What is needed to achieve the goal of interoperability?
The most fundamental change towards interoperable data exchange is the replacement of 1:1 provider-user relationships with user-driven machine-to-machine connections. Just as when visiting foreign countries, this requires some agreement about the "language" in which information is exchanged. In the data network, these are the "protocols" (e.g. WCS, WFS, WMS, SOS, etc.) and the data formats (e.g. netcdf, csv, etc.). A client application and a data server must support the same protocol so that it is possible to obtain information about the data that are stored on the server and to formulate specific requests for data extraction. Once the data arrive, the client must be able to handle the data format in which the content is packaged.
Beyond the basic data access described above, there are other important technical and non-technical elements without which interoperability cannot be achieved. In order to find relevant data sets (the first step in each analysis), data catalogues must be established and agreement must be sought with respect to the metadata facets which describe the actual data sets. Related to this is the definition of a common vocabulary (for example species names, platform or instrument names, etc.). Furthermore, individual data providers may have specific requirements concerning the traceability of data, descriptions of ownership, tracing of data users or data access restrictions. There are different ways to define a "network topology" consisting of client and catalogue applications, data servers, mediators, web processing tools, etc.. Some agreement must be reached how this topology may look like in the AQ world in order to achieve the goal of integrating data and to avoid the creation of a new splinter network.
In August 2011, a meeting was organized upon invitation by the GEO AQ CoP in order to take stock of the existing AQ data network and its interoperability status (see | Solta workshop 2011) and to discuss the challenges and potential solutions on the technical and networking level. From the set-up of this workshop, a number of specific topics were identified. The links below lead to summaries of the workshop discussions and serve as a basis for further elaboration which shall proceed in this Wiki.