DORIS (Doppler Orbitography and Radiopositionning Integrated by Satellite) was proposed by CNES, GRGS (Groupe de Recherches de Géodésie Spatiale) and IGN in 1982 as a dedicated fully optimised system in support of POSEIDON oceanographic altimetric experiment. Later on this experiment was merged with NASA TOPEX project to become the TOPEX/POSEIDON mission which has been launched August 10, 1992. To get an in-flight validation of DORIS before TOPEX/POSEIDON it was flown on board the SPOT2 satellite as a passenger experiment. Recognising the ability of the system to provide precise positioning of ground beacons, DORIS was approved for flying on board SPOT3, SPOT4, ENVISAT-1, JASON-1 (TOPEX-POSEIDON follow on mission), SPOT5, JASON-2, CRYOSAT-2 and on HY-2A.

The precise positioning is based on Doppler shifts measurements of RF signals transmitted by a world wide beacons network (one way thanks to stability of board and beacons USOs (Ultra Stable Oscillator)).

DORIS products are available in AVISO directory and IDS data centers