不同采样与插值方法的DEM质量分析

Influence of Sampling Methods in Combination with Interpolation Methods on DEM Quality

通过编程实现数字高程模型DEM数据采集的随机采样、规则采样和成层随机采样的3种算法;再对某一地区的格网大小为30 m×30 m的栅格格式的高程数据进行采样,使用克立金法(Kriging)、样条函数法(Spline)和距离倒数加权法(Inverse Distance Weighted)3种插值方法分别对采样数据进行插值;然后计算出平均高程值之差的绝对值、中误差和单点最大误差。通过分析发现,成层随机采样与距离倒数加权插值组合适合于对高程总体偏差要求较高的应用;规则采样与样条函数插值组合适合于对相对高程要求较高的应用。

With the programming method, a 30 m× 30 m DEM was used to test the effect of the combination of three common used sampling methods （simple random sampling, systematic sampling, stratified sampling） and three interpolation methods including Kriging, Spline, and Inverse Distance Weighted （IDW）. Every sampling result of each sampling methods was interpolated using the three ways. Finally, three values were calculated, including the absolute value of the average altitude difference, mean square error and a maximum error of single point. By a combined analysis of experimental results, it was demonstrated that the combination of stratified sampling and Inverse Distance Weighted is suitable for applications that require precise average altitudes ; the combination of systematic sampling and Spline is suitable for applications that require precise relative altitudes.