Types of dataset: auxiliary products Contents: mean over the 1993 - 2012 period of the sea surface height above geoid. (aviso.altimetry.fr)
It is the objective of the geodesists to exactly determine the so - called geoid of Earth to a few centimeters. (sciencedaily.com)
The gravitational models used can't have been that good, because the US Navy launched the GEOSAT mission in 1985 specifically to map the marine geoid (and gravity field) as the fields they had weren't good enough for much of the world's oceans. (realclimate.org)