PACE OMPONENT ENTINEL AYLOAD ATA ROUND ...emits.esa.int/emits-doc/ESRIN/Sentinel-2/System...The GMES...

Appendix B

D O C U M E N T

document title/ titre du document

PACE OMPONENT

ENTINEL AYLOAD ATA ROUND EGMENT

YSTEM EQUIREMENTS OCUMENT

prepared by/préparé par Sentinel-2 PDGS Project Team

reference/réference GMES-GSEG-EOPG-RD-09-0028 issue/édition 1 revision/révision 2 (draft) date of issue/date d’édition 25.07.2010 status/état Draft Document type/type de document Requirements Document Distribution/distribution

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.

GSC Sentinel-2 PDGS SRD issue 1 revision 2 (draft) - 25.07.2010

GMES-GSEG-EOPG-RD-09-0028 page ii of ix



A P P R O V A L

Title

Titre

GMES Space Component - Sentinel-2 Payload Data Ground Segment (PDGS) - System Requirements Document (SRD)

issue

issue

1 revision

revision

2 (draft)

author

auteur

Sentinel-2 PDGS Project Team date

date

25.07.2010

approved by

approuvé par

O.Colin date

date

authorised by

autauris’e par

E.Monjoux

C H A N G E L O G

reason for change /raison du changement issue/issue revision/revision date/date

Creation 1 0 21.12.2009

Update post PDGS-SRR 1 1 25.06.2010

Updated as per ngEO scenarios .

1 2 (draft) 25.07.2010


GMES-GSEG-EOPG-RD-09-0028 page v of ix



T A B L E O F C O N T E N T S

1 INTRODUCTION ................................................................................................10 1.1 Purpose .......................................................................................................................10 1.2 Background..................................................................................................................10

2 DOCUMENTATION............................................................................................13 2.1 Normative Reference Documents................................................................................13 2.2 Informative Reference Documents ..............................................................................14 2.3 Acronyms.....................................................................................................................17 2.4 Terms and Abbreviations .............................................................................................23 2.5 Document Overview.....................................................................................................26

3 GMES SENTINEL-2 PDGS OVERVIEW............................................................27 3.1 PDGS Context .............................................................................................................27 3.2 Functional Decomposition............................................................................................29

3.2.1 Data Management Functions................................................................................29 3.2.2 System Control Functions.....................................................................................32 3.2.3 Data Communication Functions............................................................................33

4 ASSUMPTIONS & OPEN ISSUES.....................................................................35 4.1 Assumptions ................................................................................................................35 4.2 Open Issues.................................................................................................................37

5 GMES SENTINEL-2 PGDS REQUIREMENTS ..................................................38 5.1 PDGS System-Level Requirements.............................................................................38

5.1.1 Functional Requirements......................................................................................38 5.1.2 Performance Requirements..................................................................................49 5.1.3 Sizing Requirements.............................................................................................50 5.1.4 Operational Requirements....................................................................................51 5.1.5 Interface Requirements ........................................................................................58 5.1.6 RAMS Requirements ............................................................................................62


GMES-GSEG-EOPG-RD-09-0028 page vi of ix



5.1.7 Design & Development Requirements..................................................................63 5.1.8 Security Requirements .........................................................................................66

5.2 Data Reception (DRX) Requirements ..........................................................................69 5.2.1 Functional Requirements......................................................................................69 5.2.2 Performance Requirements..................................................................................72 5.2.3 Sizing Requirements.............................................................................................73 5.2.4 Operational Requirements....................................................................................73 5.2.5 RAMS Requirements ............................................................................................76 5.2.6 Design & Development Requirements..................................................................76

5.3 Data Processing Control (DPC) Requirements............................................................77 5.3.1 Functional Requirements......................................................................................77 5.3.2 Performance Requirements..................................................................................83 5.3.3 Operational Requirements....................................................................................84 5.3.4 RAMS Requirements ............................................................................................85 5.3.5 Design & Development Requirements..................................................................86

5.4 Instrument Data Processing (IDP) Requirements ........................................................87 5.4.1 Functional Requirements......................................................................................87 5.4.2 Performance Requirements..................................................................................89 5.4.3 Operational Requirements....................................................................................89 5.4.4 RAMS Requirements ............................................................................................89 5.4.5 Design & Development Requirements..................................................................90

5.5 MSI Decompression Software (MDS) Requirements ...................................................90 5.5.1 Functional Requirements......................................................................................90 5.5.2 Performance Requirements..................................................................................91

5.6 On-Line Quality Control (OLQC) Requirements...........................................................91 5.6.1 Functional Requirements......................................................................................91 5.6.2 Performance Requirements..................................................................................94 5.6.3 Operational Requirements....................................................................................94 5.6.4 RAMS Requirements ............................................................................................94 5.6.5 Design & Development Requirements..................................................................94

5.7 Archive & Inventory (AI) Requirements........................................................................95 5.7.1 Functional Requirements......................................................................................95


GMES-GSEG-EOPG-RD-09-0028 page vii of ix



5.7.2 Performance Requirements................................................................................101 5.7.3 Operational Requirements..................................................................................101 5.7.4 RAMS Requirements ..........................................................................................103 5.7.5 Design & Development Requirements................................................................104

5.8 Long-Term Archive (LTA) Service Requirements ......................................................105 5.8.1 Functional Requirements....................................................................................105 5.8.2 Performance Requirements................................................................................105 5.8.3 Operational Requirements..................................................................................106 5.8.4 RAMS Requirements ..........................................................................................106

5.9 Data Circulation (DC) Requirements..........................................................................107 5.9.1 Functional Requirements....................................................................................107 5.9.2 Performance Requirements................................................................................109 5.9.3 Operational Requirements..................................................................................110 5.9.4 RAMS Requirements ..........................................................................................111 5.9.5 Design & Development Requirements................................................................112

5.10 Precise Orbit Determination (POD) Requirements ....................................................112 5.10.1 Functional Requirements....................................................................................112 5.10.2 Performance Requirements................................................................................113 5.10.3 Operational Requirements..................................................................................114 5.10.4 RAMS Requirements ..........................................................................................116 5.10.5 Design & Development Requirements................................................................116

5.11 Auxiliary Data Supply (ADS) Requirements...............................................................116 5.11.1 Functional Requirements....................................................................................116 5.11.2 Performance Requirements................................................................................117 5.11.3 Operational Requirements..................................................................................117 5.11.4 RAMS Requirements ..........................................................................................117 5.11.5 Design & Development Requirements................................................................117

5.12 Data-Access Index (DAX) Requirements...................................................................117 5.12.1 Functional Requirements....................................................................................117 5.12.2 Performance Requirements................................................................................121 5.12.3 Operational Requirements..................................................................................121 5.12.4 RAMS Requirements ..........................................................................................122


GMES-GSEG-EOPG-RD-09-0028 page viii of ix



5.12.5 Design & Development Requirements................................................................123 5.13 Data Access Gateway (DAG) Requirements .............................................................124

5.13.1 Functional Requirements....................................................................................124 5.13.2 Performance Requirements................................................................................128 5.13.3 Operational Requirements..................................................................................128 5.13.4 RAMS Requirements ..........................................................................................129 5.13.5 Design & Development Requirements................................................................130

