星载SAR图像几何校正影响要素分析

几何校正是SAR图像应用的基础，而影响校正效果的要素有多种。论文首先从SAR图像成像机理出发，阐述了几何校正中定位模型的建立和解算过程，主要分析了两类影响要素：高程和卫星轨道插值方法。然后以一幅高分辨率TerraSAR-X图像的几何校正为基础，对比分析了三种高程和两种轨道插值算法对定位精度的影响。实验结果表明，只有距离向定位受这些因素的影响，高程的分辨率和垂直精度对定位精度都有很大影响、四次多项式直接插值方法只能满足一般的几何校正需要，更高精度的校正还需要其他辅助手段。

Analysis of the Main Factors Effecting Geometric Correction of Spaceborne SAR Image

Geometric correction is the basis of SAR image application and there are many factors effecting the correction. First, starting from the imaging mechanism of SAR image, this paper expatiates the establishing and solving process of location model of geometric correction, and focuses on the analysis of two main influencing factors: elevation and satellite orbit interpolation methods. Then, the comparative analysis of the effects of three kinds of elevation and two kinds of orbit interpolation algorithms on the location precision is done. The results indicate that only range location is influenced by these factors,the resolution and vertical accuracy of elevation have great influences on location accuracy. The direct quartic polynomial interpolation method can satisfy general geometric correction requirement. The higher precision correction needs other auxiliary means.