南宁市地表形变InSAR监测及时空分析

Surface Deformation Monitoring and Temporal Spatial Analysis in Nanning City with InSAR

基于Sentinel1-A数据,首先利用SBAS-InSAR(satellite-based augmentation system-interferometric synthetic aperture radar)技术对南宁市区2017年12月至2019年1月的地表形变进行计算,获得研究区的地表形变速率图和累积形变量;其次,从Sentinel1-A卫星影像数据中选择6景影像进行差分干涉处理,提取5个时间段内的形变信息,并叠加分析得到总形变量;最后利用D-InSAR(differential-InSAR)获得的形变结果对SBAS监测结果进行验证分析。结果表明:2017-2019年,南宁市地表形变极不均匀,其最大沉降速率约为23.52 mm/a,最大抬升速率约为17.77 mm/a;SBAS和D-InSAR所得监测结果总体上具有一致性,但局部存在一定差异。其中,SBAS方法提取的最大形变量约为31.55 mm,D-InSAR提取的最大形变量为39.93 mm。

Based on Sentinel1-A images,this paper first calculates the surface deformation of Nanning urban area from December 2017 to January 2019 by using the Small Baseline Subset InSAR(SBAS-InSAR) technology,and obtaines the surface deformation rate map and cumulative shape variables of the study area.Secondly,six-scene images are selected from Sentinel1-A images for differential interference processing to extract deformation information in five time periods,and total shape variables are obtained by superposition analysis.Finally,the deformation results obtained by Differential InSAR(D-InSAR) are used to verify and analyze the SBAS monitoring results.The results show that during the period of 2017-2019,the surface deformation of Nanning is extremely uneven,with the maximum subsidence rate about 23.52 mm/yr and the maximum uplift rate around 17.77 mm/yr,that the monitoring results obtained by SBAS and D-InSAR are consistent on the whole,but there are some local differences.Among them,the maximum shape variable extracted by SBAS method is about 31.55 mm,and the maximum shape variable extracted by D-InSAR is 39.93 mm.