利用GPS位移数据校正2011日本Tohoku地震的InSAR形变场

摘要

Orbital state vectors are important parameters that play crucial roles in the processing of InSAR,from the original offset of coarse registration to the accurate generation of the ultimate DEM or deformation measurements.Errors in the baseline are caused by errors in the orbital state vectors,which present as phase errors in the interferogram.We map the coseimic deformation of the 2011 Tohoku earthquake with data from four ascending ALOS/PALSAR tracks and GPS coseimic displacements that cover most of northeastern Japan.The quadratic polynomial approximation is proposed to eliminate orbital errors from the interferogram,and we analyze the effects of incidence angle.The precision of corrected coseimic deformation measured by InSAR is verified by analyzing the residual deformation in the interferogram.%轨道误差是InSAR数据处理中的一个重要因素,对从最初的图像配准到最后的高程值或形变值图像的生成都有着重要影响.含有误差的轨道参数造成基线误差以残差条纹的形式存在于干涉图中.本文利用4个条带的61景PALSAR升轨数据,通过InSAR干涉测量得到覆盖2011日本Tohoku地震的雷达视线向的地表同震位移场.通过联合GPS同震位移数据,采用二次多项式曲面拟合的方法去除InSAR同震形变数据中的卫星轨道误差,并分析雷达入射角变化对轨道误差去除的影响.对干涉图中拟合残差进行分析,改正后的InSAR同震形变场精度得到较大提高.