Study of High Accuracy Spectral Calibration of Fourier Transform Spectrometer
ZOU Yao-pu1, 2, ZHANG Lei1, 2, HAN Chang-pei2*, LI Li-bing2
1. University of Chinese Academy of Sciences, Beijing 100049, China
2. Key Laboratory of Infrared System Detection and Imaging Technology, Chinese Academy of Sciences, Shanghai 200083, China
Abstract：In order to improve the Fourier spectrometer spectral calibration accuracy and reduce spectral calibration error, we studied the Fourier spectrometer spectral calibration algorithm. The study is based on the data of spectral calibration experiment of the atmospheric vertical detector, which is a payload of FY-4 meteorology satellite. Firstly, the spectroscopic principle of the Fourier spectrometer is analyzed. Secondly, after analyzing the principle of the spectrum shift caused by the reference laser wave number drift, the light off-axis, and the limited field of view, the Fourier spectrometer spectral calibration formula and the calibration parameter calculation method are obtained. Then, the reasons for the large spectral calibration error caused by the barrier effect of Fast Fourier Transform(FFT) and the toe function generated by the truncation of the interferogram are analyzed. By comparing several different spectral refinement methods, fast Chirp Z-transform(CZT) for spectral refinement is selected to solve the problem of lower spectral resolution of FFT resulting in larger spectral error. Gaussian expansion and convoluting the sinc function of reference gas spectral can reduce the calibration error caused by limited optical path difference. At last, the spectral calibration algorithm is validated by using experimentally measured data. By comparing the calibration errors before and after refining the spectra using CZT, and the calibration errors before and after the processing of the reference gas spectrum, the algorithm is proved to be effective in improving spectral calibration accuracy. Spectral calibration error can be reduced about 10 times at most.
Key words：Fourier transform spectrometer; Spectral calibration; Fast chirp Z-transform; Instrument function
邹曜璞，张 磊，韩昌佩，李利兵. 傅里叶光谱仪高精度光谱定标研究[J]. 光谱学与光谱分析, 2018, 38(04): 1268-1275.
ZOU Yao-pu, ZHANG Lei, HAN Chang-pei, LI Li-bing. Study of High Accuracy Spectral Calibration of Fourier Transform Spectrometer. SPECTROSCOPY AND SPECTRAL ANALYSIS, 2018, 38(04): 1268-1275.
