GEOSS Interoperability Needs and Implementation Approach
Berners-Lee declared in 2010 "the year open data went global." Since then, hundreds of nations, regions, and cities across the world have launched their own open data initiatives. This open data global movement is characterized by a philosophy and a set of practices of making the data collected by government agencies freely available to the public. Valuable examples are the USGS decision to adopt a policy (begun in 2008) of free and open access to Landsat data and the more recent European Union and ESA commitment to provide open and free access to the Copernicus (i.e., Sentinel satellites) data. In the framework of the Digital Agenda for Europe initiative, the European Union has been working for Open Data portals* to facilitate access to and reuse of public sector information. Open data portals are web-based interfaces designed to make it easier to find reusable information. Like library catalogs, they contain metadata records of datasets published for reuse, that is, mostly relating to information in the form of raw, numerical data and not to textual documents. Analogously,
the Unites States launched the "data.gov"* portal to find data, tools, and resources to conduct research, develop web and mobile applications, and design data visualizations.
The open data global movement creates many opportunities for science to address climate changes' challenges developing an effectively integrated multidisciplinary approach. However, globally shared data need to be harnessed by a new breed of data infrastructures that are based not only on the interoperability of data systems for a specific domain area, but also on the interoperability of multiple disciplines in the physical and social sciences, engineering, and humanities (GEO 2007). For disciplinary and domain applications, systems interoperability largely deals with the adoption of agreed technologies, standards, specifications, and interfaces with a disciplinary/domain services protocol or means of information exchange, if available (GEO 2007). A domain infrastructure requires to be able to address domain resources (or components), achieving interoperability for observations and data models, service interfaces, processing schemes, terms, etc. According to a study of the European Commission (2006), an infrastructure interoperability encompasses at least three overarching and different aspects:
- 1. Semantics, which ensures that exchanged information is understandable and usable by any application or user involved.
- 2. Technology, which concerns the technical issues of linking up computer and information systems, the definition of open interfaces, data formats, and protocols.
- 3. Organization, which deals with modeling organizational processes, aligning information architectures with organizational goals, and helping these processes to cooperate. This category can also include important interoperability challenges, such as data policy, legal, cultural, and people harmonization.
However, multidisciplinary efforts make more complex demands on the type of systems and arrangements needed to support cross-domain activities (GEO 2007). Interconnecting existing disciplinary systems has traditionally introduced limitations to their autonomy and scope. Because different disciplines may have different approaches to data and modeling and different vocabularies (these may be called cultural aspects) and even different interface protocols, bridging across disciplines is a more complex challenge. Thus, interoperability among diverse disciplinary and domain systems must be pursued adopting more flexible and sustainable approaches, the GEOSS brokering approach (see the next paragraph), to introduce such flexibility and evolvability (GEO 2009, 2015). Brokering philosophy is formulated to handle such differences without limiting the autonomy and without putting a significant investment burden on existing disciplinary systems (Nativi et al. 2012, Vaccari et al. 2012).