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Spectroradiometer is mainly used to measure the spectrum properties of radiation sources and radiation intensity. The accuracy of the instrument's measurement data results is a prerequisite for the determination of radiation sources, and the accuracy of the data processing method in the measurement process will directly affect the measurement results of the target to be measured. The circular variable filter type spectroradiometer uses a circular gradient filter with linear relationship between transmission wavelength and angle for spectroscopy, with a spectral range of 1.3-14.3um and a resolution of 2% of the wavelength. In this paper, the data processing method of this type of spectroradiometer is studied, the basic principle of the instrument is introduced, and the processing of the data of circular variable filter type spectroradiometer is carried out. The data processing is mainly divided into three parts: data pre-processing, drift correction and wavelength re-alignment. The raw sampling data is obtained after the data pre-processing of the original acquired data package. The drift correction is calculated using the inter-correlation method, and the calculated offset value is used to correct the acquired raw data by cyclic offset. The corrected raw samples are converted into spectral profiles by wavelength realignment. A standard blackbody is used as both the target and reference source to verify the measurement results. The accuracy of the data measurement method was demonstrated by comparing the CO2 absorption peaks in the obtained spectral data with the CO2 transmittance calculated by the atmospheric radiative transfer model MODTORAN, based on experimental data of blackbody measurements by spectroradiometer. It effectively ensures the accuracy of the measurement results and lays the foundation for the later radiometric calibration of the instrument.
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