Fig. 1. Schematic diagram of dual-pulse interference between adjacent gratings

Fig. 2. Experimental setup of distributed vibration sensing system based on UWFBG array

Fig. 3. Principle of adaptive filtering of LMS algorithm

Fig. 4. Demodulation result of the signal. (a) Original phase curve; (b) partial enlarged view

Fig. 5. Noise characteristics of SI and RI. (a) Noise floor of the RI; (b) frequency domain responses of SI and RI

Fig. 6. Noise reduction result of 0.01 kHz vibration signal. (a) Phase signal after denoising; (b) frequency domain response of vibration signal

Fig. 7. Noise reduction result of 0.5 kHz vibration signal (a) Phase signal after denoising; (b) frequency domain response of vibration signal

Fig. 8. Noise reduction result of 1 kHz vibration signal. (a) Phase signal after denoising; (b) frequency domain response of vibration signal

Fig. 9. Demodulated waveforms of different types of vibration on UWFBG array. (a) Three-dimensional display of time-domain demodulation signal; (b) three-dimensional top view

Fig. 10. Noise PSD at the end of UWFBG without interference