Subregional Fitting and Transforming GPS Height into Normal Height

On the basis of the combination of GPS and leveling information, a new method for subregional fitting and transforming GPS height into normal height is proposed. The applicability of the fitting models is analyzed. The method for using bicubic splines or bicubic surface function to carry on the smoothing junction for two fitted subregions is presented. The corresponding algorithms and accuracy evaluation standards are given. It is verified that this smoothing method is feasible.