Fig. 1. Schematic diagram of the minimum spectral imaginary part method （λ is the interferogram sampling interval）

Fig. 2. Original complex spectrum （LWIR） of ES， ICT and DSP

Fig. 3. Deviations of ES and DSP spectral phase relative to ICT spectral phase

Fig. 4. Results difference between two calculation methods

Fig. 5. Spectrum phase of ES， ICT and DSP

Fig. 6. Phase correction flow chart.

Fig. 7. δES changes with the temperature of the observed target （the left/right column shows the forward/reverse swing direction of the interferometer moving mirror）

Fig. 8. δDSP changes with Time series （the left/right column shows the forward/reverse swing direction of the interferometer moving mirror）

Fig. 9. HIRAS-CrIS spectral distribution， mean BT deviation and standard deviation of BT bias

Fig. 10. Mean BT deviation of HIRAS-CrIS （solid green line） and the variation of mean BT deviation after phase correction （dotted red line）

Fig. 11. Standard deviation of HIRAS-CrIS deviation （green solid line） and the variation of standard deviation after phase correction （red dotted line）

Fig. 12. Scatter distribution and regression line of deviations with the mean BT of HIRAS spectrum in four independent LW spectral channels （green/ red represents before/ after correction）

Fig. 13. Scatter distribution and regression line of deviations with the mean BT of HIRAS spectrum in four independent MW spectral channels （green/ red represents before/ after correction）

Fig. 14. Scatter distribution and regression line of deviations with the mean BT of HIRAS spectrum in four independent SW spectral channels （green/ red represents before/ after correction）