Fig. 1. Schematic diagram of occultation detection

Fig. 2. Structure diagram of the telescopic system. (a) two-dimensional view; (b) three-dimensional view

Fig. 3. MTF graph of the telescopic system

Fig. 4. Spot diagram of the telescopic system

Fig. 5. Structural diagram of UV-Vis spectroscopic system

Fig. 6. MTF graph of UV-vis channel at the wavelengthes of (a) λ=675 nm; (b) λ=462.5 nm; (c) λ=250 nm

Fig. 7. Spot diagram of UV-vis channel

Fig. 8. Structural diagram of infrared channel

Fig. 9. MTF graph of infrared channel at the wavelengthes of (a) λ=952 nm; (b) λ=939 nm; (c) λ=926 nm; (d) λ=773 nm; (e) λ=764.5 nm; (f) λ=756 nm

Fig. 10. RMS image of infrared channel （λ=952、939、926、773、764.5、756 nm）

Fig. 11. Overall structure diagram of the spectrometer

Fig. 12. MTF graph of the spectrometer

Fig. 13. Spot diagram of of the spectrometer

Fig. 14. Tolerance analysis of the spectrometer (λ=939、764.5、462.5 nm)