[1] Thévenaz L. Brillouin distributed time-domain sensing in optical fibers: state of the art and perspectives[J]. Frontiers of Optoelectronics in China, 3, 13-21(2010).
[2] Gyger F, Rochat E, Chin S et al. Extending the sensing range of Brillouin optical time-domain analysis up to 325 km combining four optical repeaters[J]. Proceedings of SPIE, 9157, 91576Q(2014).
[3] Urricelqui J, Sagues M, Loayssa A. Brillouin optical time-domain analysis sensor assisted by Brillouin distributed amplification of pump pulses[J]. Optics Express, 23, 30448-30458(2015).
[4] Galindez C A, Quintela A, Quintela M A et al. 30 cm of spatial resolution using pre-excitation pulse BOTDA technique[J]. Proceedings of SPIE, 7753, 77532H(2011).
[5] Dong Y K, Chen L, Bao X Y. Time-division multiplexing-based BOTDA over 100 km sensing length[J]. Optics Letters, 36, 277-279(2011).
[6] Zhang Z L, Gao L, Sun Y Y et al. Strain transfer law of distributed optical fiber sensor[J]. Chinese Journal of Lasers, 46, 0410001(2019).
[7] Liu J Y, Wang T, Zhang Q et al. Research progress of temperature and strain dual-parameter sensing technology in BOTDA system[J]. Laser & Optoelectronics Progress, 58, 1306001(2021).
[8] Luo Y, Yan L S, Shao L Y et al. Golay-differential pulse hybrid coding technology based on Brillouin optical time domain analysis sensors[J]. Acta Optica Sinica, 36, 0806002(2016).
[9] Wang J J, Li Y Q. Review of methods for improving performance of Brillouin optical time-domain analysis system[J]. Laser & Optoelectronics Progress, 55, 110003(2018).
[10] Soto M A. Bolognini G, di Pasquale F, et al. Simplex-coded BOTDA fiber sensor with 1 m spatial resolution over a 50 km range[J]. Optics Letters, 35, 259-261(2010).
[11] Rao Y J, Jia X H, Wang Z N et al. 154.4 km BOTDA based on hybrid distributed Raman amplifications[J]. Proceedings of SPIE, 9157, 91575P(2014).
[12] Soto M A, Faralli S, Taki M et al. BOTDA sensor with 2-m spatial resolution over 120 km distance using bi-directional distributed Raman amplification[J]. Proceedings of SPIE, 7753, 775325(2011).
[13] Li W H, Bao X Y, Li Y et al. Differential pulse-width pair BOTDA for high spatial resolution sensing[J]. Optics Express, 16, 21616-21625(2008).
[14] Soto M A. Bolognini G, di Pasquale F. Long-range simplex-coded BOTDA sensor over 120 km distance employing optical preamplification[J]. Optics Letters, 36, 232-234(2011).
[15] Soto M A, Bolognini G, Pasquale F D. Optimization of long-range BOTDA sensors with high resolution using first-order bi-directional Raman amplification[J]. Optics Express, 19, 4444-4457(2011).
[17] Martin-Lopez S, Alcon-Camas M, Rodriguez F et al. Brillouin optical time-domain analysis assisted by second-order Raman amplification[J]. Optics Express, 18, 18769-18778(2010).
[18] Guo N, Wang L, Wu H et al. Enhanced coherent BOTDA system without trace averaging[J]. Journal of Lightwave Technology, 36, 871-878(2018).
[20] Xu H Z, Zhang D. Wavelet-based data processing for distributed fiber optic sensors[C]∥2006 International Conference on Machine Learning and Cybernetics, August 13-16, 2006, Dalian, China., 4040-4045(2006).
[22] He J P, Zhou Z, Chen G D et al. Measurement accuracy improvement of Brillouin signal using wavelet denoising method[J]. Proceedings of SPIE, 7293, 72930B(2009).
[23] Xu H Z, Shi B, Zhang D et al. Signal processing of the fiber optic BOTDR sensor based on wavelet analysis[J]. Journal of Optoelectronics·Laser, 14, 737-740(2003).
[25] Li X, Wang L X, Duan Z Q. Application of improved adaptive wavelet noise reduction in laser gyroscope signal processing[J]. Laser & Optoelectronics Progress, 57, 210401(2020).
[26] Wang C, Xi L X, Zhang Y A et al. Denosing scheme of BOTDR system based on the combination of lifting wavelet threshold and cumulative average[J]. Chinese Journal of Lasers, 48, 1706001(2021).
[27] Zhao J R, Wang T, Zhang Q et al. Signal-to-noise ratio improvement of Brillouin optical time domain analysis system based on empirical mode decomposition and finite impulse response[J]. Applied Optics, 59, 4220-4227(2020).
[28] Huang N E, Shen Z, Long S R et al. The empirical mode decomposition and the Hilbert spectrum for nonlinear and non-stationary time series analysis[J]. Proceedings of the Royal Society of London Series A: Mathematical, Physical and Engineering Sciences, 454, 903-995(1998).
[29] Li L, Ji H B. Signal feature extraction based on an improved EMD method[J]. Measurement, 42, 796-803(2009).
[30] Li Y Q, Wang Q, Deng Q K. Research on EMD and its application in biomedical signal processing[J]. Journal of Biomedical Engineering, 22, 1058-1062(2005).
[31] Wu Q, Liu Y. De-noising method for gyroscope signal based on improved ensemble empirical mode decomposition[J]. Laser & Optoelectronics Progress, 57, 150601(2020).
[33] Huang C J, Cao W S, Chen T J et al. Application of local mean decomposition in power quality disturbance detection[J]. Electric Power Automation Equipment, 33, 68-73, 81(2013).
[34] Zhang C, Yang L D, Li J J. The performance contrast between local mean decomposition and empirical mode decomposition[J]. Machine Design & Research, 28, 38-40, 54(2012).