An Open Source Linked Data Infrastructure for Publishing Geospatial Data Arif Shaon, Andrew Woolf, Shirley Crompton, Will Rogers, Mike Jackson, Robert Boszec

“Place matters…” “everything happens somewhere” –Location Strategy for the UK Combine information about places –Stretch of road –Speed limit orders –Underground pipes, cables, ducts –Accident statistics Benefits –Improve decision making –Deliver better services

Querying location data GIS Service (Known) GIS Service (Unknown) query

INSPIRE EU directive –15 th May 2007 – EU-wide infrastructure for spatial information –All levels/scales of detail Standard –Model ontology in UML –Expose as XML –Access via web services

Semantic Web

Linked data Use URIs as names for things Use HTTP URIs so that people can look up those names When someone looks up a URI, provide useful information, using the standards (RDF, SPARQL) Include links to other URIs, so that they can discover more things Tim Berners-Lee

Querying linked location data Linked GIS Service (Known) Linked GIS Service (Unknown) Query (URI/SPARQL)

Querying linked location data Potential for developing more flexible means of data sharing and accessibility Potential for solving the problems of data harmonisation through complex web services Linked GIS Service (Known) Linked GIS Service (Unknown) Query (URI/SPARQL)

Location URIs for the UK “Designing URI sets for location”, 2010 –STFC advised on development Part of the UK Location Strategy Extend INSPIRE to include linked data publication

URIs for the UK public sector “Designing URI Sets for the UK Public Sector”, 2009 Identifier (id) Document (doc) Representation Definition / ontology (def)

How it works (ID URI) Thing Generic Document (Doc URI) RDFHTML redirect Content Negotiation application/rdf+xml wins text/html wins.../def/school.../def/school (Def URI) definition

Location URIs for the UK ‘Spatial Thing’ ‘web document’ rdfs:seeAlso rdfs:seeAlso ov:similarTo ‘303 See other:’ ‘Spatial Object’ ‘content negotiation’ ‘Id’ URI ‘Doc’ URI ‘So’ URI

GeoTOD-II Geospatial Transformation with OGSA-DAI Publish spatial data as linked data Conform to UK Cabinet Office recommendations Leverage existing related technologies

Requirements Community Data Model/ Vocabulary/Ontology VS Existing data and GIS services Linked Data Service Opaque URIs Bespoke human-readable URIs

How to interpret the guidelines? Spatial Object (SO URI) Spatial Object (SO URI) Spatial Thing (ID URI) Spatial Thing Metadata (Doc URI) ??? 303 redirect What info Master Catalogue of Spatial Objects ??? Who owns it ??? Register Spatial Object (SO URI)

How to represent the ontology? INSPIRE’s UML conceptual models How to transform to OWL/RDF? How to address import of ISO schemas? e.g. ISO (spatial schemas) ISO (geospatial meta data) Unofficial and incomplete ontologies UK Environmental Agency’s Bathing Water ontology OGC GeoSPARQL working group Substantial tasks Require involvement of the wider community

Converting UML to RDFS

Existing linked data solutions Existing open source linked data server products UK Environmental Agency linked data server (data.ordnancesurvey.co.uk) Spanish geo-linked data server (geo.linkeddata.es) Existing Linked-Data Services

Existing linked data solutions May not always have database access Limited scope for extending functionality –Add GIS service for GML-based data –Expose GML formats Need an extensible solution

GeoTOD-II linked data framework

OGSA-DAI SO store Web resources Relational resources Linked SO Store OGSA-DAI service Geotod- D2RQ RDB Workflow Generate RDB-specific SQL using mapping file SPARQL query + output formatting D2RQ Mapping File SQL GeoServer WS GML query

GeoTOD prototype Test data Ordnance Survey Strategi data set UK natural and man-made features ESRI shapefiles => SQL Ontology generation Relevant INSPIRE models e.g. HY, TN INSPIRE UML => XML Schema => RDFS Easier than UML => RDFS direct

GeoTOD-II demo server

Spatial thing HTML /heathrow-terminal-4-station

Spatial thing RDF /heathrow-terminal-4-station

Spatial object GML e/tn-ra/984

Conclusions GeoTOD framework Conforms to UK Cabinet Office location URIs Plug-in support for new data sources or representations Should benefit projects and organisations looking to deploy existing geospatial data assets as linked data Advanced Climate Research Infrastructure for Data Further work Engage with linked data and geospatial communities Develop into efficient and reliable product