Fig. 1. Schematic diagram of the position relationship between the target surface and the probe's entrance pupil

Fig. 2. The simplified model used in simulation

Fig. 3. Grid division in simulation cases

Fig. 4. Comparison of calculation results of orbit external heat flow by proposed method and commercial software without taking into account the occulusion effect

Fig. 5. Calculation results of orbit external heat flow with taking into account the occlusion effect

Fig. 6. Temperature of each surface

Fig. 7. Infrared radiation intensity in 3~5 μm band

Fig. 8. Infrared radiation intensity in 8~14 μm band

Fig. 9. Infrared radiation spectral intensity of ascending detection

Fig. 10. Infrared radiation spectral intensity of descending detection

Fig. 11. Infrared radiation spectral intensity of ascending detection with the atmosphere impact

Fig. 12. Infrared radiation spectral intensity of descending detection with the atmosphere impact