A five-year joint satellite mission between NASA and the Centre National d’Études Spatiales (CNES) of France, launched on 7 December 2001, that monitors the global ocean circulation and events such as El Niño and ocean eddies, and collects data on the ties between atmospheric and ocean circulation. It passes over every point on the surface at intervals of ten days at an altitude of about 1336 km, and it flew in tandem with TOPEX/Poseidon until that craft ceased operation in 2005. Jason-1 now continues the work of the earlier mission.

http://www.nasa.gov/centers/jpl/missions/jason.html A joint CNES and NASA mission to study global ocean circulation and its link with atmosphere and climate.