数字高程模型DEM精度研究

Research on Precision of Digital Elevation Models

用不同地貌类型地区的实验数据对数字高程模型(规则格网DEM)的格网间距与中误差(RMSE)、平均高程、剖面曲率的关系进行研究,采用比较分析的方法,得到格网间距与中误差的数学模型,可以用通式:Y=A+BX+CX2表示,并且把地形因子(平均高程、剖面曲率)作为自变量,进一步分析通式中3个系数与地形因子的关系,发现两个地形因子与系数函数关系比较相似,并得到Y=A+BX+CX2+DX3的数学模型。由验证结果表明,所得模型效果良好。

Taking digital elevation models of different relief areas as experiment data, a multi - resolution and multi - relief comparative approach was used as the major methodology in the research of the relationship among DEM grid size and RMSE （Root Mean Square Error）, average elevation, and profile curvature. A mathematics model of DEM grid size and RMSE is acquired, which is represented as Y = A ＋ BX ＋ CX^2. In addition, the average elevation and profile curvature is separately regarded as independent variable to analyze the relationship between the three coefficients and terrain factors. It is proved that the two function models are similar, which are both represented as Y = A ＋ BX ＋ CX^2 ＋ DX^3. The testing results showed that the mathematics models are good .