利用MERIS水汽数据改正ASAR干涉图中的大气影响  

Correcting atmospheric effects in ASAR interferogram with MERIS integrated water vapor data

作　　者：许文斌[1,2] 李志伟[1,2] 丁晓利[1,3] 冯光财[3] 胡俊[1,2] 龙江平[1,2] 尹宏杰[1,2] 杨亚夫[1,2] 

机构地区：[1]中南大学信息物理工程学院,长沙410083 [2]湖南省普通高校精密工程测量及形变灾害监测重点实验室 [3]香港理工大学土地测量与地理资讯学系,香港九龙

出　　处：《地球物理学报》2010年第5期1073-1084,共12页Chinese Journal of Geophysics

基　　金：国家自然科学基金(40774003,40974006);香港研究资助局项目(PolyU5161/06E);教育部新世纪优秀人才支持计划(NCET-08-0570);国家西部1:50000空白区测图工程2009年度研究课题;湖南省科技厅重大专项(2008FJ1006);中南大学研究生教育创新工程项目(2009ssxt179)资助

摘　　要：大气对流层对雷达信号的传播延迟是制约重复轨道InSAR高精度测量应用的重要因素之一.本文描述了MERIS水汽数据用于ASAR干涉图大气改正的方法;并以美国南加州地区为例,选取4对ENVISAT ASAR数据进行了大气改正的研究.结果显示对这4幅干涉图,经过MERIS水汽数据改正后InSAR与GPS差异的RMS分别降低了41.7%,65.2%,19.3%和39.4%.平均改善程度达41.4%.更重要的是,经过MERIS水汽改正后,从2005～2007年干涉图和2004～2007年干涉图中,能清楚地识别出三处形变最明显的区域:Long Beach-Santa Ana盆地、Pomona-Ontario和San Bernardino,其形变速率从 8 mm/a到-28 mm/a,大部分在-20 mm/a左右,与这些地区2003年以前的历史形变速率基本一致.因此,采用无云条件下的MERIS水蒸汽数据改正同步获取的ASAR干涉图,可以显著地降低大气水汽对干涉图相位的影响,从而更真实地反映地表形变等地球物理信号。The troposphere delay of radar signals has been one of the major limitations for the application of high precision repeat pass InSAR. In this paper, we present the atmospheric correction methods for ASAR interferograms with MERIS integrated water vapor （IWV） data. Then, using four ASAR interferometric pairs over Southern California as examples, this paper conducts the atmospheric corrections with MERIS IWV data. The results show that after the correction the RMS differences between InSAR and GPS were reduced by 41.7%,65.2%,19.3%, and 39.4%, respectively for the four selected interferograms, with an average improvement of 41.4%. Most importantly, after the correction, three distinct deformation areas have been identified, i.e., Long Beach-Santa Ana Basin, Pomona-Ontario and San Bernardino, with the deformation velocities ranging from -8 mm/a to -28 mm/a and on average around -20 mm/a. The deformation is quite consistent with the historical deformation derived by other researchers. Thus, using the cloudless MERIS IWV data for correcting the synchronized ASAR interferogram can significantly reduce the atmospheric effects in the interferograms and further better capture the ground deformation and other geophysical signals.

关 键 词：合成孔径雷达干涉 MERIS ASAR GPS 大气改正 地表形变 

分 类 号：P407[天文地球—大气科学及气象学]