中文摘要：

采用ROI—PAC软件处理汶川地震前后ALOSPALSAR474轨道的4景影像，利用ERA—Interim资料和NeQuick电离层模型对其进行对流层和电离层延迟误差修正，得到地表垂直位移，并和5个GPS台站测量的地表沉降值进行比较，结果表明合成孔径雷达差分干涉测量（D—InSAR）得出的垂直位移和其经过对流层、电离层延迟改正后的垂直位移，与GPS实测值相比，前者差值平均值为0．104m，后者差值平均值为0．057m，说明加入对流层和电离层大气延迟误差改正后，D—InSAR的精度得到了提高。

英文摘要：

Four images for ALOS PALSAR of the track 474 before and after Wenchuan earthquake are pro cessed by the software ROLPAC, and then the tropospheric and ionospheric delay are corrected by ERAInterim data and NeQuiek model. The sedimentation is compared with that derived from five GPS observations, the results show that the mean value of the differences between the sedimentation derived from DInSAR and that from GPS ob servations is 0. 104 m, which is 0. 057 m when the sedimentation derived from DInSAR which the tropospheric and ionospheric delay are corrected. This illuminates that the accuracy of the sedimentation from DInSAR is improved after the tropospheric and ionospheric delay are corrected.