Ocean observations with a space-based delay-Doppler altimeter constellation

A constellation of (nominally) three DDA satellites can all be placed in the same orbit plane by a single launch vehicle. Earth rotation spreads their respective nadir tracks by a spacing that is proportional to their along-orbit separation. This constellation which we have called WITTEX (Water Inclination Topography and Technology Experiment) is a candidate approach that would meet nearly all of the requirements identified by the user community for oceanographic altimetry. The WITTEX constellation can be tuned to favor dense spatial coverage, relatively tight temporal coverage, or other priorities. In addition the constellation can be used in a dual-use mode as was Geosat, in that geoid observations over a dense ground track can be made, after which the constellation can be maneuvered into an oceanographic exact repeat mission.