Over-the-horizon radar: ground-based ocean remote sensing on basin-wide scales

The U.S. National Oceanic and Atmospheric Administration (NOAA) has been testing high-frequency, ground-based, over-the-horizon (OTH) radars for mapping winds, waves, and surface currents over very large ocean areas. Recent results show that unambiguous surface wind direction can be mapped by combining meteorological insight with seeds from in-situ data. Vector surface currents can be mapped using two OTH radars whose coverage overlaps. A map of surface currents in the vicinity of a hurricane is an example.