The Reference System is a key element of the Ground Segment architecture, responding to multiple needs and aiming mainly at:

• preventing the industrial lock-in for the production and data download operations by implementing and maintaining an open-source solution for these functions
• operating an “under-scaled” production service, cloud-based, able to be scaled up to support an operational load should it be necessary, and offering a reference production and quality control environment (with well-defined access and sizing conditions)
• providing a ready-to-use representative environment for the integration of new User Level Data and their pilot production phase
• serving as potential representative CSC ground segment operational environment for the pre-launch activities related to the new satellite units/new Copernicus missions.

As a secondary service, The Reference System ensures the publication of the historical, new and updated versions of the Sentinel Data processors packages which are used in various components of the Copernicus Operations (e.g. Production Services, Data Access).
The Reference System covers the following main functionalities and scope:

• Implementation and maintenance of an operational open-source cloud-based solution for the (scaled-back) production, routine quality control and data download
• Offering the interfaces for triggering the production of any Sentinel User Level Data, from fresh or archived data, and from any processing baseline
• Operating an “under-scaled” production service, cloud-based, able to be scaled up to support an operational load should it be necessary, and offering a reference production and quality control environment (with well-defined access and sizing conditions)
• Offering the tools and functionalities allowing a streamlined pilot integration of new data processors and the associated pilot production activities
• Implementing and maintaining the tools and functionalities allowing the streamlined integration of new data flows for new Sentinel units, including associated data processing and routine quality control
• Providing a suitable environment to support the pre-launch Copernicus Operations preparation activities for new Sentinel units/new Copernicus missions.
• Providing the possibility to trigger the processing of any historical User Level Data with any former processor version no longer part of the operational baseline.
• Managing the publicly accessible repositories for all RS software related documentation, open-source code, and executables / containerised deployment images available to the various Copernicus Ground Segment operational services and to the Collaborative Ground Segment partners community in general.
• Operating a dedicated Web portal and API for the publication of the Sentinel Data Processors packages, in native form and as RS addons, accessible towards duly authorized entities (e.g. Production Service operators).