Doc. No: EC-RS-ESA-SY-0001 Issue: 1A Date: 20 May 2008 Page: 1 of 171 EarthCARE Project System Requirements Document for Phases B, C/D, E1 Prepared by EarthCARE Team Checked by D. Maeusli ESTEC Noordwijk The Netherlands Approved by A. Lefebvre Doc. No: EC-RS-ESA-SY-0001 Issue: 1A Date: 20 May 2008 Page: 2 of 171 DOCUMENT CHANGE RECORD ISSUE/REV. DATE CHANGE 1 02 February 2007 EarthCARE ITT Release 1A 20 May 2008 § 2.1 correction of AD-27 title § 2.2 ND-26 (PSS-04-253 replaced by ECSS-E-50-14), ND-27 (title correction) and ND-99 (refered in § 7.2.6.1.2 req MEC-FC-13) § 2.1 addition of ECSIM ID-13 & ID-14 § 4.1.1 OBS-OR2 (requirement locat time limited to 13:45-14:00 range and removal of morning option); OBS-OR-4 (Table 4-1 (descending node & local time & addition of a Design Case orbit column plus a note explaining Design Case range limits); OBS-OR- 5 (ATLID margin revised); OBS-OR-6 (geometric parameters vs Design-case orbits & MSI swath) § 4.1.3: OBS-RO2 (reduced MLST range to 13:45-14:00 plus replacement of TBD in req. plus table 4-2; second part of req. listed as a note) § 4.1.4: OBS-RO4 (reduced MLST range to 13:45-14:00 plus replacement of TBD in req. plus table 4-3; second part of req. listed as a note) § 4.2 (req. renumbering to remove duplication of OBS-SP4 ref.) § 5.2.1 Depolarisation Ratio definition § 5.3.10 CPR-DR-22 (TBD replaced by figure with explanative note); CPR-DR-54 (correction of pitch pointing value plus inclusion of a goal); CPR-DR-62 (TBD replaced by TBC STEP) § 5.3.12 (CPR-SP-1 is linked to CPR-FO12, and not to -11) § 5.5.6.2 BBR-SR-2 Table 5.5-2 (max value of λ-axis in graph corrected to 5 for being in line with underlying table values) § 5.5.7 (BBR-LW-1: LW channel range value – correction of lower value) § 6.7 OPS-IC-5 (req. wording changed/clarified) § 7.2.5 (correction of wrong reference § 7.2.4 into § 7.2.5) § 7.2.6.1.2 (req MEC-FC-13 refers to ND-99) § 7.3.5.6 DHS-MM-25 (note extended to address packet interleaving on X-band) § 7.3.6.3 COM-HR-6 deletion (requirement applying to COM HR terminal on ground only); COM-HR-8 (deletion of smaller antenna reference) § 7.3.7.2 & Annex 4 (correction of requirement references changed from HAR-DE-xx into HAR-FU-xx) § 7.4.1 AIT-GS-17&18 (EGSE equipment initially referred as SEIS is renamed into PISA) § 8.2 (edito) § 8.3 DPR-SI-11 (addition of ID-13) Doc. No: EC-RS-ESA-SY-0001 Issue: 1A Date: 20 May 2008 Page: 3 of 171 § 8.4 DPR-GP-7 (addition of ID-13) and DPR-GP-14 (use of a separate ECGP module for CCDB updates) Annex 2 ARDL (added); CDB (removed as duplicating CCDB); PISA (renaming of former EGSE SEIS equipment); SEIS (deletion) Annex 3 (HAR-FU) Doc. No: EC-RS-ESA-SY-0001 Issue: 1A Date: 20 May 2008 Page: 4 of 171 Table of Contents 1 INTRODUCTION AND SCOPE OF DOCUMENT..............................................................................................8 2 DOCUMENTS ................................................................................................................................................... 9 2.1 Applicable Documents.........................................................................................................................................................9 2.2 Normative Documents .........................................................................................................................................................9 2.3 Informative Documents.....................................................................................................................................................11 3 EARTHCARE MISSION................................................................................................................................... 12 3.1 Mission Objectives Overview ...........................................................................................................................................12 3.2 EarthCARE System and Interfaces.................................................................................................................................12 3.3 Mission Assumptions .........................................................................................................................................................14 3.3.1 Launcher.......................................................................................................................................................................14 3.3.2 Environment.................................................................................................................................................................14 3.3.3 Operational concept .....................................................................................................................................................14 3.4 Mission Phases....................................................................................................................................................................15 3.5 Definitions ...........................................................................................................................................................................15 3.5.1 Altitude Definitions .....................................................................................................................................................15 3.6 Reference Frames...............................................................................................................................................................15 3.6.1 Yaw Steering Reference Frame (index YS)................................................................................................................16 3.6.2 Zero-Doppler Reference Frame (Index 0D)................................................................................................................17 3.6.3 International Celestial Reference Frame (ICRF) ........................................................................................................17 3.6.4 International Terrestrial Reference Frame (ITRF)......................................................................................................17 3.6.5 Spacecraft Frame (SCF) ..............................................................................................................................................17 3.7 Measurement Units............................................................................................................................................................17 4 OBSERVATION REQUIREMENTS ................................................................................................................. 18 4.1 Orbit Requirements...........................................................................................................................................................18 4.1.1 General .........................................................................................................................................................................18 4.1.2 Coverage & Re-visit Cycle..........................................................................................................................................19 4.1.3 Reference Orbit for CAL/VAL Phase.........................................................................................................................20 4.1.4 Reference Orbit for Routine Phase..............................................................................................................................20 4.1.5 Orbit Maintenance .......................................................................................................................................................21 4.1.6 Orbit Determination and Prediction ............................................................................................................................21 4.1.7 Space Debris Avoidance..............................................................................................................................................21 4.1.8 End of Mission - Deorbiting........................................................................................................................................22 4.2 System-level Pointing Requirements ...............................................................................................................................22 4.3 Geo-location Requirements ..............................................................................................................................................22 Doc. No: EC-RS-ESA-SY-0001 Issue: 1A Date: 20 May 2008 Page: 5 of 171 5 INSTRUMENTS REQUIREMENTS ................................................................................................................. 23 5.1 General Requirements.......................................................................................................................................................23 5.2 Atmospheric Backscatter Lidar (Atlid)...........................................................................................................................25 5.2.1 Terms and Definitions .................................................................................................................................................25 5.2.2 Functional Requirements.............................................................................................................................................28 5.2.3 Operational Requirements ...........................................................................................................................................29