SRTM DEM高程精度评价

为了全面认识SRTM DEM数据精度特征并完善SRTM DEM数据精度评定方法,该文以我国1∶5万比例尺DEM为参考数据,以具有多种地貌类型的陕西省为实验样区,利用高程中误差模型及空间插值方法对SRTMDEM进行高程精度分析。结果表明:陕西省的SRTM DEM高程中误差在3.5~60.7 m,呈现出较为显著的空间分异特征;并且高程中误差与实验样区平均坡度有较强的指数相关性,拟合的指数函数具有较高的模拟精度。

Evaluation of SRTM DEMs' Elevation Accuracy:A Case Study in Shaanxi Province

Treating the state 1:50 000 DEM as reference contrastive data,investigating in Shaanxi Province which has many different geomorphological types,the SRTM DEM's elevation accuracy are researched in this paper,using elevation RMSE model and method of spatial interpolation.Above all,the elevation RMSE of each test area is calculated through writing programs in ArcGIS according to RMSE model.Then,interpolating the calculated RMSEs using IDW method,the spatial differentiation of SRTM DEM's RMSE of whole Shaanxi Province is gained.The SRTM DEM's elevation RMSEs are from 3.5 m to 60.7 m and have the much more notable special distribution characteristic in Shaanxi Province:the SRTM DEM's elevation RMSEs are biggest in the mountain areas,bigger in loess hill and tableland areas and smaller in plain areas.There is the exponential correlation between the elevation RMSEs and the average slope of samples.The fitting exponential function has better accuracy.This study has certain reference significance to knowing the characteristic of SRTM DEM accuracy thoroughly and improving the evaluation method of SRTM DEM accuracy.