Fig. 1. Raman distributed optical fiber sensing scheme based on multi-order time domain differential reconstruction correlation method. (a) System simulation model; (b) multi-order time-domain differential reconstruction and correlated compression demodulation schemes

Fig. 2. Timing characteristics of three typical sensing signals. (a) Chaos signal timing; (b) ASE signal timing; (c) noise signal timing

Fig. 3. Results of Raman anti-Stokes scattering signal construction with different signals. (a) Chaos signal; (b) ASE signal; (c) noise signal; (d) comparison of dynamic ranges of Raman anti-Stokes scattering signal

Fig. 4. Position demodulation results. (a) Chaos optical signal correlation result; (b) ASE signal correlation result; (c) noise signal correlation result

Fig. 5. Sensing signal spectra and timing autocorrelations. (a1) Chaos signal autocorrelation curve; (b1) ASE signal autocorrelation curve; (c1) noise signal autocorrelation curve; (a2) chaotic signal spectrum; (b2) ASE signal spectrum; (c2) noise signal spectrum

Fig. 6. Effect of time-domain differential reconstruction order on correlated peak-to-peak for different sensing signal schemes. (a) Results of chaotic signal sensing schemes; (b) results of ASE signal sensing schemes; (c) results of noise signal sensing schemes; (d) influence of differential reconstruction order of chaotic signal scheme on correlated peak-to-peak; (e) influence of differential reconstruction order of ASE signal scheme on correlated peak-to-peak; (f) influence of differential reconstruction order of noise signal scheme on correlated peak-to-peak

Fig. 7. Temperature demodulation results. (a) Relationship of positively correlated peak and FUT temperature; (b) results of double FUT temperature demodulation experiment