GRGS > Research > Subjects > Orbital Mechanics

Bureau des longitudes Centre national d’études spatiales Institut national de l'information géographique et forestière - Laboratoire LAREG Observatoire de Paris Institut national des sciences de l'Univers Observatoire de la Côte d'Azur Service Hydrographique et Océanographique de la Marine Observatoire Midi-Pyrénées Université de la Polynésie Française Ecole Supérieure des Géomètres et Topographes - Conservatoire national des arts et métiers Ecole et Observatoire des Sciences de la Terre

Orbital Mechanics

Our work in orbital mechanics is based on the need to analyze the trajectory of artificial satellites, which has several purposes :

  • Analysis of sensitivity to the gravitational environment in which the satellite travels : the applications concern the determination of the Earth’s gravitational field, with its temporal variability, or the evaluation of the trajectories’ stability over long periods of time. We also develop tools for solar system navigation; one of the applications we are currently working on analyzes Doppler data from the Pioneer 10 & 11 probes, in which we are looking for an acceleration anomaly (a very weak effect which was originally misunderstood).
  • Analysis of sensitivity to the gravitational environment in which the satellite travels : modeling of the thermosphere, in terms of total density encountered at various altitudes (above 200 km), and studying the effects of heating by the Sun on LAGEOS satellites.
Mécanique orbitale

Other developments in orbital mechanics are based on the needs and challenges presented by new space projects concerning the Earth (the GALILEO mission analysis, new measurement functions for missions studying the gravitational field).

Our methodological developments have been implemented in the software applications GINS, LAGRAN, CANEL, ODYSSEY, and MATLO.