基于加权最小二乘曲面拟合的规则格网DEM建立

The Setting-Up of Grid DEM Based on Surface Fitting Using Weighted Least Square

数字高程模型(DEM)是描述地表起伏形态特征的空间数据模型。DEM完全可以代替传统使用等高线对地形表面的描述,进而满足对等高线数据相同的各种需求。内插是DEM的核心问题,它是DEM各种应用的基础。介绍了加权最小二乘曲面拟合法构建规则格网DEM的理论和方法。试验结果表明:加权最小二乘曲面拟合算法具有插值结果较精确、处理效率较高和模拟地表效果较好等优点。

Digital Elevation Model （DEM） is the model used to describe the waving surface of the earth which is capable of taking the place of the orthodox contour lines in the describing capability. Interpolating is the core of the DEM and lays foundations for applications of DEM. This paper systemically discussed the theory and method of setting-up grid DEM based on surface fitting using weighted least square and introduced the method of setting-up index grid in this algorithm, for improving the index efficiency in the interpolating in the range of nearby points. The experiment results show that the good effect was obtained by using surface fitting using weighted least square. It has overcome the shortcomings of distance weights algorithm and artificial neural network algorithm, and has strongpoint of exactness, efficiency and good simulation effect.