Distributed acoustic sensing: System and experiments

This paper presents a fully distributed fiber acoustic sensing (DAS) system. Combined with the phase-sensitive optical time domain reflectrometry (Φ-OTDR) technology and phase generated carrier (PGC) demodulation technology, the system can detect and acquire seismic wave signal in real time. The system has a 3.05dB flatness of frequency response from 5Hz to 1kHz, which with sampling interval of each channel of one meter on total sensing distance up to 10 km. Experiments are carried out to demonstrate the performance of DAS system, which indicate that DAS has significant advantages in multi-channel information acquisition and weak signal detection. The DAS system is expected to become the next generation of seismic exploration equipment.