Secondary spectrum filtering method and system for hyperspectral camera

Abstract

The invention discloses a secondary spectrum filtering method and system for a hyperspectral camera, and the method comprises the steps: determining the theoretical overlapping wavelength of a primary spectrum and a secondary spectrum based on the measurable theoretical wavelength range and actual wavelength range of the hyperspectral camera, and obtaining the actual wavelength range of the secondary spectrum in an overlapping region; adjusting the integral time, and analyzing the corresponding relation between the first-level spectrum intensity and the second-level spectrum intensity of each wave band in the actual wavelength range of the second-level spectrum in the overlapping region to obtain a relation parameter and a characteristic parameter matrix; generating secondary spectrum data of the overlapped wavelength range according to the actual wavelength range of the secondary spectrum in the overlapped region and the characteristic parameter matrix interpolation; the secondary spectrum data is filtered from the original spectrum to obtain the final hyperspectral data, so that the secondary spectrum in the hyperspectral camera is filtered, the problem of adjacent spectrum overlapping generated during grating light splitting is solved, the interference of the secondary spectrum on the primary spectrum is reduced, and the accuracy of spectral analysis is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of secondary spectral filtering of a hyperspectral camera, and in particular to a secondary spectral filtering method and system for a hyperspectral camera. Background Art

[0002] In a hyperspectral camera, when a grating is used for spectral separation, except for the zero-order spectrum line, the other spectra usually follow the order of short wave to long wave from the inside to the outside. According to the grating equation, starting from the secondary spectrum, there will be overlap between adjacent spectra, especially the short-wave part of the secondary spectrum and the long-wave part of the primary spectrum. This phenomenon is unacceptable in spectral analysis because it interferes with the analysis results. For example, in a hyperspectral camera operating in the wavelength range of 400-1000nm, the secondary spectrum of 400-500nm may overlap with the primary spectrum of 800-1000nm, thus affecting the accuracy of spectral analysis. Therefore, the secondary spectra in these overlapping areas must be eliminated.

[0003] At present, hyperspectral cameras on the market usually use a semi-coated long-wave pass filter installed in front of the detector to filter out the secondary spectrum. However, this method has two main problems: first, due to the limitations of the coating process, the edge of the semi-coated filter may cause unknown light scattering, resulting in distortion of the measured spectrum, which is not conducive to accurate spectral analysis; second, the use of filters will increase the production time and cost of the instrument. Therefore, it is necessary to find a new solution to effectively filter out the secondary spectrum while reducing the impact on spectral analysis and reducing production cycle and cost. Summary of the invention

[0004] In view of the problems in the related art, the present invention proposes a secondary spectral filtering method for a hyperspectral camera to overcome the above-mentioned technical problems existing in the existing related art.

[0005] To this end, the specific technical solution adopted by the present invention is as follows: A secondary spectral filtering method for a hyperspectral camera, comprising: S1: Based on the theoretical wavelength range and actual wavelength range that can be measured by the hyperspectral camera, the theoretical overlapping wavelength of the primary spectrum and the secondary spectrum is determined, and the actual wavelength range of the secondary spectrum in the overlapping area is obtained; S2: Adjust the integration time, analyze the corresponding relationship between the primary spectrum intensity and the secondary spectrum intensity of each band in the actual wavelength range of the secondary spectrum in the overlapping area to obtain the relationship parameters, fill the relationship parameters into the characteristic matrix as characteristic parameters, and obtain the characteristic parameter matrix of the actual wavelength range of the secondary spectrum in the overlapping area; S3: Generate secondary spectrum data of overlapping wavelength range according to the actual wavelength range of secondary spectrum in the overlapping area and characteristic parameter matrix interpolation; S4: Filter out the secondary spectrum data from the original spectrum to obtain the final hyperspectral data.

