SLIPO develops tools for the quality-assured integration of Big POI data using Linked Data technologies. One of the most valuable global sources for the industry, innovators and researchers, is OpenStreetMap, a community of volunteers whose open geospatial data power thousands of services and products.
We are happy to announce that SLIPO provides a free download service for global POI data in RDF format extracted from OpenStreetMap. The data is organized in zip archives of RDF triples (N-TRIPLE serialization) per country or region and contain more than 18.5 million POIs worldwide. This archive will be updated once a month, so that you can download the latest RDF POI data for your line of work.
Just visit this site and download RDF POIs for any part of the world.
The reason we provide this service is twofold. First, to demonstrate the scalability and performance of SLIPO at a world-scale. The technologies we have developed for POI data integration work efficiently from the local to the global level. Second, we have received multiple requests from POI value chain stakeholders to streamline and automate the data transformation process of OpenStreetMap POI data to RDF.
The original OpenStreetMap data was transformed into RDF and serialized as N-TRIPLES using our TripleGeo ETL software developed in the context of SLIPO. TripleGeo aims to bridge the gap between typical geographic representations from a variety of proprietary files, DBMSs, and georeferenced systems with the demands of processing Big Geospatial Linked Data.
Here is an overview regarding transformation of OpenStreetMap POI data in RDF:
- A custom filtering has been applied against the original OpenStreetMap data in order to select features that represent Points of Interest (POIs).
- The URIs of all POI features are generated according to OpenStreetMap specifications in order to be resolvable. This ensures that an HTTP GET request to those URIs, with an appropriate mime type, will result in machine-readable representations of the OpenStreetMap resources they denote.
- All original tags are retained per POI and a data property is generated for each key under the OpenStreetMap wiki namespace, so as to be resolvable as well.
- Geometries of OpenStreetMap POIs are represented as Well-Known Text (WKT) literals according to the GeoSPARQL standard. Original OpenStreetMap nodes, ways or relations are suitably converted into WKT geometries, i.e., (multi)points, (multi)linestrings, (multi)polygons, geometry collections, etc.
- For each RDF file, an accompanying JSON file provides useful metadata regarding the transformation process. This JSON file lists all available OpenStreetMap tags concerning POIs in the original data, the spatial extent of the respective area (in WGS1984 reference system), as well as the amount of input OpenStreetMap features and output RDF triples.