Relativity & Reference Frame Working Group. 6th Meeting -----

Transcription

1 Relativity & Reference Frame Working Group 6th Meeting F. Mignard 1

2 Registered attendants A. Andrei G. Anglada B. Bucciarelli P. Charlot M. T. Crosta F. De Felice D. Hestroffer S. A. Klioner J. Kovalevsky M. G. Lattanzi Y. Ledu C. Leponcin-Lafitte H. Manche F. Mignard I. Roxburgh J.L. Simon J. Souchay P. Teyssandier A. Vecchiato 2

3 Objectives of the meeting Status of the GAIA mission Status of the actions agreed on Review of the on going acitvities and report of task leaders Future of the working group Set guidelines for the next six months 3

4 AGENDA 13/01 10h00 Opening and welcome message D. Egret, Ph. Tuckey 10h15 Meeting introduction and Gaia update F. Mignard 10h45 WG activities, membership, actions F. Mignard 11h30 Coffee 11h45 Update of RAMOD 4 12h15 Relativistic effects in the motion of Gaia A. Vecchiato & al. S. Klioner 12h45 lunch break 14h30 Mass multipole moments and light deflection Ch. Leponcin-Lafitte 15h00 Determination of β and solar J2 D. Hestroffer 15h30 Reference galactic potential J. Kovalevsky 16h00 Coffee 16h30 Numerical integration of the solar system H. Manche et al. Specification, status and schedule for Gaia ephemeris 4

5 AGENDA 14/01 09h00 The ICRS product center and relvance for Gaia J. Souchay 09h30 Status of the photometric recognition of QSOs (F. Mignard) 10h00 Astrometric contribution to QSO selection F. Mignard 10h30 coffee 11h00 QSO physical structure and implication for Gaia P. Charlot 11h30 Discussions, actions, next meeting F. Mignard ~ 12h30 End of the meeting 5

6 Status of GAIA 6

7 GAIA ESA Rudi Schmidt has been appointed as project manager on 1 st July Oscar Pace (study manager) will retire by the end of 2004 Mid-term presentation of the phase B1 of industrial design from Alenia and Astrium (14-15 September) So far no major revision of the main concepts Despite delay in CCD/FPA TDA are running nominally reassessment of the thermo-mechanical stability, Basic Angle Stability Concerns with the mass budget, the availability of micro-newton thruster (FEEP of cold-gas), CCD procurement times. Reassessement of the mission costs The ITT for industry is intended to be released by 15 August Phase B2 should start, with one prime contractor, in January 2006 with a target launch date of the second half of From my slide of the last meeting A launch date of 2010 implies start of B2 in April

8 From the GST Proceedings of the Paris meeting in press A common photometric system has been agreed in December Bright stars will be handled with gates report of M. Lattanzi Still big uncertainy on CCD radiation damage, CTE and impact on centroiding. A steering committee has been set up for GDAAS : First meeting on Dec Problems with maximum star density regions Investigation to go from 3 millions */deg 2 to 750,000 > Options : magnitude selection, binning, fraction of observation down, modified SL As an answer to cost and mass limitation several on-going assessements : Change of the SAA (Sun Aspect Angle) from 50 to 40 deg > Detrimental to the relativity testing Primary mirror size, number of CCDs New requirements for the BAS (Basic Angle stability) due to possible systematic in the parallax : Periodic effect in BA results in an undectable parallax shift Can Quasars be used to correct the bias? 8

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11 From the GST Telemetry simulator (U. Lammers, ESTEC) Simulation of the data flow from Astro, RVS, MBP Galaxy model with 10 9 objects Scanning law Day-to-day optimised GS visibility ( h/day) Compression factor of 3, dead time of 2.5% > Astro = 2 x 1.2 Mb/s 48 TB > RVS = > MBP = > Total = 5.7 Mb/s On board mass storage of Gb needed 11

12 Galactic Model 12

13 Data Rate From U. Lammers, ESTEC 13

14 Short term data rate From U. Lammers, ESTEC 14

15 Data rate : current status Mbits/s Total volume (TB) raw comp =3 raw Astro_ Astro_ RVS MBP Total With the planned antenna : 4.3 Mb/s during downlink Average station visibility of 11h / day Equivalent to 1.95 Mb/s in sustained rate Feasible with current design and compression factor of three 15

16 Industry Schedule 2005 Jul End of competitive definition phase 2005 Jun Begin of CCD procurement 2005 Aug I T T released to industry Drafted by 15 Feb Reviewed 15 March Issue I 15 April 2005 Oct Response by industry 2005 Dec Prime contractor selected by ESA 2006 Jan Start of 5-year construction phase mid 2011 LAUNCH 16

17 Data processing Data processing is a community task ESA pays for: satellite, payload, launch, ground-segment ESA will not pay for the data processing (DP) Funding from national agencies DP study (GDAAS) has been running since 2001 objective: assess feasibility of DP approach system, hardware, database, integration algorithms definition and testing Replaced by data processing consortium from 2006 To develop, implement and manage DP system until ca

