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 250 of 350
2) Bit synchronisation and locking on IF carrier signal after AOS and until LOS is
autonomously performed by the demodulation hardware;
3) Front-end activities are triggered either autonomously based on the received signal or
according to a specific commanding as specified by the acquisition schedule. The
archive folder is created for the pass;
4) Front-end processing activities are performed autonomously including data acquisition,
demodulation, frame synchronisation, decoding (descrambling and Reed Solomon
FEC), telemetry data time annotation and reconstruction of the acquired ISPs as per
configuration;
5) Decoded and annotated data is archived in real-time according to the DRX
configuration;
6) In parallel, the DRX function autonomously initiates the data-driven supply of AISPs to
the DPC function as per configuration until LOS. Real-time distribution is performed in
parallel for all configured output interfaces. In case the connections required for data
distribution cannot be initiated or if they are closed by the remote end, the operator is
alerted but no retry is autonomously attempted;
7) At the planned LOS event, the acquisition activities are stopped leaving the output
interfaces complete the AISP distribution operations until end-of-file, then releasing the
network connections automatically.
This operation scenario is used nominally for the real-time data reception and data supply to
the DPC function when performing the Level-0 data processing simultaneously to the data
reception.
This scenario does not constrain the on-demand data supply activates as defined in the next
scenario; both can be performed in parallel.
Although triggered by the DRX function, the effective data-supply rate is systematically
managed by the data consumers (i.e. the DPC function) through standard flow-control
mechanisms.
6.1.2.4 On Demand ISP Supply
This scenario accounts for the operator-driven data supply operations as requested by the
data-consumers possibly using one of the hot redundant front-end equipments.
The following steps are identified for this operation scenario:
1) Through an appropriate HMI, the operator selects a pass folder previously acquired
and maintained in the rolling archive and activates the operation;
2) According to the operator-defined configuration, the DRX function autonomously
initiates the supply of the ISPs from the archived pass data until reach the end-of file.
The data supply operations are performed in parallel for all the activated output
interfaces. No automatic retry is attempted in case the connections required for data
distribution cannot be initiated or if they are closed by the remote end.
The following use cases of this operation scenario are identified:
ESA UNCLASSIFIED – For Official Use
© ESA
The copyright of this document is the property of ESA. It is supplied in confidence and shall not be reproduced, copied or
communicated to any third party without written permission from ESA.