Catalog Service for the Web (CS/W)

Short description of the CS/W standard

The OGC Catalogue Service for the Web (CS/W) provides the ability to publish and search collections of descriptive information (metadata) for data, services, applications, and related information objects. Metadata in catalogues represent resource characteristics that can be queried and presented for evaluation and further processing by both humans and software. Catalogue services are required to support the discovery and binding to registered information resources within an information community. 

Source: http://www.opengeospatial.org/standards/cat

The Role of CS/W in SDDI

Currently, the Catalog Service for the Web is in use in the SSD districts London QEOP, Paris Docks de St. Ouen and Berlin Moabit West. All the resources including the running services, data, and the applications for individual districts have been registered to the respective Catalog Service. With the help of the Catalog Service, the resources and their descriptions can be searched and queried using "filters" on thematic and spatial aspects (much like a SQL query). In addition, the team at TUM is working on setting up a master catalog for the entire SSD project which will automatically harvest the metadata from the local catalog services (cascading catalog services).

Standard Specification

Specification documents: http://www.opengeospatial.org/standards/cat

Implementations / Products

The following selection of products was made by the SDDI team and includes those implementations which are (or likely will be) used in the SSD project and from which we know that they are compatible with the requirements of the Smart Sustainable Data Infrastructure. Please note that the list is not a complete list of available or suitable CS/W implementations. The Open Geospatial Consortium provides a catalog of implementations of their standards which can be found at http://www.opengeospatial.org/resource. Note that also the OGC list is not complete and not necessarily completely up-to-date.

CS/W service implementations:

CS/W implementations of clients, interfaces, and libraries required to access and work with a CS/W service:

Additional Information

The CS/W plays a decisive role in the realization of so-called Service Oriented Architectures (SOA). SOA are information architectures where data resources and services are organized in a distributed way. The overall information architecture consists of a network of linked web services. In contrast to a monolithic information system all data and services are not physically integrated into one platform, but resources and services are provided (and kept updated) by the original owners. Applications make use of the different resources by connecting to the respective web services. In this way, access to information can be restricted to specific applications by the individual information owners and service providers. There is no need for resource providers to copy their data in advance into a central datastore, which typically is problematic for non-open datasets like energy consumptions or personal data. Open standards defining the different web service interfaces as well as the data models and exchange formats ensure that the different services and data items can be mutually used and connected in an interoperable way avoiding any vendor lock-in. SOAs can easily be extended by adding additional web services and applications making use of them.

CS/W is a central element to every Spatial Data Infrastructure (SDI).

(Give links to geoportals of INSPIRE, national, and state-wide SDIs) 

CS/W services can be automatically harvested by and the metadata be incorporated into the CKAN system [https://ckan.org/]. CKAN is often being used for the realization of the official Open Data Stores of many cities worldwide. For example, the London Data Store, the Berlin, Frankfurt, Helsinki, and Utrecht Open Data Portals, the U.S. Government’s open data store, and many others are implemented using CKAN. This means that the metadata about the applications, services, tools, and datasets belonging to the SDDI of a city district can automatically be included and updated within the datastore of the respective city.