Law Of Mining Subsidence In Xikuangshan Using InSAR

Over-exploitation of mineral resources in the underground space formed large area of the goaf, which lead to the rock and surface move. Buildings, roads and other facilities on the ground are damaged, those not only endanger the safety of human life and property, but also result in the exploitation of mineral resources more difficult or even unable to mining. Synthetic aperture radar technology has been some successful cases used in mine monitoring. It has the advantage of all-weather, planar observation and monitoring centimeter-level deformation. This article explores two problems. One is the research on registration between InSAR subsidence and topographic map. Another is to use small baseline (Small-Baseline Subset SBAS) technology to analysis the laws of mining subsidence of Xikuangshan. The research work includes:1) We can obtain high-precision subsidence field by the technique of InSAR, while its practical application is confined by using different coordinate system and projection method with respect to those used in China, as well as the deviations of geocoding caused by satellite orbital and atmospheric errors. To solve these problems, in this paper we research on the registration algorithm between subsidence field of InSAR and topographic map based on corner reflectors (CR). Firstly, we detect SAR image to identify the positions of CR points, which can be regard as control points for registration and rectification. Then, we use a quadratic polynomial to rectify the geocoded InSAR image. Finally, the method of affine is used to convert coordinate reference frames between InSAR image and vector map. By these ways, the subsidence fields of InSAR not only have accurate coordinates, but also build conversion relationship between the topographic maps. The results show that, the algorithm is accurate and reliable, and the theory is rather easy to be realized in programming.2) D-InSAR technology cannot be obtained a temporal deformation sequence due to spatial and time decorrelation. In order to get a temporal deformation sequence, we use SBAS algorithm to weaken the influence of decorrelation. In this paper, we try to analysis the curve of ground movement in Tongjiayuan of Xikuangshan by fourteen observation data using SBAS algorithm. Experiments show that the sinking curves both in direction of strike and tendency have the same characteristic, which can fit by Gaussian curve. By overlay between goaf and subsidence field, we can understand the features of the ground movement in Xikuangshan clearly. We calculate the slopes of66th exploration line for further understand the feature of ground movement in Xikuangshan, but the slopes calculated by subsidence values are not good. Then we use moving average to correct the subsidence values, by this step, we find the slope have a reasonable physical explanation. Figures30, tables6, references50.