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张锦明,游雄(信息工程大学地理空间信息学院, 郑州 450052)

摘 要
Quantitative descriptive model of DEM fidelity accuracy

Zhang Jinming,You Xiong(Institute of Geospatial Information, Information Engineering University, Zhengzhou 450052, China)

Reconstructing contours through a DEM is one of the methods of the DEM accuracy assessment. It can be used to detect terrain levels of fidelity. However, these methods show all a relative fidelity accuracy.Therefore, we present a membership function of the matching between drainage and terrain in this paper, we use the matching difference between drainage and terrain to quantitatively assess the DEM precision and to detect terrain levels of fidelity. First, we establish the matching offset membership function in accordance with the linear element displacement criterion, the scale criterion, the average slope criterion, the maximum matching offset criterion, and the visual effect criterion. Second, we use a 1:50 000 topographic map data of the four regions as the source data. Then the experiment of quantitative descriptive model of the matching precision explained how to use it in scaling transform of DEM. Finally, the experimental results show that the quantitative descriptive model of the matching precision not only can be used for the quantitative assessment of the extent of DEM terrain fidelity, but also can be used to determine the conversion of DEM scale appropriate range.