GSC Sentinel-2 PDGS SRD - emits - ESA

GSC Sentinel-2 PDGS SRD
Issue 1 Revision 2 (draft) - 25.07.2010
GMES-GSEG-EOPG-RD-09-0028
page 29 of 204
3.2 Functional Decomposition
The first-level of the PDGS functional decomposition discriminates between Data
Management functions, System Control functions and Data-Communication functions.
Whilst the first group refers to the primary core duty of the PDGS of translating the satellite
acquired data into data-access services to the Sentinel-2 product users, the second
regroups all functions required at system-level to control, manage and coordinate the
overall system behaviour. Some specific functions although relevant to both groups have
been allocated to a specific one, with the logic that they mostly apply to the specificities of
the allocated group by their primary functionality and main drivers.
The last group includes all physical data communication functions between or within Data-
Management or System-Control functions.
3.2.1 DATA MANAGEMENT FUNCTIONS
As primary goal, the Data-Management Functions aim at reliably and systematically
transporting the Sentinel-2 constellation data from the antenna down to its authorised
users into elaborated user-products of controlled quality, timeliness and access
performances. Following this logic the following primary functions are identified as
illustrated on Figure 3-2.
○ A Data-Reception (DRX) function responsible for data acquisition from the
spacecrafts and front-end data-handling activities. This function aims for a
maximum reuse of existing ground-infrastructure X-Band tracking antennas (or
EDRS compatible Ka-Band still antennas) and a sentinel-generic Demodulator and
Front-End Processing (DFEP) equipment;
○ A Data Processing Control (DPC) function responsible for managing all data
processing activities, in charge of the systematic processing of Level-0 products
and higher-level production management through dedicated data-processors. It is
also in charge of supervising on-line quality control activities on the performed
production and for hosting user-provided processors fruit of third-party hostedprocessing
collaborations.
The DPC function aims for a rule-based data-driven management of the real-time
dataflow, whilst offering additional on-demand processing capabilities as required
for Data-Access. It is intended as providing most of the required parallel processing
management and be highly scalable with computing hardware in this respect.
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