An interpolation method for the floor elevation of coal seams based on a local anisotropy radial basis function

The elevation interpolation of coal seam floors is an indispensable geological work to the production of coal mines. In this study, an improved radial basis function (RBF) interpolation method was proposed to support the interpolation of a feature with the local anisotropy characteristic. First, the local anisotropy of the floor elevation of coal seams was characterized by using the method of geographically weighted regression. The interpolation was realized by fitting residuals between actual values and geographically weighted regression values with RBF. Second, an adaptive selection of interpolation reference points was realized. The Delaunay triangulation network was used to define the relationship of natural proximity between the point to be interpolated and reference points and it ensured the relatively uniform distribution of reference points around the point to be interpolated. Based on this, the appropriate selection radius of reference points for the study area was obtained by cross validation. Third, the influence of faults was considered in the interpolation, and the value of reference points were augmented or deducted according to the attributes of faults concerned. Finally, the method was applied in the mining region 302 of Yanzishan Coal Mine in North China. The proposed method was illustrated to be effective with better robustness and interpolation accuracy compared with some typically used methods.