基于互相关卷积与高阶矩质心计算的布里渊散射谱特征提取

发布时间：2018-04-24 10:30

本文选题：散射 + 布里渊光时域分析　；参考：《中国激光》2017年11期

【摘要】：针对目前布里渊光时域分析(BOTDA)分布式光纤传感系统存在的实时性较差的问题,为了缩短测量时间,提出一种基于互相关卷积与高阶矩质心计算相结合的布里渊散射谱特征提取方法。首先将布里渊散射谱沿光纤的扫频数据与理想Lorentz曲线作互相关卷积,然后利用卷积结果峰值附近的理想Lorentz线型特征进行高阶矩质心提取,并将提取结果作为布里渊频移(BFS)的估计值;其次,搭建1.5km的瑞利BOTDA温度传感系统对所提算法进行可行性验证。结果表明:不同于常用的Lorentz拟合(LCF),所提算法避免了复杂的迭代求解所造成的测量时间延长,具有良好的实时性与测量精度,选取恰当的数据点数与阶数可将误差控制在小于1 MHz;当进行长距离高分辨率的动态测量而不得不加大扫频间隔以减少测量时间时,所提算法的测量误差远小于基于莱文伯-马奈特(LM)算法的LCF的测量误差。
[Abstract]:In order to shorten the measurement time, the distributed optical fiber sensing system of Brillouin optical time domain analysis (BOTDA) has poor real-time performance. A Brillouin scattering spectrum feature extraction method based on cross correlation convolution and high order moment centroid calculation is proposed. The Brillouin scattering spectrum is firstly correlated with the ideal Lorentz curve along the scanning frequency data of the optical fiber, and then the high order centroid of moment is extracted by using the ideal Lorentz linear feature near the peak value of the convolution result. The extracted results are used as the estimated values of Brillouin frequency shift (BFS). Secondly, the feasibility of the proposed algorithm is verified by the Rayleigh BOTDA temperature sensing system of 1.5km. The results show that the proposed algorithm avoids the delay of measurement time caused by complex iterative solution, and has good real-time performance and measurement accuracy, which is different from the conventional Lorentz fitting algorithm. The error can be controlled to less than 1 MHz by selecting the appropriate number and order of data. When dynamic measurement with long distance and high resolution is carried out, the sweep interval has to be increased to reduce the measurement time. The measurement error of the proposed algorithm is much smaller than that of LCF based on Levenbert-Manette algorithm.
【作者单位】：华北电力大学电气与电子工程学院;
【基金】：国家自然科学基金(61377088) 河北省自然科学基金(F2014502098)
【分类号】：TP212

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