Radial HF Radar Data

Radial HF radar data is the raw current product from a single coastal HF radar site: the component of surface current moving toward or away from that antenna, resolved by range and bearing. One site cannot give a full velocity vector because it senses only the radial direction. Two or more overlapping sites combine their radials, where the look directions cross at a useful angle, into a total vector surface-current map. Data quality drops where radials are near-parallel, the geometric dilution of precision problem, and near the baseline between sites. Radials are archived and distributed in standard form by networks such as US IOOS for assimilation and drift modeling.