Raman光谱分析中,由于仪器光谱分辨率的限制和复杂的目标成分,经常存在着谱峰重叠现象.容易导致谱峰参数提取乃至样品成分分析错误,更为现场光谱的自动分析处理增加了难度.重叠光谱峰的识别已成为现场光谱学处理的难点,针对这个问题,建立了一套自动识别重叠谱峰的方法:以多个高斯峰的组合作为重叠光谱解析模型,首先以对称零面积变换寻峰方法确定高斯峰的个数和初步的峰位、峰高、宽度参数,并以Levenberg-Marquardt方法对获得的初始高斯峰参数进行拟合优化,最终获得各个独立谱峰的拟合参数.对该方法进行了测试,其中以仿真数据进行的算法实验证明,对称零面积变换寻峰获得的初始参数与真实值较为接近,在此基础上进行的参数优化收敛速度快,对峰参数的提取可获得较高的准确度;以具有不同信噪比的实测Raman光谱数据进行的算法实验证明,该方法可以适用于信噪比在较大范围变化的信号,但对信噪比过低的实测信号则容易产生虚假峰和漏峰.研究证明,以对称零面积变换寻峰结合L-M拟合自动识别重叠光谱峰的方法具有一定的实用价值.

The peaks’ overlapping often exists in Raman spectroscopy analysis,because of the low spectral resolution of the spectrograph and the complex sample components.The overlapped peaks lead to the errors in peak parameters extraction easily,and at last lead to the analysis error of sample components,which increases the difficulty in automatic analysis of field spectra.The identification of overlapped peaks is the key difficulty of in-situ spectra analysis.To solve this problem,an automatic method of identifying the overlapped peaks was established basing on an analysis model with multiple Gaussian shape peaks.The peak number and the initial parameters(the peak position,peak height,and width) were obtained by symmetric zero-area transformation firstly,and then the parameters were optimized by Levenberg-Marquardt fitting method eventually.Some algorithm experiments were executed to test the method respectively by simulated data and Raman spectra data,and the former showed that the symmetric zero-area transformation method can extract the initial peak parameters with high accuracy,and then converges fast,and is adaptive to signal with wide dynamic range of SNR ,but has false and omissive peaks to low SNR signal.The research results show that the automatic method of identifying the overlapped peaks with symmetric zero-area transformation combined with L-M fitting has a certain practical value.