Wave Height Estimation From X-Band Radar Data Using Variational Mode Decomposition
Zhiding Yang, Weimin Huang
Abstract
In the paper, a variational mode decomposition (VMD)-based method is proposed to estimate significant wave heights (<i>H<sub>s</sub></i>) from X-band marine radar images. Firstly, 10 intrinsic mode functions (IMFs) are decomposed from the selected radar sub-images with VMD. Then, a linear fitting method is conducted to estimate <i>H<sub>s</sub></i> by using the sum of the amplitude modulation (AM) components extracted from the 6<sup><i>th</i></sup> to 9<sup><i>th</i></sup> IMFs. The radar data were collected from a ship at sea around 300 km from Halifax, NS, Canada. The real-time <i>H<sub>s</sub></i> data were obtained by drifting Triaxys buoys around the moving vessel. Experiment results show that the proposed VMD-based linear fitting method generates improvement in the <i>H<sub>s</sub></i> measurements, compared to the typical ensemble empirical mode decomposition (EEMD)-based linear fitting method, by reducing the root-mean-square error (RMSE) from 0.34 m to 0.32 m and increasing the correlation coefficient (CC) from 0.90 to 0.92 after using the moving average.