Airborne measurements of the ocean radar cross section at 5.3 GHz as a function of wind speed

Measurements of the normalized radar cross section (NRCS) at 5.3 GHz (C band) of the sea surface as a function of wind speed and direction are presented. The data were obtained by a coherent scatterometer mounted on a small two-engine airplane performing circle flights over the Atlantic. Our data show that the wind speed exponent at 5.3 GHz is typically 20% smaller than at 13.9 GHz (Ku band). Furthermore, the upwind/crosswind ratio of the NRCSs at C band is typically 20% smaller, and the upwind/downwind ratio typically 30% smaller than at Ku band.