谱减降噪法在相位敏感OTDR扰动传感系统中的应用  

Application of spectral subtraction method in phase sensitive OTDR disturbance sensing system

作　　者：张春熹[1] 邓卓 王夏霄[1] 于佳[1] ZHANG Chunxi;DENG Zhuo;WANG Xiaxiao;YU Jia(Instrumentation Science and Opto-electronics Engineering, Beihang University, Beijing 100191 ,China)

机构地区：[1]北京航空航天大学仪器科学与光电工程学院,北京100191

出　　处：《激光杂志》2019年第3期16-19,共4页Laser Journal

基　　金：国家重大仪器设备开发专项(No.2013YQ040877)

摘　　要：针对当前基于相位敏感光时域反射计(Φ-OTDR)的分布式光纤扰动传感系统降噪算法复杂且效果不明显的问题,提出了谱减降噪法。首先对采样信号进行加窗分帧和傅里叶变换;其次取前十五帧无扰动信号功率谱的平均值作为噪声的功率谱估计,用含有扰动信号的功率谱减去噪声的估计谱得到降噪信号的功率谱;最后降噪信号通过逆傅里叶变换得到其时域信号。谱减法运算快且失真小,研究结果表明了在传感距离为53. 6 km的情况下,降噪信号的信噪比提高了2. 7 dB。Aiming at the problem that the current noise reduction algorithm of distributed fiber-optic disturbance sensing system based on phase sensitive optical time domain reflectometer(Φ-OTDR) is complex and the effect is not obvious,the spectral subtraction method is proposed. Firstly,the sampling signal was windowed and Fourier transformed. Secondly,taken the average of the power spectrum of the undisturbed signal in the first fifteen frames as the power spectrum estimation of the noise,and obtained the power spectrum of the noise reduction signal by subtracting the estimated spectrum of the noise from the power spectrum containing the disturbance signal. The final noise reduction signal obtained its time domain signal by inverse Fourier transform. The spectral subtraction method has fast operation and less distortion. The results show that the signal-to-noise ratio of the denoised signal increases by 2. 7 dB at the sensing distance of 53. 6 km.

关 键 词：谱减法 相位敏感光时域反射计 分布式光纤扰动传感 功率谱 

分 类 号：TN212[电子电信—物理电子学]