[1] [1] Li P H, Wang Y, Wang P F, et al. Pulse coding in distributed optical fiber vibration sensor: A Review[J]. IEEE Sensors Journal,2021,21（20）: 22371—22387.

[2] [2] Chen J F, Li H, Xiao X P, et al. Fully distributed fiber-optic streamer with small channel spacing for marine seismic acquisition[J]. Ocean Engineering,2024,294:116852.

[3] [3] Duan Y X, Liang L, Tong X L, et al. Application of pipeline leakage detection based on distributed optical fiber acoustic sensor system and convolutional neural network[J]. Journal of Physics D-Applied Physics,2024,57（10）:105102.

[4] [4] Fu S C, Zhang D, Peng Y, et al. A simulation of gas pipeline leakage monitoring based on distributed acoustic sensing[J].Measurement Science and Technology,2022,33（9）:095108.

[5] [5] Williams E F, Fernndez-Ruiz M R, Magalhaes R, et al. Distributed sensing of microseisms and teleseisms with submarine dark fibers[J]. Nature Communications,2019,10:5778.

[6] [6] Ding Z W, Zhang X P, Zou N M, et al. Phi-OTDR based online monitoring of overhead power transmission line[J]. Journal of Lightwave Technology,2021,39（15）:5163—5169.

[8] [8] Liu X, Jin B Q, Bai Q, et al. Distributed fiber-optic sensors for vibration detection[J]. Sensors,2016,16（8）:1164.

[9] [9] He H J, Shao L Y, Li H C, et al. SNR enhancement in phase-sensitive OTDR with adaptive 2-D bilateral filtering algorithm[J]. IEEE Photonics Journal,2017,9（3）:6802610.

[10] [10] Lu Y L, Zhu T, Chen L, et al. Distributed vibration sensor based on coherent detection of phase-OTDR[J]. Journal of Lightwave Technology,2010,28（22）:3243—3249.

[12] [12] Dong Y K, Chen X, Liu E H, et al. Quantitative measurement of dynamic nanostrain based on a phase-sensitive optical time domain reflectometer[J]. Applied Optics,2016,55（28）:7810—7815.

[13] [13] He H J, Yan L S, Qian H, et al. Enhanced range of the dynamic strain measurement in phase-sensitive OTDR with tunable sensitivity[J]. Optics Express,2020,28（1）:226—237.

[14] [14] Li H, Sun Q Z, Liu T, et al. Ultra-high sensitive quasi-distributed acoustic sensor based on coherent OTDR and cylindrical transducer[J]. Journal of Lightwave Technology,2020,38（4）:929—938.

[15] [15] Zhang L, Chen L, Bao X Y. Unveiling delay-time-resolved phase noise statistics of narrow-linewidth laser via coherent optical time domain reflectometry[J]. Optics Express,2020,28（5）:6719—6733.

[16] [16] Alekseev A E, Vdovenko V S, Gorshkov B G, et al. A phase-sensitive optical time-domain reflectometer with dual-pulse phase modulated probe signal[J]. Laser Physics,2014,24（11）:115106.

[17] [17] Liu S Q, Shao L Y, Yu F H, et al. Quantitative demodulation of distributed low-frequency vibration based on phase-shifted dual-pulse phase-sensitive OTDR with direct detection[J]. Optics Express,2022,30（6）:10096—10109.

[18] [18] He X G, Xie S R, Liu F, et al. Multi-event waveform-retrieved distributed optical fiber acoustic sensor using dual-pulse heterodyne phase-sensitive OTDR[J]. Optics Letters,2017,42（3）:442—445.

[20] [20] Ju Z W, Yu Z J, Hou Q K, et al. Low-noise and high-sensitivity -OTDR based on an optimized dual-pulse heterodyne detection scheme[J]. Applied Optics,2020,59（7）:1864—1870.