OSGeodata metadata exchange protocol: Unterschied zwischen den Versionen

Version vom 21. August 2006, 10:46 Uhr

We definitively need a metadata exchange protocol!

This is part of a discussion around a geographic metadata model and an exchange protocol.

See also OSGeodataMetadataModel and generally OSGeodata.

Overview

A protocol specification consists of requests (operations) and responses (information model encoded in a streaming format and error messages, as codes).

We distinguish specifically query/search protocols and harvesting procotols.

We need "a protocol for the incremental exchange of metadata about geographic resources between systems" which is open, lean and mean.

Searching or Harvesting?

Geographic Metadata Harvesting Protocol approaches and specifications:

• Use HTTP and XML ('autonomous discovery')
• OAI-PMH including a comparison with WFS (profiled)

CSW, WFS and for example SRU/SRW are implementations of a search protocol. Proposals like OGC's CSW 2.0 do not fulfill these requirements. Profiled specifications like OAI-PMH or WFS are currently on our short list (see Proposals below).

Proposals

We tend to propose a harvesting approach which means, that

1. in a first step data according to OSGeodataMetadataModel and encoded as XML files are published
2. and in a second step OAI-PMH could be utilized, moving around the same XML files.

Better name sought (catalogue is probably not the most appropriate noun):

• Geographic Metadata Syndication Protocol (my favourite)
• Geographic Metadata Harvesting Protocol
• Other proposals?
  • Geographic Data Discovery Protocol
  • Geographic Metadata Dissemination Protocol

Weblinks

• Simple Catalog Interface at OSGeo Wiki as well as the OSGeodata mailing list mentioned above
• OAI-PMH - including home, wikipedia, documents, tutorials, tools and demos
• Introduction to the IESR: A Registry of Collections and Services, by Hill and Ann Apps, MIMAS, Univ. of Manchester, 2006.
• Other
  • OGC's CSW 2.0
  • OGC's WFS