基于DInSAR方法监测南京地表沉降的结果与分析

Analysis of land subsidence detection in Nanjing city area using DInSAR

针对 InSAR 数据预挑选过程中一直存在着人为的主观性问题,提出了基于相干系数的像对可用性判断因子的概念,利用 DInSAR 技术对可用性判断因子检测出的可用像对进行处理,获得了南京市区1996年8月到2000年12月间地表沉降结果。通过对沉降结果的时空分析,指出这期间南京地区没有发生持续性的沉陷漏斗,但该地区的地面沉降受地下水位的影响较大,呈现明显的季节性变化。

The paper presents the conception of available judgment factor based on the InSAR coherence coefficient since the InSAR processing highly depends on subjective experience in preelection of pairs of interferometric SAR images. The availability of SAR data can be determined by calculating the proposed factor, and SAR images can be processed using the two-pass DInSAR technology. The high-resolution results of the land subsidence detection in Nanjing city acquired from Aug. 1996 to Dec. 2000 are analysed and the land subsidence characters in space and time are given. It can be seen from the results that there is not continuous land subsidence in Nanjing city area but it is greatly affected by the change of ground water. There is a close relationship between the land subsidence and the season change in Nanjing city.