Fig. 1. Block diagram of the Φ-OTDR experimental system

Fig. 2. Experimental test platform of the Φ-OTDR system. (a) Experimental device; (b) device for simulating the condition of optical fiber link

Fig. 3. Test results of the system in simulated fault environment

Fig. 4. Information entropy at different locations of the fault signal

Fig. 5. Processing results of segmented information entropy. (a) Information entropy of each position in different segments; (b) SNR of the system in different segments

Fig. 6. Signal information entropy at each position in different segments

Fig. 7. Processing result of multiplying the information entropy of the integral section. (a) Information entropy of the signal at each position in different segments; (b) information entropy of the signal at each position when k=2

Fig. 8. System SNR under different processing algorithms

Fig. 9. Positioning accuracy of different period