Differential SAR Interferometry for the Monitoring of Underground Coal Spontaneous Combustion Zone Surface Deformation

Abstract

The surface deformation is one of the available indicators for monitoring and analysis of the coalfield fire area.However,it is difficult to extract surface deformation in the coalfield area if serious decorrelation noise exists.Based on analyzing the surface deformation characteristics of the coalfield fire area and comparing a variety of SAR datasets,the authors chose L band ALOS PALSAR dataset to conduct a differential synthetic aperture radar interferometry processing.Interferometric fringe was calculated for estimating the accurate baseline.The adaptive filter method was used to eliminate decorrelation noise after generating interferogram.Then surface deformation in the coal mine fire zone was extracted after two processes,i.e.,flattening and topography phase removal.It is found that surface deformation is correlated with the coal spontaneous combustion zone to some extent,as evidenced by past in situ investigation and data analysis.The surface deformation analysis is helpful to confirming the situation of the underground coal fire burning.The on-site verification proves that detecting surface deformation of the underground coal spontaneous combustion zone by D-InSAR is acceptable.