Sea surface observations using a VHF radar with multireceiver beamforming technique

A VHF pulse radar was used to observe the sea surface in the northern Taiwan Strait. Radar frequency is 52 MHz, and a range cell was 300 m. Four vertical dipole antennas, arranged linearly along the coastline with 3 meter separation between adjacent antennas, were used to collect the radar returns. The self-adaptive Capon method was employed in this study to determine the direction of arrival (DOA) of the sea echoes. Analysis shows that pronounced semidiurnal tidal modes were presented in the temporal variations of observed DOA, echo power, and Doppler velocity.