The document discusses the role of geographic information in government linked data. It describes how spatial data infrastructure (SDI) can be published as linked data to create a linked spatial data infrastructure. This would allow government geospatial data to be integrated into the linked open data cloud. Publishing lightweight location data from reports and using citizen sensor data are also discussed. Standards like GeoSPARQL could help bridge the semantic web and geo web by enabling spatial queries over RDF graphs. Tools and best practices are still needed for tasks like converting and publishing geospatial data as linked data.

1. Geographic Information in Government Linked Data W3C Government Linked Data F2F 29 June 2011 Todd Pehle tpehle (at) orbistechnologies.com

2. Agenda The Emerging Web of Linked Locations The Role of Government SDI (Spatial Data Infrastructure) in Linked Data The Role of Lightweight Linked Locations in Government Linked Data The Role of Citizen Sensors and VGI (Volunteered Geographic Information) in Linked Data Geo Vocabularies, Tools & Best Practices Needed in Government Linked Data

3. The Emerging Web of Linked Locations

4. Linked Locations Linked Data + Location Data = Linked Locations Web of Linked Locations = a spatiotemporal projection of the Web of Linked Data (a global spatial KB) Orbis Technologies, Inc. Cartographic Projection GeoSPARQL Spatial Reasoning LOD Spatial Projection

5. Building the World’s Spatial KB Geo Web has base vector layers (GIS Data) to be connected to Web of Linked Data. Linked Locations inter-connects Geo Web features & bridges Linked Data with Geo Web. Linked Data exposes thematic attribution & relationships of Linked Locations. Linked Data + Geo Web Geo Web Links (horizontal links) (vertical links)

6. The Role of Government SDI (Spatial Data Infrastructure) in Linked Data

7. Spatial Data Infrastructure (SDI) Spatial Data Infrastructure (SDI) : “ An SDI is a coordinated series of agreements on technology standards , institutional arrangements, and policies that enable the discovery and use of geospatial information by users and for purposes other than those it was created for.” - Werner Kuhn, IFGI Succinctly, SDI is interoperability and sharing of geospatial information SDI utilizes many OGC service and ISO metadata specifications: WMS, WFS, CSW, WCS, GML, ISO19xxx metadata profiles, etc. SDI important in government for science, environmental monitoring, emergency response, natural disasters, homeland security, etc. SDI spans local, state, federal government plus industry & academia SDI in U.S. began in 1994; President Clinton signed an Executive Order calling for the establishment of a NSDI (National SDI) EU INSPIRE, GEOSS, UNSDI, GMES also examples of SDI

8. Linked Spatial Data Infrastructure Linked Spatial Data Infrastructure (Linked SDI) : SDI data published as Linked Data Work in progress Traditional SDI largely utilized by the GIS domain only Linked SDI offers the chance to open up rich location data to a much wider audience Linked SDI could be consumed just like all Linked Data via SPARQL (to include GeoSPARQL) and URI dereferencing Linked SDI could uniformly expose the massive amounts of structured GIS data into the Linked Data Cloud Thus the lines between the Semantic Web and Geo Web could become very blurry!

9. Examples of SDI (Cited in Wikipedia)

10. Importance of Government Linked SDI to Linked Open Data Governments are HUGE producers/consumers of geo data Governments as producers have an opportunity to bootstrap billions of triples into LOD and RDF clouds Governments as consumers have an opportunity to make better informed analytic decisions; but also to produce enriched correlations and republish to LOD Government Linked SDI could bootstrap LOD with “ base layers ” of spatial knowledge (NASA, USGS, Census Bureau, Ordnance Survey, INSPIRE, etc.) Government Linked SDI can also provide “ overlay layers ” for certain contexts (EPA, FEMA, HHS, etc.) Published data will have varying degrees of complexity; some agencies may simply publish W3C Basic Geo while others may publish heavyweight GIS

11. Bootstrapping LOD with Government Linked SDI (LSDI) Government LSDI Base Raster Layers Government LSDI Core Vector Layers Government LSDI Contextual Overlays

