Wind Speed Extraction From First-Order Sea Echoes Using a Small-Aperture Multifrequency High-Frequency Radar

Wind speed inversion is a challenging work in the field of ocean surface remote sensing with high-frequency (HF) radars. Recently, the wind speed inversion method based on the first-order HF radar sea echoes attracts much attention. However, most methods, which use radar data at a fixed operating frequency, provide a limited range for wind speed measurement. To overcome the drawback, a wind speed inversion method based on radar data collected with a multifrequency HF radar is proposed. This new method first fits the relationship between the wind speed and the power of the broad-beam first-order HF radar sea echoes and then combines the fit models with the multifrequency HF radar data to estimate wind speed. The proposed method makes use of the information contained in the first-order sea echoes of various operating frequencies so as to improve the performance of the wind speed measurements. Finally, a comparison between radar-estimated and anemometer-measured wind speeds is made to validate the proposed method. Compared with the anemometer data, the wind speeds estimated by the proposed method have a root-mean-square error (RMSE) of 2.27 m/s.