基于超地图原理的分布式空间数据模型

Hypermap-Based Distributed Geospatial Data Model

分布式、部件化、交互性与互操作是因特网地理信息系统的 4个主要特征 .为了实现对空间信息的分布式管理与处理 ,以便将大容量、多源地理信息纳入统一的框架管理 ,基于超地图与分布式数据库的原理 ,提出了满足上述特征的因特网地理信息系统分布式地理信息空间数据模型 ,并以目录服务作为空间信息全球化的范式 ,同时定义了不同层次超链节点的目录服务数据结构 ,以便通过超链接实现分布式空间数据模型的关联 ,该模型已在Geosurf中得以应用 ,并取得了良好效果 .

With the development of internet technology, internet GIS have applied popularly. Distribution, interoperability, component are the main characters of internet GIS. In order to access, manage, process and distributed geodata, the paper proposes a distributed geospatial data model, which is based on hypermap concepts and distributed database principle. According to the distributed geospatial model, various geospatial data including electronic maps, images, pictures, videos, attributes, hyper documents can be constructed in the model, and they are linked by a hyper link. Every medium can have one or more hyper nodes, which link another medium. A hyper node recodes some information including the IP address and catalog of linked medium. After clicking a hyper node, we can move to another IP address and browse linked medium. Furthermore, the paper defines data structure of different type hyper nodes and discusses its implementation. An internet GIS software-GeoSurf based on the distributed hypermap geospatial model have developed by our university. Many application systems based on GeoSurf have been built. These applications has shown many advantages of the distributed hypermap geospatial data model.