[1] [1] K N Choi, J C Juarez, H F Taylor. Distributed fiber-optic pressure/seismic sensor for low-cost monitoring of long perimeters[C]. SPIE, 2003, 5090: 134-141.

[2] [2] Z Qin, T Zhu, L Chen, et al.. High sensitivity distributed vibration sensor based on polarization- maintaining configurations of phase-OTDR[J]. IEEE Photon Technol Lett, 2011, 23(15): 1091-1093.

[3] [3] J C Juarez, E W Maier, K N Choi, et al.. Distributed fiber-optic intrusion sensor system[J]. J Lightwave Technol, 2005, 23(6): 2081-2087.

[4] [4] Michael G Taylor. Phase estimation methods for optical coherent detection using digital signal processing[J]. J Lightwave Technol, 2009, 27(7): 901-914.

[5] [5] Z Pan, K Liang, Q Ye, et al.. Phase-sensitive OTDR system based on digital coherent detection[C]. SPIE, 2011, 8311: 83110S.

[6] [6] Z Pan, K Liang, J Zhou, et al.. Interference-fading-free phase-demodulated OTDR system[C]. SPIE, 2012, 8421: 842129.

[7] [7] Li Qin, Zhang Chunxi, Li Lijing, et al.. Influences of the frequency drift of the laser on location precision of the phase-sensitive optical time-domain refleactometry[J]. Chinese Lasers, 2014, 41(3): 0305003.

[8] [8] An Yang, Feng Hao, Zhang Jingchun, et al.. Phase sensitive optical time domain reflectometer based on two-beam interference[J]. Acta Optica Sinica, 2013, 33(7): 0706005.

[9] [9] Liu Jianxia. Research progress of distributed optical fiber sensing and monitoring technology based on f- OTDR[J]. Laser & Optoelectronics Progress, 2013, 50(8): 080021.

[10] [10] B Atal, L Rabiner. A pattern recognition approach to voiced-unvoiced-silence classification with applications to speech recognition [J]. IEEE Trans on Acoustics, Speech and Signal Processing, 1976, 24(3): 201-212.

[11] [11] D Berndt, J Clifford. Using Dynamic Time Warping to Find Patterns in Time Series[R]. AAAI-94 Workshop on Knowledge Discovery in Databases, 1994: 359-370.

[12] [12] F Gouyon, F Pachet, O Delerue. On the use of zero-crossing rate for an application of classification of percussive sounds[C]. Proc COST G-6, Conference on Digital Audio Effects, 2000: 1-6.

[13] [13] H Zhu, C Pan, X Sun. Vibration pattern recognition and classification in OTDR based distributed optical-fiber vibration sensing system[C]. SPIE, 2014, 9062: 906205.

[14] [14] J Zhou, Z Pan, Q Ye, et al.. Characteristics and explanations of interference fading of a phase-OTDR with a multi-frequency source [J]. J Lightwave Technol , 2013, 31(17): 2947-2954.

[15] [15] Zhou Jun, Pan Zhengqing, Ye Qing, et al.. Phase demodulation technology using a multi- frequency source discrimination of interference-fading induced false alarm in a f-OTDR system[J]. Chinese J Lasers, 2013, 40(9): 0905003.