[0006] Further, step S1 includes: S1.1: Obtain the theoretical wavelength range and actual wavelength range that can be measured by the hyperspectral camera, and determine the theoretical overlapping wavelength of the primary spectrum and the secondary spectrum based on the diffraction theory; S1.2: Use a monochromator to collect several wavelength bands of theoretical overlapping wavelengths of the primary spectrum and the secondary spectrum, obtain the overlapping wavelength range of the actual secondary spectrum and the primary spectrum in each wavelength band and process them, and then perform fitting to obtain several precise wavelengths of the primary spectrum and several precise wavelengths of the secondary spectrum; S1.3: Analyze the correspondence between several precise wavelengths of the primary spectra and several precise wavelengths of the secondary spectra, determine the overlapping wavelength range of the final secondary spectrum and the primary spectrum, and obtain the actual wavelength range of the secondary spectrum in the overlapping area.

[0007] Furthermore, in step S1.2, the dark background of the spectrum is deducted when processing the overlapping wavelength range of the actual secondary spectrum and the primary spectrum of each wavelength band, and Gaussian fitting is used for fitting.

[0008] Further, step S2 includes: S2.1: Use bandpass filters and broadband light sources to adjust the integration time T1-T n , measuring the average values ​​of the primary spectrum intensity and the secondary spectrum intensity at different integration times at each wavelength within the actual wavelength range of the secondary spectrum in the overlapping region, and obtaining several groups of primary spectrum intensity average values ​​and several groups of secondary spectrum intensity average values; S2.2: Fitting several groups of average values ​​of primary spectral intensities and several groups of average values ​​of secondary spectral intensities to obtain the relationship between the primary spectral intensity and the secondary spectral intensity in the wavelength band; S2.3: Fill the wavelength and the parameters in the corresponding relationship as characteristic parameters into the characteristic matrix to obtain the characteristic parameter matrix of the actual wavelength range of the secondary spectrum in the overlapping area.

[0009] Furthermore, S3 includes: performing dark background subtraction on the data collected by the hyperspectral camera, and generating corresponding secondary spectral data according to the acquired primary spectral wavelength range, the secondary spectral wavelength range overlapping the primary spectral wavelength range, and the characteristic parameter matrix interpolation.

[0010] Further, S4 includes: deducting the secondary spectrum data obtained in step S3 from the hyperspectral data after deducting the dark background, and obtaining the hyperspectral data after filtering out the secondary spectrum as the final hyperspectral data.

[0011] A secondary spectral filtering system for a hyperspectral camera, used to implement any of the above-mentioned secondary spectral filtering methods for a hyperspectral camera, comprising: The module for acquiring the actual wavelength range of the secondary spectrum in the overlapping area: based on the theoretical wavelength range and actual wavelength range that can be measured by the hyperspectral camera, the theoretical overlapping wavelength of the primary spectrum and the secondary spectrum is determined, and the actual wavelength range of the secondary spectrum in the overlapping area is obtained; Characteristic parameter matrix generation module: adjust the integration time, analyze the corresponding relationship between the primary spectrum intensity and the secondary spectrum intensity of each band within the actual wavelength range of the secondary spectrum in the overlapping area to obtain the relationship parameters, fill the relationship parameters into the characteristic matrix as characteristic parameters, and obtain the characteristic parameter matrix of the actual wavelength range of the secondary spectrum in the overlapping area; Secondary spectrum data generation module: generates secondary spectrum data of overlapping wavelength range according to the actual wavelength range of secondary spectrum in overlapping area and characteristic parameter matrix interpolation; Secondary spectral data filtering module: filter out secondary spectral data from the original spectrum to obtain the final hyperspectral data.

[0012] Furthermore, the module for acquiring the actual wavelength range of the secondary spectrum in the overlapping area includes: Theoretical overlapping wavelength determination module of primary spectrum and secondary spectrum: obtains the theoretical wavelength range and actual wavelength range that can be measured by the hyperspectral camera, and determines the theoretical overlapping wavelength of the primary spectrum and the secondary spectrum based on the diffraction theory; Fitting module: Use a monochromator to collect several wavelength bands of theoretical overlapping wavelengths of the primary spectrum and the secondary spectrum, obtain the overlapping wavelength range of the actual secondary spectrum and the primary spectrum in each wavelength band and process them, and then perform fitting to obtain several precise wavelengths of the primary spectrum and several precise wavelengths of the secondary spectrum; The module for acquiring the actual wavelength range of the secondary spectrum in the overlapping area analyzes the correspondence between several precise wavelengths of the primary spectrum and several precise wavelengths of the secondary spectrum, determines the overlapping wavelength range of the final secondary spectrum and the primary spectrum, and obtains the actual wavelength range of the secondary spectrum in the overlapping area.

