Measurement Accuracy Enhancement via Radio Frequency Filtering in Distributed Brillouin Sensing
Measurement Accuracy Enhancement via Radio Frequency Filtering in Distributed Brillouin Sensing
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DOI：
10.3390/s19132878
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发表时间：
2019-07-01
期刊：
影响因子：
3.9
通讯作者：
Schneider, Thomas
中科院分区：
文献类型：
--
作者：
Feng, Cheng;Preussler, Stefan;Schneider, Thomas
在这篇文章中，我们展示了布里渊光时域分析器（BOTDA）的噪声降低和信噪比（SNR）的增强。结果表明，虽然主要的噪声贡献来自布里渊相互作用本身，一个简单的低通滤波的检测到的射频（RF）信号显着降低噪声水平的BOTDA痕迹。相应的SNR增强取决于所采用的低通滤波器的截止频率。由于信噪比的增强，布里渊频移（BFS）的标准偏差误差的缓解已被证明。然而，具有低截止频率的RF滤波器可能导致跟踪信号的失真，从而导致非均匀BFS上的检测误差。文中详细讨论了噪声抑制和信号失真之间的折衷关系以及最佳截止频率。
In this article, we demonstrate the noise reduction and signal to noise ratio (SNR) enhancement in Brillouin optical time-domain analyzers (BOTDA). The results show that, although the main noise contribution comes from the Brillouin interaction itself, a simple low pass filtering on the detected radio frequency (RF) signal reduces remarkably the noise level of the BOTDA traces. The corresponding SNR enhancement depends on the employed cut-off frequency of the low pass filter. Due to the enhancement of the SNR, a mitigation of the standard deviation error of the Brillouin frequency shift (BFS) has been demonstrated. However, RF filters with low cut-off frequency could lead to distortions on the trace signals and therefore detection errors on a non-uniform BFS. The trade-off between the noise reduction and the signal distortion as well as an optimal cut-off frequency are discussed in detail.