Ontology-Based Data Access And Visualization Of Big Vector And Raster Data

We present an Ontology-based data access technique for the integration of geospatial data from different sources and different formats using ontologies and mappings. Our technique is implemented in the system Ontop-spatial, which enables the execution of GeoSPARQL queries over geospatial relational databases storing vector or raster data by performing on-the-fly GeoSPARQL-to-SQL translation using ontologies and mappings. Ontop-spatial is generally more efficient than traditional geospatial RDF stores. Linked geospatial data can then be visualised on the map using Sextant, an online tool for browsing and visualisation of linked geospatial data.