Application of time series InSAR technology in monitoring ground deformation of mining area：A case study at Huolinhe open pit mining area in Inner Mongolia

In view of the inconsistency of surface coherence between the open-pit mining area and its urban area, an improved time-series InSAR(synthetic Aperture radar interferometry) technique is proposed to monitor the surface deformation of Huolinhe mining area and its surrounding urban area in this paper. First of all, through increasing the density of time sampling to control the coherence, so as to screen interference data with certain coherent point density around the mining area;Secondly,a distributed scatterer selection method with optimized parameters is used to select distributed targets and the permanent scatterers are extracted by traditional methods; Finally, the Delaunay triangulation network was constructed by mixing the distributed target and the permanent scatterer target, and the surface deformation rate in the study area was obtained by two regression analyses. The experimental results shows that the largest mine slope deformation rate of Huolinhe reached -630 mm/a, the maximum subsidence rate of surrounding roads of mining area ground reached 71 mm/a, the surface subsidence rate in Holingol city reached 15 mm/a, compared with GPS monitoring results of the same period, the applicability of this method is proved to be good.