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GREPE, GRoup for an European Planetary Ephemeris

EUROPLANET – 26 th February 2007. Networking Activity. GREPE, GRoup for an European Planetary Ephemeris.

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GREPE, GRoup for an European Planetary Ephemeris

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  1. EUROPLANET – 26th February 2007 Networking Activity GREPE, GRoup for an European Planetary Ephemeris A. Fienga(1),(2) , J.Laskar (1), H.Manche (1), M.Gastineau (1), B.Levrard (1) , C. Le Poncin-Lafitte (3) , S. Bouquillon (4), G. Francou (4), J. Chapront (4) , A. Correia(5) , I. Cognard (6) (1) IMCCE / Paris Observatory (2) Besançon Observatory (3) Lohrmann Observatory, Dresden, Germany (4) SYRTE, Paris Observatory (5) Universitad de Aveiro, Portugal (6) Pulsar, Orléans University, France

  2. Planetary ephemeris: state-of-art Only accurate, fitted PE freely avaliable Since 1998 (DE405), no official new release Use by JPL navigation teams for interplanetary missions DE405: ICRS official planetary ephemeris DE405 accuracy now ~several 100 m on Mars distances JPL DExxx (Newhall et al 1983,… Standish 1998) Very similaire to DExxx Fitted to observations but not easily avaliable IAA EMPxxx (Pitjeva 1998,… Pitjeva 2006) BDL VSOP (Bretagnon 1982,… Simon et al. 2007) VSOP:Analytical solution fitted on DE405 VSOP2000: not accurate enough for space data analysis Short-term and long-term use Fitted to observations http://www.inpop.eu INPOP (Fienga et al 2006)

  3. Needs for an european planetary ephemeris With the European space missions like MEX, VEX…Galileo, GAIA, Bepi-Colombo Europe needs independant very accurate planetary ephemeris to: • prepare (GAIA: 1 mm/s for Earth radial velocity) • realize the mission (Bepi-Colombo: ~10 cm /Earth-Mercury distance) • analyse the data (for ex, MEX:few meters /Earth-Mars distance)

  4. INPOP Planetaryephemeris Intégrateur Numérique Planétaire de l’Observatoire de Paris began in 2003 with J.Laskar et al. Short-term (few centuries) and long-term (few millions years) use INPOP06 (Fienga et al. 2006) Numerical integrationwith extended precision 80b Planets, Asteroids , Moon, Earth Rotation Einstein-Infeld-Hoffman equation of motion INPOP(TCB) and INPOP(TDB) Fit to ~ 55 000 space and Earth-based data Asteroid masses and densities J2 estimated (β,γ tested) INPOP realisation of TCB ESA ephemeris (GAIA) ESA tracking data (MEX)

  5. INPOP General Aspect – II: The Moon and Moon Libration • EIF pertubations of planets, Sun and 300 asteroïds (integrated) • Non-spherical bodies  point mass bodies • Deformation of extended bodies (tides)  point mass bodies • Earth Shape  Moon shape (torque exerted by the Moon ) • DE/LE405 : fitted to LLR / INPOP06 • Fit to LLR data ( in progress)

  6. INPOP General Aspect – III: Earth rotation INPOP Earth Rotation solution = Integration of the angular momentum Takes into account the Earth tidal deformation does not depend of the Inner Earth modelling Allows long-term integrations CIP(03)-INPOP [arcs]

  7. General Relativity and INPOP For ESA missions (GAIA), Einstein-Infeld-Hoffman equation of motion Barycentric Celestial reference frame : IAU 2001 BCRS ifTeph = TCB Each planetary ephemeris realises its own TCB (Klioner 05) (TCBinpop – TCG) estimated via an iterative process and INPOP fit to observations ( Le Poncin-Lafitte et al., 2006) In INPOP, RG SSB definition is i *i ri = 0 and i *i dri /dt + d*i dt ri = 0 (Fienga et al. 2006)

  8. INPOP06 Observations • Original CCD data • ESA MEX/VEX • [1898-2006] data set • JPL space data • US/Russian direct radar • Transit data JPL/Observatoire de Paris Astrometric Planetary Data Base

