Geodetic Application of Satellite Altimetry

Satellite altimetry has developed to an operational remote sensing technique with important applications to many geosciences. In the present paper we consider in particular geodetic applications of satellite altimetry. It is shown that this space technique not only allows mapping and monitoring a major part of the Earth surface, but also did contribute to essential improvements for the Earth gravity field. Even with the new dedicated gravity field missions of CHAMP, GRACE and GOCE satellite altimetry will be needed for the determination of the high-resolution gravity field. The mean sea level can be mapped and monitored for seasonal and secular changes through the combination of altimeter mission with different space-time sampling. The realisation of the global mean sea surface will help to unify national height systems, to clarify local sea level trends visible in tide gauge records and contribute to studies on the global sea level rise, the most prominent indicator of global change.