Winds are a critical factor in determining regional weather patterns and global climate.
At present, weather data can be acquired over land, but our only knowledge of surface winds over oceans comes from infrequent and sometimes inaccurate reports from ships. Scatterometers use a highly indirect technique to measure wind velocity over the ocean. These instruments transmit microwave pulses and receive backscattered power from the ocean surface. Changes in wind velocity cause changes in ocean surface roughness, modifying the radar cross section of the ocean and the magnitude of the backscattered power. Multiple, collocated, measurements acquired from several direction can thus be used to solve wind speed and direction simultaneously.