基于优化MRVA的Φ-OTDR相干衰落抑制方法

AΦ-OTDR interference fading suppression method based on optimized MRVA

本文针对相位敏感光时域反射(Φ-OTDR)系统的一种相干衰落抑制方法旋转矢量移动平均(MRVA)进行了优化,获得了性能更优的相干衰落抑制.该优化方法从两个方面展开,首先使用加权窗口代替MRVA方法中的矩形窗口,兼顾测量精度和空间分辨率;然后根据移动平均与低通滤波的数理等效性,将时域移动平均转换为运算速度更快的频域低通滤波,提高信号处理效率.实验结果表明,相较于MRVA方法,该方法的解调相位精度提高了约23%,计算时间从0.957 s缩短至0.026 s,运算速度提高约36倍.

In this paper,an optimized rotating vector moving average(MRVA)method is proposed to suppress interference fading in phase-sensitive optical time-domain reflectometry(Φ-OTDR)system.The proposed optimization method is developed from two aspects.Firstly,the weighted window is used to replace the rectangular window in the MRVA method,which mitigates the tradeoff between measurement accuracy and spatial resolution.Then,the time domain moving average is converted to frequency-domain computation according to the mathematical equivalence of moving average and low-pass filtering,thus achieving faster processing speed.Experimental results show that,compared with MRVA method,the demodulation phase accuracy of this method is improved by about 23%,and the calculation time is reduced from 0.957 s to 0.026 s,achieving about 36-times improvement.