Evaluation of availability on passive acoustic devices on underwater platforms

The noise evaluation of the platform is necessary to use passive acoustic monitoring. In this study, we measured background noise of underwater platforms such as AUVs and deep sea landers. AUV that has thrusters was higher background noise level, when control own position and speed. However, background noise level was deduced, when stopped thrusters. The background noise of AUV of the type of control buoyance of own and of the deep sea lander was low. The background noise of AUVs on low frequency range was higher than high frequency range. A biological sound was observed using AUV. Even if AUV was to depth of the water 900m, the sound of the creature was measured. Therefore, the biological sound could be observed using AUVs or the deep sea lander, and the possibility that the biological sound could be observed automatically and extensively was indicated.