条带式InSAR大气效应影响分析研究

InSAR Atmospheric Effects Analysis of ASAR Image Mode Products

针对重复轨道合成孔径雷达干涉测量(InSAR)中的大气效应问题,以伊朗巴姆地区Envisat ASAR条带模式数据为例,在开源软件ROI_PAC基础上自主编程实现了InSAR大气效应的去除,并通过干涉处理过程不同阶段的输出结果,定性及定量比较了大气校正前后的差异。研究结果表明:条带式SAR数据干涉处理过程中,大气相位一定程度上影响了残余平地相位的去除,校正后雷达视线向形变量测量误差降低了约20 mm,证明大气效应的去除能够提高InSAR测量结果的精度。

Atmospheric effect represents one of the major limitations of repeat-pass InSAR technique for precise land deformation measurements. To solve this problem, an approach is developed to remove the atmospheric effect on InSAR measurements based on the JPL/Caltech Repeat Orbit Interfeormetric PACkage （ROI_PAC） that performs the InSAR processing. As an example, the Image Mode （IM） mode data covering the Barn of Iran from the Envisat ASAR instrument is chosen to test the approach. The InSAR results without atmospheric correction and that with atmospheric correction are compared from three individual aspects respectively. The results show that the atmospheric phase affects the removal of the residual orbital fringes and the error of the InSAR LOS （line of sight） displacement reduce about 20 mm after the atmospheric effect is removed. It indicates that the removal of the atmospheric effect can improve the accuracy of the InSAR measurement results.