Earth Explorer CFI Software CONVENTIONS DOCUMENT Code: EE-MA-DMS-GS-0001 Issue: 1.5 Date: 13/03/09 Name Function Signature Prepared by: Mariano Sánchez-Nogales Project Engineer Fabrizio Pirondini Project Engineer José Antonio González Abeytua Project Manager Juan José Borrego Bote Project Engineer Checked by: Javier Babe Quality A. Manager Approved by: José Antonio González Abeytua Project Manager DEIMOS Space S.L. Ronda de Poniente, 19, Edificio Fiteni VI, Portal 2, 2ª Planta, Tres Cantos 28670 Madrid, SPAIN Tel.: +34 91 806 34 50 Fax: +34 91 806 34 51 E-mail: [email protected] © DEIMOS Space S.L., 2009 All Rights Reserved. No part of this document may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without the prior written permission of DEIMOS Space S.L. or ESA. Code: EE-MA-DMS-GS-0001 Date: 13/03/09 Issue: 1.5 Page: 2 Document Information Contract Data Classification Contract Number: 15583/01/NL/GS Internal Public Contract Issuer: ESA / ESTEC Industry X Confidential External Distribution Name Organisation Copies Electronic handling Word Processor: Adobe Framemaker 6.0 Archive Code: P/MCD/DMS/01/026-003 Electronic file name: ee-ma-dms-gs-0001-12 Mission CFI Software Conventions Document 3 Code: EE-MA-DMS-GS-0001 Date: 13/03/09 Issue: 1.5 Page: 3 Document Status Log Issue Change Description Date Approval 1.0 New document based on Envisat Mission CFI Soft- 08/11/01 ware Mission Convention Document 1.1 Minor changes on ASCII time formats (Table 2) 04/02/02 1.2 Minor changes on ASCII time formats (Table 2) 15/04/02 Added CryoSat SIRAL extra counter description (sec- tion 4.4.3) Corrected an error in Mean Local Solar Time drift for- mula (pag.33) 1.3 Added GOCE values in ANNEX A. 15/07/03 See change bars for other minor changes 1.4 New Reference frame definitions 02/08/07 New Attitude reference frame definitions Updates for new missions. 1.5 New propagation models 13/03/09 Mission CFI Software Conventions Document 3 Code: EE-MA-DMS-GS-0001 Date: 13/03/09 Issue: 1.5 Page: 4 Table of Contents 1. SCOPE......................................................................................................... 9 2. ACRONYMS............................................................................................. 10 3. APPLICABLE AND REFERENCE DOCUMENTS............................ 12 3.1. Applicable Documents ........................................................................................12 3.2. Reference Documents .........................................................................................12 4. TIME REFERENCES AND MODELS.................................................. 13 4.1. Time References..................................................................................................13 4.2. Time formats .......................................................................................................14 4.2.1. Earth Explorer time formats ............................................................................................14 4.3. Time resolution ...................................................................................................17 4.4. Earth Explorer On-board times ...........................................................................17 4.4.1. Envisat On-board clock ticks...........................................................................................17 4.4.2. TAI time ..........................................................................................................................18 4.4.3. CryoSat SIRAL extra counter .........................................................................................18 4.4.4. SMOS On-board time......................................................................................................18 4.4.5. Aeolus On-board Time ....................................................................................................19 4.4.6. GOCE On-board Time ....................................................................................................19 5. REFERENCE FRAMES.......................................................................... 20 5.1. General Reference Frames ..................................................................................21 5.1.1. Galactic............................................................................................................................21 5.1.2. Barycentric Mean of 1950...............................................................................................21 5.1.3. Barycentric Mean of 2000...............................................................................................21 5.1.4. Heliocentric Mean of 2000..............................................................................................21 5.1.5. Geocentric Mean of 2000 ................................................................................................21 5.1.6. Mean of Date ...................................................................................................................22 5.1.7. True of Date.....................................................................................................................22 5.1.8. Earth Fixed ......................................................................................................................22 5.1.9. Topocentric......................................................................................................................22 5.2. Satellite Reference Frames..................................................................................22 5.2.1. Satellite Orbital................................................................................................................23 5.3. General Reference Frames Transformations.......................................................24 5.3.1. Galactic to Barycentric Mean of 1950.............................................................................25 5.3.2. Barycentric Mean of 1950.0 to Barycentric Mean of 2000.............................................26 5.3.3. Barycentric Mean of 2000 to Geocentric Mean of 2000.................................................26 5.3.4. Heliocentric Mean of 2000 to Geocentric Mean of 2000................................................27 5.3.5. Geocentric Mean of 2000 to Mean of Date .....................................................................27 5.3.6. Mean of Date to True of Date..........................................................................................28 Mission CFI Software Conventions Document 6 Code: EE-MA-DMS-GS-0001 Date: 13/03/09 Issue: 1.5 Page: 5 5.3.7. True of Date to Earth Fixed.............................................................................................30 5.4. Satellite Reference Frames Transformations ......................................................31 6. ORBIT CHARACTERISATION............................................................ 32 6.1. Orbit Definition...................................................................................................32 6.1.1. Sun-synchronous Orbit....................................................................................................32 6.1.2. Quasi Sun-synchronous Orbit..........................................................................................32 6.1.3. Geo-synchronous Orbit ...................................................................................................33 6.2. Orbit Types..........................................................................................................33 6.2.1. Reference Orbit ...............................................................................................................33 6.2.2. Predicted Orbit.................................................................................................................33 6.2.3. Restituted Orbit ...............................................................................................................33 6.2.4. TLE Orbit ........................................................................................................................33 6.3. Orbit Propagation Definition...............................................................................33 6.4. Orbit Propagation Models ...................................................................................33 6.4.1. Mean Keplerian Orbit Propagator ...................................................................................34 6.4.1.1. Simulation mode ..................................................................................................34 6.4.1.2. Operational mode ................................................................................................34 6.4.1.3. Non-Sun-synchronous Simulation mode..............................................................34 6.4.1.4. Non-Sun-synchronous Operational mode............................................................34 6.4.2. Precise Orbit Propagator..................................................................................................34 6.4.3. TLE Propagator ...............................................................................................................35 7. PARAMETERS ........................................................................................ 36 7.1. Orbit Parameters..................................................................................................36 7.1.1. Cartesian State Vector .....................................................................................................36