambiguity calculation method of spaceborne SAR is based on range one-dimensional pattern and azimuth one-dimensional pattern,and the range ambiguity and azimuth ambiguity are analyzed independently.However,the azimuth ambiguity is based on range ambiguity signal,which is caused by image processing.In order to solve the problem that the estimated range ambiguity value in system design is inconsistent with the actual imaging effect and to restore the essence of azimuth ambiguity,a new method of ambiguity analysis and calculation for spaceborne SAR was proposed.Firstly,the causes of range and azimuth ambiguity and the relationship between them were analyzed.Then,the range conversion model between the arbitrary pointing angle of the pattern and the actual observation to the earth was established.At the same time,based on the two-dimensional pattern,the calculation method and steps of the omnidirectional ambiguity were given.Finally,the simulation design was carried out and the results show that the omnidirectional ambiguity calculation method is more in line with the actual imaging effect,providing a reference for the subsequent high-resolution spaceborne SAR system design and ambiguity suppression.

关 键 词：星载SAR 距离模糊 方位模糊 全方位 二维方向图 

分 类 号：TN951[电子电信—信号与信息处理]