An evaluation of the performance of a hydrophone on sea floor

DONET (Dense Ocean-floor Network system for Earthquakes and Tsunamis) is a submarine cabled real-time observation network for earthquakes and tsunamis monitoring around the Nankai trough, southwestern Japan. The scheduled twenty observatories have operated since August 2011. Various sensors such as a broadband seismometer, a pressure gauge, a hydrophone, etc. are equipped with each observatory, because DONET has expected to obtain the data to understand the Nankai trough mega thrust earthquake seismogenic zones. Therefore, in order to supply data stably, it´s important to have a method of an investigation of the performance of each sensor in DONET. In this research, we will evaluate the performance of a hydrophone of DONET. The reference hydrophone was installed several meters from an observatory of DONET. Here, it assumes that both hydrophones will record the acoustic data according to same sound source. And, we will evaluate the performance of a hydrophone by the comparison between reference hydrophone and DONET´s one in actual field, and will report the result of the evaluations.