The positive direction is counter-clockwise when looking down on the surface. However, scatterometers are now producing 'observations' of friction velocity and equivelent neutral wind speed. Use of the wrong phase speed can lead to large overestimations of fluxes. Vector components are calculated parallel and perpendicular to the direction in which the dominant waves are propagating. For most applications there will be insufficient wave information, requiring the assumption of local wind-wave equilibrium.
All output is single precision floating point.
Positive values indicate a lack of specific problems. There are more details on the conversion to zonal and meridional components .