Design of a High-frequency Wideband Doppler Current Meter

This study presents the design of a high-frequency (HF) wideband Doppler current meter based on the principles of the acoustic Doppler effect. The Doppler current meter employs a complex autocorrelation algorithm to analyze the echo signals of HF acoustics emitted by its transducer, thereby deducing Doppler frequency shifts and subsequently computing the velocity of water currents in each direction. Compared with the low-frequency Doppler current meter, the HF wideband current meter has a lower measurement blind area and higher measurement resolution, although it has a more confined measurement range. To validate its performance, the velocity measurements of the HF wideband current meter were calibrated using a steady-flow circulating tank. Assessments against measurements from a narrowband Doppler current meter were also conducted. The results revealed high accuracy of the HF wideband Doppler current meter, with indication errors not exceeding 0.1 m/s.