Dual beam along-track interferometic SAR to MAP total ocean surface current vectors with the airborne wavemill proof-of-concept instrument: Impact of wind-waves

Synoptic maps of total ocean surface currents from space are needed to improve the characterisation and parameterisations of oceanic sub-mesoscale dynamics and represent their impact on global ocean circulation, air-sea exchanges and the marine ecosystem. Wavemill is a satellite mission concept based on a dual beam along-track interferometric SAR principle. An airborne proof-of-concept campaign took place in the tidally-dominated Irish Sea in 2011. A comprehensive collection of airborne flights arranged in a star pattern permitted to sample various azimuthal directions. Here, it is shown that the impact of ocean waves on the measured ocean surface motion can be as large or even larger than the strong tidal current (0.7m/s). Using in situ validation measurements and airborne Wavemill data, the azimuth dependence and magnitude of this wind-wave velocity artefact is characterised.