Fig. 1. Wavelet threshold denoising algorithm

Fig. 2. The three-dimensional fluorescence spectrum and contour map of sample 5 before and after removing the scattering
(a): Three-dimensional fluorescence spectrum with scattering; (b): Contour map with scattering;(c): Three-dimensional fluorescence spectrum after removing the scattering; (d) Contour map after removing scattering;(e): Three-dimensional fluorescence spectrum after wavelet denoising; (f): Contour map after wavelet denoising

Fig. 3. (a) Core consistency value; (b) Residual sum of squares

Fig. 4. (a)—(f)Comparison chart of analytical spectrum and standard spectrum of mixed oil;(g)—(l)Comparison of analytical spectrum and standard spectrum of jet fuel
(a): The emission spectrum of the original spectrum; (b): The excitation spectrum of the original spectrum; (c): The emission spectrum of the emission wavelength partial derivative spectrum; (d): The excitation spectrum of the emission wavelength partial derivative spectrum; (e): The emission spectrum of the excitation wavelength partial derivative spectrum; (f): The excitation spectrum of the excitation wavelength partial derivative spectrum; (g): The emission spectrum of the original spectrum; (h): The excitation spectrum of the original spectrum; (i): The emission spectrum of the emission wavelength partial derivative spectrum; (j): The excitation spectrum of the emission wavelength partial derivative spectrum; (k): The emission spectrum of the excitation wavelength partial derivative spectrum; (l): The excitation spectrum of the excitation wavelength partial derivative spectrum

Table 1. Correlation coefficient and root mean square error between analytical spectrum and standard spectrum

Table 2. Correlation coefficient and root mean square error between analytical spectrum and standard spectrum