Real-Time Distributed Vibration Monitoring System Using $\Phi$ -OTDR

The purpose of this paper is to theoretically analyze and experimentally demonstrate the investigation on a distributed optical fiber sensor based on phase-sensitive optical time domain reflectometry (Φ-OTDR) for real-time vibration monitoring with different signal processing methods. The Φ-OTDR system is investigated in two aspects: the hardware parameter and the interrogation scheme. The effect of pulsed light power that enters into the sensing fiber on Φ-OTDR is first discussed. Then, two systems based on the differential method and the Prewitt edge detection method applied for Φ-OTDR are presented for 1-D and 2-D vibration location, respectively. Finally, a highspeed acquisition system based on FPGA is applied to realize the 3-D real-time vibration monitoring. This new distributed vibration sensor can be used as an ideal source for the thirdparty intrusion identification, pipeline monitoring, and ultrasonic wave detection in explosive environment.