GSC Sentinel-2 PDGS STBD - emits - ESA

GSC Sentinel-2 PDGS STBDIssue 1 Revision 2 (draft) - 25.07.2010GMES-GSEG-EOPG-TN-09-0031page 51 of 60The results of the analysis based on a year of possible supply scenario are shown in Table11. Thus, about 24% of the overall amount intended to the GMES services is foreseen to bedelivered in NRT.In terms of scenes (290x290 km), the number of requested images needed to cover theGMES interested areas, is thus around 1000 per year, in terms of tiles (100 x 100 km) it isalmost nine times greater.24%76%NominalNRTFigure 17: Nominal/NRT Product Usage ExpectationsThe data-access requirement analysis reported in [RD-02] Annex-A has further underlined asubstantial expected growth from the DAP/R extrapolated estimates justified by the veryopen data-policy assumed for Sentinel-2. As a matter of fact, the recent experience ofLANDSAT open archive suggests that the overall annual amount of images datadownloaded should be 100 times greater than the ones extrapolated from DAP/R andresulting to an overall yearly estimate of 400 TBytes.The resulting average required data dissemination bandwidth apportioned between NRT(24%) and nominal (76%) access requirements is reported in the following table. The dataratefigures refer to an average useful data-rate and are expressed in Mebibit per second(Mib/s).Data AccessRequirementsYearly VolumeAverage SustainedData-RateNRT 96 TBytes/year 25.5 Mib/sOther 304 TBytes/year 80.9 Mib/sTotal 400 TBytes/year 106.4 Mib/sTable 12: Estimated Dissemination Throughput RequirementCustomarily, the physical network bandwidth will be dimensioned to the double of theestimated useful data rate so as to ensure a correct functioning. Assuming a regulardistribution of the requests along time, the dimensioned physical network bandwidth tosupport the overall dissemination would result to about 210 Mib/s.ESA UNCLASSIFIED – For Official Use© ESAThe copyright of this document is the property of ESA. It is supplied in confidence and shall not be reproduced, copied orcommunicated to any third party without written permission from ESA.