机载差分干涉SAR 双轨法和三轨法的误差比较分析

机载差分干涉SAR 是一种极具潜力的地表形变监测技术，该文对该技术中经常使用的双轨法和三轨法两种工作模式的误差进行了比较分析。分析过程中根据互相独立的原则对各种误差进行分解和归类，并且考虑了运动误差与其它误差因素之间的耦合关系，在此基础上推导出两种工作模式下形变测量误差的解析表达式。结果表明:当运动误差幅度较小的时候，三轨法可以降低对外部地形数据的要求，相对于双轨法，它的优势非常显著；当运动误差幅度较大的时候，三轨法需要使用高精度的地形数据，它相对于双轨法的优势就不再明显。 

Error Comparison and Analysis of the Two-pass and Three-pass Approaches in Airborne D-InSAR

Airborne differential synthetic aperture radar interferometry (D-InSAR) is a kind of potential technology to survey the surface deformation. In this paper, the errors of two usually used modes of this technology, namely, two-pass and three-pass approaches, are compared and analyzed. In the analysis, all the errors are decomposed and sorted according to the principle of independence, and the coupling between motion error and other errors is considered. Based on the analysis, analytical expressions are derived for the deformation measurement errors in the two modes. The results demonstrate that when the amplitude of the motion error is small, the three-pass approach can reduce the requirement on the precision of the external topography data, so it distinctly outperforms the two-pass approach; when the amplitude of the motion error is large, high-precision topography data are needed in the three-pass approach, and as a result, its advantage over the two-pass approach is not distinct any more.