5.14 Multi-Mission User Services (MMUS) Requirements .................................................131 5.14.1 Functional Requirements....................................................................................131 5.14.2 Performance Requirements................................................................................139 5.14.3 Sizing Requirements...........................................................................................140 5.14.4 Operational Requirements..................................................................................140 5.14.5 RAMS Requirements ..........................................................................................141 5.14.6 Design & Development Requirements................................................................141

5.15 On-Line Images Browser (OLIB) Requirements ........................................................142 5.15.1 Functional Requirements....................................................................................142 5.15.2 Performance Requirements................................................................................143 5.15.3 Operational Requirements..................................................................................143 5.15.4 RAMS Requirements ..........................................................................................144 5.15.5 Design & Development Requirements................................................................144

5.16 Mission Configuration Control (MCC) Requirements .................................................144 5.16.1 Functional Requirements....................................................................................144 5.16.2 Performance Requirements................................................................................148 5.16.3 Operational Requirements..................................................................................148 5.16.4 RAMS Requirements ..........................................................................................149 5.16.5 Design & Development Requirements................................................................150

5.17 Mission Planning (MPL) Requirements......................................................................150 5.17.1 Functional Requirements....................................................................................150 5.17.2 Performance Requirements................................................................................160 5.17.3 Operational Requirements..................................................................................161 5.17.4 RAMS Requirements ..........................................................................................163 5.17.5 Design & Development Requirements................................................................164


GMES-GSEG-EOPG-RD-09-0028 page ix of ix



5.18 Mission Performance Assessment (MPA) Requirements ..........................................164 5.18.1 Functional Requirements....................................................................................164 5.18.2 Performance Requirements................................................................................167 5.18.3 Operational Requirements..................................................................................167 5.18.4 RAMS Requirements ..........................................................................................173 5.18.5 Design & Development Requirements................................................................174

5.19 Reference Platform (RP) Requirements ....................................................................175 5.19.1 Functional Requirements....................................................................................175 5.19.2 Performance Requirements................................................................................177 5.19.3 Operational Requirements..................................................................................177 5.19.4 RAMS Requirements ..........................................................................................178 5.19.5 Design & Development Requirements................................................................178

5.20 Monitoring & Control (M&C) Requirements................................................................179 5.20.1 Functional Requirements....................................................................................179 5.20.2 Performance Requirements................................................................................181 5.20.3 Operational Requirements..................................................................................181 5.20.4 RAMS Requirements ..........................................................................................182 5.20.5 Design & Development Requirements................................................................182

5.21 Data Communication Requirements ..........................................................................182 5.21.1 Functional Requirements....................................................................................182 5.21.2 Performance Requirements................................................................................184 5.21.3 Operational Requirements..................................................................................185 5.21.4 RAMS Requirements ..........................................................................................186 5.21.5 Network Security Requirements .........................................................................187 5.21.6 Design & Development Requirements................................................................187

APPENDIX-A PDGS REQUIREMENTS SEMANTIC AND FORMAT .....................................189

APPENDIX-B PDGS TRACEABILITY REQUIREMENT MATRIX (TRM) ...............................192

GSC Sentinel-2 PDGS SRD Issue 1 Revision 2 (draft) - 25.07.2010

GMES-GSEG-EOPG-RD-09-0028 page 10 of 204



1 INTRODUCTION

1.1 Purpose

The purpose of this document is to define the Sentinel-2 PDGS system requirements, which will be the driver for the PDGS design & implementation and will constitute the reference for the PDGS validation. The PDGS SRD constitutes the highest-level requirements document for the GMES Sentinel-2 PDGS, defining the parent system requirements for the specifications of the Sentinel-2 PDGS facilities and elements/components. PDGS centres specifications and operational scenarios are provided in the Sentinel-2 PDGS Operations Concept Document [ND-9].

1.2 Background

The GMES (Global Monitoring for Environment and Security) programme is a European initiative for the implementation of information services dealing with environment and security. It is based on observation data received from Earth Observation satellites and ground based information. Within the GMES programme, the GMES Service Segment (GSS) composed over several GMES Service Projects (GSPs) is in charge of providing value-added data and services to the GMES final users, while the GMES Space Component (GSC) is responsible for providing to the GMES Service Segment the necessary Earth-Observation (EO) data and services. As part of the GMES Space Component Programme, ESA is responsible for developing a fully operational space-based capability to feed the GSS with satellite data. This capability will be achieved with the implementation of GMES dedicated Earth Observation Missions, the Sentinels missions, under development by ESA. The Sentinel-2 mission is one of this series of GMES EO missions, scheduled for launch by 2013. Access to EO data and services by the GSS shall however be ensured already before the Sentinel era. This is being achieved by relying on a set of EO missions capable of satisfying the data requirements from the GSS. These missions contributing to the GSC are generically referred to as GSC (or GMES) Contributing Missions (GCMs). The GSC Coordinated Data Access System (CDS) is the pre-operational infrastructure being developed by ESA for providing access to GSC data and services to the GSS before the GMES Sentinels are launched. Although the CDS is initially implemented for the GMES pre-operations phase, it is however designed to support the successive operational phase with the Sentinels. The Sentinels PDGS shall therefore be conceived as being part of the GSCDA as a fully integrated GMES mission. The GSCDA data and services are accessible through a portfolio of Data Sets (DSs). These DSs are derived from the GMES Services requirements captured in the DAP/R [RD-5],





which after trade-off with the system available capacity are propagated in the GSC DAP, where GMES Services updated requirements and evolving space systems capacity are taken into account. The DAP Data Sets are pre-defined collections of coherent multi-mission products responding to specific different users needs and therefore with different characteristics. The CDS interfaces with the GMES Service Component for gathering data requests and providing coordinated data access and services, and with the Ground Segments of the GCM’s and the Sentinel missions for coordinating the data provision from the GCM’s in response to the requests. Figure 1-1 sketches the GSC Data Access System context, the role of the Coordinated Data Access System (CDS) and its interface with the GMES Service Segment (for gathering data requests and providing coordinated data access and services), and with the Ground Segment of the GCM’s and the Sentinel missions (for coordinating the data provision in response to the requests). The GSCDA data and services provision from the GMES Contributing Missions (GCMs) is regulated through specific agreements with ESA through the DAP Management function. Being dedicated GMES missions, the latter interface is not strictly necessary for the Sentinel missions.

GSC SentinelMissions



•GCM Products•Reports

• Registrations• Data Requests • Subscription

RegistrationsGMES GMES GMES Service Service Service ProjectsProjectsProjects

Long-term EO Data Requirements

GMES GMES GMES Service Service Service ProjectsProjectsProjects

Agreements

GSC ProductsGSC Data Sets

• Data Requests• Subscription Requests

CoordinatedData Access

System (CDS)

DAP Management

DAP Management

GMES ServicesGMES ServicesGMES Services

GSC Data Access

GCM & Sentinel Products

•Products•Reports

• Data Requests• Subscription

Requests

GSCContributing

Missions

GSCContributing

MissionsGSC

ContributingMissions

Figure 1-1 GMES Space Component Data Access System Overview





The Sentinel missions, as dedicated GSC missions, will be integrated with the CDS to contribute to the overall data provision to the GSC. The Sentinel missions will interface with the CDS through the Sentinel Ground Segment (GS) and particularly though the Payload Data Ground Segment (PDGS), as illustrated in Figure 1-2. Being part of the GSCDA, the Sentinel-2 PDGS shall conform to the standard GSCDA interfaces both towards the GMES Services and towards the GMES coordinated functions as detailed in [ND-22] and they shall comply as well with the GSCDA operational scenarios as detailed in [ND-4].

