On the accuracy of HF radar measurement in the Tsushima Strait

Abstract

The accuracy of HF radar measurement in the Tsushima Strait is investigated. A comparison between radial velocities measured by HF radar and acoustic Doppler current profiler (ADCP), which provides an upper bound of HF radar measurement error, shows that the root‐mean‐square (RMS) velocity difference obtained from the principal component analysis is 6.62∼11.3 cm s −1 . A comparison of velocities measured by two facing HF radars, which provides a lower bound of HF radar measurement error, shows that the variance error of hourly radial velocity is 5.75∼13.3 cm s −1 . The bias error of HF radar measurement is also found to be reasonably small through a comparison of tidal ellipses estimated from 1 year of HF radar data with those from 5 years of ADCP data. These results suggest that the variance error of HF radar measurement is the dominant source of the velocity difference found between ADCP and HF radar.