  9. INPOP06 adjusted physical parameters Planet Initial Conditions + INPOP06b: 1  β  1.0001, 1 γ  1.00002

  10. Works in progress… • LLR INPOP fit and Moon dynamics • IMCCE (H. Manche, J.Laskar, B. Levrard), • SYRTE – Paris Observatory (S.Bouquillon), • Besançon Observatory (A. Fienga), • Universitad de Aveiro (A. Correia) • Analysis of new VEX and MEX Data • ESOC (J. Fertig, T.Morlay), • Besançon Observatory (A. Fienga), • IMCCE (B. Levrard, H. Manche, J.Laskar), • Universitad de Aveiro (A. Correia) • Pulsar Timing for EMB orbit fit • Besançon Observatory (A. Fienga), • Orléans Univiservity (I. Cognard), • SYRTE – Paris Observatory (J.Souchay) • RG ,  , Sun J2determinations • Dresden Lohrmann Observatory (C.Le Poncin-Lafitte) • Kastler Brossel Laboratoty (S. Reynaud ) • IAP (L. Blanchet, G. Esposito-Farese)

  11. GTEP: Groupe de Travail sur les Ephémerides Planétaires GTEP: working group related to planetary ephemeris www.imcce.fr/Equipes/ASD/GTEP/ login:gtep, pass : inpop06 • ½ day meeting / month in Paris Observatory since February 2006 • Past topics: LLR data, science with Pulsar timing, GR in time scales, Tides and planetary ephemeris • Next meetings: GR tests, IAU resolutions, reference frames • Participants: INPOP team + N. Capitaine, F. Mignard, S. Klioner, J. Chapront, S. Bouquillon, I. Cognard … C. Will, P. Wallace…and everybody who wants !

  12. GREPE: GRoup for a European Planetary Ephemeris Based on GTEP, Networking Activity : Development of the GTEP activity • Exchange of GREPE members • Organisation of International Workshops • Invitation for international senior researchers • Possibility of training and exchange (postdoc grants) Proposed Budget (per year) • Exchange missions and workshop : 15 KE • Postdoc positions (12 months) : 36 KE

  13. INPOP06 / DE414 • INPOP06: Original dynamical modele • Asteroids / all planets 5 Bigs + 297 in 3 classes+ Asteroid ring General Ephemeris over [1899:2005.43] • DE414 : 64 Asteroids GM fitted + Asteroid ring 236 in 3 classes Mars & Saturn Space missions dedicated [2000:2005.3]

  14. The Moon Positions: Comparisons to LE405 Few mm for Moon geocentric distances on LLR data interval Moon-Earth distances [mm] Years + J2000 Differences in positions [mm]

  15. MEX (Morley 06) data MEX – INPOP06 + MEX – 410 x MEX – 405  MEX residuals [m]

  16. FIN FIN FIN FIN

  17. The Moon Libration: Comparisons to LE405 < 1 mas for the 3 Euler angles / 1 cty Years + J2000

  18. MEX (Morley 06) / MGS data MEX – DE414: (11 ± 12) m MGS – DE414: (7 ± 4) m MEX – INPOP: (8 ± 7) m MGS - INPOP: (2.5 ± 7) m

  19. MEX (Morley 06) / MGS data MEX – INPOP + MEX – 410 x MEX – 405  MEX residuals [m]

  20. The Moon Positions: Comparisons to DE405 Few mm for geocentric distances to the Moon on LLR data interval Moon-Earth distances [mm] Years + J2000 Error in geoc. Moon positions [mm] Years + J2000

  21. MEX (Morley 06) / MGS data MEX – INPOP + MEX – 410 x MEX – 405  MEX residuals [m]

  22. INPOP General Aspect – I: Planets and Asteroids PPN RG (==1) Einstein-Infeld-Hoffman equation of motion BCRF (IAU 2001) β,γ, J2 Asteroids integrated like planets Asteroid Ring perturbations included SSB (Newhall, 1983)

