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Copyright © 2014 Open Geospatial Consortium
4 Conventions
4.1 Abbreviated terms
API Application Program Interface
CRS Coordinate Reference System
ER Engineering Report
FES Filter Encoding Standard
GML Geography Markup Language
GMLSF Simple Feature Geography Markup Language
HTTP Hypertext Transfer Protocol
KVP Keyword-Value Pair
MIME Multipurpose Internet Mail Extensions
NGA National Geospatial-Intelligence Agency
OWL Ontology Web Language
RDF Resource Description Framework
SPARQL SPARQL Protocol and RDF Query Language UML
Unified Modelling Language USGS
United States Geological Survey WFS
Web Feature Service WFS-C
Cascading Web Feature Service XML
Extensible Markup Language
4.2 UML notation
Most diagrams that appear in this standard are presented using the Unified Modeling Language UML static structure diagram, as described in Subclause 5.2 of [OGC 06-
121r3].
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5 Virtual Global Gazetteer overview
The Virtual Global Gazetteer effort extended the Single Point of Entry Global Gazetteer SPEGG work from OWS-9, building on the framework established in the earlier testbed
and expanding gazetteer functionality to include gazetteer conflation and gazetteer linking.
The key task in this thread focused on the development of an enhanced Virtual Global Gazetteer Client, advancing fault-tolerant capabilities, and opening the service to the
wider community for comment.
There are two agencies in the United States in charge of maintaining the official gazetteers:
The USGS gazetteer manages all domestic place names, accessible through a WFS 2.0
The NGA gazetteer manages all non-domestic place names, accessible through a WFS 1.1.0
Both gazetteers not only run on different WFS versions with different capabilities, but also utilize the proprietary data and classification schemes of each organisation. Hence a
query, e.g. for a summit, needs to be mapped to a query for elevated point for the NGA service and hill for the USGS service to ensure the client receives all relevant
matches from both underlying services.
The basic requirements and concepts from OWS-9 remains largely unchanged for the Virtual Global Gazetteer, with the notable difference that in Testbed-10 the Gazetteer is
expected to access large scale data-sets, as opposed to a limited demo data-set in OWS-9. In addition the requirements were extended to include query filters for country and
feature type.
Extended gazetteer linking capabilities support tapping into information services beyond the NGA and USGS gazetteers. Once the desired location is selected from either
gazetteer, linked information such as DBPedia, LinkedGeoData OpenStreet Map Data, Geonames through Image Matters GeoSPARQL , Canadian Geobase can be accessed in
a unified way using GeoSPARQL protocol and query language.
This ER addresses the implementation of the extended client and endpoints as well as the applied semantic mediator, conflation approaches and gazetteer linking to further
information services using GeoSPARQL endpoints for semantic mapping components to data sources Geonames stored in PostGIS or NGA, USGS, Canadian Geobase WFS-G
or by using SPARQL endpoint to other knowledge source DBPedia, LinkedGeoData.
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6 Gazetteer Schema
6.1 Introduction