Ocean surface current measurement with high-frequency hybrid sky-surface wave radar

High-frequency hybrid sky-surface wave radar (HFHSSWR) is a new remote sensing instrument with potential for applicability to large-area sea state monitoring. This study investigated the use of HFHSSWR for ocean surface current measurements. Based on the Doppler shift of the first-order Bragg peak of HFHSSWR, the component of the Doppler shift caused by the ocean surface current was calculated, and the elliptical velocity of the ocean surface current measured by HFHSSWR was derived. Land clutter was used as a reference source to correct the linear variation of the ionospheric effect, and the average of the current inversion results within many coherent integration times was used to eliminate the nonlinear variation of the ionospheric effect. Finally, the inversion results of the ocean surface current were validated using synchronised in situ measurements from a current meter. Their comparison (correlation coefficient: 0.81, root mean square error: 0.138 m s(-1)) demonstrated the feasibility of measuring ocean currents with HFHSSWR.