[0013] Furthermore, the characteristic parameter matrix generation module includes: Average calculation module: Use bandpass filter and wide spectrum light source to adjust the integration time T1-T n , measuring the average values ​​of the primary spectrum intensity and the secondary spectrum intensity at different integration times at each wavelength within the actual wavelength range of the secondary spectrum in the overlapping region, and obtaining several groups of primary spectrum intensity average values ​​and several groups of secondary spectrum intensity average values; Average value fitting module: Fitting several groups of average values ​​of primary spectrum intensity and several groups of average values ​​of secondary spectrum intensity to obtain the relationship between the primary spectrum intensity and the secondary spectrum intensity in the wavelength band; Characteristic parameter matrix analysis and generation module: fill the wavelength and the parameters in the corresponding relationship as characteristic parameters into the characteristic matrix to obtain the characteristic parameter matrix of the actual wavelength range of the secondary spectrum in the overlapping area.

[0014] The beneficial effects of the present invention are: (1) This application proposes a new method to filter out the secondary spectrum in a hyperspectral camera and solve the problem of adjacent spectrum overlap caused by grating spectroscopy. This method reduces or eliminates the interference of the secondary spectrum on the primary spectrum and improves the accuracy of spectral analysis. (2) This application avoids the use of semi-coated filters, thereby reducing spectral distortion caused by coating edge scattering, improving the accuracy of spectral analysis, and reducing the production cycle and cost of hyperspectral cameras, reducing dependence on complex coating processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 This is a flowchart of the steps of a secondary spectrum filtering method for a hyperspectral camera according to the first embodiment of the present invention; Figure 2 This is a schematic diagram of a monochromator measuring a single-wavelength primary spectrum and a corresponding secondary spectrum in a secondary spectrum filtering method for a hyperspectral camera in accordance with the first embodiment of the present invention; Figure 3 This is a relationship diagram between the secondary spectrum wavelength and the primary spectrum wavelength obtained by fitting in the secondary spectrum filtering method for a hyperspectral camera according to the first embodiment of the present invention; Figure 4 It is a schematic diagram of measuring a primary spectrum and a corresponding secondary spectrum using a bandpass filter and a wide-spectrum light source in a secondary spectrum filtering method for a hyperspectral camera according to a first embodiment of the present invention; Figure 5 It is a relationship diagram of the secondary spectrum intensity and the primary spectrum intensity of the corresponding wavelength of channel 1 at different integration times obtained by fitting in the secondary spectrum filtering method for a hyperspectral camera in the first embodiment of the present invention; Figure 6It is a relationship diagram of the secondary spectrum intensity and the primary spectrum intensity of the wavelength corresponding to the channel 50 at different integration times obtained by fitting in the secondary spectrum filtering method for a hyperspectral camera in the first embodiment of the present invention; Figure 7 This is a secondary spectral filtering effect diagram of a secondary spectral filtering method for a hyperspectral camera according to the first embodiment of the present invention. DETAILED DESCRIPTION

[0017] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Embodiment 1

[0018] According to an embodiment of the present invention, a secondary spectral filtering method for a hyperspectral camera is provided. Figure 1-Figure 7 As shown, including: S1: Based on the theoretical wavelength range and actual wavelength range that can be measured by the hyperspectral camera, determine the theoretical overlapping wavelength of the primary spectrum and the secondary spectrum, and obtain the actual wavelength range of the secondary spectrum in the overlapping area. Specifically: S1.1: Obtain the theoretical wavelength range of 400-1000nm and the actual wavelength range of 376-1021nm that can be measured by the hyperspectral camera. Based on the diffraction theory and the hyperspectral camera design method, it is preliminarily determined that the wavelength range of the secondary spectrum overlapping the hyperspectral detection range of 400-1000nm is 400-500nm, which overlaps with the 800-1000nm of the primary spectrum. Since the wavelength of the secondary spectrum that falls within the actual wavelength range of 385.6-521.9nm corresponds to the theoretical wavelength range of the primary spectrum, which should be 188-511nm, but the actual camera starts from the 376nm band, 376nm is used as the starting band range, that is, the theoretical overlapping wavelength of the primary spectrum and the secondary spectrum is 385.6-521.9nm; S1.2: If Figure 2 As shown, a monochromator is used to collect several wavelength bands within 385.6-521.9nm, and the overlapping wavelength range of the actual secondary spectrum and the primary spectrum of each wavelength band is obtained, and the dark background of the spectrum is subtracted. The curve obtained after processing is first peaked, as shown in Figure 3 As shown, the primary spectrum and the secondary spectrum are fitted with Gaussian functions respectively to obtain several precise wavelengths of the primary spectrum and several precise wavelengths of the secondary spectrum at the center position; S1.3: Analyze the correspondence between several precise wavelengths of primary spectra and several precise wavelengths of secondary spectra, determine the overlapping wavelength of primary spectrum and secondary spectrum 751.4-1021.7nm, and obtain the actual wavelength range of secondary spectrum in the overlapping area 385.6-521.9nm.

