Geodetic parameters such as Earth Orientation Parameters (EOP) and coefficients of the Earth's gravity field are highly correlated with satellite orbit parameters. For a reliable estimation of these various parameter groups in one common adjustment, satellites with different orbit characteristics have to be combined. At DGFI-TUM, laser ranging observations (SLR) to up to 11 different satellites are combined in order to decrease correlations between the different parameters using the Combination and Solution library of the DOGS software.
The combination of laser observations to different satellites also allows to enlarge the parameter space (e.g., thermospheric parameter) or to significantly increase the sensitivity to the Earth gravity field. The SLR multi-satellite solution can be used as a case study for the consistent estimation of the Earth's geometry, rotation and gravity field in one common adjustment. Therefore, the multi-satellite solution allows a step forward towards one of the major goals of the Global Geodetic Observing System (GGOS).