拉曼光谱基线校正与噪声抑制技术研究

发布时间：2018-09-05 14:46

【摘要】：拉曼光谱物质检测技术作为一种新兴发展起来的的分析手段可提供快速、简便、可重复的检测。但是在实际检测中,激光对被测物质进行激发时会引入环境和设备的噪声干扰,特别是荧光等干扰会造成基线漂移,严重降低拉曼光谱的质量,影响物质检测的准确性,因此开展拉曼光谱基线校正和噪声抑制技术研究具有重要意义。论文采用理论分析、仿真分析、实验验证的方法,针对拉曼光谱中的噪声和基线漂移影响拉曼光谱检测有效性的问题,开展了噪声抑制技术和基线校正技术研究。论文阐述了拉曼光谱的基本理论,分析了拉曼光谱中噪声的来源和分类,研究了拉曼光谱中基线漂移现象产生的原因。论文开展了拉曼光谱噪声抑制技术研究。在讨论了移动窗口平均法、移动窗口均值法和Savitzky-Golay最小二乘法各自局限性的基础上完成了基于多尺度自适应动态窗口平均法的噪声抑制方案的设计,并仿真验证了方案的去噪效果。方案解决了拉曼光谱噪声抑制技术中噪声抑制程度与光谱失真程度无法兼顾的问题,实现了噪声抑制的自适应。针对拉曼光谱中的基线漂移现象,论文开展了基线校正技术研究。论文讨论了极小值分段线性拟合法和移动窗口局部极值中值法的局限性,完成了基于局部动态移动平均自适应方法的基线校正方案的设计,并通过仿真对比验证了方案的基线校正效果。方案通过计算每次迭代中估计基线的残差并与其标准差进行比较,自动确定拟合区间宽度,解决了基线校正技术中基线估计不准确的问题,实现了基线校正的自适应。论文开展了实验验证工作,通过搭建拉曼光谱物质检测平台开展的测试验证结果表明,论文所设计的基线校正方案和噪声抑制方案具有可行性和有效性。
[Abstract]:As a newly developed analytical method, Raman spectroscopy can provide rapid, simple and repeatable detection. However, in the actual detection, when the laser excites the measured material, it will introduce the noise interference of the environment and equipment, especially the interference of fluorescence will cause baseline drift, seriously reduce the quality of Raman spectrum, and affect the accuracy of material detection. Therefore, it is of great significance to study the baseline correction and noise suppression of Raman spectroscopy. In order to solve the problem that the noise and baseline drift in Raman spectrum affect the effectiveness of Raman spectrum detection, the noise suppression technique and baseline correction technique are studied by theoretical analysis, simulation analysis and experimental verification. In this paper, the basic theory of Raman spectroscopy is introduced, the source and classification of noise in Raman spectrum are analyzed, and the cause of baseline drift in Raman spectrum is studied. In this paper, the Raman spectrum noise suppression technique is studied. On the basis of discussing the limitation of moving window averaging method, moving window mean method and Savitzky-Golay least square method, the noise suppression scheme based on multi-scale adaptive dynamic window averaging method is designed. The effect of de-noising is verified by simulation. The scheme solves the problem that the degree of noise suppression and the degree of spectral distortion can not be taken into account in the Raman spectrum noise suppression technology, and realizes the adaptive noise suppression. In view of the baseline drift in Raman spectroscopy, the baseline correction technique is studied in this paper. In this paper, the limitations of the minimum piecewise linear fitting method and the moving window local extremum median method are discussed, and the baseline correction scheme based on the local dynamic moving average adaptive method is designed. The effect of baseline correction is verified by simulation. By calculating the residual error of baseline in each iteration and comparing it with its standard deviation, the scheme automatically determines the width of fitting interval, solves the problem of inaccuracy of baseline estimation in baseline correction technology, and realizes the self-adaptation of baseline correction. The experimental results show that the baseline correction scheme and noise suppression scheme are feasible and effective.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O657.37

【相似文献】