[0019] S2: Adjust the integration time, analyze the corresponding relationship between the primary spectrum intensity and the secondary spectrum intensity of each band in the actual wavelength range of 385.6-521.9nm of the secondary spectrum in the overlapping area, obtain the relationship parameters, fill the relationship parameters into the characteristic matrix as characteristic parameters, and obtain the characteristic parameter matrix of the actual wavelength range of the secondary spectrum in the overlapping area; Step S2 includes: S2.1: If Figure 4 As shown, using a bandpass filter and a broadband light source, the integration time T1-T n , measure the average values ​​of the primary spectrum intensity and the secondary spectrum intensity at different integration times at each wavelength within the actual wavelength range of the secondary spectrum in the overlapping area, and obtain several groups of primary spectrum intensity average values ​​I 1n and the average values ​​of several groups of secondary spectral intensities I 2n , as shown in the following table:

[0020] S2.2: Because the data are accidental, the average of the primary and secondary spectral intensities is taken, and the average is fitted to obtain the I 1n and I 2n The linear relationship of is: The function represented by f can be a linear or quadratic function, such as Figure 5 and 6 As shown, a linear relationship is assumed here, so the fitting relationship becomes: , the least squares method is used to fit, and the slope a and intercept b are obtained by fitting (if it is a quadratic function, the parameters a, b and c are obtained by fitting), as shown in the following table:

[0021] S2.3: Fill the wavelength, slope, and intercept into the characteristic matrix as eigenvalues ​​to obtain the characteristic parameter matrix, as shown in the following table:

[0022] S3: Perform dark background subtraction on the data acquired by the hyperspectral camera each time, and generate corresponding secondary spectrum data based on the acquired primary spectrum wavelength range, the secondary spectrum wavelength range overlapping with the primary spectrum wavelength range, and the characteristic parameter matrix interpolation. According to the position of each wavelength in the characteristic matrix, the corresponding characteristic parameters are extracted, and the corresponding secondary spectrum data is generated according to the corresponding values ​​generated by the primary spectrum collected by the actual hyperspectral. However, in practice, according to the linear correspondence between the primary spectrum and the secondary spectrum we fitted, the wavelength of the secondary spectrum may not completely correspond to the band of the hyperspectral camera. For example, the secondary spectrum wavelength corresponding to 385.6nm may fall between the center wavelengths of the two bands. Therefore, we perform linear interpolation on the acquired secondary spectrum data to obtain the secondary spectrum data of the integer band corresponding to the hyperspectral band.

[0023] S4: Subtract the secondary spectrum data obtained in step S3 from the hyperspectral data after deducting the dark background, and obtain the hyperspectral data after filtering out the secondary spectrum as the final hyperspectral data, such as Figure 7 As shown, the method of the present application is used to perform secondary spectrum filtering. The dotted line in the figure is: the original spectrum data without filtering; the dotted line is: the generated secondary spectrum data; the straight line is: the clean hyperspectral data after filtering the secondary spectrum.

