Fig. 1. Principle diagram of Michelson interferometer

Fig. 2. Spectral coverage of GIIRS (February 20, 2017 at 10:00 UTC). (a) Long-wave spectral region from 700 to 1130 cm-1; (b) mid-wave spectral region from 1650 to 2250 cm-1

Fig. 3. Root-mean-square error of spectral radiance of GIIRS as function of laser sampling frequency (June 16, 2017 at 06:15 UTC). (a) Long-wave spectral region from 700 to 718 cm-1; (b) mid-wave spectral region from 2207 to 2220 cm-1

Fig. 4. Comparison between observed spectra of GIIRS and simulated spectra of LBLRTM (June 16, 2017 at 06:15 UTC)

Fig. 5. On-orbit spectral calibration coefficient of GIIRS on-board FY-4A satellite (October 20, 2017 at 02:30 UTC). (a) Long-wave, forward sweep; (b) long-wave, reverse sweep; (c) mid-wave, forward sweep; (d) mid-wave, reverse sweep

Fig. 6. Comparison of brightness temperature between 47th pixel in mid-wave region of GIIRS and matching sample of IASI (August 20, 2017 at 14:30 UTC). (a) Spectral calibration coefficient in laboratory; (b) on-orbit spectral calibration coefficient