[1] [1] HE Q, ZENG Z, ZHAO Q, et al. SNR improvement of vibration sensing in a conventional phase-OTDR by k-parameter statistical analysis[J]. Optics Communications, 2022, 509: 127789-1-127789-6.

[2] [2] QIN Z, CHEN H, CHANG J. Signal-to-noise ratio enhancement based on empirical mode decomposition in phase-sensitive optical time domain reflectometry systems[J]. Sensors, 2017, 17(8): 1870-1-1870-10.

[3] [3] PARK J, LEE W, TAYLOR H F. Fiber optic intrusion sensor with the configuration of an optical time-domain reflectometer using coherent interference of Rayleigh backscattering[C]//SPIE. Optical and Fiber Optic Sensor Systems. Bellingham: SPIE, 1998, 3555: 49-56.

[5] [5] ZHANG J, YAN Y, LIU S, et al. Signal-to-noise ratio enhancement of -OTDR based on Block-matching and 3D filtering[C]//Opto-Electronics and Communications Conference(OECC) 2023, July 2-7, Shanghai, China. New York: IEEE, 2023: 1-3.

[7] [7] CHEN W, MA X, MA Q, et al. Denoising method of the -otdr system based on EMD-PCC[J]. IEEE Sensors Journal, 2021, 21(10): 12113-12118.

[11] [11] HE M, FENG L, ZHAO D. A method to enhance SNR based on CEEMDAN and the interval thresholding in -OTDR systems[J]. Applied Physics B, 2020, 126: 1-10.