[0024] In summary, the method of the present application is used to filter out the secondary spectrum in the hyperspectral camera and solve the problem of adjacent spectrum overlap generated during grating splitting. This method reduces or eliminates the interference of the secondary spectrum on the primary spectrum and improves the accuracy of spectral analysis. Embodiment 2

[0025] A secondary spectral filtering system for a hyperspectral camera, used to implement the secondary spectral filtering method for a hyperspectral camera of embodiment 1, comprising: The module for acquiring the actual wavelength range of the secondary spectrum in the overlapping area: based on the theoretical wavelength range and actual wavelength range that can be measured by the hyperspectral camera, the theoretical overlapping wavelength of the primary spectrum and the secondary spectrum is determined, and the actual wavelength range of the secondary spectrum in the overlapping area is obtained; Characteristic parameter matrix generation module: adjust the integration time, analyze the corresponding relationship between the primary spectrum intensity and the secondary spectrum intensity of each band within the actual wavelength range of the secondary spectrum in the overlapping area to obtain the relationship parameters, fill the relationship parameters into the characteristic matrix as characteristic parameters, and obtain the characteristic parameter matrix of the actual wavelength range of the secondary spectrum in the overlapping area; Secondary spectrum data generation module: generates secondary spectrum data of overlapping wavelength range according to the actual wavelength range of secondary spectrum in overlapping area and characteristic parameter matrix interpolation; Secondary spectral data filtering module: filter out secondary spectral data from the original spectrum to obtain the final hyperspectral data.

[0026] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A secondary spectrum filtering method for a hyperspectral camera, characterized in that: include: S1: Based on the theoretical wavelength range and actual wavelength range that can be measured by the hyperspectral camera, the theoretical overlapping wavelength of the primary spectrum and the secondary spectrum is determined, and the actual wavelength range of the secondary spectrum in the overlapping area is obtained; S2: Adjust the integration time, analyze the corresponding relationship between the primary spectrum intensity and the secondary spectrum intensity of each band in the actual wavelength range of the secondary spectrum in the overlapping area to obtain the relationship parameters, fill the relationship parameters into the characteristic matrix as characteristic parameters, and obtain the characteristic parameter matrix of the actual wavelength range of the secondary spectrum in the overlapping area; S3: Generate secondary spectrum data of overlapping wavelength range according to the actual wavelength range of secondary spectrum in the overlapping area and characteristic parameter matrix interpolation; S4: Filter out the secondary spectrum data from the original spectrum to obtain the final hyperspectral data.

2. The secondary spectrum filtering method for a hyperspectral camera according to claim 1, characterized in that: Step S1 includes: S1.1: Obtain the theoretical wavelength range and actual wavelength range that can be measured by the hyperspectral camera, and determine the theoretical overlapping wavelength of the primary spectrum and the secondary spectrum based on the diffraction theory; S1.2: Use a monochromator to collect several wavelength bands of theoretical overlapping wavelengths of the primary spectrum and the secondary spectrum, obtain the overlapping wavelength range of the actual secondary spectrum and the primary spectrum in each wavelength band and process them, and then perform fitting to obtain several precise wavelengths of the primary spectrum and several precise wavelengths of the secondary spectrum; S1.3: Analyze the correspondence between several precise wavelengths of the primary spectra and several precise wavelengths of the secondary spectra, determine the overlapping wavelength range of the final secondary spectrum and the primary spectrum, and obtain the actual wavelength range of the secondary spectrum in the overlapping area.

3. The secondary spectrum filtering method for a hyperspectral camera according to claim 2, characterized in that: In step S1.2, the dark background of the spectrum is deducted when processing the overlapping wavelength range of the actual secondary spectrum and the primary spectrum of each wavelength band, and Gaussian fitting is used for fitting.

4. The secondary spectrum filtering method for a hyperspectral camera according to claim 1, characterized in that: Step S2 includes: S2.1: Use bandpass filters and broadband light sources to adjust the integration time T1-T n , measuring the average values ​​of the primary spectrum intensity and the secondary spectrum intensity at different integration times at each wavelength within the actual wavelength range of the secondary spectrum in the overlapping region, and obtaining several groups of primary spectrum intensity average values ​​and several groups of secondary spectrum intensity average values; S2.2: Fitting several groups of average values ​​of primary spectral intensities and several groups of average values ​​of secondary spectral intensities to obtain the relationship between the primary spectral intensity and the secondary spectral intensity in the wavelength band; S2.3: Fill the wavelength and the parameters in the corresponding relationship as characteristic parameters into the characteristic matrix to obtain the characteristic parameter matrix of the actual wavelength range of the secondary spectrum in the overlapping area.

