Wave Height Estimation From X-Band Radar Data Using Variational Mode Decomposition

In this letter, a variational mode decomposition (VMD)-based method is proposed to estimate significant wave heights (
$H_{s}$
) from X-band marine radar images. First, ten intrinsic mode functions (IMFs) are decomposed from the selected radar sub-images with VMD. Then, a linear fitting method is conducted to estimate
$H_{s}$
by using the sum of the amplitude modulation (AM) components extracted from the sixth to ninth IMFs. The radar data were collected from a ship at sea around 300 km from Halifax, NS, Canada. The real-time
$H_{s}$
data were obtained by drifting Triaxys buoys around the moving vessel. Experimental results show that the proposed VMD-based linear fitting method generates improvement in the
$H_{s}$
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 to 0.32 m and increasing the correlation coefficient (CC) from 0.90 to 0.92 after using the moving average.