Fig. 1. CPC-ROTDR system principle model

Fig. 2. Raman anti-Stokes scattering signals and dynamic range of chaotic pulse clusters with different number of pulses. (a) Raman anti-Stokes scattering signal and FUT magnification plot for pulse number 5 (Np is the number of pulses); (b) Dynamic range comparison

Fig. 3. Localization demodulation results of CPC-ROTDR system for FUT at different sensing distances

Fig. 4. Effect of the number of pulses in a chaotic pulse cluster on the amplitude of the positively correlated peaks

Fig. 5. Half-height full-width (FWHM) curves of the autocorrelation function of the CPC-ROTDR system with different numbers of pulses and the relationship between the number of pulses and FWHM. (a) Autocorrelation curve at Np=1; (b) Autocorrelation curve at Np=2; (c) Autocorrelation curve at Np=3; (d) Autocorrelation curve at Np=4; (e) Autocorrelation curve at Np=5; (f) Relationship between the number of pulses and the half-height and full width of the autocorrelation function

Fig. 6. FUT temperature versus positive correlation peak-to-peak values for different number of pulses. (a) Np=1; (b) Np=2; (c) Np=3; (d) Np=4; (e) Np=5; (f) Relationship between the number of pulses and the temperature -positively correlated peak-to-peak plot slopes