Sea Surface Current Estimation From a Semi-Enclosed Bay Using Coastal X-Band Radar Images

The potential of marine X-band radar images for estimating sea surface currents in open sea areas was confirmed. However, when the spatial current estimation was performed using radar images of the semi-enclosed bay areas, the challenge of dealing with inhomogeneity became apparent. Our study employed the method of the local phase gradient to estimate the spatial currents in bay areas. The feasibility of using the phase gradient method for current estimation has been demonstrated in various studies; however, for application of this method in highly inhomogeneous bay waters, we conducted a review of the various parameters that needed to be determined via the algorithm. Through comparison with actual measurement data, we confirmed that the local phase gradient method was more suitable than the traditional method for estimating sea currents within bay areas. Spatial flood and ebb currents obtained from radar images revealed the presence of eddies within the bay. We also verified the significant relationship between spatial current inhomogeneity and tidal phases in the study area.