摘要
在布里渊光时域反射计(Brillouin Optical Time Domain Reflectometer,BOTDR)光纤传感系统中,自发布里渊后向散射信号非常微弱,尤其是光纤远端的布里渊散射信号,信噪比非常差,分析难度非常高。提出了一种基于互相关理论的布里渊谱信号质量提升方法,通过与理想布里渊散射谱进行互相关运算,降低了对光纤远端极微弱布里渊散射信号应变分析的难度。经试验验证,该方法可以有效提升信噪比较差时应变分布数据的信号质量以及BOTDR的应变传感精度。
In the Brillouin optical time domain reflectometer(BOTDR) fiber-optic sensing system, the scattering signal from Brillouin back scattering is very weak, especially the Brillouin scattering signal at the far end of the fiber, the signal-to-noise ratio is very poor and is very difficult to analyze. A method of improving Brillouin signal quality based on cross-correlation theory was presented. Through cross-correlation with ideal Brillouin scattering spectrum, the difficulty of strain analysis for very weak Brillouin scattering signal at the far end of optical fiber was reduced. It was verified by experiments that this method can effectively improve the signal quality of strain distribution data and the strain sensing accuracy of BOTDR when the signal-to-noise ratio is poor.
引文
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