Study On SAR Interferogram Filtering Methods In Mining Area

Ground subsidence caused by coal mining would damage ground production andliving facilities. Monitoring and controlling the surface subsidence effectively aredirectly related to economic development and improvement of living standards.Monitoring surface subsidence effectively, thoroughly studing the subsidencemechanism and regularity of surface movement, controling and reducing subsidencedisaster losses in time are all very important to the development of national economy.DInSAR is an advanced deformation monitoring method, which can work all day inall-weather situations and quick access a large number of real-time monitoring data.But owing to the comprehensive influence of many factors, there exist a lot of noise ininterference data, which directly interfere with the accuracy of data processing. So itis particularly important to remove noise effectively and keep details of interferencefringes for effective application of DInSAR technology.The surveying theory and data processing key algorithms of InSAR areconcluded in this article, and then researching and improving the filtering algorithmare focuses on. Several common used complex domain filtering algorithms andquality evaluation indices are expounded, and the simulation of noise interferogram isalso realized. Based on the sensitivity analysis of filtering results to window selectionwith different density interferograms, an adaptive filtering window selection methodbased on stripe width is proposed. The simulated and real data experiments validateits effectiveness. According to the relationship between correlation and SNR of localphase, an mask filtering method based on correlation is put forward. The filteringresults of contrast experiment show that the improved algorithm can effectivelydenoising and keep phase detail information. Using the improved algorithm, two passdiffericial managements are down on three pair images, which are acquiredcontinuously over the area of Nantun coal mine. The surface subsidence and influencerange of Nantun coal mine93上10and93上08working face are calculated duringdifferent monitoring periods.