Over 10,000,000 altimetric sea height crossovers from 3 satellites, singly and in pairs in missions spanning over 10 years from 1985 through 1996 have been reduced to yield an improved (50x50) geopotential (correcting radial errors in the reference Jgm3 trajectory for the 3 orbits) as well as corrections for other non-geopotential orbit errors and altimeter biases.
It is necessary to severely downweight the dual satellite crossovers to achieve a solution compatible with the reference geopotential whose covariance matrix is used as a priori information.
The residuals to the best solution for these parameters show strong east-west trends which appear to be expressions of long-term averaged interannual oceanography in this 10+ year period. The residuals correlate fairly well with equivalent tide-gauge differences in the Pacific and also in a narrow tropical band with a Global Circulation Model which assimilated salinity and heat measurement as well as some collinear altimetry from two of these satellites.
These "interannual oceanographic" residuals should be useful as global controls on the numerical circulation models.
The residual analysis also shows the altimeter's reference tide model probably is responsible for additional bias in the averaged data at a level of 1-2 cm on both short and long scales across the oceans, but greater in certain margins of the seas.
There is still a small geocenter coordinate shift (order 2 cm) observable
from sea surface differences between satellites whose orbits were computed from
different tracking systems, but the solution for these are much reduced than
when first computed without higher geopotential correction.