基于高精度曲面模型的DEM构建与误差分析

DEM construction based on HASM and related error analysis

引入地形表达误差(terrain representation error,Etr),选择标准曲面和甘肃省董志塬地区作为研究对象,利用窗口分析法实现Etr的提取;用统计分析法得出Etr随网格分辨率变化的回归方程;根据误差传播定律计算DEM中误差。数值结果表明,该方法能更准确的计算HASM生成的DEM精度;相同的采样数下,HASM较传统方法(IDW,Spline和Kriging)能生成更高精度和分辨率的DEM。在难以获取已知数据的地区,HASM提供了生成相对准确DEM的高效工具。

In former researches, High Accuracy Surface Modelling （HASM） constructed based on the fundamental theory of surface is more accurate than the classical methods in DEM construction. In order to give HASM a full evaluation, this paper introduced terrain representation error （Etr）, which was calculated by multi-resolution comparative analysis. Terrain representa- tion model was built, which was regressed against resolution. The total DEM simulation error containing interpolation RMSE, Etr, etc., is calculated in terms of error propagation theory. Canonical surface and Dong-Zhi-Yuan in Gansu province of China were selected to validate the efficiency of our methods. The results showed that the method presented in this paper can give a full evaluation of DEM error. HASM can construct more accurate and higher resolution DEM than the classical methods.