基线误差、相位误差和大气延迟误差对InSAR数据处理的影响分析

基于星载InSAR的基本原理,首先推导了基线误差、相位误差和大气延迟误差对高程测量的影响公式,得出了他们均与有效基线长度成反比的影响规律。接着讨论了大气延迟误差对二轨法和三轨法形变测量的影响规律:大气延迟误差对二轨法形变测量的影响随入射角变化不明显,对三轨法形变测量的影响随基线比变化不明显。当入射角取23°,基线比取1/2,欲使大气延迟误差对形变测量的影响＜1 cm,二轨法要求其测量误差＜6.5 mm,三轨法要求其测量误差＜7.5 mm。

Error Analysis of Baseline, Phase and Atmosphere Delay in InSAR Data Processing

Based on the basic principles of InSAR,we can draw the following conclusions:an inverse proportion relation exists between errors of baseline,phase and atmosphere delay and length of effective baseline in terms of height measurement; atmosphere delay error impact on two|pass deformation measurement changes little with incidence angle difference,and its impact on three-pass deformation measurement changes little with baseline ratio.When incidence angle is 23°and baseline ration 1/2,if we let its impact on deformation error less than 1 cm,atmosphere delay error must be less than 6.5 mm for two|pass DInSAR and 7.5 mm for three-pass DInSAR.