The document outlines the life cycle of linked geospatial data, including modeling geospatial domains and ontologies, generating RDF data from heterogeneous sources, publishing the data online according to linked data principles, and developing applications to unlock the value of the published geospatial data. It provides examples of tools used for each stage, such as geometry2rdf for generating RDF, Virtuoso for publishing, and map4rdf for a map-based visualization application.
1. Alexander De Leon, Boris Villazon-Terrazas, Luis M. Vilches, Victor
Saquicela
Ontology Engineering Group
Universidad Politécnica de Madrid
Madrid, Spain
jueves 7 de abril de 2011
2. Motivation
• 80% information has a geospatial part.
• GeoLinkedData is an open initiative whose
aim is to enrich the Web of Data with Spanish
geospatial data.
http://geo.linkeddata.es
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3. Motivation
• It is publishing diverse information from the
National Geographic Institute (IGN) and
the National Statistics Institute (INE).
http://geo.linkeddata.es
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4. Linked Data Life
Cycle
Modeling Generation Publication Exploitation
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5. Domain Modeling
Modeling Generation Publication Exploitation
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6. Domain Modeling
• Designing the vocabularies/ontologies that
model a view of the domain at hand.
• Reuse existing vocabularies in full or partially.
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7. Geometry Model
• Simple Features Specification as base
hyerarchy of geometry types.
• Feature and Geometry are separate objects
Requirements captured at GeoVoCamp Southampton 2011 7
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8. Geometry Model
• A feature can have multiple geometries,
geometries are parameterized (e.g. reference
system, dimension, resolution, temporal aspects)
• Different geometry representations are
resolvable via content negotiation.
Requirements captured at GeoVoCamp Southampton 2011 8
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9. Geometry Model
• Topological relations (as per RCC8) can be
inferred or made explicit between geometries.
Requirements captured at GeoVoCamp Southampton 2011 9
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10. Geometry Model
Simple Feature Specification 2010 OGC. 10
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11. Geometry Model
• One importante issue: How to handle order
of points in composite geometries?
• Using an order data property.
• rdf:seq
• rdf:List
• SPARQL 1.1 allows to query this.
Requirements captured at GeoVoCamp Southampton 2011 11
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12. Data Generation
Modeling Generation Publication Exploitation
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13. Data Generation
• Adquiere data from heterogenous data sources
and transforme it to RDF using the choose
domain model;
• Or generate new data directly as RDF.
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14. Data Generation
olb ox?
ou r to •Domain independent tools:
at’s in
Wh • ODEMapster
• NOR2O
• Domain specific tools:
• geometry2rdf
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15. geometry2rdf
Generation of RDF from geospatial relational
databases.
• Configurable data model
• Support of geo datatypes in RDBMS (e.g.
Oracle, GML, WKT)
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17. geometry2rdf
Oracle STO UTIL package
SELECT TO_CHAR(SDO_UTIL.TO_GML311GEOMETRY(geometry))
AS Gml311Geometry
FROM "BCN200"."BCN200_0301L_RIO" c
WHERE c.Etiqueta='Arroyo'
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19. Data Publication
Modeling Generation Publication Exploitation
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20. Data Publication
• Make data accessible on the Web according to
the Linked Data Principles
• Make your dataset visible
• Dataset Repositories (e.g. CKAN)
• Indexing Services (e.g. Sindice, sameas.org)
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21. Data Publication
olb ox?
ou r to
h at’s in • Virtuoso
W
• Apache Webserver +
Pubby
• Snorql
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22. Exploitation
Modeling Generation Publication Exploitation
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23. Exploitation
• Develop application that unlocks the value
of the data to provide benefits to a specific
community of end users.
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24. Exploitation
olb ox?
ou r to
at’s in
Wh
• map4rdf
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25. map4rdf
Map-based visualization of RDF Linked Data
with Geospatial dimensions.
• Faceted navigation.
• Suport for complex geometries (Lines,
Polygons, etc)
• Extensible overlays (e.g. statical data)
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26. map4rdf
SPARQL map4rdf
Endpoint Server Visualization in
User’s Browser
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