Finding Desirable Orbit Options for the “Extension of Life” Phase of Jason-1

The ageing of Jason-1, the risk of losing control of the satellite, and the collision risk with TOPEX/Poseidon (still in orbit and no longer maneuverable) initiated a reflection on a so-called “extension of life phase” (EoL) phase that would involve moving Jason-1 to a new orbit to mitigate collision risks while optimizing its science return. This paper describes three practical consequences of any such EoL phase: 1) the ability to build an unprecedented low inclination and high precision geodetic dataset, 2) the loss of coordination with Jason-2 and the associated mesoscale (and sea state) sampling degradation, and 3) the increased topography height error budget stemming from the use of a gridded mean sea surface in place of the classical repeat track analysis that operational systems have been using and improving for almost two decades. More than 17,000 potential orbits were analyzed to identify desirable altitude ranges that could host a Jason-1 EoL phase. The objective was to minimize the sampling deg...