Contexte
The Space Geodesy team of GET has been involved for more than 40 years in global Earth gravity field modeling. The early models, the series of GRIM Earth models from GRIM1 to GRIM5, were static. Since the year 2000 these models are called EIGEN models and contain now a time-variable part. The geodetic missions CHAMP and particularly GRACE have allowed a tremendous improvement (by a factor of one hundred) in our knowledge of the gravity field. Thanks to the GRACE mission we observe today not only the static gravity field, but also its time variations, namely hydrology, glaciology and post-glacial rebound since the other temporal effects (oceanic and solid Earth tides, gravitational effect of the atmospheric pressure and of its oceanic response) have been removed through modeling. Our group routinely produces temporal solutions of these new observables.
The Space Geodesy team of GET was also involved in the data processing of the high-resolution gravity mission GOCE.