INPOP08, a 4-D planetary ephemeris: from asteroid and time-scalecomputations to ESA Mars Express and Venus Expresscontributions

摘要

The latest version of the planetary ephemerides developed at the Paris Observatory and at the Besancon Observatory is presented.INPOP08 is a 4-dimension ephemeris since it provides positions and velocities of planets and the relation between Terrestrial Time andBarycentric Dynamical Time. Investigations to improve the modeling of asteroids are described as well as the new sets of observationsused for the fit of INPOP08.New observations provided by the European Space Agency deduced from the tracking of the Mars Expressand Venus Express missions are presented as well as the normal point deduced from the Cassini mission. We show importance ofthese observations in the fit of INPOP08, especially in terms of Venus, Saturn and Earth-Moon barycenter orbits.