A STUDY OF SPATIAL METADATA AND ITS APPLICATIONS

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.