基于规则格网的DEM插值实验

摘要

Through terrain modeling ,this experiment turns six geomorphic membership functions into six terrain units grid DEM ,with seven grid densities :101 × 101 ,112 × 112 ,126 × 126 ,144 × 144 ,168 × 168 , 201 × 201 ,and 257 × 257 .Using IDW and other six interpolation algorithms ,it interpolates the first six densities of grid DEM into 257 × 257 grid DEM ;Then it selects some checkpoints from the original 257 × 257 DEM randomly ,calculating residuals and RMSE for further statistical analysis .With interpolation experiments in group ,the methods of controlling variable and variance analysis are used to analyze the effects of terrain morphology ,sampling density and interpolation algorithms on grid DEM accuracy .%通过地形建模 ,将6个地形隶属函数按照101 × 101 ,112 × 112 ,126 × 126 ,144 × 144 ,168 × 168 ,201 × 201 , 257 × 257 7种格网密度生成6种局部地形单元的规则格网DEM ;使用反距离加权(IDW)等7种插值算法 ,将前6种格网密度下的DEM插值成257 × 257规格 ;从原始257 × 257DEM 中随机抽取检查点计算残差 ,并对残差中误差进行分析.通过分组插值实验 ,运用控制变量法、方差分析等方法研究地貌类型、采样密度和插值算法对DEM 插值精度的影响.