Core Ground Segment

It includes elements for monitoring and controlling the Sentinel satellites and for downloading, processing and disseminating the data to the users. It also has mechanisms for monitoring and controlling the quality of the data products, as well as facilities for data archiving.

The infrastructure is 'distributed', meaning that although the various centres are in different places they are linked and coordinated. Despite the complexity of the system, users are offered a single virtual access point for locating and downloading the products.

The main elements are:

• The Flight Operations Segment (FOS) –  responsible for all aspects of Sentinel flight operations, including monitoring and control, the execution of all platform activities and command of payload schedules. 

• The Core Ground Stations – where the Sentinel data are downlinked and products are generated in near-real time. A network of X-band ground stations allows Sentinel data to be downlinked. The network is complemented by the European Data Relay Satellite (EDRS) for the additional downlink of Sentinel data to EDRS ground stations.

• The Processing and Archiving Centres (PACs) – where systematic non-time-critical data processing is performed. All data products are archived for online access by users. A network of PACs supports all the processing and archiving of Sentinels data.

• The Mission Performance Centres (MPCs) – responsible for calibration, validation, quality control and end-to-end system performance assessment. The MPCs include expert teams for specific calibration and validation, offline quality control and algorithm correction, and evolution activities.

• The Sentinel Precise Orbit Determination (POD)facility – makes use of the GNSS receiver data on the Sentinels to deliver the orbital information needed to generate the data products.

• The Copernicus Space Component Wide Area Network (CSC WAN) – allows all products and auxiliary data to be carried across the various ground segment facilities and provides disseminated data products to the end users.

All Sentinel data are systematically processed up to the designated level and according to different timelines, ranging from near-real time to non-time-critical, available typically within 3–24 hours of being sensed by the satellite.