A Three-dimensional Error Model of Grid Dem Based on the Reconstructed Contours

In this paper, a three-dimensional error model of grid digital elevation model (DEM) is proposed based on the reconstructed contours. Though analyzing the construction of three-dimensional error model, the paper disassembles the three-dimensional error to a series of triangular pyramids and quadrangular pyramids, and it can make the calculation simpler. The three-dimensional error is continuous and unique, and the proposed model can evaluate the accuracy of raster DEM totally. The model can avoid the nonuniqueness in the root mean square of error (RMSE) where different checking groups have different results. The proposed approach to evaluate raster DEM is more reasonable and more reliability than to evaluate by RMSE. At last, the proposed model is validated and analyzed by the some experiments.