Coordination of geographic information and geographic information systems Metadata

1. Coordination of geographic information and geographic information systemsMetadata

2. www.e-geo.ch

3. National Spatial Data Infrastructure (NSDI) Basic Geo- information Metadata Basic Geo- services e-geo.ch Network EducationTraining Technical infrastructure Research Standards Legal bases Strategy for distri-bution and pricing NSDI Impact Political economical profit Easy available Optimal offer • added value for: • public sector • (Federal, Cantons, • Communes) • organizations • (private sector, • science etc.) • General public wider use Favorable prices Transparency

4. National Spatial Data Infrastructure (NSDI) Basic Geo- information Metadata Basic Geo- services e-geo.ch Network EducationTraining Technical infrastructure Research Standards Legal bases Strategy for distri-bution and pricing Metadata is a part of the NSDI

5. Outline • geocat.ch • Concept • Timetable • Pilot application • The metadata model for Switzerland • GeoMeta, the swiss profile of ISO 19115 • Our model-based approach • Our experiences with the implementation • Catalog gateway protocol • Goals • Overview • Query language

6. Service de découverte geocat.ch geocat.ch concept (1) • The geocat.ch project wants to set up a metadata catalogue for GI • Geocat.ch will permit to add, edit, manage and to search for metadata on the Internet • It will be realised as a framework of distributed metadata and applications in a federated and heterogeneous infrastructure.

7. geocat.ch concept (2) Source: GSDI Cookbook, Version 1.1

8. geocat.ch concept (3) 2 type of database are connected: • One central database: the geocat.ch database, which is accessible to the geocat.ch search application • Distributed databases, which are connected to the Catalog Gateway of the geocat.ch search application 3 partnership possibilities exist for the producer of data: • Partner A: they manage their metadata directly in the central database • Partner B: they manage their metadata in their own database. To make their metadata accessible to the geocat.ch search application, they use the import/export tool to put them in the central database. • Partner C: they manage their metadata in their own database. The metadata is accessible, because the database is connected to the Catalog Gateway

9. Schedule of geocat.ch

10. Pilot application geocat.ch

11. Outline • geocat.ch • Concept • Timetable • Pilot application • The metadata model for Switzerland • GeoMeta, the swiss profile of ISO 19115 • Our model-based approach • Our experiences with the implementation • Catalog gateway protocol • Goals • Overview • Query language

12. GeoMeta the Swiss profile • Based on ISO 19115 • Additional requirements were derived from an analysis of existing data catalogs (SIK-GIS and CDS) • ISO Standard covered most of these requirements • Swiss profile as presented at the workshop on May 22, 2002 in Bangkok: • legal information is an additional metadata component • Multilingual support is essential (should be normative in ISO 19115) • Several components and classes are not needed • Since Bangkok workshop: • Model revised with the results from the elicitation and the FDIS version

13. ISO approach of Profiles Profiles are reductions of a general model This approach proved to be not feasible in our case Local models are not necessary based on common model Swiss approach Comprehensive Swiss profile is an extension of the core profile All additional models are derived from the same base model Experience with implementation of GeoMeta (I)

14. Experience with implementation of GeoMeta (II) Responsible party can not be modeled as data type. • A specific party is responsible for several datasets • It can have different roles • Should only be stored and maintained once

15. From UML to XML-Schema • External classes were moved into 19115 package • All other packages were deleted • Multiplicity removed from attribute name and defined as a tagged value • Data types reviewed and stereotype changed where needed to fit the semantics predefined by UML • Export from Rational Rose to XMI • Import into UML/INTERLIS-Editor • Additional data type definitions • Export to XML-Schema

16. Additional data type definition: Example

17. Outline • geocat.ch • Concept • Timetable • Pilot application • The metadata model for Switzerland • GeoMeta, the swiss profile of ISO 19115 • Our model-based approach • Our experiences with the implementation • Catalog gateway protocol • Goals • Overview • Query language

18. Goals of the protocol • A catalog gateway protocol needs to be defined: • to manage a connection between the gateway application (client) and an external server; • to be able to send a query from the client to the server; • for the client to be able to receive query results from the server. • This query mechanism must be: • independent of the platform/system/vendor of both the client and the server; • independent of the programming language used on either side; • independent of the network protocol used between the client and the server; • The protocol must support multiple languages and spatial query criteria • The protocol must be relatively cheap to implement

19. geocat.ch Server OverviewQuery OverviewAnswer DetailQuery DetailAnswer Overview of the protocol • The OpenGIS Catalog Service and the Z39.50 protocols were considered to be too general for a cost effective implementation. • SOAP (Simple Object Access Protocol) was chosen. It’s an XML based wrapping structure, like the postal services which use an envelope for letters that contain questions and answers.

20. The query language of the protocol

21. The geocat.ch query language solution example

22. Conclusion • The ISO 19115 standard covered most of our requirements • A model-based approach : Comprehensive Swiss profile is an extension of the core profile • To realisea framework of distributed metadata and applications in a federated and heterogeneous infrastructure, a catalog gateway protocol is necessary