基于梳状频谱探测光和图像特征提取技术的BOTDA系统研究

项目名称： 基于梳状频谱探测光和图像特征提取技术的BOTDA系统研究

项目编号： No.61465009

项目类型： 地区科学基金项目

立项/批准年度： 2015

项目学科： 无线电电子学、电信技术

项目作者： 万生鹏

作者单位： 南昌航空大学

项目金额： 47万元

中文摘要： 对基于梳状频谱连续探测光和编码泵浦光、采用外差检测和图像特征提取技术的BOTDA系统进行研究，以提高BOTDA系统的检测速率和空间分辨率，为BOTDA在结构健康监测领域的应用奠定技术基础。本项目主要研究内容包括：根据布里渊增益谱的特点，研究梳状频谱间隔和数目对布里渊增益谱重建精度和速率的影响；研究产生极窄梳状频谱连续探测光的实现方法、以及频谱幅度不均匀对系统性能的影响及补偿技术；研究0.1ns脉冲宽度时，不同类型及长度的编码序列的频谱特性，选取可实现厘米量级空间分辨率的编码类型及最小编码长度；同时研究0.1ns脉冲序列情况下预激发声波对后续脉冲散射的影响；根据三维（空间位置、频率及功率）布里渊增益谱的特点，研究基于小波变换的图像特征提取技术，找到布里渊频移、布里渊功率突变的空间位置，在这些位置进行增益谱重建，以克服全部位置谱重建所需要的大量时间。

中文关键词： 光纤传感；光散射；传感器；光电检测

英文摘要： In order to improve the detection rate and the spatial resolution of the BOTDA system, lays the technical foundation for application of BOTDA in the field of structural health monitoring, the heterodyne detection and image feature extraction technology are used to research on the BOTDA system based on comb spectrum of continuous probe light and coding the pump pulse. The main research contents of this project include: According to the characteristics of Brillouin gain spectrum, the influence of spectrum interval and the number of the spectrum on the reconstruction accuracy and rate of the Brillouin gain spectrum; the method constructing very narrow comb frequency spectrum of continuous probe, and the effects of the uneven of the spectrum amplitude on the system performance and compensation technology; the spectral characteristics of different code types and lengths, finding the code type and the minimum length to realizing centimeter spatial resolution; the pre-excited acoustic effects in the 0.1ns pulse system; According to the three dimensional (position, frequency and power) characteristics of Brillouin gain spectrum, the techniques of image feature extraction based on the wavelet transform of spatial position are adopted to find the positions where Brillouin frequency shift or the Brillouin power mutating, the Brillouin gain spectrum reconstructed in these mutating positions, therefore, the time reconstructing the gain spectrum along the whole fiber is overcome.

英文关键词： optical fiber sensing;optical scattering;sensor;photo-electric detection