Research On InSAR Three-dimensional Deformation Extraction Method And Application Based On Mining Subsidence Knowledge

Interferometric Synthetic Aperture Radar(InSAR)is widely used to monitor ground deformation because of its high resolution,wide coverage,all-day,all-weather,etc,which can make up for the shortcomings of traditional geodetic means such as small monitoring range,large workload,low efficiency and low spatial and temporal resolution.China is a big coal consumption country,and underground coal mining has caused a series of damage to the surface and environment.InSAR is a new method for deformation monitoring in mining areas.Vertical subsidence obtained by Differential Interferometric Synthetic Aperture Radar(DInSAR)often neglects the horizontal deformation.However,the horizontal movement of the mining area is relatively large,so the subsidence will lead to errors.In addition,the damage of the mining area structures is judged by the surface tilt,horizontal deformation and curvature,and the three-dimensional(3D)deformation monitoring is urgently needed.Therefore,it is necessary to study the 3D surface deformation monitoring in mining area,which is not only necessary for mining area application,but also necessary for InSAR algorithm optimization.At present,3D surface deformation resolution methods mainly include integrating multi-source/multi-orbit SAR images,integrating DInSAR and Offsettracking,integrating DInSAR and multi-aperture interferometry(MAI),integrating DInSAR and GPS,and method based on prior knowledge.The main problems of the first four methods need certain conditions,for example,sufficient SAR images or GPS observation points,rigorous data processing theory,etc.These restrictions prevent their widespread use.3D deformation calculation method based on prior knowledge makes corresponding assumptions according to the characteristics of surface deformation,and then simplifies the process of 3D deformation calculation.At present,single-track SAR images can be used to obtain 3D surface deformation of mining area,which greatly solves the restriction of the number of SAR images on retrieving 3D deformation.This paper is devoted to further study the method of using single-track SAR images to retrieve 3D deformation,and improve the shortcomings of previous methods.The main research results are as follows:(1)The different characteristics of surface movement basin between horizontal or near-horizontal and inclined coal seam mining were analyzed and compared,and the InSAR 3D deformation calculation model based on probability integral method was established.The model is based on the proportional relationship between surface horizontal movement and surface tilt along the main section of inclined coal seam mining,and 3D deformation can be retrieved only by using single-track SAR images.The simulated experiment was carried out and Radarsat-2 images covered 15235 working face of a mine in Fengfeng mine area were selected for verification.The results show that if the inclination angle of coal seam is neglected,there will be large errors in the horizontal movement along inclined direction,and the improved method can obtained 3D deformation with a higher accuracy.(2)Based on surface subsidence characteristics of mining area,the method of obtaining 3D deformation is proposed.This method utilizes the symmetrical features of the surface subsidence and horizontal movement to construct the 3D surface deformation model using single-track images.The simulated experiment are carried out and Sentinel-1A images covered B102 working face of a mine in Suzhou City,Anhui Province are selected for verification.The results show that this method can acquire the 3D surface deformation of mining area,and the vertical displacement obtained is stable and reliable,the azimuth angle of the working face along strike direction has certain influence on the horizontal displacement accuracy.(3)The Graphical User Interface(GUI)is designed by MATLAB programming language.The codes of the above two methods of obtaining 3D deformation are sorted out,and the 3D deformation solution interface is designed.Finally,examples of 132610 working face of a mina in Fengfeng mine area and B102 working face in a mine in Suzhou City,Anhui Province are used to verify.And the results show that the designed interface can run smoothly to obtain 3D deformation,the 3D deformation results are clearly demonstrated and has certain practicability.