Research on ground deformation monitoring method in mining areas using the probability integral model fusion D-InSAR, sub-band InSAR and offset-tracking

With the aim of addressing the problem of accurately monitoring complete deformation fields over mining areas by means of Synthetic Aperture Radar (SAR), this paper proposes a solution to obtain complete deformation fields using the probability integral model to fuse deformation data derived from Differential Interferometric SAR (D-InSAR), sub-band InSAR and offset-tracking. This method is used for small-scale, medium-scale and large-scale deformation monitoring using D-InSAR, sub-band InSAR and offset-tracking, respectively. Finally, the probability integral model is utilized to integrate the three deformation fields, and a complete deformation field with high-accuracy over the study area can be obtained. The method is tested on 13 TerraSAR-X (TSX) images from December 2, 2012 to April 24, 2013 of the working face 52,304 of the Daliuta mining area in Shaanxi province, China. The complete deformation field of the working face during the 113-day mining period is obtained. The results show that during the process of working face advancing, the subsidence basin has been expanding along the direction of excavation. The relationship between the average maximum subsidence rate and the advancing distance of the working face can be described by a quadratic polynomial. It has been also observed that, when the underground mining reaches the full mining condition, the maximum subsidence value does not increase further. The accuracy of the proposed method is verified against the global positioning system field survey data. The root mean square errors in the strike and dip directions are 0.134 m and 0.105 m, respectively. Due to the support provide by the reserved coal pillars, the subsidence value above the reserved coal pillars is smaller.