The JASON-2 project is a response to the international demand for programmes to study and observe oceans and the climate, through a worldwide ocean observation system. It is a continuation to the TOPEX/POSEIDON and JASON-1 altimetry missions developed by CNES and NASA. Altimetry, i.e. the precise measurement of ocean surface topography, has indeed become since 1992 (launch of TOPEX/POSEIDON) an essential tool for the study of oceans on a global scale.

JASON-2 is part of cooperation between CNES, EUMETSAT, NASA and NOAA. Space and ground segments of the Jason-2 mission strongly inherit from the JASON-1 mission.

Onboard the JASON-2 satellite, which uses a PROTEUS platform, the payload is composed of a Poseidon-3 radar altimeter supplied by CNES, an Advanced Microwave Radiometer (AMR) supplied by NASA/JPL, and a triple system for precise orbit determination: the DORIS instrument (CNES), GPS receiver and a Laser Retroflector Array (LRA) (NASA). Three further onboard instruments (T2L2, LPT, CARMEN-2) will also be included.

In order to ensure continuity and optimal inter-calibration of observations over the long term, JASON-2 will fly the same orbit as JASON-1 and TOPEX/POSEIDON. Moreover, data processing will be integrated into the CNES ground segment "SALP" (altimetry and precise positioning system), which already operates the altimetry missions TOPEX/POSEIDON, JASON-1, ENVISAT, GFO, whose data is distributed on the AVISO website.