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GSC Sentinel-2 PDGS OCD - Emits - ESA

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<strong>GSC</strong> <strong>Sentinel</strong>-2 <strong>PDGS</strong> <strong>OCD</strong><br />

Issue 1 Revision 2 (draft) - 25.07.2010<br />

GMES-GSEG-EOPG-TN-09-0008<br />

page 271 of 350<br />

This scenario is always initiated by the other <strong>PDGS</strong> functions when searching for archived<br />

product data items based on some inventoried data (e.g. data-type, time segments, etc). The<br />

query interface relies on the inventory metadata associated to every product data item<br />

archived. Accordingly the AI function supports queries based on the inventoried metadata.<br />

The following steps are identified for this operation scenario:<br />

1) A <strong>PDGS</strong> function generates a query and passes it to the AI function;<br />

2) The AI function processes the query request, thus it checks syntax & semantics with<br />

respect to the defined interface. Once the request has been validated, the AI function<br />

based on the metadata inventoried, looks for the matching PDIs;<br />

3) The AI function generates the query result (i.e. the list of product data items matching<br />

the request) and provide it to the originator request according to defined query<br />

interface.<br />

Some use cases are presented according to this operation scenario:<br />

The DPC function queries on the required PDIs for a given processing job. By the<br />

query result, the DPC function knows whether the required data for such processing<br />

job is available;<br />

The DAG function queries to the AI inventory for some product data items availability<br />

according to the user requests.<br />

6.8.3.4 Archived Data Retrieval<br />

This scenario accounts for the autonomous data retrieval activities as requested by other<br />

<strong>PDGS</strong> functions.<br />

The following steps are identified for this operation scenario:<br />

1) The DPC function requests for required input data for a given processing job according<br />

to the data retrieval interface;<br />

2) The AI function processes the retrieval request, validates by checking syntax &<br />

semantics;<br />

3) The AI function leaves the PDIs on the defined out-tray.<br />

The main use cases are presented according to this operation scenario:<br />

The DPC function relies on the AI function for the management and high performance<br />

data retrieval operations needed for the subsequent processing activities. In this<br />

scenario, due to the required archival/retrieval operations performance, the DPC and<br />

the AI function interact locally through a specific dedicated interface;<br />

The DAG function requests for the archived product data items needed to build a userproduct.<br />

The DAG function can interact remotely with the AI function due to lower data<br />

retrieval timeliness constraints with respect to the processing activities.<br />

<strong>ESA</strong> UNCLASSIFIED – For Official Use<br />

© <strong>ESA</strong><br />

The copyright of this document is the property of <strong>ESA</strong>. It is supplied in confidence and shall not be reproduced, copied or<br />

communicated to any third party without written permission from <strong>ESA</strong>.

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