Figure 1-2 Sentinel-2 Mission Context

Figure 1-2 also illustrates the Sentinels PDGSs as components of the overall Ground-Segment (GS) including the Flight-Operation-Segment (FOS) interfacing the PDGS on one side and the spacecrafts on the other for commanding and control.





2 DOCUMENTATION

2.1 Normative Reference Documents

[ND-1] GMES Sentinel-2 Mission Requirements Document - EOP-SM/1163/MR-dr [MRD]

Is. 2 Rev. 1 08/03/2010

[ND-2] GMES Sentinel-2 Ground Segment Requirements Document [GSRD] - S2.RS.ESA.SY.0094

Is.1 Rev. 1 08/12/2009

[ND-3] GSC Data Access Portfolio Requirements Document [DAP-R], GMES-PMAN-EOPGRD-08-0002, Is. 1.1 2009

[ND-4] GSC Data Access System Operational Scenarios for GMES Contributing Missions - GMES-GSEG-EOPG-TN-08-0005

Is.1 Rev. 1 10/09/2008

[ND-5] Sentinel-2 Spacecraft Operations Concept Document [SOCD] - GS2.TN. ASD.SY.00010 Is. 3 30/10/2009

[ND-6] Satellite to Ground Segment Interface Control Document [S2GICD], GS2.ICD.ASD.SY.00006 Is. 4 10/11/2009

[ND-7] GMES Sentinel-2 PDGS Master Interface Control Document [MICD], GMES-GSEG-EOPG-IC-09-0032,

1.2 (draft) 25/07/2010

[ND-8] ESA Earth Observation PDGS Requirements Document [EO-PDGS], PGSI-GSOP-EOPG-RD-09-0005, I 1.1

[ND-9] GMES Sentinel 2 PDGS Operations Concept Document [OCD], GMES-GSEG-EOPG-TN-09-0008

1.2 (draft) 25/07/2010

[ND-10] Sentinel-2 PDGS System Technical Budget Document [STBD], GMES-GSEG-EOPG-TN-09-0031

1.2 (draft) 25/07/2010

[ND-11] Sentinel-2 PDGS Products Definition Document [PDD], GMES-GSEG-EOPG-TN-09-0029

1.2 (draft) 25/07/2010

[ND-12] ECSS-E-ST-70C, Space Engineering Ground Systems and Operations

[ND-13] ECSS-E-ST-40C - Space Engineering Software

[ND-14] ECSS-E-ST-10-02C - Space Engineering Verification

[ND-15] ECSS-Q-ST-80C, Space Product Assurance – Software Product Assurance

[ND-16] ECSS-P-001B, ECSS Glossary Of Terms





[ND-17] INSPIRE Directive 2007/03/14, http://inspire.jrc.ec.europa.eu/

[ND-18] INSPIRE Metadata Regulation 04/12/2008

[ND-19] EC DECISION regarding INSPIRE monitoring and reporting 05/06/2009

[ND-20] GMES Fast Track Land Monitoring Core Service Strategic Implementation Plan

Final Version 24/04/2007

[ND-21] GMES Fast Track Emergency Response Core Service Strategic Implementation Plan

Final Version 24/04/2007

[ND-22] GSC Data Access Operational Interface Requirements for GCMs – GMES-GSEG-EOPG-RD-08-0003

Is.1 Rev. 3 06/04/2009

2.2 Informative Reference Documents

[RD-1] GMES Sentinel-2 System Requirements Document - S2-RS-ESA-SY-0001

Is. 5 Rev. 0 15/10/2007

[RD-2] Joint Principles for a GMES Sentinel Data Policy, ESA/PB-EO(2009)98 Rev.1 23/10/2009

[RD-3] GMES Sentinel-2 PDGS System Test Concept Document [STCD], GMES-GSEG-EOPG-TN-09-0030

1.2 (draft) 25/07/2010

[RD-4] Sentinel-2 MSI – Level 2A Auxiliary Data Definition, S2PAD-VEGA-AUX-0001

Issue 2.2 19/04/2010

[RD-5] Data Access Portfolio Requirement Document (DAP/R) – GMES-PMAN-EOPG-RD-08-0002

Is. 1 Rev. 1 15/03/2009

[RD-6] ICD SCI Coverage Reports - OSME-GSCDA-SEDA-ISS-09-0039 ?? GCM Coverage Report ICD (IF-GCM-SCI-06 2.0 24/04/09)

[RD-7] GML 3.1.1 Application schema for Earth Observation products. Ref. OGC 06-080

[RD-8] EO Products Extension Package for ebRIM (ISO/TS 15000-3) Profile of CSW 2.0. OGC 06-131

[RD-9] Ordering Services for Earth Observation Products, OGC 06-141

[RD-10] European Long-Term Data Preservation Common Guidelines, GSCB-LTDP-EOPG-GD-09-0002 http://earth.esa.int/gscb/ltdp/EuropeanLTDPCommonGuidelines_DraftV2.pdf

Draft V2 04/06/2009

http://inspire.jrc.ec.europa.eu/http://earth.esa.int/gscb/ltdp/EuropeanLTDPCommonGuidelines_DraftV2.pdfhttp://earth.esa.int/gscb/ltdp/EuropeanLTDPCommonGuidelines_DraftV2.pdf





[RD-11] GMES Sentinel-2 Phases B2, C/D, E1 – Mission Analysis Report, GS2-RP-GMV-SY-00006

Issue 2.1 04/02/2009

[RD-12] EOP-G Ground segment security policy [RD-13] ESA Security directives (chapter 5.7, annex 2) [RD-14] EO Network security implementation policy [RD-15] Regulation EC No 45/2001 [RD-16] EU Directive [COM(2005)_438 final)] on data retention [RD-17] European Data Relay Satellite System – Appendix-2 The

ESA Data Relay Satellite Service Requirements, D-TIA/2008-12152/CE App2

Issue 1 rev 1 09/10/2008

[RD-18] Sentinel-2 Design Description, GS2.RP.ASD.SY.00024 Issue 2 11/11/2009[RD-19] Sentinel-2 NUC Table Uplink Scenario,

GS2.TN.ASD.SY.00046 Issue 1 08/05/2009

[RD-20] GMES Sentinels Payload Data Downlink Simulation in X-Band, PE-TN-ESA-GS-0264

Issue 1.1 19/07/2009

[RD-21] Sentinel-2 PDGS Distributed Level-1 Data Processing Study, GMES-GSEG-EOPG-TN-09-0037

Issue 1.0 21/12/2009

[RD-22] Sentinel-2 Ground Prototype Processor - Processing Specification for Level 1A, 1B and 1C Production, GS2-ST-GSGP-40-CNES

Issue 1.0 10/06/2009

[RD-23] Sentinel-2 MSI - Level-2A Products Definition, S2PAD-VEGA-PD-0001

Issue 2.1 06/11/2009

[RD-24] Sentinel-2 MSI – Level 2A Ancillary and Auxiliary Data Definition, S2PAD-VEGA-AUX-0001

