자동기록 방식의 수중청음기 개발

Abstract

A self-recording hydrophone combined with a hydrophone and a data logger was developed to consist conveniently of a hydrophone array. The self-recording hydrophone is made up of a hydrophone, amplifiers, filters, a/d converters, flash memories, an inductive coupler, and batteries. The self-recording hydrophones are used with a wireless trigger transmitter, a wireless trigger receiver inserted in a buoy, an inductive coupler, and an inductive cable to make up a hydrophone array. The self-recording hydrophones are attached to an inductive cable at an appropriate spacing, and independently receive and store underwater sound signal due to each channel. At this time all hydrophones simultaneously start to store underwater sound signal by the wireless starting trigger signal, and simultaneously finish storing the acoustic signal by the wireless finishing trigger signal. There are several advantages in use of the self-recording hydrophone to consist of a hydrophone array. The self-recording hydrophone is very strong to the electric noise because the hydrophone independently uses the self-contained battery as an electric source. It is very easy to adjust spatial hydrophone interval. We present some measurement results on oceanic ambient noise conducted to test availability of the hydrophone.