Short-range velocity field observation by coastal acoustic tomography

Abstract

Coastal acoustic tomography can perform a realtime field observation, and can be an important supplement to the Marine Ranch Observation. In this paper, a short range experiment has been conducted in ZhaiRuo Island, ZhouShan on January 20,2019. Four acoustic stations sent signals to each other to obtain the travel time of the signal between stations. ADCP and CTD were used to collect reference data. The horizontal velocity fields are mapped by inversion. The range-average currents calculated by inversion and travel time difference are close, and the inversion results are almost the same as the velocities obtained by ADCP. Vloume transports are also proved to reach balance by calculating flow rates of upper 2m crossing perpendicularly to the peripheral paths. Experiments show the feasibility of the coastal acoustic tomography to observe small area.