Fiber optic ocean bottom seismograph

In this paper we report the fiber optic ocean bottom seismograph (FOBS) system which is promising to be installed in the Ocean Bottom Observation Network (OBON). The FOBS system consists of an ocean bottom seismometer and a demodulator. The fiber laser sensors are used in the seismometer to detect the seismic signal. There are four sensors, three fiber laser accelerometers (FLA) and one fiber laser hydrophone (FLH) in the seismometer. The demodulator, with an underwater connector, is designed to be linked to the node of OBON. Tests of durability in marine environment, such as high-temperature test, vibration test, high pressure test, were carried out. In 2014 and 2015, field tests were performed in the Dayindian Lake in Yunnan Province. The results show that the FOBS has similar performance to GOBS, which implies a promising application in OBON.