基于独立成分分析的拉曼光纤温度传感系统去噪算法研究

Denoising algorithm of Raman distributed temperature sensor system by independent component analysis

针对拉曼光纤温度传感系统中拉曼散射信号被噪声淹没的问题,利用快速独立成分分析(ICA)法对单模光纤(SMF)中红外激光产生的拉曼散射信号进行去噪处理,并在拉曼散射信号前端添加一定幅值和相位的正弦信号,根据正弦信号处理前后幅值和相位的变化校正拉曼散射信号的幅值和相位,从而完全恢复拉曼散射信号。在20km SMF拉曼温度传感仿真系统中,拉曼散射信号的信噪比(SNR)由14.90dB提高到20.99dB,提高了6.09dB。结果表明,本文方法能有效提高拉曼测温系统的SNR,是一种针对拉曼光纤温度传感系统有效的去噪算法。

In the fiber Raman distributed temperature sensor system, the spomaneous Raman scattering signal is weak and easily lost within the background noise. To solve this problem,an algorithm based on independem componem analysis （ICA） is presemed. First,add a sine signal in from of the spomaneous Raman scattering signal. Then the changes of the prefix sine signal＇s amplitude and phase after fast ICA are used to correct the spontaneous Raman scattering signal＇s amplitude and phase. Thus the Raman scattering signal is fully recovered from the background noise. In the simulation system of a 20--km-- long fiber Raman distributed temperature sensor system, the signal-to-noise ratio （SNR） of the Raman scattering signal can be increased by 6.09 dB from 14. 90 dB to 20.99 dB. The results show that this method can effectively improve the SNR of Raman temperature measurement system.