DEM地形复杂因子的确定及与地形描述精度的关系

Terrain Complexity Factor and Its Relationship with Accuracy of DEM Terrain Representation

以相邻地形单元正法向量的夹角作为判断准则,提出了地形复杂因子的概念,用来量化描述DEM地形复杂度,并推导出栅格DEM和不规则三角网DEM地形复杂因子的计算公式。利用高斯合成曲面模拟不同的栅格DEM地形,研究地形复杂因子ECF与平均高程-h对DEM地形描述精度RMSEEt的影响。利用线性回归方法对模拟结果进行统计分析,得到栅格DEM地形描述精度RMSEEt与地形复杂因子ECF和平均高程h-之间的线性关系。该结果可以根据地形复杂程度推算DEM地形描述精度,而且可为DEM生产和误差研究提供可靠的理论依据。

Based on estimating rule of the normal vector angles between two adjacent terrain units, we use the conception of Terrain Complexity Factor to quantify the terrain complexity of DEM, and then the formula of Terrain Complexity Factor in Raster DEM and TIN DEM has been deduced theoretically. In order to make clear how the Terrain Complexity Factor and the Average Elevation RMSEEt affect the accuracy of DEM Terrain Representation RMSEEt , the formula of Gauss Synthetical Surface has been hired to simulate several real terrain surfaces, each of which has different terrain complexity. Through the statistical analysis method of linear regression in simulation data, the linear equation between Accuracy of DEM Terrain Representation RMSEEt , Terrain Complexity Factor ECF and the Average Elevation h^- has been achieved. We provide a new method to estimate the accuracy of DEM Terrain Representation RMSEEt. with a certain terrain complexity, and also will supply convincing theoretical evidence for DEM production and the corresponding error research in the future.