Issue 2.0 06/11/2009

[RD-25] Sentinel-2 MSI – Level 2A Products Algorithm Theoretical Basis Document - Volume A (SMAC), S2PAD-VEGA-ATBD-0001

Issue 2.0 09/11/2009

[RD-26] Sentinel-2 MSI – Level 2A Products Algorithm Theoretical Basis Document - Volume B (ATCOR), S2PAD-DLR-ATBD-0002

Issue 1.3 06/11/2009

[RD-27] QA4EO, “A quality assurance framework for Earth Observation, key guidelines”, approved by CEOS, http://qa4eo.org/documentation.html

[RD-28] Standard Archive Format for Europe (SAFE), http://earth.esa.int/SAFE/

[RD-29] Network and ICT Security Requirements for the EO PDGS, MGT-SENE-EOPG-RS-09-0002 Is. 1.0 28/07/2009





[RD-30] Sentinel-2 MMFU Design Adaptations – S2-CR-ESA-SY-0009

Issue 1.0 09/03/2010

[RD-31] EDRS: The Sentinel Requirements Data Relay Services - GM-RS-ESA-SY-27

Issue 1.0 09/03/2010

[RD-32] EDRS: The Sentinel Requirements Extended Services Data Repatriation & Dissemination - GM-RS-ESA-SY-31

Issue 1.0 09/03/2010

[RD-33] EDRS: The Sentinels/EDRS Operations Constraints and Concept - GM-RS-ESA-SY-28

Issue 1.0 09/03/2010

[RD-34] Next Generation User Services for Earth Observation (ngEO) System Description & Operational Scenario [NGEO-OS] – GMES-GSEG-EOPG-TN-10-0005

Draft 18/06/2010





2.3 Acronyms

AI Archive and Inventory ADP Auxiliary Data Providers ADS Auxiliary Data Supply AOCS Attitude and Orbit Control System AOD Aerosol Optical Depth AOS Acquisition-Of-Signal ATCOR Atmospheric Correction and Haze Reduction BOA Bottom-Of-Atmosphere CADU Channel Access Data Unit CCSDS Consultative Committee for Space Data Systems CDAM Collaborative Data-Access Mirror CDS GSC Coordinated Data Access System CDN Content Delivery Network CEOS Committee on Earth Observation Satellites CGS Core Ground Station CNES Centre National d’Études Spatiales CSM Calibration and Shutter Mechanism CSS Collaboration Support Service CST Centre Spatial de Toulouse CUC CCSDS Unsegmented Time Code DA Data Access DAG Data-Access Gateway DAIL Data Access & Integration Layer DAP Data Access Portfolio DAX Data-Access Index DC Data Circulation DCN Digital Circulation Network DDN Data Dissemination Network DEM Digital Elevation Model DFEP Demodulator & Front-End Processor





DPC Data Processing Control DPM Data Processing Model DRX Data-Reception DS Data Set DTED Digital Terrain Elevation Data DUE Data User Element EDRS European Data Relay Satellite EEPROM Electrically Erasable and Programmable ROM ERCS Emergency Response Core Service ESA European Space Agency ESOC European Space Operations Centre EO Earth Observation FCN FOS Communication Network FEE Front End Electronic FEEM Front End Electronic Module FES Front-End Services FIFO First-In First-Out FOS Flight Operations Segment FPA Focal Plane Assembly FPGA Field Programmable Gate Array FTP File Transfer Protocol FTS Fast Track Services GCM GMES Contributing Mission GCP Ground Control Point GEO Geostationary GIPP Ground Image Processing Parameters GMES Global Monitoring for Environment and Security GMFS Global Monitoring for Food Security GPP Ground Prototype Processor GPS Global Positioning System GRI Global Reference Image GS Ground Segment GSC GMES Space Component GSCB Ground-Segment Coordination Body





GSCDA GMES Space Component Data Access GSE GMES Service Element (ESA projects) GSP GMES Service Project GSRD Ground-Segment Requirements Document GSS GMES Service Segment GUI Graphic User Interface HKTM House Keeping Telemetry HLOP High-Level Operation Plan HMA Heterogeneous Mission Accessibility HMI Human-Machine Interface HPDI Heavy Product Data Item HR High Resolution HW Hardware IAS Image Algorithm Software ICCDB Instrument Calibration & Characterisation Database ICD Interface Control Document ICM Instrument Control Module IDP Instrument Data Processing INSPIRE Infrastructure for Spatial Information in Europe IPF Instrument Processing Facility IPS Image processing Parameters Set IQP Image Quality Processor ISO International Organization for Standardization ISP Instrument Source Packet JPIP JPEG Interactive Protocol JRC Joint Research Centre LAN Local Area Network

OCP Optical Communication Payload (formerly called Laser Communication Terminal, LCT) LEO Low Earth Orbit LEOP Launch and Early Operations Phase LES Land Equipped Sites LGS Local Ground-Stations LMCS Land Monitoring Core Service





LPDI Lightweight Product Data Item LTA Long-Term Archive LTDP Long-Term Data Preservation LUT Look-Up-Table M&C Monitoring & Control MCC Mission Configuration and Control MCS Mission Control Service MCS Marine Core Service MCN Media Circulation Network MDP MSI Decompression Software Provider MDS MSI Decompression Software MMA Mission Management Authority MMFU Mass Memory Formatting Unit MMUS Multi-Mission User-Services MODTRAN MODerate resolution atmospheric TRANsmission MPA Mission Performance Assessment MPAC Mission Performance Assessment Centre MPL Mission Planning MRD Mission Requirements Document MSI Multi-Spectral Instrument MSIC MSI Control application (part of the Central Control Software) MSS Mission Scheduling System MT Medium Term MTF Modulation Transfer Function MTL Mission TimeLine NOAA National Oceanic and Atmospheric Administration NRT Near-Real-Time NUC Non-Uniformity Coefficients OBC On-Board Computer OBCD On-Board Configuration Data OCP Optical Communication Payload OGCD On-Ground Configuration Data OLIB On-line Image Browser OLQC On-Line Quality-Control





OPS Orbit Position Schedule OSV Overall System Validation PDGS Payload Data Ground Segment PDHT Payload Data Handling Transmission system PDI Product Data Item PDMC Payload Data Management Centre PDT Payload Data Transmission POD Precise Orbit Determination POF Predicted Orbit File POM PDGS Operation Manager PPS Pulse Per Second PSK Phase Shift Key PUS Packet Utilisation Standard QC Quality-Control QI Quality Indicator QL Quick-Look QR Qualification Review RAM Random Access Memory ROM Read Only Memory RP Reference-Platform RT Real-Time S2CP Sentinel-2 Commissioning-Plan SAFE Standard Archive Format for Europe SCI Service Coordinated Interface (GSCDA) SEC Security Pilot Service SECOPS Security Operating Procedures S-FEE SWIR FEE SFTP Secure File Transfer Protocol SMAC Simplified Method for Atmospheric Corrections SNR Signal-to-Noise Ratio SPOT Satellite Pour l’Observation de la Terre SPR Software Problem Report SOCD Spacecraft Operations Concept Document SRTM Shuttle Radar Topographic Mission





SSCF Spacecraft Safety Constraint File SW Software SWIR Short-Wave Infrared TBC To Be Confirmed TBD To Be Defined TCI True Colour Image TCM Thermal Control Module TCS Thermal Control Subsystem TDI Time Delay and Integration TF Transfer-Frame (CCSDS) TLE Two Line Elements TMA Tree-Mirror-Anastigmat TMTC Telemetry and Tele-command TOA Top-Of-Atmosphere TTO Transfer to Operation TWTA Travelling Wave Tube Amplifiers URL Universal Resource Locator USGS United States Geological Survey UTM Universal Transverse Mercator VCDU Virtual Channel Data Unit VCM Video Compression Module VCN Voice Communication Network VCU Video and Compression Unit VOIP Voice-Over-IP WAN Wide Area Network WICOM Wavelet Compression Module VNIR Visible and Near Infrared VPM Video Processing Module WGS World Geodetic System WICOM Wavelet Image COmpression Modules XBS X-Band Subsystem





2.4 Terms and Abbreviations

Downtime Period of time when a service is not operational or there is a packet loss higher than 40%.

