Horizontal ADCP, new instrument for measuring current speed in a horizontal plane

摘要

We have developed a new instrument for measuring current speed and direction in a horizontal plane. The purpose of the development is to observe strong currents in narrow channels where many vessels pass through. The instrument is designed to be placed on a vertical wall beneath the sea surface. The instrument utilizes the Doppler Shift principal for its measurement. Very narrow acoustic beams are transmitted horizontally to the center of the channel from the transducer and the back-scattersignals are analyzed to find current speed and direction.We have carried out the field tests at the Kanmon Strait, which is the important sailing route connecting the Sea of Japan and the Seto Inland Sea. The tests confirmed that current speed and direction within 500m far from the transducer can hemeasured by the new instruments.