Fig. 1. Schematic diagram of Φ-OTDR system

Fig. 2. Φ-OTDR curve with vibration event loaded

Fig. 3. Differential curve

Fig. 4. Data process flow chart

Fig. 5. 3-D time domain curve distribution

Fig. 6. Optical time domain reflecting curves

Fig. 7. Attenuation coefficient compensation before and after curve comparison

Fig. 8. Difference curve after attenuation coefficient compensation

Fig. 9. Difference variance curve interval contrast diagram

Fig. 10. Results for vibration event location