18 Community schedule 2005 Jan ESA s issues a Letter of Intent (LoI) 2005 Mar 20 Response to LoI 2006 Jan ESA s (AO) for the data reduction 2006 mid response by a data reduction consortium (or consortia) early 2011 readiness review of data reduction mid 2011 launch early 2017 nominal end of science mission 2019/2020 completion of data reduction, final results 18

19 GAIA Schedule Acceptance Technology Development Design, Build, Test Launch Observations Analysis Catalogue 19

20 Design 20

21 Relative position of the FOV's Current design under study Sequence Spin axis P = 6h t = 0 Observation + 28 mn + 78 mn AF1 Spectro AF Astro 1 (PFOV) mn etc AF1 Spectro/MBP Astro 2 (FFOV) Scan direction 21

22 Focal Plane ASM1-2 AF1-11 BBP1-4 Astro Field Cell size : 49 x 60 mm 2 CCD size : 45 x 59 mm mm k x 2 k Pixel size 10 x 30 µm 2 = 44 x 133 mas 2 TDI : ms Airy (along) 103 mas Integration time : 3.3 s 45 mm ~ 800 mm mm 22

23 MBP Fields (new design) MBP 2.1 = 125s = 88 mm MBP 2.1 = 125s = 88 mm SM/NEO R V S mm mm R V S CCDs Scan MBP : 800 x 1960 pxs Pixel size 10 x 15 µm x 1.35 arcsec 2 Full read-out or windowing mode Optical axis Integration time MBPSM ~ 6.7s MBP ~ 12.5 s RVS FOV 23

24 The Relativity and Reference Frames Working Group 24

25 Core members Membership Associates B. Bucciarelli P. Charlot M.T. Crosta F. DeFelice D. Hestroffer S. Klioner M. Lattanzi L. Lindegren F. Mignard J.L. Simon A. Smette M. Soffel A. Vecchiato A. Andrei G. Anglada L. BLanchet J. F. Claesckens J. de Bruijne W. Evans A. Fienga J. Torra J. Kovalevsky Ch. Leponcin-Lafitte S. Pireaux I. Roxburgh P. Royer J. Souchay E. Slezak J. Surdej P. Teyssandier 25

26 Task break-down Relativistic modelling - Software development M. Lattanzi - Model development S. Klioner - Simulation A. Vecchiato Reference system - QSO detection A. Smette - ICRF F. Mignard - Earth and planetary Ephemeris J.L. Simon 26

27 Review of pending actions 27

28 Actions (June 04) Send quickly PPT or PDF files of your presentation (all) Schedule : within a couple of weeks :: very satisfactory investigate the feasibility of the velocity recovery from astro data (SK, FM) schedule : 10/04 Setting the problem next meeting : Preliminary results on simulation Update of the fortran code for the astrometric model (LL) schedule : 10/04 : done Software for TCB τ + Tech. Note (FM, MTC) schedule : 09/04 :: Note and algorithm completed Note on the PN effects on the Lissajous Orbit (SK) schedule : 09/04 : this meeting Check the implementation of new ephemerides with EM, LL (FM) schedule : 07/04 :: completed 28

29 Actions (June 04) Assessement of the relativity experiment with Jupiter (MTC, FM) schedule : 10/04 : 1st stage completed Additional thoughts on the timing accuracy requirements (FM, JB) schedule : 09/04 : completed Accuracy and practical solution for the link between on-board and GB timescales (FM, MP,+ ESOC?) schedule : 09/04 : not yet done Availability of GSC2 to A. Andrei (ML) schedule : 09/04 : Astrometric criteria for the selection of the clean sample of QSOs (AS, FM) schedule : 12/04 : this meeting Update the C code for the light deflection in the solar system (SK) schedule : 09/04 : Completion of the RAMOD4 testing (ML, AV, MTC, FdF) schedule : next meeting 29

30 Next Meeting 30

31 Invitation from S. Klioner 1 - Torino 2 - Liège 3 - Dresden 4 - Nice 5 - Leyden 6 - Paris 7 - Dresden 8 - Bordeaux Date : September, 2005? 31

32 Discussions & Actions 32

33 Actions Jan 05 Send quickly PPT or PDF files of your presentation (all) Schedule : within a couple of weeks Updated note on the Lissajous motion - (SK) schedule : 03/05 New runs of tests of RAMOD4 (AV) schedule : 06/05 Refine the astrometric testing with RV (FM) Schedule : next meeting Reference Galactic potential for the simulation (JK) Schedule : next meeting Include QSO spectra in the error budget algorithm of LL-JdB(FM, ML) Schedule : 05/05 Assessment of the chromaticity on the QSO astrometry (ML) Schedule : next meeting Ephemeris reference frame and relativistic scaling( SK) Schedule : next meeting Impact of the SAA on the relativity experiments (FM, ML) Schedule : next meeting 33