For a routine observation of surface current by dual-site high-frequency radar(HF and VHF radar), it is absolutely necessary to develop an automatic extraction method of the surface current information from the narrow-beam sea-echo data with stable accuracy and without being checked by an expert.
In developing the automatic procedures mentioned above, we took full advantage of the Bragg resonant mechanism, radar measurement's characteristic and statistical analysis. Features of the developed methods are;
Surface currents extracted by this process are in good agreement with those measured by current meters at the same time in a bay with a dominant tidal flow, and the distribution mapped by these surface current data illustrate a well-known dominant feature in the bay.
The conclusion is that the developed method is valid for the purpose of a routine observation by the radar.