讨论了DEM生成方法和高精度、高保真问题.指出评价生成方法的误差必须顾及内插模型的截断误差,并把它作为主要部分;给出了新型的地图代数DEM生成方法——MADEM(map algebra DEM),它是定义在最速下降线水平投影上的线性插值方法,通过赋值点线间的加权Voronoi的递归内插过程实现.它在同样条件下,具有远高于Delaunay构网下三角形上的线性插值方法精度,并具有高保真特性.分析和实例比较表明它是目前DEM最优的线性内插方法.
DEM generation method and its high precision and fidelity were discussed. It is pointed out that the truncation error of interpolation model should be considered as the main error in estimating the error of DEM generation method. A new DEM generation method basing on map algebra is given. It is in fact a linear interpolation on horizontal projection of the steepest descent line realized by recursive powered Voronoi interpolation between evaluated points and lines. Its precision is much better than that of the DEM generation methods basing on linear interpolation on Delaunay triangulation under the same conditions, and it also has the feature of high fidelity. Having compared with other methods, the DEM generation method should be the best linear interpolation method of all.