5. The secondary spectrum filtering method for a hyperspectral camera according to claim 1, characterized in that: S3 includes: performing dark background subtraction on the data collected by the hyperspectral camera, and generating corresponding secondary spectral data according to the acquired primary spectral wavelength range, the secondary spectral wavelength range overlapping the primary spectral wavelength range, and the characteristic parameter matrix interpolation.

6. The method for secondary spectrum filtering for a hyperspectral camera according to claim 1, characterized in that: S4 includes: deducting the secondary spectrum data obtained in step S3 from the hyperspectral data after deducting the dark background, and obtaining the hyperspectral data after filtering out the secondary spectrum as the final hyperspectral data.

7. A secondary spectral filtering system for a hyperspectral camera, used to implement the secondary spectral filtering method for a hyperspectral camera described in any one of claims 1 to 6, characterized in that: include: Acquisition module for the actual wavelength range of the secondary spectrum in the overlapping area: Based on the theoretical wavelength range and actual wavelength range that can be measured by the hyperspectral camera, the theoretical overlapping wavelength of the primary spectrum and the secondary spectrum is determined, and the actual wavelength range of the secondary spectrum in the overlapping area is obtained; Characteristic parameter matrix generation module: adjust the integration time, analyze the corresponding relationship between the primary spectrum intensity and the secondary spectrum intensity of each band within the actual wavelength range of the secondary spectrum in the overlapping area to obtain the relationship parameters, fill the relationship parameters into the characteristic matrix as characteristic parameters, and obtain the characteristic parameter matrix of the actual wavelength range of the secondary spectrum in the overlapping area; Secondary spectrum data generation module: generates secondary spectrum data of overlapping wavelength range according to the actual wavelength range of secondary spectrum in overlapping area and characteristic parameter matrix interpolation; Secondary spectral data filtering module: filter out secondary spectral data from the original spectrum to obtain the final hyperspectral data.

8. The secondary spectral filtering system for a hyperspectral camera according to claim 7, characterized in that: The module for acquiring the actual wavelength range of the secondary spectrum in the overlapping area includes: Theoretical overlapping wavelength determination module of primary spectrum and secondary spectrum: obtains the theoretical wavelength range and actual wavelength range that can be measured by the hyperspectral camera, and determines the theoretical overlapping wavelength of the primary spectrum and the secondary spectrum based on the diffraction theory; Fitting module: Use a monochromator to collect several wavelength bands of theoretical overlapping wavelengths of the primary spectrum and the secondary spectrum, obtain the overlapping wavelength range of the actual secondary spectrum and the primary spectrum in each wavelength band and process them, and then perform fitting to obtain several precise wavelengths of the primary spectrum and several precise wavelengths of the secondary spectrum; The module for acquiring the actual wavelength range of the secondary spectrum in the overlapping area analyzes the correspondence between several precise wavelengths of the primary spectrum and several precise wavelengths of the secondary spectrum, determines the final overlapping wavelength range of the secondary spectrum and the primary spectrum, and obtains the actual wavelength range of the secondary spectrum in the overlapping area.

9. The secondary spectral filtering system for a hyperspectral camera according to claim 7, characterized in that: The feature parameter matrix generation module includes: Average calculation module: Use bandpass filter and wide spectrum light source to adjust the integration time T1-T n , measuring the average values ​​of the primary spectrum intensity and the secondary spectrum intensity at different integration times at each wavelength within the actual wavelength range of the secondary spectrum in the overlapping region, and obtaining several groups of primary spectrum intensity average values ​​and several groups of secondary spectrum intensity average values; Average value fitting module: Fitting several groups of average values ​​of primary spectrum intensity and several groups of average values ​​of secondary spectrum intensity to obtain the relationship between the primary spectrum intensity and the secondary spectrum intensity in the wavelength band; Characteristic parameter matrix analysis and generation module: fill the wavelength and the parameters in the corresponding relationship as characteristic parameters into the characteristic matrix to obtain the characteristic parameter matrix of the actual wavelength range of the secondary spectrum in the overlapping area.

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