数字高程模型精度评价及其问题探讨

ASSESSMENT METHOD OF DIGITAL ELEVATION MODELS ACCURACY AND ITS LIMITATIONS

分析了数字高程模型(DEM)精度评价中检查点"中误差"法的局限及DEM产品的实际质量问题,提出了采用等高线回放法以逼近误差的概念,以衡量DEM全域出现的最大误差。

We analyzes the limitations of the accuracy assessment by the root mean square error（RMSE）,which is routinely used for accuracy assessment of a DEM.Then we give two examples showing how the DEM quality problems arise from the use of RMSE assessment.Finally,we emphasize that correct understanding of the nature of the interpolation model error is fundamental to define the criteria for the scientific assessment of a DEM,thus plotting the contour overlay should be a effective method for DEM accuracy assessment.