Study On The Ground Deformation Extraction In Mining Area Based On RADARSAT-2 Interferometric Data

Ground subsidence has become an important factor to influence and restrict the sustainable development in mining areas.The damage to the ecological appears not only at the coal mining area,but also at the cities and towns. The surface subsidence poses a serious threat to people’s production and life safety. Therefore, it would be of great significance to explore a high-efficiency, high-precision, low-cost settlement monitoring method.Contrast to conventional method of land subsidence monitoring,D-InSAR technology has full time,full weather,large area observations and low cost, high accuracy monitoring ground deformation capacity. In theory, D-InSAR technology has the accuracy of millimeter level, becoming an important technical means to monitor the ground deformation.This paper discusses the feasibility of subsidence monitoring in Pingsuo mining based on a new generation of satellite radar interferometry data.And,the monitoring method of time series InSAR(SBAS-InSAR) is studied in towns around Pingshuo mine. The main research contents and conclusions are as follows:(1) The research status at home and abroad of InSAR is analyzed.And the interferometric data sources are summarized on the current both domestic and foreign.The principle of InSAR is analyzed in detail. This paper also analyses and researchs the interferometric phase composition and deformation sensitivity.(2) This paper has make an analysis of several key steps of D-InSAR data processing.And Pingshuo mine is taken as the study area.Then,five interferometry pairs are selected based on the principle of small baseline(small spatial baseline and small temporal baseline).Using D-InSAR technique to process the five pairs selected data.Finally,the study area sedigraph is getted.On this basis,subsidence information is post-processed with the GIS system to analyze the temporal and spatial evolution of the surface settlement. Three large settlement area can be observed from the sedigraph. Two of which correspond to the open-cast coal mines of Antaibao and Anjialing,The results correspond the conclusion of subsidence mainly consistent in exploration area. The results of quantitative analysis from the profile graphs:the sedimentation value decreased from the settlement center outward,and forming a subsidence funnel which takes the maximum settlement value as the center. Another large subsidence area may be caused by landslide subsidence, and the possible causes of the landslide collapse is analyzed.(3) The paper analyzes the limitations of traditional D-InSAR technique,and then discusses the feasibility of using time series InSAR(SBAS-InSAR) based on a small number of interferometric data to monitor subsidence.At first,the principle of PS-InSAR and SBAS-InSAR are analyzed in detail,and comparing the advantages and disadvantages of both.And then,15 interferometry pairs are selected based on SBAS-InSAR technique.The study area is Shuocheng district which is the main urban area of Shuozhou City in Shanxi Province.Using SARscape to process the selected interferometry data by SBAS technique.Finally, Obtaining the average settlement rate map of the study area. Individual regional sedimentation rate reached 70mm/a.Four key research areas is analyzed in time series. The SBAS technology in less data can still timing analysis is verified.