基于TTDF和CNS算法的多路BOTDR散射谱信息高精度分析研究

传统的BOTDR光纤传感系统采用单路传感光纤实现对信息特征的测量，交叉敏感等不可控因素会使散射谱拟合精度较低，信息分析偏差较大。设计了一种同时对多路传感信息进行检测的BOTDR系统。针对基于布里渊光时域反射(BOTDR) 的多路传感散射谱高精度特征提取的要求，提出了一种三次数据融合(TTDF)与布谷鸟牛顿搜索(CNS)相结合的散射谱信息分析方法。该方法利用TTDF对信息数据的融合能力，根据狄克逊准则和格拉布斯准则，剔除了异常值的影响，减小了传感信号的误差;采用布谷鸟牛顿搜索算法进行频谱拟合，不仅通过布谷鸟的智能搜索能力得到全局最优解，而且以该最优解作为牛顿算法的初值进行局部寻优，保证了频谱拟合的精度，提高了布里渊散射谱信息分析的准确度。在温度信息散射谱线性权重比为1∶9的情况下，分析了不同线宽散射谱信息的提取。采用该方法进行多路数据融合的方差约为0.003 0，散射谱的中心频率约为11.213 GHz，温度误差小于0.15 K。理论分析和仿真结果表明，将此方法用于基于布里渊光时域反射的多路分布式光纤传感系统，可有效提高多路传感信号的准确度和布里渊散射谱信息分析的精确度。

The High Precision Analysis Research of Multichannel BOTDR Scattering Spectral Information Based on the TTDF and CNS Algorithm

Traditional BOTDR optical fiber sensing system uses single channel sensing fiber to measure the information features. Uncontrolled factors such as cross-sensitivity can lead to a lower scattering spectrum fitting precision and make the information analysis deflection get worse. Therefore, a BOTDR system for detecting the multichannel sensor information at the same time is proposed. Also it provides a scattering spectrum analysis method for multichannel Brillouin optical time-domain reflection (BOTDR) sensing system in order to extract high precision spectrum feature. This method combines the three times data fusion (TTDF) and the cuckoo Newton search (CNS) algorithm. First, according to the rule of Dixon and Grubbs criteria, the method uses the ability of TTDF algorithm in data fusion to eliminate the influence of abnormal value and reduce the error signal. Second, it uses the Cuckoo Newton search algorithm to improve the spectrum fitting and enhance the accuracy of Brillouin scattering spectrum information analysis. We can obtain the global optimal solution by smart cuckoo search. By using the optimal solution as the initial value of Newton algorithm for local optimization, it can ensure the spectrum fitting precision. The information extraction at different linewidths is analyzed in temperature information scattering spectrum under the condition of linear weight ratio of 1∶9. The variances of the multichannel data fusion is about 0.003 0, the center frequency of scattering spectrum is 11.213 GHz and the temperature error is less than 0.15 K. Theoretical analysis and simulation results show that the algorithm can be used in multichannel distributed optical fiber sensing system based on Brillouin optical time domain reflection. It can improve the accuracy of multichannel sensing signals and the precision of Brillouin scattering spectrum analysis effectively.