【摘要】 为了满足日益增长的对地理空间信息的需求,各软件商开发的软件都在试图提供一些空间信息处理功能。除了GIS之外,越来越多的CAD产品已能提供把语义数据联结到二维、三维几何数据的方法,并组织拓扑结构层,而DBMS产品中也引入了空间描述符来表达几何数据并将其与语义数据一起维护。本文从GIS角度分析比较了几种常用的CAD/DBMS软件,主要的是Oracle和MicroStation,并考察了其中新扩展的GIS新功能。更多还原

【Abstract】 Nowadays, to meet the increasing need of 3D information, vendors attempt to provide some GIS functionality. It is sure that among all types of systems dealing with spatial information GIS has proven to be the most sophisticated system. At same time, more and more CAD vendors provide means to link semantic data to 2D, 3D geometry and organize topologically structured layers, and DBMS introduce spatial descriptors to represent geometry data and maintain them together with the semantic data, too. Actually, there are some geographic information systems based on the extended GIS model of CAD and DBMS. This paper analyses several CAD/DBMS systems in common use and exam the geospatial operations available in those systems from the point of GIS.更多还原