双通道傅立叶变换红外光谱快速复原方法研究与实现

发布时间：2018-04-02 06:01

本文选题：双通道FTIR光谱仪　切入点：采样误差分析　出处：《中国科学技术大学》2017年硕士论文

【摘要】：本文主要讨论了双通道傅里叶变换红外光谱仪光谱复原方法及其实现,深入研究了涉及到的关键问题,对采样误差对光谱图质量的影响、He-Ne激光干涉信号过零点重建方法,红外干涉信号重建方法等问题进行了深入研究,实现了光谱仪光谱复原系统,并在实验中开展了实际应用。首先,本文为了研究采样误差对光谱图的影响,建立了误差模型,从数学上建立了采样误差与光谱鬼线之间的理论联系。同时对误差模型进行仿真,并且仿真了线性插值方法和三次样条插值方法对He-Ne激光干涉信号过零点的复原效果。通过上述仿真验证了误差模型的正确性,并得出了用一个He-Ne周期采样点进行三次样条插值能够最好的减少采样误差的结论,误差范围降低了 93%。其次,通过实验对比了不同方法重建红外干涉信号对光谱质量的影响。实验结果表明,只有两个插值点的线性插值法重建的红外干涉信号所得的光谱图信噪比最高,信噪比平均提升5.7%。在上述研究的基础上,实现了双通道傅里叶变换红外光谱仪光谱复原系统。此系统使用一束He-Ne激光干涉信号作为参照,同时复原两束偏振红外干涉信号,然后对其进行切趾和快速傅里叶变换得到两幅具有不同偏振方向的光谱图。
[Abstract]:In this paper, the spectral restoration method and its realization of dual-channel Fourier transform infrared spectrometer are mainly discussed. The key problems involved are deeply studied, and the effect of sampling error on the quality of spectral image is discussed. The method of zero-crossing reconstruction of He-Ne laser interference signal is discussed.The methods of infrared interference signal reconstruction are studied in detail. The spectral restoration system of spectrometer is realized, and the practical application is carried out in the experiment.Firstly, in order to study the influence of sampling error on spectral map, the error model is established, and the theoretical relation between sampling error and spectral ghost line is established mathematically.At the same time, the error model is simulated, and the effect of linear interpolation and cubic spline interpolation on the zero-crossing point of He-Ne laser interference signal is simulated.The correctness of the error model is verified by the simulation above, and the conclusion that cubic spline interpolation with a He-Ne periodic sampling point can best reduce the sampling error is concluded, and the error range is reduced by 933%.Secondly, the influence of different methods on spectral quality is compared.The experimental results show that the spectral signal to noise ratio of the infrared interference signal reconstructed by the linear interpolation method with only two interpolation points is the highest, and the average SNR is increased by 5.7.Based on the above research, a dual-channel Fourier transform infrared spectrometer spectral restoration system is implemented.In this system, a He-Ne laser interference signal is used as a reference, two polarized infrared interference signals are restored at the same time, and then two spectral images with different polarization directions are obtained by apodization and fast Fourier transform.
【学位授予单位】：中国科学技术大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP391.41;O434.33

【参考文献】