38 pages, 24 figures, 1 tableSMOSops will introduce several technological modifications to provide an improved determination of soil moisture and ocean salinity from space. It is proposed to measure H and V polarisations in parallel, a good approach since it increases radiometric sensitivity with respect to the present SMOS set up. A fully populated hub will provide better measurement of the short baselines, also a very good approach since it allows redundancy to improve error correction and robustness. Longer arms will lead to improved spatial resolution. A reduced spacing between antenna elements will improve the swath and revisit time by enlarging the alias free field of view, while the Flat Target correction can cope with the increase of antenna coupling due to the reduced spacing. [...]Peer reviewe