12. The Role of Lightweight Linked Locations in Government Linked Data

13. Lightweight Linked Locations in Government Data SDI offers rich data, but traditionally is “heavy” GIS Often requires specialized knowledge and tools to utilize However, many agencies have data (unstructured reports and semi-structured work products) that have simple location information within it: Placenames Addresses/Geocoding Latitude/Longitude fields GeoTagged Images This shouldn’t require GIS departments to publish as LOD With the rise of Neogeography (DIY mapping) simpler tools can expose geographic information on the Geo Web Neogeography tools could also be used to publish lightweight government Linked Locations data

14. The Role of Citizen Sensors and VGI (Volunteered Geographic Information) in Linked Data

15. Citizen Sensors, NGOs and Linked VGI Volunteered Geographic Information (VGI): “ The harnessing of tools to create, assemble, and disseminate geographic data provided voluntarily by individuals” – Mike Goodchild (UCSB) User-generated geo content, crowd sourcing, collective intelligence generated by ordinary citizens and NGOs Cell phone sensors (cameras, GPS, augmented reality, etc.) VGI produces “hyper local” and “hyper temporal” knowledge that complements SDI data Linked Gov Geo Data can embrace VGI to produce “hi-res” knowledge of location & events USGS held VGI workshop in 2010 OSM volunteers produced amazing maps for Haitian earthquake first responders What if Gov VGI was Linked VGI? VGI in Haiti: Earthquake Damaged Buildings from Open Street Map

16. Geo Vocabularies & Tools Needed in Government Linked Data

17. FOAF = Person Organization Ontology = Organizations OWL-Time = Time Event Ontology = Events (sort of???) SIOC = Linking online communities, wikis, blogs, etc. SKOS = Thesauri, classification schemes, taxonomies Dublin Core = Authoring Metadata voiD = Vocabulary Of Interlinked Data W3C Provenance = source metadata The Lack of Common Geo Vocabularies in the Web of Linked Data W3C Basic Geo = 1 Geo Model! (GeoSPARQL soon)

18. GeoSPARQL Draft specification recently released by OGC Consists of a small vocabulary that defines a geographic feature and a set of spatial relations Defines a set of spatial functions based on OGC Simple Features Specification Allows powerful query over RDF graphs and geometry GeoSPARQL vocabulary does not replace W3C Basic Geo; should be complementary Represents MAJOR bridge between the Semantic Web and Geo Web Represents a key enabler to more uniformly access and integrate geospatial information in Linked Data

19. Example GeoSPARQL Query SELECT ?airport WHERE { ?airport rdf:type :Airport . ?airport :hasPointGeometry [ ogc:asWKT ?aPointGeom ] FILTER(ogcf:distance(?aPointGeom, “ POINT(-122.4192 37.7793)”^^ogc:WKTLiteral, ogc:km) <= 100) } Example Query: Find airports within 100 KM of San Francisco :SemTech2011 :locatedIn :SanFrancisco . :SanFrancisco :hasPointGeometry [ ogc:asWKT “POINT(-122.4192 37.7793)”^^ogc:WKTLiteral ] . Example Data: SemTech 2011 is located in San Francisco

20. Example GeoSPARQL: Features Contained In User-Defined Polygon GeoSPARQL enables rich spatial queries over RDF Example Query : Find tourist attractions contained in Capitol Mall area in Washington D.C.

21. The Linked Locations Core? GeoSPARQL Spatial Relations Events Feature Types Metadata Note: Citizen Sensor “Observations” are separate but make use of these core models

22. Linked Locations Tools & Best Practices Almost no tools exist! Almost no best practices exist! Need many of the following tools: Geo2RDF converters GeoD2RQ More GeoSPARQL-enabled triple stores GeoSPARQL publishing tools Slippy Map extensions Need many of the following best practices: Geo Provenance publishing Geo voiD and geo SCOVO publishing GeoSPARQL & W3C Basic Geo alignment & interplay Spatiotemporal data publishing best practices (place + time) Spatial Dataset Change publishing Linked SDI (OGC-to-LOD) publishing best practices Linked VGI (citizen sensor) publishing best practices

23. Thanks!