利用时序InSAR技术反演塘沽地区沉降历史
Inversion of Subsidence Based on TemporalInSAR Method in Tanggu Area
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摘要: 目的 以塘沽区为研究对象,对1992~1998年间的19景 ERS-1/2影像,采用时序InSAR技术反演其由过量开采地下水引起的沉降历史。采用三次多项式模拟实际沉降模型,精确获取SAR成像时间点的下沉值,与反演值对比验证,结果表明,时序InSAR技术反演的历史累积沉降信息与水准数据一致,两者的平均沉降速率之差在5mm/a以内;研究区域以20~50mm/a的速率在整体下沉,西部地区下沉最为严重。Abstract: Objective The temporal InSAR technique overcomes the temporal/spatial decorrelation with the slowdecorrelating filtered phase(SDFP)pixels identified by phase stability.In this paper,the Tanggu are-a has been selected as study area,where the subsidence information due to groundwater overexploita-tion from May 1992to December 1998has been inversed by processing 19ERS-1/2acquisitions usingthe temporal InSAR method.The subsidence in time of the SAR imaging has been estimated accurate-ly using cubic polynomial model.And the result derived from temporal InSAR was consistent with thelevel data which was regarded as GCPs with a little difference that less than 5mm/a.Besides,the re-sult also showed that the whole study area has suffered subsidence with a mean rate 20~50mm/a dur-ing 1992to 1998,and the subsidence is severity in the eastern.