空间元数据研究及应用

A STUDY OF SPATIAL METADATA AND ITS APPLICATIONS

分布式地理空间数据的快速导航一直是分布式 GIS研究的重点 .针对地理空间数据的特点 ,在已有空间元数据标准的基础上 ,构造了一个分层空间元数据库框架 ,设计实现了不同级别的空间元数据库 ,很好地组织和管理了分布在网络上的地理空间数据库及其数据 ;在分层空间元数据库的支持下 ,基于地图 (图层 )的 4个基本要素〈专题、空间范围、地层、时间〉,设计了一个面向用户的地理空间数据请求描述规范 ,并据此实现了一个基于多 Agent的分布式地理空间数据查找策略 。

Fast navigation of distributed spatial data has been the keystone of distributed GIS. In this paper, a hierarchical spatial metadata database framework is presented based on the existing spatial metadata standard. This framework can efficiently organize the distributed spatial data in network. With the support of the hierarchical spatial metadata databases, a user oriented descriptive specification for spatial data requirement is proposed. A map(map layer) is described as a tuple consisting of four basic elements of 〈subject, scope, stratum, time〉. An agent based searching scheme for spatial query is also introduced, which can satisfy the requirement of fast navigation in terms of spatial query that can often be non deterministic or with uncertainty.