Scheduled Downtime/ Planned outage

The Scheduled Downtime is the time required to perform necessary evolution and maintenance activities (e.g. upgrade on the network equipments to achieve a higher band-width).

Incident Any event which is not part of the standard operation of a service and which causes or may cause an interruption to or a reduced quality of that service.

Problem Resolution Time Service Time elapsed between a problem occurrence and the solving of a problem, excluding the stop-clock periods.

Scheduled Maintenance Notification Time

The elapsed time between the time of the e-mail notification to users and the start of the maintenance.

Availability It is the availability of the service during the Service Coverage hours

Monthly Service Time - Monthly Service Downtime Monthly Service Time

IP-VPN service availability is measured between two ESA Sites Internet Service availability is measured between an ESA Site and the Providers Internet gateway that is directly connected to the Internet. Several Availability requirements (RAMS) are defined by a percentage ”computed over a one month time window and assuming a degradation of such figure for no more than one day.” This refers to the availability observed in average during a 30-days sliding time window. Within the 30-days period, a degradation of the availability value shall never exceed 24 hours of duration (i.e. the period during which the availability figure is below the monthly average required).





Maintainability The ease with which a product can be maintained in order to:

correct defects (corrective maintenance)

cope with a changed environment (adaptive maintenance)

meet new requirements (perfective/improving maintenance)

make future maintenance easier (preventive maintenance)

Service Downtime Service Downtime = Downtime - Stop-clock Periods

Stop-clock Periods Stop-clock Periods are scheduled downtimes and downtimes that are beyond the direct control of the Operational Support, as the resolution of incidents in the service scope of the Internet Network Providers.

MTTR Maximum Time To Repair. The MTTR starts when an outage occurs and is to be concluded when the service is restored.

Round Trip Delay Round trip delay, also called propagation delay. Round trip delay is the amount of time it takes for a packet for being (de-) encapsulated, routed/switched and transmitted to the other end and back; i.e. it is propagation delay + transmission delay + processing delay. This is measured from the outside interface of the Contractor’s WAN border device on one site to the outside interface of the Contractor’s WAN border device on the other site.

Outage Lead Time An outage is an incident during which the warranted service is not provided. Lead-time is the time allowed to the service operator to recover from the outage condition. After this lead-time, the outage is taken into account in the credit scheme calculations.

Mission Lifetime The Sentinel-2 mission lifetime covers a minimum of 13.5 years with active space-segment operations.

PDGS Operational Lifetime The PDGS operational lifetime covers the Mission Lifetime plus 25 additional years to support Long Term Data Preservation (LTDP)

activities. LTDP activities are the ones related to the maintenance and the exploitation of the Sentinel-2 data archives including data preservation, processing, cataloguing, data access, etc activities performed during and sustained beyond the satellite operational periods.





Data-Rate units Megabit per second (Mbps) 1 Mbps = 106 bits per second = 1.25 105 bytes per second

Mebibit per second (Mib/s) 1 Mib/s = 220 bits per second = 217 bytes per second

Data-Volume units Gigabit (Gbit or Gb): 1 Gbit = 230 bits Gigabyte (GByte or GB): 1 GByte = 230 Bytes = 233 bits Terabyte (TByte or TB): 1 TByte = 240 Bytes = 243 bits





2.5 Document Overview

The present document is divided into the following chapters: Chapter-1: Introduction, provides document purpose and background information; Chapter-2: Documentation provides the list of applicable and reference documentation as well as definition of acronyms and terms; Chapter-3: GMES Sentinel-2 PDGS Overview, provides an overview of the GMES Sentinel-2 PDGS, its role and objectives within the Sentinel-2 Ground Segment: a summary of the main PDGS interactions with external entities. Chapter-4: Assumptions and Open Issues, provides the list of assumptions and open issues at PDGS system level that lead to the definition of the PDGS requirements. Chapter-5: GMES Sentinel-2 PDGS Requirements, provides the exhaustive list of PDGS system requirements as derived from the applicable documents. Appendix-A: Requirements Semantic and Format, describes the conventions applicable to the requirements identification, classification and wording. Appendix-B: Traceability Requirement Matrix (TRM), outlines the main sources of requirements leading to the definition of the PDGS requirements and lists the traceability records.





3 GMES SENTINEL-2 PDGS OVERVIEW

3.1 PDGS Context

The Sentinel-2 Ground-Segment (GS) is composed of the FOS and the PDGS. During Phase-E1 of each satellite unit, the CNES centre in Toulouse (CNES/CST) will also be considered an integral part of the Sentinel-2 GS as providing dedicated services on-ground for commissioning the spacecrafts until the start of Phase-E2 operations. The FOS is responsible for all flight operations of the Sentinel-2 spacecrafts including satellite tasking, telecommanding and telemetry monitoring, flight dynamics monitoring and orbit control. It will be operated at ESA’s European Space Operations Centre (ESOC) in Darmstadt in Germany during the entire Sentinel-2 mission. The PDGS is responsible for payload and downlink planning, data acquisition and processing of the Sentinel-2 satellite data, while contributing to the overall monitoring of the payload and platform in coordination with the FOS. The PDGS is a distributed ground-system including ground-stations, processing centres and embedding all additional third-party centres falling in the scope of its responsibilities for Sentinel-2 (e.g. auxiliary data providers). The GSCDA system is not considered part of the Sentinel-2 mission GS as providing multi-mission services within the GSC and as such is not strictly dedicated to Sentinel-2. To meet its objectives the Sentinel-2 PDGS interfaces with:

○ The Sentinel-2 PDGS Operation Manager (POM) having the responsibility of the overall performance, operations, and configuration of the PDGS;

○ The Sentinel-2 Users for access to and exploitation of the PDGS product archives. The GMES Service Projects (GSPs) are a specific class of Sentinel-2 users.

○ Local Ground Stations (LGS) authorised through the HLOP for the Real-Time reception of Sentinel-2 payload data through the X-Band direct downlink interface.

○ The Coordinated Data Access System (CDS) as the common GSC service interface providing coordinated data-access and reporting versus GSPs.

○ The Sentinel-2 Flight Operations Segment (FOS) at ESA/ESOC as a working interface with the PDGS for mission planning as well as stakeholder for the operational exploitation of HKTM products generated by the PDGS.

○ The European Data Relay System (EDRS) for the coordination of space-to-ground data-relay activities and ground-to-ground data broadcast interfaces to support the PDGS internal data circulation or external dissemination to Users.

