The SARAL/AltiKa project is a collaboration between France and India in the environment monitoring domain. On a platform developed by the indian space agency (ISRO), two independant payloads will be embarked, ARGOS-3 and AltiKa (+DORIS, +LRA), but their missions have the save objective: to promote the study of the environment from space.

ARGOS-3 is an element of the ARGOS system, dedicated to localisation, acquisition and distribution of environmental data.

AltiKa is an innovating Ka-band altimeter system, dedicated to accurate measurement of ocean surface topography. It is envisioned as a successor of RA-2 instrument on board ESA's satellite ENVISAT.

The AltiKa project is part of a French program of operational oceanography development including notably the deployment of in situ measurements (CORIOLIS project) and the implementation of an analysis and forecasting center (MERCATOR project). These two programmes are the French contribution to GODAE (Global Ocean Data Assimilation Experiment), first international operational oceanography experiment. Thanks to the work of the French and international community, diverse applications of modeling/assimilation systems such as MERCATOR are in operation to begin to answer the scientific needs as well as civil or defense operational applications. Altimetry is a key observation parameter of the system and continuity of observations is a critical factor of its efficiency. A participation to the permanent observation system that will feed operational oceanography thus constitutes a major objective of AltiKa. The perspective of Marine Core Services (MCS) implementation within the GMES framework and the MERSEA project continuity, gives even more importance to this goal.

The data processing will be integrated to the CNES ground segment "SALP" (Système d'Altimétrie et de Localisation Précise), which already operates the altimetry missions Topex/Poseidon, Jason-1, Envisat, GFO, and Jason-2.

SARAL/AltiKa will fly on the same orbit than ENVISAT, to ensure a continuity of altimetry observations in the long term. On the other hand, the local time of passage over the equator will be different due to specific cover requirements for the instruments constellation of ARGOS system.