Geolinking IE


This Interoperability Experiment (IE) will implement a number of prototype GeoLinking services based on the interface specification originally described in the Geolinked Data Access Service (GDAS) and GeoLinking Service (GLS) Discussion Papers. The purpose of the IE will be to confirm that OGC specifications completely support the ability to link attribute data to its geospatially representations when stored at separate locations on the Internet, and to improve the specifications if they do not support these requirements.


Specification Development

The current GDAS and Geolinking specs date back to 2004. Since that time, the Canadian Forestry Service has recommended a number of improvements to GDAS, and the implementation of Geolinking in Agriculture Canada and its partners has turned up some additional issues. In addition, the pending release of the Web Processing Service (WPS) provides an opportunity to rewrite both GDAS and GLS as an application profile of WPS, which brings some additional functionality and simplifies compliance with the OWS Common specification.

The two geolinking specifications have beeen rewritten as a suite of WPS processes. Although complete, this rewrite is untested. It involves superficial changes, primarily to the syntax of the requests. The GeoLinkIE will implement and test this suite of processes, and then focus on implementing and testing the improvements that have been recommended since the release of version 0.9.1 of the specs.

The primary focus of this IE will be on the new GDAS and GLS specifications, although some services based on other OGC specifications will be invoked in order to access data or provide visualization services. The compete list of specifications that may be affected include:

- Geospatially-linked Data Access Service (GDAS)

- Geospatial Linking Service (GLS)

- Web Processing Service (WPS)

- Catalog Service (CSW)

- Web Map Service (WMS)

- Web Feature Service (WFS)

- Web Map Context Document (Context)

(Note that the names of the GDAS and GLS services have changed since the publication of the original discussion documents.)