基于哨兵双极化数据的城市地表形变监测方法

Urban Surface Deformation Monitoring Method Based on Sentinel Dual-polarization Data

为提升传统时序InSAR在城市区域的地表形变监测结果,探究双极化数据在城市变形监测中的优势,本文基于双极化Sentinel-1数据,利用时序合成孔径干涉雷达技术(time-series interferometric synthetic aperture radar,TS-InSAR)和极化时序InSAR技术(polarimetric persistent scatterer interferometry,PolPSI)对上海市主要城市区域进行了地表形变监测研究,并进一步对影响PolPSI技术优化效果的因素进行了分析。结果表明:采用极化优化技术对Sentinel-1双极化数据进行干涉图优化后,干涉图相位质量和像元相干性都能得到明显提升,高质量像元数量大量增加;通过对比26幅优化前后干涉图,干涉图相位标准差由未优化前的0.607降低至优化后的0.518,相位质量得到明显的提升;使用双极化数据较单极化数据获得的研究区域监测点密度提升63%,能反映更丰富的地表形变细节,为解决相干性较差区域PS监测点过少问题提供了一种新的解决思路。

In order to enhance the accuracy of surface deformation monitoring in urban areas using traditional time-series InSAR and to investigate the advantages of utilizing dual-polarization data in urban deformation monitoring,this study is based on dual-polarization Sentinel-1 data.Time-series interferometric synthetic aperture radar(TS-InSAR)and polarimetric time-series InSAR(PolPSI)were utilized to monitor surface deformation in the primary urban region of Shanghai.Furthermore,the factors influencing the optimization effect of PolPSI technology are analyzed.The results show that the interferogram phase quality and pixel coherence of Sentinel-1 dual-polarization data can be significantly improved by utilizing polarization optimization technology,and the number of high-quality pixels can be greatly increased.By comparing 26 interferograms before and after optimization,the phase standard deviation of interferograms decreases from 0.607 before optimization to 0.518 after optimization,and the phase quality is obviously improved.The density of monitoring points in the study area,obtained using dual-polarization data,is 63%higher than that obtained with single-polarization data.Having more monitoring points can capture a richer array of surface deformation details,offering a new solution to the issue of inadequate PS monitoring points in areas with low coherence.