네 개의 하이드로폰 배열을 이용한 동해안 수중음향 장기 관측

Abstract

KRISO has developed an underwater acoustic measurement module that operates at low power for long-term acquisition of underwater sound data. The developed module is equipped with a planar array of four hydrophones and is capable of measuring acoustic signal with the frequencies between 20 Hz and 20 kHz at a sample rate of 50 ksps. In this study, we present the analysis result of a month-long seaside experiment data which were gathered at the northeastern coast of Korea from mid-December, 2016 to mid-January, 2017. The result shows that the measured ambient noise level is a few dB higher than the existing ambient noise models and the level changes diurnally by 5dB at the frequencies of a few hundred hertz to a few kilohertz. The data measured in the early morning is shown to have the highest noise level, and its statistical characteristics reveal that it was presumably generated by the rotating propellers of passing boats.