天绘二号卫星双基成像几何模型改正算法  

Algorithm to changing bistatic imaging geometric model for TH-2 satellite

作　　者：陈刚 钱方明[1,2] 刘志铭 楼良盛[1,2] CHEN Gang;QIAN Fangming;LIU Zhiming;LOU Liangsheng(State Key Laboratory of Geo-information Engineering,Xi an 710054,China;Xi an Research Institute of Surveying and Mapping,Xi an 710054,China)

机构地区：[1]地理信息工程国家重点实验室,陕西西安710054 [2]西安测绘研究所,陕西西安710054

出　　处：《测绘学报》2022年第12期2417-2424,共8页Acta Geodaetica et Cartographica Sinica

摘　　要：主辅星的成像几何模型直接影响着InSAR数据处理的多个环节,包括复影像概略配准、去平地效应、InSAR定位、基线定标、区域网平差、正射纠正等。天绘二号卫星在成像时,为了保证算法统一,主辅星都采用了收发分置的双基成像几何模型。对于影像概略配准、去平地效应、InSAR定位等环节,双基成像模型只是增加了算法的复杂度,但对于基线定标,这带来了新的挑战:(1)现有基线定标算法均针对主辅星为单基成像的几何模型,无法适用于天绘二号;(2)收发两两组合产生4条基线,4条基线存在相关,导致基线定标难以实施。为了确保基线定标精度,本文提出了主辅星双基成像几何模型改正算法,并对辅星成像几何模型的改正精度进行了分析。理论分析和试验表明该方法引入误差很小,可以忽略不计。Imaging geometric model of master and slave satellite directly affects many steps in InSAR data processsing, such as complex image rough registration, flat plain effect removing, InSAR location, baseline calibration, block adjustment and ortho-rectification. In order to keep unified algorithm in imageing, both master and slave satellite of TH-2 use bistatic imaging geometric model. For complex image rough registration, flat plain effect removing and InSAR location step, bistatic imaging geometric model just increase algorithm complexity, but for baseline calibration, it brings new chanlleges. On one hand, most current baseline calibration algorithms are based on monostatic imaging geometric model and can not be used in TH-2;on the other hand, pair position combines to form four baselines, and four baselines exist correlation in calibration, which leads to difficulty for baseline calibration. In order to keep accuracy of baseline calibration, the paper presents algorithm to chang bistatic geometric model into monostatic model and anlyses the transformation accuracy for slave satellite. It’s proved that the algorithm has high accuracy and the brought error can be ignored by theoretical analysis and test.

关 键 词：干涉合成孔径雷达 分布式卫星 等效相位中心 成像几何模型 基线定标 

分 类 号：P227[天文地球—大地测量学与测量工程]