Getting practical with GeoSPARQL and Apache Jena
Proceedings of the 6th International Workshop on Geospatial Linked Data 2024 co-located with 21st Extended Semantic Web Conference (ESWC 2024), volume 3743 of CEUR Workshop Proceedings, Hersonissos, Greece, (May 2024)Abstract
This paper explores the integration of geo-spatial data into RDF (Resource Description Framework) using Apache Jena, a popular Java-based framework for building Semantic Web applications. We explain the basic representation of geo-spatial data in RDF with a focus on both the new GeoSPARQL 1.1 standard and Apache Jena. Our investigation covers advanced techniques, such as transformation of coordinate reference systems, aggregation of geo-spatial data, creation of new geo-objects, and simplification of polygons. Additionally, we discuss the usage of the H3 Grid as a Discrete Global Grid System (DGGS) for geo-spatial conversion. Furthermore, we present performance optimisations specific to Apache Jena, including per-graph geo-indexing, improved geo-index serialization for faster startup times, and manual optimisation of geo-spatial queries. We conclude with a comparison of different geo-functions and outline future directions for enhancing geo-spatial data management in RDF.