AQ Community Catalog
AQ_Community_Catalog Description: The AQ Community Catalog is the
Glossary Domain: AQInfrastructure
Community catalog was created in 2008, as part of AIP-2, in order to eliminate the need to register each individual data access service independently.
The community catalog is a component contributed by the Earth Science Information Partners and is registered in the GEOSS Component and Service Registry as both a component and a service. There were several options that the GEOSS AIP group considered when creating the community catalog, Catalog Service for the Web (CSW), Z39.50 and Web Accessible Folder (WAF). The WAF is the simplest option since the only criteria is that there is a folder accessible on a server and the WAF is “agnostic” to what metadata format is used. The Renewable Energy work group in the AIP-II and NOAA both used the WAF method for publishing metadata and were successfully harvested by the ESRI Clearinghouse early in the Pilot development. The benefit of being aware of what these other groups were doing through the AIP Plenary telecons and the Google Sites Pilot workspaces allowed the AQ community to learn faster from others and ultimately implemented this option for our initial community catalog as well.
One drawback to the WAF is that it is not a standard service interface. Additional steps were taken to register the WAF as a special arrangement in the GEOSS Standard Registry. This process of testing the GEOSS architecture through the AIP-II identified the need for the WAF and the special arrangement was based on a group agreement within the Pilot.
Another drawback to the WAF versus the CSW or Z39.50 interfaces is that records in the WAF don’t have reliable date stamps to identify changes in content. Therefore the only way to ensure that the most recent content is harvested is to re-harvest the entire WAF every time. CSW and Z39.50 records include a modification date so that clearinghouses only re-harvest records that have modification date more current than the last harvest.