Exploitation scientifique des données de navigation des sondes spatiales pour l'amélioration des éphémérides planétaires et applications

Improvement of the planetary ephemerides using spacecraft navigation data and its application to fundamental physics

• Auteur / Autrice : Ashok Kumar Verma
• Direction : Agnès Fienga
• Type : Thèse de doctorat
• Discipline(s) : Astrophysique
• Date : Soutenance le 19/09/2013
• Etablissement(s) : Besançon
• Ecole(s) doctorale(s) : École doctorale Carnot-Pasteur (Besançon ; Dijon ; 2012-....)
• Partenaire(s) de recherche : Laboratoire : Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules
• Jury : Président / Présidente : Véronique Dehant
• Jury : Examinateurs / Examinatrices : Agnès Fienga, Véronique Dehant, Jacques Laskar, José Lages, Luciano Less
• Jury : Rapporteur / Rapporteuse : Gilles Métris, Richard Biancale

Mots clés

Mots clés contrôlés

Planètes -- Éphémérides

Mots clés libres

Éphémérides planétaires

Navigation

Relativité générale

Couronne solaire

Solar corona

General relativity

Radioscience

Orbit determination

Résumé

Les éphémérides planétaires jouent un rôle important pour la navigation des missions spatiales actuelles et la mise en place des missions futures ainsi que la réduction et l'analyse des observations astronomiques les plus précises. Les éphémérides planétaires actuelles (DE, INPOP, EPM)L'objectif de la thèse est d'utiliser des archives de données de missions spatiales passées et présentes et de fournir des outils d'analyse pour l'amélioration de l'éphéméride de données pour l'amélioration de l’éphéméride planétaire planétaire INPOP, ainsi que pour une meilleure utilisation des éphémérides pour effectuer des teste de la physique tels que la relativité générale, les études de la couronne solaire [...]

The planetary ephemerides play a crucial role for spacecraft navigation, mission planning, reductionand analysis of the most precise astronomical observations. The construction of suchephemerides is highly constrained by the tracking observations, in particular range, of the spaceprobes collected by the tracking stations on the Earth. The present planetary ephemerides (DE,INPOP, EPM) are mainly based on such observations. However, the data used by the planetaryephemerides are not the direct raw tracking data, but measurements deduced after the analysisof raw data made by the space agencies and the access to such processed measurements remainsdifficult in terms of availability.The goal of the thesis is to use archives of past and present space missions data independentlyfrom the space agencies, and to provide data analysis tools for the improvement of theplanetary ephemerides INPOP, as well as to use improved ephemerides to perform tests ofphysics such as general relativity, solar corona studies, etc.The first part of the study deals with the analysis of the Mars Global Surveyor (MGS)tracking data as an academic case for understanding. The CNES orbit determination softwareGINS was used for such analysis. The tracking observations containing one-, two-, and threewayDoppler and two-way range are then used to reconstruct MGS orbit precisely and obtainedresults are consistent with those published in the literature. As a supplementary exploitationof MGS, we derived the solar corona model and estimated the average electron density alongthe line of sight separately for slow and fast wind regions. Estimated electron densities arecomparable with the one found in the literature. Fitting the planetary ephemerides, includingadditional data which were corrected for the solar corona perturbations, noticeably improves theextrapolation capability of the planetary ephemerides and the estimation of the asteroid masses(Verma et al., 2013a).The second part of the thesis deals with the complete analysis of the MESSENGER trackingdata. This analysis improved the Mercury ephemeris up to two order of magnitude comparedto any latest ephemerides. Such high precision ephemeris, INPOP13a, is then used to performgeneral relativity tests of PPN-formalism.[...]