1. MAGE Mid-term review (23/09/04): network report
* Financial support provided through the
European Community's Improving Human Potential Program
under contract RTN , MAGE
MAGE Mid-term review (23/09/04): network report
S. Pireaux

2. MAGE factual information:
Name: Sophie PIREAUX
Nationality: Belgian
Age at appointment: 28
Start of appointment: 1st January 2003
End of appointment: 31st December 2004
Category: post-doc
Specialty: - relativistic gravitation
- IAU recommendations (relativistic ref. systems, space-time transfo, metric) PPN formalism for testing alternative theories of gravitation
- satellites and laser ranging tests of relativity
Place of work: UMR5562 Dynamique Terrestre et Planétaire (DTP) Groupe de Recherche en Géodésie Spatiale (GRGS) Observatoire Midi-Pyrénées, Toulouse
Country of work: France
Previous experience in network: none

3. Sketches of the young researcher:
A/ Scientific background:
Sept 02-Sept 98: PhD, research assistant, doctoral school, FYMA, UCL (Belgium)
Thesis: “Light deflection experiments as a test of relativistic theories of gravitation.”
Advisor: JM. Gérard
Contract: UCL researcher on exterior funds (IISN, convention n° )
15 Nov 02 – 31 Dec 02: Assistant INSU/CNRS, DTP, OMP (France)
Jan 03 – Dec 04: present MAGE post-doc
B/ Future:
Jan Dec 2006 (or 2007?): CNES Post-doc, UMR GEMINI, OCA (France)
Subject: ``Solar astrodynamics and relativistic spin-orbit coupling'',
Collaboration: JP. Rozelot, E. Bois
…: apply to CNRS/CNAP, UMR ARTEMIS, OCA
Subject: ``Tensor Scalar signatures in gravitational wave emission and detection with LISA?''
Collaboration: with B. Chauvineau.

4. C/ Comments on present post-doctoral position:
Mobility:
contacts with geodesy community: their needs relativistic gravitation?
a synergy gravitational theoreticians geodesists is crucial!
contacts with previous institute: regular home missions
Advantages:
Interesting research project: good prospects
native relativistic approach ultimately needed
Drawbacks:
Ambitious project: single person, 2-year post-doc
Presently no joined effort
…but GRGS expressed interest at GRGS Summer School 2004 ???

5. Royal Observatory of Belgium
MAGE research subject:
« Integrating the motion of satellites in a consistent relativistic framework »
(Semi-Classical) Relativistic Motion Integrator
Observatoire
Midi-Pyrénées
Royal Observatory of Belgium
JP. Barriot
P. Rosenblatt
Collaborators:

6. Achievements: basis of RMI software
First post-doctoral year:
Study of IAU2000 conventions for astronomy / space-astrometry
Comparison of different relativistic time transfo TT-DTB: SOFA libraries (IAU 2003), DE405 Time-Ephemeris (Irwin and Fukushima, 1999)
Implement transfo between different time scales: TAI , TT, t, TDB, TCB, TCG
Basis of native relativistic software: implementation for simple metrics (Schwarzschild, Kerr, mono / multi-pole)
Started implementation of GCRS metric recommended by the IAU2000 resolutions
Started implementation of new NRO model for Earth rotation (IAU2000)
IAU = International Astronomical Union
TDB = Dynamic Barycentric Time scale used in the JPL ephemerides
TAI = International Atomic Time
TT= Terrestrial Time
t = Proper time
TCB = Barycentric Coordinate Time
TCG = Geocentric Coordinate Time
GCRS = Geocentric Coordinate Reference System
NRO = Non Rotating Origin
RMI =Relativistic Motion Integrator
2nd post-doctoral year
How non-gravitational forces fit in the relativistic framework
How relativistic equations with non-gravitational forces reduce to the classical ones
Order of magnitude of relativistic corrections

7. Projects for the near future: develop RMI software
What still needs to be done:
Continue implementation of IAU 2000 GCRS metric
Continue implementation of coordinate transfo
Verify internal / external coherence of ephemeris, astronomical constants used
Make actual comparisons with pre-existing classical orbitography softwares
Symplectic numerical integrator to conserve norm of quadrivector propre velocity
Transpose results to the case of a probe orbiting Mars
Contact