关键词: 光谱处理, 谱对准偏差, 最小二乘法

Abstract:

In the retrieval of atmospheric trace-gas concentrations, it’s a widely used method to fit the calculated reference spectra to the measured spectra with least-squares methods. However, because of inaccuracy of the grating position, thermal changes in the spectrometer, and the resolution difference between the two spectra; there is a spectral misalignment between the measured spectra and the reference spectra: the measured spectra may be shifted or stretched/squeezed. These misalignments will affect the accuracy of the retrieval. An algorithm doing the shift-and-squeeze spectral correction in the process of the retrieval is introduced and the concentration error caused by spectral shift under different resolutions is calculated.

Key words: spectrum adjustment, wavelength misalignment, least-squares method