The Copernicus programme is based on a fleet of European Earth observation satellites, built and operated by ESA, member states and commercial entities. Copernicus will also offer data from non-European satellites.

The demand and the requirements for Earth observation (EO) data have evolved drastically. Not only the amount but the volume of requested data have increased by a factor of 10 over the years, in line with the users' processing and analysing capabilities. In addition, the variety and the diversity of data requests have increased to a level where more than 80% of the users request and use data from more than one satellite or satellite operator.

This, in turn, has increased the challenge for Earth observation satellite operators, Space Agencies and EO Data providers to process the data and to offer the access to the different data as coherently and easily as possible.

Last but not least, it forced to optimise the allocation of the available financial resources to handle an increasing number of different EO missions through a closer cooperation in the ground segment development, the operations and the data exploitation.

ESA's Earth Observation Programme Board (PB-EO) had setup in 2003-2004 a task force that came up with a set of recommendations on how to deal with these challenges in the EO ground segment among ESA member states.

Beyond recommendations concerning mission independent design, modularity, competition in the industrial approach, the coordination and cooperation was considered of primary importance. The task force recommended to set-up a 'Ground Segment Coordination Body' (GSCB) of all agencies in member states investing in and managing Earth Observation Payload Data Ground Segments.

This group was established in June 2005 and shares the respective expertise in the development and operations of Payload Ground Segments of missions such as:

• Meteosat, MSG and EPS by EUMETSAT
• TerraSAR-X, RapidEye, TanDEM and EnMAP and third party missions handled by DLR
• the RADARSAT missions by CSA
• COSMO-SkyMed by ASI
• the POT, Topex- Jason and Pleiades missions by CNES
• ERS-1 & ERS-2, Envisat, the different Earth Explorer missions and third party missions by ESA.

The group coordinated and shared its findings with other coordination and standardisation entities like CEOS, OGC and CCSDS; and it planned for regular consultation with industry and commercial missions.

This collaboration became even more important for the GMES Programme and in particular for the GMES Space Component (GSC) at which the sustainability of the EO data supply was assured equally through dedicated missions and through contributing missions from different Agencies, providers and operators.

Based on an initial three-year plan defined at the end of 2005, GSCB began to work on the more critical domains for which harmonisation at the European level would bring cost savings in the ground segments and a discernible improvement in access to the EO data for users and service providers.

The first (and main) project, the Heterogeneous Mission Accessibility (HMA) study, aimed at the joint definition and adoption of interoperability standards required to guarantee seamless and harmonised access to heterogeneous EO datasets.

The initial step was to define standards for the discovery, cataloguing, ordering, accessing and delivery of EO data. To do this, the GSCB relied on the experience of its members, while following international standards and coordination with the European Commission's INSPIRE programme.

The first standardisation version through the Open Geospatial Consortium (OGC) and the European Committee for Standardisation (CEN) was targeted for 2007, with initial implementation in 2009. Standardisation through the European Cooperation on Space Standardisation (ECSS) followed.

The following steps of the project were devoted to defining the harmonised format of EO data products and their quality certification and reporting. The first milestone for the data and quality harmonisation definition was 2008.

The second project was the definition of the Payload Ground Segment reference architecture by identifying the different building blocks and interfaces, and exploiting the experience of the different ground segment operators.

The adoption of a reference EO ground architecture for a simple, user-friendly, cost-efficient and inter-operable infrastructure was eventually recommended, to:

• Ease the implementation and integration of new missions and EO data
• Reduce competitiveness in ground segment development by industry
• Serve the European EO data user community in a harmonised way
• Provide a unified European technical standard towards GEOSS

The third project was the definition and adoption of a common strategy for the long-term preservation of EO data. The strategy defined the technical and managerial approach and provided recommendations for data access, security and archive operations, maintenance and evolution, including data reprocessing and data integrity.

The activity capitalised on policies already in force for preserving digital data archives (at ESA, national space agencies, EUMETSAT) and considered European Union initiatives like the CASPAR project. The first strategy proposal was planned for 2007.

Other areas of common interest were:

• The sharing of telecommunications networking infrastructure, both ground and satellite. The concept relies on the cost-benefit advantages of procuring a common higher capacity network infrastructure, aggregating the needs from different EO operators, rather than proceeding with independent procurements;
• The optimisation of security requirements for the future benefit of dual European missions;
• The identification and sharing of tools for the description, test data generation and manipulation of EO products and ground system interfaces.
• GSCB is not a new standardisation body. Its purpose was to identify and promote the use of a common set of standards to perform the above activities. In doing so, it liaised with the various existing standardisation bodies or initiatives, such as OGC, GEO and INSPIRE.