Semantic retrieval of geospatial datasets based on a semantic repository

Abstract

In this chapter, we propose a methodology to semantically search geospatial datasets by means of their metadata. It consists of structuring a semantic repository in order to provide the inclusion mechanisms of distributed data to be retrieved, as well as the extraction of those geographic objects with respect to their conceptual similarity. The approach proposes a conceptual measure called the Conceptual Distance algorithm to determine the conceptual similarity among concepts. The features of geographic objects are conceptualized in an ontology on the domains: thematic, spatial, and temporal. The ontology is populated by using Federal Geographic Data Committee specification with instances of geographic objects distributed in several locations on a network. In the retrieval process according to a query, the objects are presented as a ranking list, which provides other results that are semantically close by means of radius of search and it avoids empty results. The approach has been implemented in a web system called SemGsearch.