基于VMD-SVD的拉曼分布式光纤测温系统降噪方法

Noise reduction method of Raman distributed optical fiber temperature measurement system based on VMD-SVD

针对分布式光纤测温系统,其产生的包含温度信息的后向拉曼散射信号极其微弱,因此极易被白噪声掩盖的问题。本文设计了一种基于VMD-SVD联合降噪算法,并提出通过对构造的仿真信号做降噪对比实验,以更优的降噪性能指标选取该算法的重要参数。实验表明,将该联合算法及EMD、VMD、EMD-SVD算法分别用于多组测试信号降噪时,VMD-SVD降噪算法相较于EMD算法有均有15 dB以上提升,相较于VMD算法有均有9 dB以上的提升,最后相较于EMD-SVD算法也均有1 dB以上提升,最后将上述算法应用于分布式光纤测温系统测量的多组后向拉曼散射信号降噪时,VMD-SVD降噪算法也能最有效的消除该信号的白噪声,为后续高质量测温奠定基础。

For distributed optical fiber temperature measurement system,the back Raman scattering signal containing temperature information generated by it is extremely weak,so it is easy to be masked by white noise.In this paper,a joint noise reduction algorithm based on VMD-SVD is designed,and the important parameters of the algorithm are selected with better noise reduction performance indicators by comparing the noise reduction of the constructed simulation signal.Experiments show that when the joint algorithm and EMD,VMD,EMD-SVD algorithm are used to reduce the noise of multiple groups of test signals respectively,the VMD-SVD noise reduction algorithm has an improvement of more than 15 dB compared with the EMD algorithm,and more than 9 dB compared with the VMD algorithm.Finally,compared with the EMD-SVD algorithm,the VMD-SVD algorithm has an improvement of more than 1 dB.Finally,when the above algorithm is applied to reduce the noise of multiple groups of backward Raman scattering signals measured by the distributed optical fiber temperature measurement system,VMD-SVD noise reduction algorithm can also effectively eliminate the white noise of the signal,laying the foundation for subsequent high-quality temperature measurement.