Atmospheric absorption ratio algorithm for airborne short-wave infrared hyperspectral imagery spectral calibration based on carbon dioxide and water vapor

In view of the fact that the hyperspectral imager can simultaneously obtain the target's geometric and spectral characteristics, it has been widely applied in many research fields. However, due to the changes in the laboratory and the on-board environment, center wavelengths of the on-board spectral response function (SRF) need to be recalibrated to ensure high-precision measurement of the target's spectral characteristics retrieved by hyperspectral imager. In this paper, an on-board spectral calibration method for short-wave hyperspectral imager based on constructing differential function between the simulated and the actual absorption ratios is introduced in detail, and the center wavelength offsets of the on-board SRF during the operation process can be monitored through the statistics of the best spectral smoothing position of each frame of the flight image. Moreover, the onboard offsets of SRF in different spectral channels is studied in this paper. Experiments show that the deviation of SRF of on-board hyperspectral imager is not linear, and the three-sigma confidence interval is +/- 0.38 nm. The method is beneficial to improve the practical application ability of short-wave hyperspectral imagers.