基于改进VMD-WTFD算法的二次谐波光谱信号反演分析OA

When using the variational mode decomposition and wavelet threshold adjustment function(VMD-WTFD)algorithm to deal with noise,the signal waveform recovery often deviates from the standard harmonic signal,resulting in deviations of the inversion results.An improved VMD-WTFD algorithm is proposed,which uses a new threshold function to improve the VMD-WTFD algorithm,and then uses this improved algorithm to perform inversion analysis on the second harmonic spectral sig-nal.The simulation and experimental results show that compared with several other denoising algorithms,the improved VMD-WTFD algorithm can invert the peak,peak position,and peak valley values of the original signal under different modulat ion degrees more closely to the original standard second harmonic spectral signal,with a signal-to-noise ratio of 17.545 dB and a correlation coefficient of 0.9929 after denoising.It can clearly invert the second harmonic amplitude of CO2 in human exhaled gas.