采用振幅和相位联合分析的PS探测方法,以上海市作为实验研究区,进行PSI城市地表沉降监测并对成因进行了详细分析.实验结果表明:①由于大规模的城市建设、地下水开采、工业化生产和交通运输等活动,研究区内最大沉降速率达-47mm/年,平均沉降速率达-16.96mm/年,地表沉降比较明显.②2008年以前的沉降中心得到有效控制,现阶段有3个沉降中心较为明显,即罗泾镇宝山工业园区,平均沉降速率为-29.8mm/年；虹口足球场,平均沉降速率为-24.58mm/年；闵行经济技术开发区,平均沉降速率为-32.2mm/年.③地表沉降随着城市建设的发展向北、南、西南、东南逐步扩展.④水准数据验证了监测结果,精度可达土6mm,表明PSI技术在城市地表沉降监测中具有很大的优势.%This study focuses on the monitoring by Persistent Scatterer Interferometry (PSD technique and analyzes the reason of surface settlement By the analysis of the PS amplitude and phase detection method, the experiments of subsidence monitoring and a detailed analysis of surface settlement are performed using 16 high resolution SAR images collected by the X-band radar sensor onboard the German satellite TerraSAR-X over Shanghai between 28 March 2009 and 30 January 2010. We obtained the following main conclusions. Firstly,there are obvious subsidence signatures in the entire study area,which can be attributed to large-scale urban construction, excessive withdrawal of groundwater, industrial production, transportation and so forth. The maximum relative subsidence rate in the study area is as high as-47 mm/yr and the averaged subsidence rate is -16. 96 mm/yr. Secondly,previous settlement center in 2008 has been effectively controlled. At this stage,three centers of subsidence are more obvious,namely Baoshan Industrial Park in Luo Jing Town which an average sedimentation rate is -29. 8 mm/year,Hongkou Football Stadium which an average sedimentation rate is -24. 58 mm/year,and Minhang Economic and Technological Development Zone which an average sedimentation rate is -32. 2 mm/year. Thirdly,the land subsidence has gradually extended to north, south,southwest,and southeast along with urban construction. Lastly,the experiment results have been validated with leveling data and the accuracy is ±6 mm, which shows that the PSI technique can be used to monitor urban ground deformation.
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