Research On Land Subsidence Monitoring Based On InSAR Technology

In recent years,with the large-scale construction of cities,land subsidence has attracted much attention.It is of great significance to monitor and study the land subsidence in cities,find out the areas with serious subsidence in time and prevent them.Traditional time-consuming and settlement of GPS leveling monitoring,advanced InSAR technology to get high precision of the surface subsidence information,not only hard to access data and software,and it is difficult to verify its accuracy,based on open source Sentinel-1 a and ENVI software and data,for example,through the D-InSAR technique of kunming city on March 15,2017 to 30 January 9,2018 range scene data processing analysis.The main research c ontents and achievements of this paper are as follows:The main research contents of this paper include :(1)comparative analysis of the processing effects of sentinel-1a data with different orbital directions under the same polarization mode;(2)comparat ive analysis of the processing effects of sentinel-1a data with different polarization modes in the same orbital direction;(3)compare and analyze the effect of different filtering methods and unwrapping methods in filtering and unwrapping processes;(4)the sentinel 1A data and data processing method most suitable for the study area were selected to obtain the surface subsidence information of kunming using d-insar technology.The main research results of this paper are as follows :(1)by visual interpretation of the image,the coverage of the orbit lifting image is more comprehensive than that of the orbit lowering image,and the processing effect of the orbit lifting image in the research area is better than that of the orbit lowering image;(2)the processing effect of vv-polarized images with the same orbital direction is better than that of vh-polarized images;(3)in the process of filtering,the processing effects of various filters are compared.The most suitable filtering method for the study area is the modified Goldstein filtering method;(4)when phase untangling is carried out,through comparative analysis of different untangling methods,the minimum cost flow method is most suitable for the treatment of the study area;(5)land surface subsidence results of the target area from March 15,2017 to January 9,2018 were obtained through d-insar technology;(6)the inducing factors of the sedimentation funnel of xiaobanqiao in the southern urban area mainly include quaternary system,groundwater over draft,tectonic movement,large-scale urban construction and concentrated precipitation.