1. JCDL 07/ 2002 JCDL W5 Digital Gazetteers Portland, 2002-07-18 jens.fitzke@uni-bonn.de http://www.giub.uni-bonn.de/gisfe/ Standard-based Gazetteer Services

2. JCDL 07/ 2002 Agenda Intro Open GIS Consortium and ISO TC 211 OGC Web Feature Service (WFS) ISO 19112 OGC Web Gazetteer Service (WGS)

3. JCDL 07/ 2002 Project background 5 years of research in Web-based geoprocessing (projects in Germany) biodiversity documentation: GROMS, GBIF (to come) environmental atlases (regional scale) e-government: GeoMIS.Bund geospatial data infrastructures: GDI NRW Main project today: JaGo, a Java framework for interoperable GIS (implements ISO 19107, OGC WMS, SLD, WFS, Catalog Service, CTS) JaGo Web Gazetteer Service is currently being developed

4. JCDL 07/ 2002 Open GIS Consortium mission OpenGIS® Specifications support interoperable solutions that "geo-enable" the Web and mainstream IT, and empower technology developers to make complex spatial information and services accessible and useful with all kinds of applications. > 230 members –government agencies, universities –companies: hard-/software, data –consulting, integrators liaison with ISO TC 211 (Geographic Information)

5. JCDL 07/ 2002 OGC WGS basics OGC Gazetteer Service Draft Candidate Implementation Specification 0.84 (discussion paper, editor: Rob Atkinson, date: 2001-03-15) ISO DIS 19112 Geographic information - Spatial referencing by geographic identifiers

6. JCDL 07/ 2002 OGC WGS concept WGS is a special WFS („a WFS profile“) WFS is adopted technology for feature access (query, update, delete) via XML/HTTP Powerful query language: Filter encoding example: see next slide... Standard output format is GML, others are allowed

7. JCDL 07/ 2002 WGS request

8. JCDL 07/ 2002 ISO DIS 19112 ADL: gazetteer entry ADL: feature type ADL: class scheme Thesaurus structures

9. JCDL 07/ 2002 OGC Gazetteer Service Base: Web Feature Service –GetCapabilities –DescribeFeatureType –GetFeature Extensions –GML Application Schema for „GazetteerEntries“: SI_LocationInstance inherited from AbstractFeature –Feature Relationships: child, parent, related (not yet) Web Gazetteer Service Response Example...

10. JCDL 07/ 2002 WGS response (1)

11. JCDL 07/ 2002 WGS response (2)

12. JCDL 07/ 2002 ISO DIS 19112 Pros Fits well into the 191xx family Comprehensive versioning concept Cons Poor support for related terms Poor multi-language support (pronounciation, character set) Versioning concept propably hard to implement No quality metadata yet

13. JCDL 07/ 2002 unresolved issues Use of xlinks to reduce redundancy in gazetteer service responses and to allow for external referencing Implementing ISO 19112 Gazetteer Versioning Predefined response types might be helpful (hits, brief, full, summary) Handling feature changes over time

14. JCDL 07/ 2002 Questions? Standard-based Gazetteer Services jens.fitzke@uni-bonn.de http://www.giub.uni-bonn.de/gisfe/