About
Wind information over open waters where observations are scarce is critical for shipping concerns. Sustained strong winds can generate dangerous waves. GCOM is a polar-orbiting satellite that uses microwave data from AMSR-2 (Advanced Microwave Scanning Radiometer 2) to infer wind speeds. Microwave emissions are detected with a scanning antenna that rotates once per 1.5 seconds, measuring a swath 1450km wide. Sea-surface winds are computed using the 36.5 GHz channel. Sea foam and surface waves both influence the microwave signal used to infer wind speeds.
Limitations
Rain Blockages: Heavy convective rain, as above over the Western Atlantic, can affect the wind signal and degrade the estimate of wind speeds.
Coastal Areas: The interpretation algorithm omits areas within 50km of shorelines, because reflection from land areas wash out those from ocean surfaces.
