Study On Some Issues Of Calculating The Ground Subsidence In Mining Area With SRA Data

As an active microwave imaging remote sensing technology, D-In SAR has acquired an all-weather operational capability.It can penetrate clouds and to some extent, get images under rain belt,earth surface and vegetation. Compared with traditional surveying techniques which have been used in mining subsidence monitoring, D-In SAR has the advantages of low cost,fast data processing, special capability in accurately determining settlement scope and stress field due to its areascan characteristic and potentiality in extracting millimeter deformation. However, in coal mine area where the environment is complex and always changing, and usually has big deformation gradient, there are some limitations to monitor coal mining subsidence with D-In SAR.This paper summarized the main constraints of D-In SAR monitoring mining subsidence,and made a depth study on coherence and detectable deformation gradient. As the oblique distance imaging mode of SAR, This paper introduced the pixel offset deformation monitoring method based on amplitude information.It calculated the subsidence in Fengfeng mining area with data from Radarsat-2 and made a comprehensive analysis of the results.(1) It introduced basic principles, such as SAR imaging,SAR imaging geometry and the basic characteristic of SAR image, then analyzed the principles and data processing flow of D-In SAR surveying.(2) According to coherence decomposition model,it analyzed the impact of several components associated with the SAR system parameters(such as incident angle, wavelength, resolution, bandwidth) of coherence observations.Based on real data,it summarized the coherence of coal mine area.(3) According to analysis of the function model of detectable deformation gradient, it studied the impact of pixel resolution, radar wavelength and the coherence of DIn SAR detectable deformation gradient, verified the effection of the image registration precision and multi look on settlement calculation results.(4) It focused on the pixel offset deformation monitoring method based on the amplitude information. According to the principle of D-In SAR,it deduced the data processing,then determined the optimal key algorithms and analyzed the factors affecting the accuracy of the algorithm with experiment.(5) In Fengfeng mining area as an example, it calculated the ground subsidence by using Radarsat-2 image.Firstly,it analyzed and evaluated the results of D-In SAR in terms of its ability of detecting and locating subsidence basin,monitoring subsidence with spatio-temporal evolution,as well as its actual monitoring precition.Then,analyzed the reliability and accuracy of ground subsidence showing that pixel offset method for monitoring the subsidence is feasible, and can make a more reliable results;Finally,got a more complete ground subsidence basin through combining D-In SAR with the pixel offset method.This paper got many favorable conclusions though to researching the major problems that monitoring coal mining area subsidence by using SAR data.The method that detecting large-level settlement based on pixel offset was introduced, to a certain extent, solved the problem of large scale subsidence basin monitoring and promoted the further application of SAR technology in the field of subsidence monitoring.