An Algorithm for Retrieving Water Surface Current by Using K-Band Coherent Radar

Water surface current velocity is an important hydrologic parameter. A novel method for retrieving surface current velocities by using K-band coherent radar is proposed. First, to mitigate the impact of noise on radar echo, a convolutional neural network (CNN) is employed to extract the main wave pattern from orthogonal radar echoes. Second, to retrieve the current velocity with high temporal resolution, a method based on continuous wavelet transform is developed. The proposed method is validated by using a K-band radar and a wave channel in field experiment. For current velocities in the range of 0–1.8 m/s, the average error between the retrieved current velocities and the true velocities is less than 0.07 m/s, and the root mean square errors between them range from 0.03 to 0.16 m/s, indicating that the proposed method is reasonable. Finally, the application condition of the method is discussed.