A full year of champ gravity field solutions has been calculated using the energy integral approach. The monthly solutions in the time frame 03.2002–02.2003 were based solely on kinematic orbits from champ gps orbit tracking and accelerometry. These kinematic orbits have not been contaminated by a priori gravity field information.
Recovery of medium-wavelength time-variable gravity signal from champ is expected to be at the edge of feasibility. This expectation is validated by comparison to an SLR solution of seasonal gravity variations and by comparison to oceanographic and meteorological models. It is shown that the error level of monthly CHAMP solutions is insufficient for revealing these time variations. Orbit decay—and consequently ground track variation—is a main contributor to this effect.