极具潜力的空间对地观测新技术——合成孔径雷达干涉

Abstract

“合成孔径雷达干涉(InSAR)”是近十年发展起来的空间对地观测遥感新技术。它具有从覆盖同一地区的星载(或机载)合成孔径雷达复数图像对提取干涉相位图,借助于雷达成像时的姿态数据重建地表三维模型(即数字高程模型)的巨大潜力。尤其是基于多幅雷达复数图像处理的差分干涉技术 (D-InSAR)可以用于监测地表形变,精度可达厘米级甚至更高 ,其监测空间分辨率是前所未有的。介绍了 In SAR和 D- In SAR的基本原理,对影响干涉结果的一些重要因素做了分析,重点回顾和展望了差分干涉技术在与地表形变有关的地震监测和震后形变测量、地面下沉和山体滑坡、火山运动监测等方面应用的现状和前景。 Synthetic Aperture Radar Interferometry (InSAR) is a new and potential technology that has been developed in the last decade or so for observation of the Earth. It can be used to generate large area (even global) DEM or to detect Earth surface deformation by means of interferometric phase data and attitude data of the radar platform. In particular, Differential InSAR (D InSAR) has been demonstrated to have unprecedented ability to measure and monitor Earth surface change with excellent characteristics of continuous spatial coverage and nearly automatic processing and high accuracy (up to cm level or even better). This paper first introduces the basic principles of InSAR and D InSAR, and summarizes the involved key processing algorithms of interferometric technology, including SAR images coregistration, phase unwrapping and baseline estimation etc. Then, some factors, that affect the quality of interferometric products, are generally analyzed, i.e., phase quality and baseline parameters play very important roles on interferometric processes. Finally, emphasis is placed on reviewing D InSAR applications in measuring and monitoring Earth surface deformations caused by earthquakes, post seismic displacements, ground subsidence, landslides and volcanic movements.