Study of high-frequency acoustic current tomography

The sea-land interface is the most concentrated region of human marine development activities, and online monitoring of river current is very important for material flux and ecosystem evolution. In this study, the high-frequency acoustic current tomography of sea-land interface was studied. Based on the principle of acoustic reciprocity, the acoustic inversion algorithm of current was investigated. The experiment was carried out on the Jiulongjiang sea-land interface in Zhangzhou. The high-frequency transducer, with a center frequency of 60 kHz and bandwidth of 40–80 kHz, was used. According to the sound speed profile and underwater topographic survey, ray acoustic simulation was performed to reveal high-frequency sound propagation. The experimental results showed that the acoustic signal has high-signal amplitude and peak value of cross-correlation, which can be used to reconstruct the current of the river. Real-time monitoring of the river current during the typhoon “haibeisi” was achieved. The results showed that high-frequency acoustic tomography can be applied to the study of hydrodynamics of sea-land interface, hydrological measurement, and monitoring of extreme events, such as flood peak and heavy rainfall.