  23. The Moon Positions: Comparisons to DE405 Few mm for geocentric distances to the Moon on LLR data interval

  24. TCG-TT= LG x ∆T with LG a defined constant xE,vE : barycentric coord. of geocenter w0,ext , wiext : gravitational U induced by by SS bodies General Relativity and Planetary ephemeris:Time scales TDB / TCB / TCG Barycentric Celestial reference frame : IAU 2001 BCRS if Teph = TCB Each planetary ephemeris realises its own TCB (Klioner 05) (Soffel et al. 03) TCB-TCG is Ephemeris dependent (TCBinpop – TCG) estimated via an iterative process

  25. The Moon Positions: Comparisons to LE405 Few mm for geocentric distances to the Moon on LLR data interval Moon-Earth distances [mm] Years + J2000

  26. General Relativity and Planetary ephemeris: Deflection of light (Moyer 00) (1/c2) development : enough accurate for observations with  > 1as GAIA is the next step …

  27. INPOP General Aspect – II: The Moon and Moon Libration • EIF pertubations of planets, Sun and 300 asteroïds (integrated) • Extended bodies / point mass bodies interactions • Earth / Moon, Sun, Venus, Jupiter • Moon / Earth, Sun, Venus, Jupiter • Sun / Mercury, Venus, …, Pluton • Deformation of extended bodies / point mass bodies • Earth (Sun, Moon) / Moon, Sun, Venus, Jupiter • Moon (Earth, spin) / Earth, Sun, Venus, Jupiter • Torque of extended Earth (J2) on extended Moon (J2,C22) • LE405 : fitted to LLR / INPOP06: Not yet fit to LLR data ( in progress)

  28. General Relativity and Planetary ephemeris I- Equations of motion (and body rotation) II- Time scales III – Deflection of light in data processing Planetary Ephemeris Fit to Observations A- PPN tests: β,γ and Sun J2 estimation B- Time scale adjustement

  29. INPOP06 adjusted physical parameters INPOP06b: Optimisation for 1  β  1.0001, 1 γ  1.00002 and J2=2.5 x 10 -7 / (Ptijeva 2006) However, Very correlated with solar J2 Very sensitive to weighting scheme β, γ More accurate data (Mercury, Venus) ? GAIA, but also planetary ephemeris dependent !!!

  30. Conclusions and prospectives Not very conclusive determinations of PPN (β, γ) Strong correlations with Sun J2 and fit weight scheme BUT, new very accurate VEX data expected for september 2006 ! Tests on improvement of (β, γ) determinations INPOP realisation of TCB in progress ...

  31. General Relativity and Planetary ephemeris – II In JPL DE, RG SSB definition is i *i ri = 0 and i *i dri /dt = 0 with *i = F(i ,vi ,rij ) In INPOP, RG SSB definition is i *i ri = 0 and i *i dri /dt + d*i dt ri = 0 In INPOP, Sun is integrated like planets Very small differences but better consistences

  32. INPOPobs (TCB = K.TDB) Data Timing TDB INPOPobs (TDB) Data Timing TCB TCBinpop-TT TCG -TT = (IAU 2001) INPOPobs (TCBinpop) (TCBinpop – TCG) estimated via an iterative process scaling factor

  33. IMCCE / Observatoire de Paris Former Service des calculs du bureau des longitudes Institut of the Observatoire de Paris Ephemeris (planets, satellites, asteroids, comets...) Several publications (books, almanachs, website...) IMCCE VSOP (Bretagnon et al.) Several Collaborations with CNES and JPL Hipparcos, GAIA Since 2003, new development at IMCCE : INPOP A. Fienga, J.Laskar, H.Manche, M.Gastineau

  34. MEX and VEX data Since February 2006,MEX / VEX data each 6 months = agreement with ESOC Mars Express (MEX) Venus Express (VEX) Launch date: 9 November 2005 Arrival at Venus: April 2006 Duration ~ 5 years Launch date: 2 June 2003 Arrival at Mars: 4 June 2004 Science start : January 2005 Duration ~ 5 years Last release in September 2006

