摘要
In this paper,the influence of laser wavelength instability,polarization fading and phase fluctuation on local heterodyne detection wavelength scanning Brillouin optical time domain reflectometer(WS-BOTDR)is theoretically analyzed,and a local heterodyne detection WS-BOTDR system is built for experimental verification.The experimental results show that with the increase of sensing distance,the adverse effect of laser wavelength instability,polarization fading and phase fluctuation on local heterodyne detection WS-BOTDR is gradually aggravated,which will lead to the broadening and distortion of the wavelength power spectrum(WPS),resulting in large errors in demodulated Brillouin central wavelength(BCW)and temperature.The average temperature measurement errors at the positions of 1 km,5 km,9 km non-heating section and 9.45 km heating section are 1.76℃,3.42℃,3.89℃and 4.3℃,respectively.
基金
supported by the National Natural Science Foundation of China(Nos.52177141,62171185 and 61775057)
the Natural Science Foundation of Hebei Province of China(Nos.F2019502112 and E2020502010)
the Fundamental Research Funds for the Central Universities(Nos.2019MS086 and 2017MS112)
the S&T Program of Hebei,China(No.SZX2020034)。