○ The Centre National d'Études Spatiales centre in Toulouse (CNES/CST) as a working interface with the PDGS during the commissioning phase of the Sentinel-2 spacecrafts.

○ Collaborative entities having agreed specific partnerships with the POM. In the frame of this document, the Collaborative entities are either third-party operated





collaborative mirror centres (CDAM), or Users themselves interacting with the PDGS under the hosted-processing collaboration framework.

In addition, although formally considered within the PDGS functional perimeter, the following interfaces to external entities that provide PDGS functional services have been identified:

○ Third-party Auxiliary Data Providers (ADP) for the operational provision of Auxiliary Data Files to be used by the PDGS for the data-processing activities.

○ The selected distributing entity for the Sentinel-2 MSI WICOM image decompression software referred as MSI Decompression Provider (MDP).

○ Expert Cal/Val Teams supporting specific CAL/VAL functions, quality control activities, etc. (e.g. Off-line POD service, MSI Cal/Val specific campaigns, etc.).

TM/TC

X-Bandsignal

EDRS

LCT

FOSLGS

PD

GS

Ope

ratio

n M

anag

er (P

OM

)

CDS Users

CST

EDRS Exploitation Segment

WICOM Decomp.S/W

Auxiliary Data Providers

Collaborative PDGS Entities

S2A/B

Ka-Band relay signal

Expert CAL/VAL Teams

GSP

s

Figure 3-1 PDGS Interfaces

The PDGS Master ICD [MICD] further identifies and details every interface and describes their operation context within the PDGS physical layout.





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 hosted-processing 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.





Figure 3-2 PDGS Data-Management Functions

○ An Instrument Data Processing (IDP) function responsible for implementing in coordination with the DPC function the data-processing algorithms of the MSI to generate the core Level-1 and Level-2 data-products. In addition, the user-provided processors resulting from hosted-processing collaborations will be integrated as independent IDP functions.

○ A Sentinel-2 mission-specific MSI Decompression Software (MDS) function to be used by the IDP function, and more generally by any third-party entity such as the LGS, for handling the MSI on-board compressed data. This function aims for a maximum reuse of an existing component developed for the Pleiades mission and for its long-term maintenance (>40 years) to meet Sentinel-2 LTDP objectives.

○ An On-Line Quality-Control (OLQC) function triggered through the DPC host function and responsible for systematically performing essential verification and





stamping of the quality of all products generated before they are made available to their intended users;

○ A central Archive and Inventory (AI) function closely coupling data sources and data sinks, in charge of storing, registering and serving the product data and associated inventory records to other functions;

○ A complementary Long-Term Archive Service function (LTA) responsible for long-term archiving and preservation as well as bulk reprocessing of Sentinel-2 products. It aims for an optimum reuse of existing ground-infrastructure in the LTDP area in synergy with other Earth-Observation missions. As such and whilst being procured as an external service implementing well-defined Sentinel-2 PDGS interfaces, it is intended to be federated within the overall PDGS through collocated Sentinel-2 PDGS specific functions.

○ A Data Circulation (DC) function responsible for all product exchanges between the distributed PDGS archives and more generally centralising the data exchanges between interfaces whether internal (between co-localised sub-systems in a PDGS centre) or external (e.g. versus FOS and auxiliary data providers, between centres, etc);

○ A Precise Orbit Determination (POD) responsible for providing precise orbital data for MSI data-processing via the DC and AI functions. This function aims for reuse of a generic multi-Sentinel POD element. For Sentinel-2, POD orbit products will be used as a contingency solution should the strict processing of the on-board GPS and AOCS data embedded in the IDP Level-1 algorithms not provide the level of accuracy required to meet the product geometrical quality requirements;

○ An Auxiliary Data Supply (ADS) function in charge of generating all other auxiliary data required to the Level-2A MSI processing. This function is aims at being mapped directly to the external data-sources identified in [RD-4].

○ A Data-Access Index (DAX) function responsible for federating the product inventories spread throughout the PDGS and providing the front-end services with a consolidated virtual view of the archive. It is in charge of transparently maintaining the relationships between the product components and their physical remote location and serving them to the data-access elements when performing the actual download operations;

○ A Data-Access Gateway (DAG) function acting as a single virtual access point to all PDGS data products and implementing the actual downloads. It is in charge of the transparent re-assembly at the user site of the final products from the granular product elements scattered throughout the archives;

○ The Front-End Services (FES) responsible for answering to the end-user data-access activities include the following PDGS functions:

o The Multi-Mission User Services (MMUS) function responsible for user interactions supporting catalogue queries and subsequent triggering product downloads based on the DAG function;

o The On-Line Image Browser (OLIB) function responsible of the true-colour image (TCI) publishing service towards the general public.





3.2.2 SYSTEM CONTROL FUNCTIONS

As primary goal, the System Control functions aim at providing the necessary means to control, monitor, assess, and fine tune the PDGS towards its goals and to mature its evolutions. The functional breakdown regarding system-control functions is depicted on Figure 3-3.

Figure 3-3: PDGS System Control Functions

It features a main mission control loop compiling three complementary functions: ○ A Mission Configuration and Control (MCC) function in charge of defining the

operation scenario according to the HLOP and performing accurate control and coordination within the PDGS of all derived key mission configuration data and leverages on mission performance. It also aims at keeping a historical registry of mission configuration baselines associating all related operational monitoring data collected throughout the PDGS for performance assessment activities;

○ A Mission Planning (MPL) function in charge of applying the mission operation scenario by performing recurrent planning of the payload and data downlink operations through the FOS and triggering accordingly the data-reception activities at the CGS and LGS.





○ A Mission Performance Assessment (MPA) function in charge of measuring the actual PDGS performance and the mission overall quality with respect to the baseline, and retrofitting as relevant the necessary configuration changes to the MCC to meet the quality objectives.

In addition, two complementary system-management support functions are identified: ○ A Reference Platform (RP) function globally in charge of system-level configuration

control, system validation and transfer to operation activities as required for maintenance and evolutions throughout the PDGS operational lifetime;

○ A Monitoring and Control (M&C) function globally scattered and embedded across all functional domains and in charge of providing a central monitoring and control view in each PDGS centre over the centre processes and resources to support operational system-management activities;

Finally, a Collaboration Support Service (CSS) function is provisioned for with the dual objective of providing technical support vis-à-vis the collaboration peers according to the needs of each type of collaboration, and liaising with the PDGS management for the definition of the collaborations and associated progress reporting during implementation.

3.2.3 DATA COMMUNICATION FUNCTIONS

As primary goal, the Communication functions aim at providing the necessary means to effectively transport data internally and externally to the PDGS. As such, they enclose all physical communication means ranging from digital communication networks to standard post mail or telephone services allowing the transportation of information between geographically remote entities. This group of functions is hence supporting all other functions requiring physical data exchanges across PDGS centres or towards external interfaces. The following primary functions are identified as illustrated on Figure 3-4:

○ A Local Area Network (LAN) Function, responsible for all digital communications within every PDGS centre;

○ A Digital Circulation Network (DCN) Function, responsible for all digital communications between PDGS centres and expandable to support communications towards collaborative entities if required. This function extends to the EDRS data-repatriation capability composed of TX and RX stations to respectively transmit and receive the data via the EDRS repatriation transponder in multicast;

○ A Media Circulation Network (MCN) Function, responsible for all data communications via physical media between PDGS centres, and expandable to support communications towards collaborative entities if required. This function embeds the physical media transportation between remote sites, e.g. using post mail services;

○ A FOS Communication Network (FCN) Function, responsible for all digital communications between the PDGS and the Sentinel-2 FOS located at ESA/ESOC in Darmstadt (Germany);





○ A Data Dissemination Network (DDN) Function, responsible for all communications versus external PDGS data-product users. This function extends to the EDRS data-dissemination capability composed of TX and RX stations to respectively transmit and receive the data via the EDRS dissemination transponder in broadcast;

Figure 3-4: PDGS Data Communication Functions

The wording Wide Area Network (WAN) globally refers to any geographically distributed TCP/IP based network such as Internet.





