数字高程模型精度标准、质量理论和科学观念讨论

Discussion of DEM Standards,Quality Theory and Conceptions

分析了数字高程模型(DEM)的国家精度标准,及其与一些实际数据间的逻辑矛盾,并运用GIS数据质量理论,从分辨率、逻辑一致性、完整性的角度,分析了DEM误差、高程的序同构原理和必须综合生成原理。提出"DEM不应是间距dx上的取样点高程,而应是间距dx×dx上颗粒度的代表高程",突出了综合在DEM中的关键作用。

We mainly discuss about some of the quality requirements in national standards.Some conflicts between these requirements and real data in practices are indicated.Based on the data quality theory of GIS,the error theory of DEM,ordered isomorphism of elevation and the generalization theory of DEM are analyzed in terms of resolution ratio,data logical consistency and integrality.DEM should not be the elevation of a specific sampling point but the typical elevation within the grain range（dx×dx）,and DEM generalization plays a key role in DEM production.