一种新的小波滤波方法在化学谱图信号滤噪中的应用

A New Wavelet Denoising Method Used in Chemical Signal

仪器分析测定中 ,噪声的存在往往影响分析的准确度和仪器的检出限。小波变换多分辨分析的特性使得它成为一种很好的滤噪方法。基于小波分解后信号与噪声的小波系数随尺度变化规律不同的特性 ,提出了一种新的滤波滤方法———空域相关法 ,即通过不同尺度上相关系数模值与小波系数模值的比较 ,达到滤波滤的目的。本文提出的方法具有无需人为选定滤噪阈值和小波函数、方法简单、失真度小等优点 ,可以大大提高信号的信噪比。模拟数据和ICP

The noise often degrades the accuracy and precision of the results in instrument analysis. Wavelet transforms are multiresolution decompositions that can be used for signal denoising. In this paper, a new wavelet denoising method-spatial correlation filtering (SCF) is proposed to processing chemical signal. Based on the fact that the wavelet coefficients module of signal and noise after wavelet decomposition have different characteristics with the wavelet scale. Therefore, directly comparing the spatial correlation module with the wavelet module at different scales can reduce the noise contents from the chemical signal. SCF needs no denoising threshold selection and has the advantages of simplicity, swiftness and little signal distortion. The simulation and inductiveyl coupled plasma-atomic emission spectroscopy experiment results prove its effective.