4 ASSUMPTIONS & OPEN ISSUES

4.1 Assumptions

High-level assumptions taken and having an impact on the settled PDGS operation baseline are enumerated hereafter. [Assumption-01] The Sentinel-2B satellite will be identical to Sentinel-2A satellite. [Assumption-02] Seven (7) years of active mission operations plus a possible 5 years

extension are considered for each Sentinel-2 satellite. [Assumption-03] Sentinel-2B will be launched 18-30 months after Sentinel-2A. 18

months is the planned value (TBC) at Sentinel-2 GS PDR. [Assumption-04] 5.5 to 10.5 years of parallel Sentinel-2A and Sentinel-2B active mission

operations (nominal or extended mission duration) plus 18 months Sentinel-2B active mission operations are envisaged.

[Assumption-05] Twenty-Five (25) years of mission operations from archive are considered.

[Assumption-06] The X/Ka-band ground stations network will be selected at a later stage. A minimum four X-band receiving PDGS Core Ground Stations baseline scenario is assumed in this document. This configuration is sufficient to downlink the Sentinel-2 data as per baseline scenario. The selection of more stations will substantially enhance the performance of the baseline scenario but is not strictly required for baseline operations.

[Assumption-07] All data handled by the Sentinel-2 PDGS is assumed to be UNCLASSIFIED (according to [RD-13]).

[Assumption-08] Sentinel-2 X-Band data will not be encrypted (according to the GSC Security Work Group Meeting #4, held on 30.01.2008, GM-MN-ESA-SY-0015)

[Assumption-09] It will be possible to use the EDRS Programme capacity to support both the Sentinel-2 payload data downlink (data relay function), as well as PDGS data circulation and dissemination activities.

[Assumption-10] EDRS capabilities and services will be preliminarily validated as part of EDRS commissioning activities which will be carried out by the EDRS program in coordination with the Sentinel programs. Those activities will make use an EDRS provided validation framework on ground that will not require specific PDGS hardware or pre-deployed facilities apart from a front-end reception equipment to perform compatibility testing of the data-relay multicast link.

[Assumption-11] The OCP will, when activated in alternative or in parallel to the XBS, transparently carries the dual 280Mbps downlink channels via the GEO transponders, in turn relaying in real-time the data stream in Ka-Band to GEO pointing ground-stations. Specific receiving equipment, still





procured via the EDRS program, will provide the adequate Ka-Band demodulation capabilities on ground and restore the dual 280Mbps data-streams in baseband ready for front-end processing. The dual 280Mbps channels restored in baseband after the EDRS ground equipment will be clear of any encryption.

[Assumption-12] The apportioned availability to Sentinel-2 for data-relay downlinks via the EDRS constellation will be pre-defined at static times phased along the Sentinel-2 orbit repeat cycle, following a preliminary agreement with the EDRS exploitation segment in coordination with Sentinel-1.

[Assumption-13] The Sentinel-2 mission can use operationally the EDRS 230Mbps data-repatriation multicast link for a third of the total time.

[Assumption-14] The operation constraints of the OCP will be later characterised by a well-defined operation duty-cycle and an overall limit to the overall number of operation switches sized for the OCP lifetime, similarly to the XBS.

[Assumption-15] The MSI timeline received on-ground after downlink will be provided with a granularity of exactly one MSI on-board scene (corresponding to 3.48 seconds of instrument operation and about 23km on ground along-track) as corresponding to the minimum indivisible packet size of the MSI. A playback-stop commanded while an MSI scene is being downlinked will effectively stop the playback and transmission only after the MSI scene has been entirely transmitted.

[Assumption-16] The on-board recording of the ancillary data does not require specific scheduling at PDGS mission-planning level as being either entirely autonomous on-board or systematically triggered and maintained through FOS flight operation procedures. The ancillary data is recorded continuously including when the MSI is not operating, or when it is operating in standby or idle modes.

[Assumption-17] The XBS can remain in operation mode without the necessity of a temporary transition to standby even when the MMFU is not feeding data to the XBS e.g. during the time separating two successive data-downlinks to ground-stations. In this case, it is assumed idle transfer frames are transmitted instead.

[Assumption-18] During orbit control and in case of attitude problems, the MSI shutter shall be closed to protect the instrument. This constraint will be managed by the FOS.

[Assumption-19] In response to potential X-Band access conflicts between Sentinels, a conflict-free coordination among Sentinels will result in a predefined allocation of downlink passes available for Sentinel-2. This allocation will be static to a large extent (e.g. on a six to three months basis at least) and will be settled after the selection of the CGS network, or in-any case at the time of the Sentinel-2 PDGS deployment phase.





4.2 Open Issues

The present document includes TBD/TBC in relation to the following issues still open.

EDRS GS and S/S technical specifications and interfaces. Technical details are missing regarding the interfaces between the PDGS and the EDRS GS as well as the PDGS functions necessary for the exploitation of the EDRS in support to the Sentinel-2 mission. Technical details are missing regarding the S2G ICD for the EDRS satellite limiting the definition/consolidation of requirements for the Ka-band data reception and ingestion function of the PDGS.

Spacecraft(s) Safety Constraints File. A complete list of Sentinel-2 Spacecraft(s)

Constraints affecting the mission planning as well as which constraints shall be verified by the FOS or by the PDGS is still to be defined.

Next Generation User Services for Earth Observation (ngEO) technical

specifications and interfaces. The ngEO system will be a new element of ESA’s Multi-Mission User Services (MMUS) environment reused for the Sentinel-2 PDGS. It is complemented with the overall MMUS by other legacy elements such as Single Sign-On (SSO), the Support-Desk, etc. As being a new element under design and development, its detailed baseline, interfaces within the Sentinel-2 PDGS, and detailed operation scenario with other PDGS elements are still to be defined at the level of Technical Specifications and ICDs.

PDGS physical layout and interconnecting network infrastructure. The PDGS

ground infrastructure composed of core ground stations, complementary centres and an interconnecting network to support the operations is still to be settled. In this respect, the system technical budget [STBD] (cf. [ND-10]) provides the logic and elements required to derive the firm PDGS technical budget once the physical layout is defined.





5 GMES SENTINEL-2 PGDS REQUIREMENTS This chapter defines the applicable requirements to the Sentinel-2 PDGS.

5.1 PDGS System-Level Requirements

5.1.1 FUNCTIONAL REQUIREMENTS

S2-PDGS-SYS-005 The PDGS shall be able to receive all the MSI, Ancillary and HKTM data downlinked by the Sentinel-2 satellite(s) and to mechanically generate HKTM Level-0 products and MSI Level-0, -1A, -1B, -1C and TCI products in a systematic manner.

