InSAR技术用于西安地区1992-1993年间活动地裂缝的定位研究

Research on positioning of ground fissures in Xi'an during 1992-1993 based on InSAR interferometry

西安地裂缝是一种典型的地质灾害,自首次出现至今已有近半个世纪.基于活动地裂缝造成的形变去相干特征,通过分析滤波后的差分干涉图的伪相干图来提取活动地裂缝的位置信息.采用两幅ERS影像对西安地区1992-1993年间的活动地裂缝进行了定位研究,通过与该时间段工程地质调查的地裂缝位置比较发现二者有很强的一致性.通过该时间段地裂缝水准对点监测资料比较发现活动地裂缝区域易于产生相位解缠粗差,因此在后续采用差分InSAR获取地裂缝不连续形变信息时需要特别注意.

Ground fissure in Xi＇an is a typical geo-hazard with nearly half a century history. Based on the theory of deformation de-correlation of the active ground fissures, this paper mainly investigates the positioning of active ground fissures by analyzing the pseudo coherence map of adaptively filtered differential interferogram. We take two ERS SAR data during 1992-1993 to investigate the active fissures position during this period. And high correlation can be achieved by comparing with the engineering geological investigation results. The leveling data are applied to demonstrate the phase unwrapping errors in the active fissure regions. Therefore special considerations should be taken for discontinuous deformation monitoring in the active fissure region by applying differential InSAR techniques later on.