Concept and Realization of Federated Spatial Database

Geographic information systems manage a large volume of spatial data. We often use it to solve some problems such as urban planning and land use management. Interoperability of GIS is the ability to access spatial data and associated services in a distributed and heterogeneous processing environment. There are many existing spatial databases and GIS applications that are built on those databases today. In order to solve problems, we often need the cooperation of many spatial databases, even if there are more complex spatial relationship and diversity between the existing spatial data models. In this paper, we will discuss the concept and methodology of a Federated Spatial Database System to implement the interoperability of GIS. At the end of paper, we introduced a project named VirtualWorld 2000. The goal of this project is to build a federated spatial database system to access the existing component spatial databases distributed in the LAN, which include graphic databases, DEM databases and image databases built with Oracle8i spatial cartridge, SQL Server 7.0 and GeoStar 3.0 file system.