S2-PDGS-SYS-010 The PDGS shall be able to receive the data downlinked from the Sentinel-2 spacecrafts by means of a network of Core Ground Stations (CGS) and to safeguard the raw data in real-time in the station local storage archive.

S2-PDGS-SYS-015 The PDGS network of CGSs shall be able to receive the data downlinked from the Sentinel-2 satellites either: in X-Band directly from the spacecrafts using LEO tracking X-Band antennas; in Ka-Band using GEO pointing Ka-Band EDRS-compatible antennas receiving the

satellite data transmitted by the OCP and relayed via the EDRS system in Ka-Band.

S2-PDGS-SYS-020 The PDGS shall be able to serve the mission data and the associated satellite ancillary data from the Sentinel-2 spacecrafts to a network of third-party operated X-Band stations - Local Ground Stations (LGS) - under direct visibility. All the data served to the LGSs shall systematically be downlinked in addition to the CGS network.

S2-PDGS-SYS-025 The PDGS shall ensure that the satellite ancillary data downlinked at every ground-station (CGS or LGS) overlaps in time with the MSI data downlinked within the same pass.

S2-PDGS-SYS-030 The PDGS shall be able to process, package, and deposit at the FOS interface the X-Band HKTM data received at the CGS network, corresponding to the data acquired on-board since the last downlink.





S2-PDGS-SYS-035 The PDGS shall be able to preserve in dedicated long-term archives, all the Sentinel-2 Level-0 product data (HKTM and MSI) together with all the associated ancillary/auxiliary data, critical software and documentation required for higher-level processing, during the whole PDGS operational lifetime.

S2-PDGS-SYS-040 The PDGS shall be able to preserve in the long-term archives a predefined set of Sentinel-2 high level products, including the related auxiliary data, during the whole PDGS operational lifetime.

S2-PDGS-SYS-045 The PDGS shall be able to elaborate systematically all the MSI raw data into elaborated Level-0, Level-1 and True Colour Image (TCI) products by means of a network of processing centres or directly at the CGSs.

S2-PDGS-SYS-050 The PDGS shall be able to generate systematically the Sentinel-2 true-colour images (TCI) at full spatial resolution as part of its nominal data-processing activities. The activation of the TCI systematic generation shall be configurable.

S2-PDGS-SYS-055 The TCIs processing performed by the PDGS shall be optimised towards the generation of visually attractive and eye-catching images.

S2-PDGS-SYS-060 The PDGS shall be able to generate systematically the Precise Orbit Determination (POD) products by processing the satellite on-board navigation data provided in the satellite ancillary data.

S2-PDGS-SYS-065 The PDGS shall be able to use the POD products for processing the MSI data in case of contingency with the on-board navigation solution.

S2-PDGS-SYS-070 The PDGS shall be able to use the Sentinel-2 MSI Decompression Software as part of Level-1 processing activities to decompress the MSI raw image data.

S2-PDGS-SYS-075 The PDGS shall ensure, by implementing appropriate mechanisms in the MSI data-elaboration chain from Level-0 to Level-1 and TCI processing cascading from every satellite acquisition, that the elaborated data is timely available to the downstream





functions in a FIFO manner, i.e. in the same order than that of the raw MSI data received from the antenna.

S2-PDGS-SYS-080 The PDGS shall be able to guarantee the timely availability of all the MSI Level-0, Level-1 and TCI data for download within three distinct timeliness classes: Real-Time (RT) timeliness, corresponding to data on-line availability no later than 100

minutes after data sensing, if the MSI data was transmitted in real-time from the spacecrafts;

Near-Real-Time (NRT) timeliness, corresponding to the data on-line availability no later than 3 hours after data sensing (matching the NRT3h timeliness denomination of the GSCDA) if the MSI data was prioritised on-board for NRT playback;

Nominal timeliness, corresponding to the data on-line availability no later than 24 hours after data sensing (matching the Fast24h denomination of the GSCDA) for all other MSI data.

S2-PDGS-SYS-085 The PDGS shall include a data reprocessing capability to cover: Significant upgrades of the data processing algorithms or of the auxiliary data justifying

a realignment of the Level-1 dataset in totality or in parts; Recovery from contingencies after malfunctions of the real-time chain at a particular

orbit.

S2-PDGS-SYS-090 The PDGS shall be able to store systematically all the generated production including the TCI products, immediately after the processing and to maintain it in the archives for a configurable duration ranging between a few weeks to several years.

S2-PDGS-SYS-095 The PDGS shall be able to store a configurable set of MSI products including the TCIs in the medium-term archives for selectable time periods (months / years).

S2-PDGS-SYS-100 The PDGS shall be able to circulate the MSI and TCI product data among the geographically distributed PDGS archives to satisfy processing, archiving and data-access needs.

S2-PDGS-SYS-105 The PDGS data-circulation shall be automated and performed in a systematic manner according to configurable circulation rules coordinating the data on-line availability throughout the PDGS geographically distributed archives.





S2-PDGS-SYS-110 The PDGS shall be able to support the following means for data circulation across centres: terrestrial networks; high speed communication links via telecommunication satellites, in particular the

EDRS data repatriation 230Mbps multicast link; physical media transportation.

S2-PDGS-SYS-115 The PDGS shall provide the following services to Sentinel-2 users accessible via the public Internet: Overview of the available services and access to user guides and FAQ documents; On-line support-desk via a ticketing system; Periodical advertising and notifications on the available mission data, instruments and

products documentation, including generic mission description and list of relevant mission products;

Periodical publishing of mission end-to-end performance reports and quality reports on the Sentinel-2 products;

Advertising of past and planned system events including instrument or system unavailabilities;

User self-registration; User authentication for registered users; Access to additional services for authenticated users including:

- Product download services supporting catalogue browsing and download of Sentinel-2 baseline products from preset or user-defined Data-Sets;

- Hosted-processing services supporting the on-the-fly generation of additional products based on the Level-1C product such as the prototype Level-2A or other products issued from the hosted processing collaboration opportunities;

- Automated subscriptions to the above services, performing the periodical and autonomous services triggering based on a user-defined or preset configuration;

- Self-management of user private configurations (e.g. user authentication information, user-defined subscriptions, etc).

S2-PDGS-SYS-120 The PDGS shall allow the configuration of different data-access profiles associating specific grants to registered users or group of registered users including: Accessibility per product type; Accessibility per Sentinel-2 spacecraft unit and sensing-time period; Accessibility based on the age of the data; Accessibility to specific versions of the available products discriminating amongst

several revisions of the processing algorithms;





Accessibility to reserved products such as calibration products or products under investigation after quality-control assessment activities;

Accessibility to hosted-processing services, separately per service; Priority settings applicable to product download and hosted-processing activities;

S2-PDGS-SYS-125 The PDGS physical archives shall be federated into a unique virtual archive accessible through a gateway transparently hiding the PDGS distributed nature and providing a single entry point for

PACE OMPONENT ENTINEL AYLOAD ATA ROUND ...emits.esa.int/emits-doc/ESRIN/Sentinel-2/System...The GMES...

Documents

Transcript of PACE OMPONENT ENTINEL AYLOAD ATA ROUND ...emits.esa.int/emits-doc/ESRIN/Sentinel-2/System...The GMES...