Sea Surface Topography

To measure sea surface height, or surface topography, scientists need to obtain the precise distance between the satellite and the center of the Earth and the precise distance between the satellite and the sea surface. Sea surface height is then calculated by subtracting the distance between the sea surface and the satellite from the distance between the center of the Earth and the satellite. The distance between the satellite and the center of the Earth is obtained by carefully monitoring the satellite position at all times.