A high precise GPS-receiver with high time resolution is operated together with the Norwegian Mapping Authority in Ny Ă…lesund since 1999. Datasets are transmitted continuously and automatically via Internet to the GFZ in Potsdam where they are evaluated for two purposes. Firstly to determine station coordinates, ephemerides for all GPS-satellites and high temporal resolved vertical integrated water vapor for the International GPS Service (IGS). Secondly they are used as reference for the CHAMP-satellite to determine its exact orbit and to calculate water vapor profiles from on board GPS-receiver-data.