Measurement and analysis of ambient noise in the South China Sea based on underwater acoustic buoy
HAN Mei;WANG Chao;SUN Qindong;WANG Wenlong;LYU Yong;Navy Submarine Academy;Qingdao National Laboratory for Marine Science and Technology;
Ocean ambient noise is a complex combination of many types of natural and anthropogenic noises.The spectrum levels and frequency composition are very important in the detection performance of a sonar system. Since the spatial and temporal characteristics are complicated, it is necessary to conduct long-term and large scales monitoring of the ambient noise to analyze its properties. Thus, we designed and developed an underwater acoustic buoy with acoustic measuring system to sample the ambient noise on spatial and temporal. The acoustic buoy can be used for multiple floating and diving, and has two working mode with in-situ bottoming and deep-draining. The maximum endurance is typically a few months in the ocean. Using a certain day experiment data collected by several underwater acoustic buoys, which were arranged in a certain area in the South China Sea in August 2019, this study investigated ambient noise spectrum level change with time at the center frequencies of the 20 Hz, 63 Hz, 100 Hz, 200 Hz, 400 Hz, 800 Hz, 1.6 kHz and 3.15 kHz.The data processing results are consistent with the typical variation law of ambient noise. The results of this study indicated that acoustic buoy as a potential underwater unmanned platform could be used in the future for monitoring of ambient noise properties in a certain sea area.