粗/精轨道数据对卫星InSAR DEM精度影响的对比分析

Comparison and Evaluation on Accuracy in Satellite InSAR DEM Derived Using Coarse and Precise Orbit Data

本文在介绍InSAR系统中卫星轨道状态矢量内插方法的基础上,从理论和实际两方面分析了轨道数据误差对参考椭球面相位、地形干涉相位和数字高程模型(DEM)精度的影响。以上海局部地区作为实验场,采用ERS-1/2卫星SAR影像数据,分别使用欧洲空间局粗略轨道数据和荷兰Delft大学空间研究中心精密轨道数据进行了干涉处理,生成了两种情况下的DEM,并对相关精度进行了对比与分析。研究结果表明,使用精轨数据建立的DEM的精度明显高于基于粗轨数据建立的DEM的精度。

This paper first introduces the interpolation technique of satellite orbit state vectors in the synthetic aperture radar interferometry （InSAR） system. From both the theoretical and practical viewpoint, we then discuss and analyze the influence of orbit data errors on the accuracy of the reference phase, the topographic phase, and the resulting digital elevation model（ DEM ）. Selecting a part area of Shanghai as the testing site, the experiment of interferometric processing and DEM generation is performed using the satellite ERS-1/2 SAR images as well as the coarse and precise orbit data provided by European Space Agency （ESA） and Delft Institute for Earth-Oriented Space Research （ DEOS ）, respectively. Comparison and analysis on the relevant accuracies are thus made for the two types of orbit data. The results show that the accuracy in the DEM generated with precise orbit data is prominently higher than that with coarse orbit data.