Fig. 1. Signal collection in Φ-OTDR system

Fig. 2. Model architecture of generative adversarial network (GAN)

Fig. 3. Model architecture of conditional generative adversarial network (CGAN)

Fig. 4. Realistic view of experimental plant site

Fig. 5. Network architecture of generator

Fig. 6. Network architecture of discriminator

Fig. 7. Flow chart of CGAN training

Fig. 8. Loss diagrams of generators and discriminators

Fig. 9. Display of generating a signal (200 rounds at a time)

Fig. 10. Comparison of generated and real signals. (a) Vehicles passing by; (b) ambient noise; (c) pedestrians passing by; (d) artificial destruction

Fig. 11. Comparison of histograms of raw and generated data. (a) Raw data; (b) generated data

Fig. 12. Comparison of detection results between raw and generated data

Fig. 13. Comparison of confusion matrix plots between raw and generated data

Fig. 14. Test results of real data