Fig. 1. (a)Relative intensity of O₂(0-1)band emission; (b)Relative intensity change curves of O₂ (0-1) band emission at rotational temperature changing with a step of 10 K

Fig. 2. Optical path design and physical chart of MASP instrument

Fig. 3. Schematic diagram of the MASP forward model

Fig. 4. Flat field calibration for MASP optical system
(a): Original calibrated image; (b): Flat field coefficient from center to the edge of image

Fig. 5. Simulation images from forward model
(a): Simulation image of pure signal value at 220 K; (b): Simulation image by adding noise and coupling parameters of optical system at 220 K

Fig. 6. Synthetic spectra of forward model
(a): Absolute intensity of synthetic spectrum; (b): Relative intensity change curves of synthetic spectrum at the rotational temperature changing with a step of 10 K

Fig. 7. The process for removing background scattered signal of continuous spectrum
(a): Original synthetic spectrum; (b): Comparison of the results by removing background scattered signal with and without flat-field coefficient; (c): The distribution of difference between two methods

Fig. 8. Flow chart of temperature inversion for MASP

Fig. 9. Temperature inversion results for MASP
(a): Two observation cases on Oct. 12 and Nov. 1, 2018;(b): Comparison of the mean observation result during Oct. 2018 with the result of MSISE-00 empirical model