  35. INPOP06 Data Set • [1898-2006] data set • JPL space data • US/Russian direct radar • Transit data • Original CCD data • ESA MEX/VEX JPL/Observatoire de Paris Astrometric Planetary Data Base

  36. INPOP06 adjusted physical parameters With β=1, γ=1

  37. General Relativity and Planetary ephemeris I- Equations of motion (and body rotation) II- SSB III- Time scales IV – Deflection of light in data processing

  38. INPOP06 / DE414 • INPOP06: Original dynamical modele • Asteroids / all planets 5 Bigs + 297 in 3 classes+ Asteroid ring General Ephemeris over [1899:2005.43] • DE414 : 64 Asteroids GM fitted + Asteroid ring 236 in 3 classes Mars & Saturn Space missions dedicated [2000:2005.3] With β=1, γ=1 for INPOP06 and DE414

  39. Planetary ephemeris: state-of-art

  40. MEX (Morley 06) / MGS data MEX – DE414: (11 ± 12) m MGS – DE414: (7 ± 4) m Better INPOP extrapolation / DE414 MEX – INPOP: (8 ± 7) m MGS - INPOP: (2.5 ± 7) m

  41. MEX (Morley 06) / MGS data DE414 Fit zone: [2005.18:2005.3] Very good dispersion MEX / MGS data INPOP Fit zone:[2005.18:2005.43]

  42. Travaux en cours - I (TCB-TCG) INPOP With (Klioner 06), (TCB-TCG) for each planetary ephemeris INPOP (TDB) Ci (TDB) K=1/1-Lb INPOP (K.TDB) ~ INPOP(TCB) Ci (K.TDB) (TCB-TCG) INPOP First complete and independant (TCB-TCG) or TB-TT determination since (Fairhead et Bretagnon 1990) Ci(TDB) = Kinpop Ci(TCB)

  43. Travaux en cours - I (TCB-TCG) INPOP With (Klioner 06), (TCB-TCG) for each planetary ephemeris INPOP (TDB) Ci (TDB) K=1/1-Lb INPOP (K.TDB) ~ INPOP(TCB) Ci (K.TDB) with OBS (TCB) (Soffel et al. 03) INPOP(TCB) (TCB-TCG) INPOP Ci(TDB) = Kinpop Ci(TCB)

  44. Travaux en cours - II Milliarcsecond pulsar timing First test with 0437-4715 and Tempo v1.1.5 DE405: (0.8e-5  0.866) s INPOP: (0.7e-5  0.886) s

  45. Travaux en cours - II Milliarcsecond pulsar timing First test with 0437-4715 and Tempo v11.005  ~ 1 mas Dd ~ 2 mas m~ 0.1 mas/an md ~ 0.05 mas/an Use of Milliarcsecond pulsar timing for EMB fit

  46. Conclusion and Perspectives • Importance of Independant Planetary Ephemeris • Dynamical modele • Asteroids / all planets => impact on Mercury orbit • Choice of reference systems: time scale, precession-nutation • => impact on Moon orbit & libration • Observations • Not rely only on JPL data => uncertainties on data analysis • => corrupted MGS data during 6 months !!! • JPL data => JPL modeles • MEX = new orbit geometry / MGS

  47. Interactions in DE405/ INPOP05 Earth-Moon • Newtonian pertubations of planets, Sun and 300 asteroïds (integrated) • General relativity corrections on Sun and planets • Extended bodies - point mass bodies interactions • Earth - Moon, Sun, Venus, Jupiter • Moon - Earth, Sun, Venus, Jupiter • Sun - Mercury, Venus, …, Pluton • Deformation of extended bodies - point mass bodies • Earth (Sun, Moon) - Moon, Sun, Venus, Jupiter • Moon (Earth, spin) - Earth, Sun, Venus, Jupiter • Torque of extended Earth (J2) on extended Moon (J2,C22) • DE405 : fitted to LLR / INPOP-05: Not yet fit to LLR data ( in progress)

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