Your SlideShare is downloading. ×

Geographic information in govt linked data


Published on

Published in: Technology, Education
  • Be the first to comment

  • Be the first to like this

No Downloads
Total Views
On Slideshare
From Embeds
Number of Embeds
Embeds 0
No embeds

Report content
Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

No notes for slide


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