A Precision Fiber Optic Microseismic Monitoring System for Underground Coal Mines

Microseismic monitoring has been predominantly taken by using moving-coil geophones. However, the drawbacks including small dynamic range, susceptibility to electromagnetic interferences, and non-intrinsically safe, seriously hinder the further progress and applications of monitoring system itself. This paper presents the development of novel precision fiber optic microseismic monitoring system. The overall composition, sensor design and interrogation scheme are introduced in detail. The results show that the system achieves a bandwidth of 1 Hz to 320 Hz, 86.5 dB dynamic range and a minimum detectable acceleration of 0.708 mm/s
²
at 30 Hz. The field test results show that this system has great potential for safety monitoring of underground coal mines.