Satellite altimeters measure the distance between satellite and sea surface and provide precise observations of the sea level heights with respect to a well-defined global references frame. By using a cross-calibrated long-term multi-mission data set the ocean variability can be described on almost all space and time scales. These measurements and their interpretation are a basic prerequisite for understanding global change processes and are of high relevance for geodesy and other Earth sciences.
DGFI-TUM computes sea level variations on global and regional scales, estimates ocean tides (amplitudes and phases) and ocean topography. The latter can be converted to ocean surface velocities and help to monitor global ocean currents as well as smaller structures such as eddies. Current investigations focus on comprehensive error estimations and on the improvement of data and methodology in coastal and polar regions.