期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：2004
卷号：XXXV Part B2
页码：604-609
出版社：Copernicus Publications
摘要：A national topographic database for Denmark was established during the 1990'ies and completed at the end of year 2000. The database comprises three components: A 3-D vector database with full topology, a database with names of places and points of interest and an elevation database. This paper is about the revision and maintenance of the databases. The vector geometry was captured photogrammetrically. The update takes place in a 5 years cycle, i.e. 20% of the country is revised every year according to detailed specifications. Due to user needs focus is now on administrative revision in order to update specific object types with a higher frequency than 5 years. Roads, road names, hydrographical networks and building are of special interest for the geo-data infrastructure. The origin of the database for place names and points of interest goes back to the 1970'ies. It is maintained by an extensive use of sources in the public and private sectors utilising the Internet. It's a dynamic process where new sources are identified frequently and agreements concluded with the data providers. The third database component, the elevation model, is based on digitised contours and heights from selected objects from the 3-D vector database. Spot heights, i.e. maximum and minimum elevation points, measured in connection with the photogrammetric revision of vector data are also included. Heights in the elevation model are estimated by a data fusion approach considering characteristics of the individual data points. Data is stored in a grid structure and as computed contours
