Wavelength calibration method and system of push-broom imaging spectrometer

Abstract

The invention discloses a wavelength calibration method of a push-broom imaging spectrometer. The method comprises the following steps that: wavelength scanning is performed on an imaging spectrometerto be calibrated with continuously wavelength-known monochromatic light; different pixel locations of the detector of the push-broom imaging spectrometer to be calibrated in a wavelength scanning process are calculated and recorded, different wavelengths falling in the different pixel locations of the detector in the wavelength scanning process; and fitting is performed on a plurality of adjacentwavelengths and corresponding different pixel locations, so that the center wavelength of each spectral channel is obtained. With the wavelength calibration method of the push-broom imaging spectrometer of the invention adopted, the problem of a complicated calibration process and difficulty in subsequent data processes which are caused by the fluctuation of spot energy in a traditional wavelength scanning calibration method of the push-broom imaging spectrometer can be effectively improved, and he calibration accuracy and efficiency of the push-broom imaging spectrometer can be effectively improved.

Description

technical field [0001] The invention relates to the technical field of spectrum calibration, in particular to a wavelength calibration method and system for a push-broom imaging spectrometer. Background technique [0002] The spectral calibration method of the imaging spectrometer is the wavelength scanning method. This method is to record different wavelengths and the DN value of the corresponding wavelength at a certain pixel, and then use Gaussian fitting to the wavelength and spot energy to calculate the specific pixel. The wavelength with the highest response value is the center wavelength of the pixel. When calibrating a certain pixel, ensure that the test conditions of the light spots to be recorded are the same, that is, the light source voltage and integration time are unchanged, otherwise it will cause The energy of the spot changes suddenly, resulting in the unusable final fitting data and inaccurate calibration results. However, in the calibration process, there...

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Problems solved by technology

[0002] The spectral calibration method of the imaging spectrometer is the wavelength scanning method. This method is to record different wavelengths and the DN value of the corresponding wavelength at a certain pixel, and then use Gaussian fitting to the wavelength and spot energy to calculate the specific pixel. The wavelength with the highest response value is the center wavelength of the pixel. When calibrating a certain pixel, ensure that the test conditions of the light spots to be recorded are the same, that is, the light source voltage and integration time are unchanged, otherwise it will cause The energy of the spot changes suddenly, resulting in the unusable final fitting data and inaccurate calibration results

However, in the calibration process, there are many reasons such as the different responses of the imaging spectrometer camera to be calibrated to different wavelengths, the different intensities of different wavelengths emitted by the monochromator, the different radiation energies of different wavelengths of the light source, and the different transmittances of the optical system for different wavelengths. , resulting in inconsistencies in the spot energies of different wavelengths during the spectral calibration process, resulting in the need to continuously adjust the integration time and light source voltage during the calibration process to ensure that the spot energy of each wavelength is not too high or too low, In this way, it is necessary to record the position of the adjusted spot energy during the calibration process, so that the corresponding position can be corrected during the subsequent processing of the calibration data, and the correction method is usually to readjust the spot energy after adjusting the position of the changed energy. Measurement, in this way, the adjustment of the spot energy in the traditional wavelength calibration method has caused great interference to the subsequent processing of the calibration data, resulting in errors, and in the re-measurement process, there is no guarantee that there will be no change in the spot energy, thereby reducing Accuracy of Calibration Results

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