Global wave height and wind speed climates from space

A vertically-mounted radar altimeter on board a satellite gives primarily an estimate of the distance from the satellite to the sea or land surface. But it also gives data from ocean returns which provide measures of the roughness of the sea surface (from which the significant wave height is calculated) and measures of the normalised radar cross-section (from which wind speed close to the sea surface can be estimated). So an orbiting satellite provides near-global coverage of wave height and wind speed-if the data can be received world-wide or stored on board for later transmission. The author looks at Geosat´s radar which has provided, for the first time, several years of near-global coverage of wind and wave data