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A Tour of the GEOSS Common Infrastructure
By Ivan B. DeLoatch, US Geological Survey and ADC Co-Chair, and Doug Nebert, USGS
The primary goal of the Global Earth Observation System of Systems (GEOSS) is to connect the producers, users, and integrators of environmental data and to enhance the relevance of Earth observations to global issues. GEOSS defines a global public data access infrastructure that provides near-real-time environmental data, information, products and analyses for a wide range of users.
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| Operational view of GEOSS Common Infrastructure. |
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During the development and deployment of the GEOSS architecture it became clear that certain information resources needed to be managed in a centralized manner – like a library – such that the functioning and interoperability of GEOSS as a whole would be assured. Several GEOSS Registries were conceived, and have since been designed and deployed as part of a GEOSS Common Infrastructure (GCI) to facilitate information access and understanding. The GCI and its Registries, shown in the figure below, serve as a central coordinating feature of GEOSS that mediates access to applications, models, data, metadata, products, and services by users from various Societal Benefit Areas (SBAs). Primary access to the elements of the GCI is provided through the GEO Web Portals.
The Components and Services Registry (shown as “Services”) provides individuals representing GEO Member countries and Participating Organizations the means to register the existence of resources: Earth-observing systems, programs, models, application software, or any other component resource that they wish to advertise and contribute to GEO. This capability provides a “yellow pages” or centralized directory of relevant resources that have a GEO affiliation and describes them in basic detail to enable users to understand and access them. If any of these resources expose a standardized Web Service interface, then a service description should also be registered. This allows application software to easily access the data or processing capabilities and facilitates the construction of decision-support software to access and analyze the appropriate data in support of a given problem domain. Registration of resources and service interfaces is a requirement for being visible in GEO and GEOSS.
The Standards and Interoperability Registry (shown as “Standards”) stores a growing list of relevant standards and common practices, known as “special arrangements,” nominated by GEOSS users. The Standards and Interoperability Forum meets regularly to process nominations. Although GEO is not in the business of creating standards, there is a benefit in having a reference list of standards to associate with offered resources, requirements, and services.
The Best Practices Wiki is a GEOSS resource that hosts suggested practices associated with Earth observation, information management, or other relevant domains. A practice may reference multiple standards and/or may be pertinent to one or more SBAs. The wiki is created to promote awareness and adoption of practices and to educate professionals across multiple application areas.
The User Requirements Registry (shown as “Requirements”) is under development, but will be populated by the User Interface Committee with user types and requirements for Earth observation data from existing and emerging sources. The concept is that generic requirements will be linked to standards and registered resources and services, and ultimately could be used to identify gaps in data collection or coverage. This Registry is intended to help end users with identifying the right information content to support specific analysis or modeling.
The GEOSS Clearinghouse (shown as “Clearinghouse”) provides an all inclusive GEOSS search facility. Serving as a geographically-aware search engine, the Clearinghouse accesses all metadata from registered catalogs and the Components and Services Registry. A user can perform a search of the Clearinghouse (through a user interface on the GEO Web Portals) and get a quick list of resources that can be further explored or accessed.
The GEOSS Registries, GEO Web Portals, and Clearinghouse provide a foundation for GEO publishers and users to offer their resources. They associate these resources with standards and practices (and soon requirements) and enable their discovery through quick visualization or more detailed analyses through specialized client software. As a core capability over the longer-term, the GCI components will assure access to comprehensive information sources, sensors, processes, models, and decision-support solutions for Earth observations and the various Societal Benefit Areas. |
