Missouri Botanical Garden Open Conference Systems, TDWG 2013 ANNUAL CONFERENCE

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The GEOSS Brokering System
Paolo Mazzetti, Stefano Nativi, Mattia Santoro, Fabrizio Papeschi

Building: Grand Hotel Mediterraneo
Room: Sala dei Continenti
Date: 2013-10-30 11:00 AM – 11:15 AM
Last modified: 2013-10-05

Abstract


The Global Earth Observation System of Systems (GEOSS) aims to provide access to Earth Observation resources proactively linking together existing and planned observing systems around the world and support the development of new systems where gaps currently exist. Since different observing systems may adopt different interfaces, metadata and data models, it is expected that interoperability is a major issue in the GEOSS development and operation.

In the recent years brokered architectures have been proposed for implementing System of Systems. Indeed they allow to make heterogeneous systems interoperable supplementing their functionalities without supplanting them. GEOSS is one of the main examples of systems of systems based on brokered architectures. At the core of the GEOSS Common Infrastructure lies the GEOSS brokering framework which is in charge of all the interoperability issues in order to connect heterogeneous capacities in GEOSS.

The brokering approach complements the standardization process leading to a well recognized and used set of community standards.

The GEOSS brokering framework (called GEO Discovery and Access Broker: GEO DAB) includes different dedicated brokers: a) the Discovery Broker providing harmonized discovery of the heterogeneous geospatial resources (e.g. disciplinary catalogues, registries, inventories). It also provides semantic discovery through external semantic assets (e.g. ontologies, thesauri, gazetteers); b) the Access Broker allowing a harmonized access to heterogeneous datasets. It also implements transformation services to achieve a Common Environment (same spatial and temporal coverage, Coordinate Reference System, formats, etc.).

Two other components have been prototyped and are under testing in the context of some projects funded by the European Commission (i.e. UncertWeb, GeoViQua, GEOWOW). They are: c) the Quality Broker, allowing to connect heterogeneous sources of quality information (including those provided by data producers, and by data users as annotation); and d) the Business Process Broker allowing to transform high-level scientific Business Processes into executable workflows, connecting accessible environmental models.

The brokering framework proved to help lowering entry barriers for both providers and users shifting most of the intermediation tasks from them to the infrastructure. Besides both data providers and users do not need to make any change to their own system.

To facilitate users’ interaction with the brokers a high level conceptual model was defined. It is based on a small set of concepts allowing the interaction with the GEOSS brokering framework for resources discovery, access, etc. This simple model is currently implemented in a well-documented Javascript library (other will follow) that developers can use for building community portals, web applications and mobile apps. Resorting to the library they can focus on the application functionalities, without taking care of interoperability issues.

The validity of the brokering approach has been recognized by the National Science Foundation EarthCube Programme; a specific project was recently funded to apply such an approach: B-Cubed.

Both GEOSS brokering framework ant the B-Cubed project leverage the GI-* (GI star) technology.