Fourier变换光谱学退卷积技术的理论研究

介绍了Fourier变换光谱退卷积技术的原理,通过数学推导从理论上对退卷积光谱的特性进行了分析,分别讨论了退卷积技术的两个重要参量,即退卷积系数和切趾长度,对复原光谱的线宽和信噪比的影响,从而得到三个结论:1) 退卷积技术的分辨率增强能力在实际中由于受到噪音的限制而不能无限提高.2) 对于光谱中宽度不同的谱线,退卷积将导致它们之间的峰高比失真.3) 在选定退卷积系数和切趾长度以满足谱线形状和宽度的要求后,只有通过选择合适的切趾函数来满足信噪比的要求.研究还发现,退卷积过程相当于一个带通滤波器,其中高通滤波器是退卷积函数,低通滤波器是切趾函数,它们共同决定着退卷积技术的滤波特性.

THEORETICAL STUDY ON FOURIER SELF-DECONVOLUTION (FSD)OF FOURIER TRANSFORM SPECTRUM

The principle of Fourier Self Deconvolution(FSD) is introduced as a resolution enhancement technique for Fourier transform spectrum.Through mathematical study on influence of deconvolution coefficient and apodization length,the most important factors of resolution enhancement performance of FSD,respectively on line shape and SNR in the resulting spectrum,three conclusions are obtained:1) The resolution of Fourier transform spectrum can not be enhanced by FSD without limit for the existence of noise in practice;2) FSD will bring line height ratio distortion among those lines with different line width;3) When coefficient of deconvolution and length of apodization are determined to satisfy the request on spectral line shape and width,the only approach to satisfy the SNR request is the proper selection of apodization function.It is found FSD performs like a band pass filter with deconvolution function as the high pass filter and apodization function as the low pass filter.They together determine the filtering characteristics of FSD.