不同地貌起伏状况下网格尺寸与DEM精度关系研究

不考虑DEM采样点上高程误差，以不同地貌类型区为试验地，运用统计分析方法，对不同地貌起伏的样地随机抽取采样点，比较当DEM网格尺寸变化时，对DEM高程值计算的误差以及对剖面曲率计算结果的误差，分析不同地貌起伏状况下DEM网格尺寸变化与DEM精度之间定量定性的关系，得出表示地形复杂程度的平均剖面曲率和网格尺寸是影响DEM精度的两个重要因素。通过一系列表达式推导得出网格尺寸变化与DEM精度之间定量关系。由此模型，用户可以根据不同地貌和DEM的精度要求选择适宜的网格尺寸范围，进一步为生产实践中应用提供理论依据。

Studies on the Relations Between the Grids Size of Various Undulate Landforms and the Accuracy of DEM

Taken different landforms as experimental area,statistical analytical methods and random samples were applied into this experiment.While comparing the variety of the grids' size in DEM(Digital Elevation Model),the authors calculated the errors of altitudes and the cross section curvatures,analyzed the qualitative relation between the size of DEM grids and the accuracy DEM through different undulate landforms,which drawn the conclusion that there are two important factors which could influence DEM precision.They are the size of grids and the average cross section curvature which shows the topographical complexity.Through a series expression formulae,the quantitative relation between the size of grids and the DEM accuracy was got.According to this model,users may choose the suitable size of DEM in accord with different landforms and accurate demands,thus offers the theoretical foundation for further use in practices.