The satellite CHAMP (CHAllenging Mini-Satellite Payload) is used for geophysical research and application. Precise orbit determination is needed for this satellite, and is achieved with satellite laser ranging.

Due to its low orbit (< 400 km at present, slowly descending) it is relatively sensitive to forces like drag etc., which are difficult to predict and to model. Therefore it is sometimes quite difficult to track CHAMP, especially during daylight. Nevertheless, we have been able to track very long passes successfully.

Further information on the CHAMP mission is found at GFZ Potsdam.