Application Research Of Ground Subsidence Monitoring Based On Time Series InSAR Technology

D-InSAR(Differential Interferometric Synthetic Aperture Radar)technology stands out from many ground observation methods with its monitoring accuracy of up to centimeters or even millimeters.However,the conventional D-InSAR technology is based on two radar images covering the same measurement area at different times for slow deformation monitoring.Due to the different data acquisition times and the fact that the platform cannot be completely overlapped in space and the scattering characteristics of the target are different,the incoherence is caused,and the subsequent phase unwrapping and practical application are very difficult.Therefore,the surface is slow in monitoring for a long time.The deformation is limited.In order to overcome the influence of incoherence and atmospheric delay phase on monitoring accuracy in the surface deformation inversion,time series InSAR technology emerged.The point where the long-term sequence scattering characteristics are stable is taken as the research object,and the ground subsidence is obtained by extracting and using the phase information inversion of these point targets.The time-series InSAR method has been rich in research results,and the high-precision deformation results in the Taiyuan,Beijing,Datong,and Yellow River Delta regions are consistent with the measured sedimentation trend,which further confirms its application in land subsidence monitoring.potential.Land subsidence is one of the serious geological disasters facing China at present.Subsidence monitoring is an indispensable link for effective supervision of land subsidence.Howto timely and detailed understanding of the temporal and spatial evolution characteristics of land subsidence,research and analysis of the ground subsidence mechanism is the primary task.Based on the principle and specific process of time series technology,this paper further discusses the key technologies in tinge series InSAR,and obtains high-precision ground subsidence information based on this technology.The main research contents and achievements of this paper can be summarized as follows:(1)Introduction to the basic principles of InSARThe basic principles and technical processes of InSAR and D-InSAR technologies are briefly introduced.On this basis.the sources of error affecting monitoring accuracy are analyzed.Aiming at the limitations of traditional D-InSAR technology,several time series InSAR technologies with a wide range of applications are highlighted.(2)Large-scale deformation detection and identification in Lvliang Mountain areaBased on the 57 sentry data covering 4 tracks in Lvliang Mountain area,based on the Stacking technology,the early identification of large-scale land subsidence disasters was carried out,and multiple land subsidence areas were successfully detected,combined with the mining distribution map in the study area,qualitative analysis the spatial and temporal evolution of land subsidence in Lvliang Mountain area.(3)Application of SBAS in land subsidence monitoring in Jiaocheng-Qingxu areaInSAR time series deformation monitoring was carried out for the Jiaocheng-Qingxu area of Shanxi Province.The deformation time series results were obtained based on SBAS technique using ALOS PALSAR data.The temporal and spatial characteristics of land subsidence development during 2007-2010 were analyzed,and the mechanism of land subsidence was further analyzed.By comparing the GPS results and monitoring results of the same period,it is found that the two have high consistency,which proves the validity and reliability of the monitoring results.(4)Research and application of short baseline interference point target analysis method in land subsidenceCombining the advantages of SBAS-InSAR and PS-InSAR technology,focusing on the key technologies and processes of the interference point target analysis technology,and drawing on the idea of SBAS technology to achieve the fusion of the two,namely the short-time-time baseline interference point target analysis technology The annual average deformation rate and deformation time series were extracted using the Sentinel-1A data of the Jiaocheng-Qingxu area between 2017.1-2018.10.The results are compared with the historical deformation information,and the history and current status of the two-stage land subsidence development arc analyzed to provide basic information for the cause and trend analysis of the settlement.