Research And Application Of Surface Subsidence Monitoring In Western Mining Area Based On InSAR Technology

Inner Mongolia Autonomous Region is one of the most abundant areas of coal resources in Western China,and there are many ethnic minorities.The problems caused by coal mining will not only be the problem of environmental change,but also affect social stability and national unity.Based on InSAR technology,this paper studies the ground subsidence in western mining area,provides a new,fast and effective method for monitoring the ground subsidence caused by coal mining in western coal mining enterprises,and obtains the development law of ground subsidence and deformation in time,which can provide scientific basis for safe mining and reasonable control of subsidence area in mining area in time.D-InSAR technology has been applied to deformation monitoring in many aspects because of its advantages of wide coverage,all-day,all-weather and high accuracy.However,due to the influence of time and space decoherence and atmospheric phase,the high phase gradient caused by large surface subsidence under long time baseline and more vegetation coverage in summer,D-InSAR technology can not accurately retrieve the surface deformation,and the decoherence is serious.CR-InSAR can solve the problem of incoherence to a certain extent,and has good prospects in the field of monitoring surface deformation in mining areas.Based on this,this paper studies the feasibility of the application of D-InSAR technology and CR-InSAR technology in surface subsidence monitoring in western mining areas.On the basis of the basic principles of InSAR,D-InSAR and CR-InSAR technologies,this paper analyses some main factors affecting the monitoring of surface deformation by D-InSAR technology.Taking Yingpan Moat Coal Mine in Inner Mongolia as an example,the data processing flow and key algorithm of differential interferometry based on sentry data and SARscape software are analyzed emphatically.Seven Sentinel-1A images were selected to compose six groups of interferometric images,and the D-InSAR surface subsidence map from 11 January 2018 to 22 July 2018 was obtained by differential interferometric data processing.The D-InSAR subsidence map is transformed into WGS84 coordinate superimposed mining area working face map for post-processing analysis,and the subsidence situation of working face is extracted and the isoline and section map are generated.The surface subsidence situation is analyzed by using GIS method.A certain number of continuous points are selected along the research direction line and the trend line,and the conclusion is drawn by comparing the D-InSAR processing results with the measured leveling data.The results show that there are obvious SUBSIDENCE BASINS above 2101 and 2201 working faces in the study area,and the center of the subsidence basin changes with the mining progress.The D-InSAR subsidence results show good consistency in time and space,and the monitoring accuracy of D-InSAR reaches millimeter level.D-InSAR technology can monitor mining area surface subsidence timely and effectively,and provide reliable basis for monitoring and predicting mining area subsidence disasters.In order to alleviate the influence of time and space incoherence of D-InSAR technology in monitoring deformation,this paper studies the method of mining area settlement monitoring based on CR-InSAR technology,develops and designs artificial angle reflector which can be applied to many satellites according to the actual situation of the mining area,and lays and installs it in the research area,explores the method of identifying and extracting the angle reflector deformation..The results show that the CR point deformation obtained by CR-InSAR technology is generally consistent with the monitoring results of GPS and D-InSAR,which verifies the feasibility of CR-InSAR technology and provides a basis and reference example for further study of mining subsidence in western mining areas.