中文摘要：

在总结两轨差分中参考DEM影响的最新研究成果基础上,以青藏高原上典型平地和山地作为研究区,利用理论上没有形变的ERS Tandem像对以及3种常用外部参考DEM（SRTM,ASTER GDEM,1∶5万DEM）,使用ROI_PAC软件进行两轨差分干涉试验。实例证明：SRTM更适合作为两轨差分中的外部参考DEM,并对此试验结果予以解释分析,即多源DEM数据质量的差异导致干涉图与DEM配准精度的不同,并最终反映在差分干涉相位误差中。本文研究结论对提高DInSAR处理精度有参考价值。

英文摘要：

In this paper,the state-of-the-art research on two-pass DInSAR under the influence of reference DEM is summarized.This paper takes typical flat ground and mountain land at Qinghai-Tibet Plateau as test regions.Using ERS Tandem image pairs without any deformation in theory and three external reference DEMs（SRTM,ASTER GDEM,1：50000 DEM）,the two-pass DInSAR processing with the help of ROI_PAC software is performed.In this paper,the way that multisource DEMs affects deformation results in two-pass DInSAR has been proved.The fact is that SRTM is more suitable to be external reference DEM in two-pass DInSAR.Finally,the differences of multisource DEMs＇ data quality resulting in differences of registration errors between interferogram and DEM are explored,and the effect of data quality can be shown in final DInSAR phase errors.