GSC Sentinel-2 PDGS OCD - Emits - ESA

GSC Sentinel-2 PDGS OCD
Issue 1 Revision 2 (draft) - 25.07.2010
GMES-GSEG-EOPG-TN-09-0008
page 287 of 350
The TCI Browser identifies the required product-data items according to the OLIB function
catalogue information and then relies on the DAG function (client-side) for the subsequent
product data items download activities.
6.13 Long-Term Archive (LTA) Operations
6.13.1 PRINCIPLES
The LTA service function is responsible of the long-term data preservation service
implementation ensuring all mission data is safely stored at least 25 years after end-ofmission.
6.13.2 OPERATION CONSTRAINTS
The LTA service function operations will be performed through different distributed centres.
Such operations involve a high data load plus a long time duration operations.
Perform reliable archive and inventory in at least two redundant European sites for
Sentinel-2 mission lifetime during at least 25 years after the end of space-segment
operations;
Make use of cost-effective storage solutions. To cope with the Sentinel-2 very high
volume of data in an effective manner, LTA service function will make use of on-line,
near-line and off-line storage mechanisms according to different products retrieval
latency based on their ageing.
6.13.3 OPERATION SCENARIOS
6.13.3.1 Data Archive & Inventory
This scenario accounts for the autonomous data archiving and inventory performed by the
LTA service function.
The following steps are identified for this operation scenario:
1) The LTA service function is fed by the AI function and work in a data-driven manner;
2) The LTA service function archives the received product components and inventories
them accordingly;
3) On the other side, the AI function inventories as well all the data archived by its
associated LTA service function.
On the PACs (Processing & Archive Centres) with the long-term data preservation role
assigned, the AI function instance locally deployed has associated a Long Term Archive
service function to accomplish such role. Accordingly, the AI function autonomous supplies to
its associated LTA service function, the data (products, auxiliary data, etc.) flagged for longterm
preservation including all the data relevant to reproduce any MSI processing in the
future.
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