Associate Professor Linus Yung-Sheng Chiu completed survey on underwater sound propagation with WHOI in South China Sea
The researchers of WHOI and NSYSU with the crew and technical team on the board of R/V Legend after the expedition. From the left in the front row is WHOI engineer John Kemp, Associate Professor Linus Yung-Sheng Chiu of the Institute of Undersea Technology at NSYSU (second from the left), WHOI scientist Ying-Tsong Lin (third from the left), captain of R/V Legend captain Chiu-Hsing Huang (in the center), and WHOI research engineer Peter Koski (first from the right in the back row). / photo provided by Associate Professor Linus Yung-Sheng ChiuThe last part of the acoustics experiment: retrieving the acoustic mooring. / photo provided by Associate Professor Linus Yung-Sheng ChiuAssociate Professor Linus Yung-Sheng Chiu of the Institute of Undersea Technology at NSYSU (on the left) with WHOI scientist Ying-Tsong Lin (on the right) celebrate the successful completion of the experiment. / photo provided by Associate Professor Linus Yung-Sheng ChiuMid- and low-frequency towfish passive sonar system, developed by Associate Professor Linus Yung-Sheng Chiu with his students, played an important role in this experiment; it included a mid- and low-frequency sound source, wide-band acoustic receiver, and seabed reflection coefficient detector. / photo provided by Associate Professor Linus Yung-Sheng ChiuNSYSU and WHOI researchers deploy an acoustic mooring to conduct the experiment. / photo provided by Associate Professor Linus Yung-Sheng Chiu
From 14 to 19 October, the international team of National Sun Yat-sen University (NSYSU) and US researchers of the Woods Hole Oceanographic Institution (WHOI), aboard the R/V Legend by the Taiwan Ocean Research Institute (TORI), conducted a survey in the South China Sea on the underwater sound propagation in relation to internal waves and shelf breaks. Associate Professor Linus Yung-Sheng Chiu of the Institute of Undersea Technology (IUT) at NSYSU, who is also the Principal Investigator of the US Office of Naval Research (ONR) for Taiwan was one of the leaders of the expedition.
The research team deployed equipment and studied how sound propagates in the waters half-way between Taiwan Island and Dongsha Island, in a shallow break 200 m deep, on the edge of a plateau – an area where the vertical displacement of internal waves can reach more than 100 m. The survey was a collaboration between Professor Chiu of NSYSU and the team of accomplished members of WHOI who had to undergo a two-week quarantine before the expedition: engineer John Kemp, scientist Ying-Tsong Lin, and research engineer Peter Koski. R/V Legend was operated by the TORI crew, who provided assistance during the whole expedition.
The expedition was part of the three-year project on underwater acoustics – Acoustic Scattering &Transmission Experiment (CASTEx) in the Northeastern South China Sea 2019-2021, sponsored by the ONR, and a project sponsored by R.O.C. Ministry of Science and Technology: Measurements and Analysis of Geoacoustic Parameters in the Northern South China Sea (III). The results of the research will have multiple applications in naval operations and wind farm technologies. Professor Chiu said that as the next step, the team plans to continue conducting research on sound propagation in the dynamic bottom scenery of the Taiwan Strait, specifically around the waters of Dongsha Island, where NSYSU established the Dongsha Atoll Research Station (DARS) in 2012.
Professor Chiu, who specializes in ocean acoustics, sound propagation, underwater communication and leads the Applied Marine Acoustics and Communication Laboratory, provided active and passive sonar systems for the underwater acoustics survey that he developed with his students over the past 9 years at NSYSU. His sonar systems, as well as research results and know-how in underwater sound propagation have been acknowledged by the Taiwanese industry and government and will be applied in projects related to the development of underwater sonar technologies.
Professor Chiu has been cooperating with the ONR for already 20 years, first, as a PhD student, before he joined the faculty of NSYSU in 2011. In 2019, he became the Principal Investigator of ONR in Asia, with focus on Taiwan waters – South China Sea and East China Sea. As a faculty member of IUT, which focuses on the research in underwater acoustics and mechatronics, he is also cooperating with US Naval Postgraduate School, US Woods Hole Oceanographic Institution, the Applied Physics Laboratory of the University of Washington, the Naval Meteorological and Oceanographic Office R.O.C, and CSBC Corporation Taiwan.
“Sunlight can penetrate only a very shallow part of the water”, said Professor Chiu, and this is why ocean sound propagation needs to be studied “to make the ocean transparent”. Marine animals communicate using sounds for a reason, he noticed.
Read more about the research expedition in Taipei Times: https://taipeitimes.com/News/taiwan/archives/2020/11/09/2003746623