Fig. 1. The internal structure of engine and the gas states of the inner channel

Fig. 2. Schematic diagram of radiative transfer computations using the LOS method

Fig. 3. Geometry of the B-2-like aircraft

Fig. 4. Computational domain and grid distributions

Fig. 5. Schematic diagram of observation angle

Fig. 6. Comparison of calculate results and reference data

Fig. 7. Contours of surface temperature

Fig. 8. Contours of main flow flied parameters

Fig. 9. Spectral radiant intensity of aircraft body at different observation angles

Fig. 10. Radiances of aircraft body in the MWIR band at different observation angles

Fig. 11. Radiances of aircraft body in the LWIR band at different observation angles

Fig. 12. Spectral radiant intensity at different observation angles

Fig. 13. Radiances in MWIR band at different observation angles

Fig. 14. Radiances in LWIR band at different observation angles

Fig. 15. Synthetic IR images of aircraft body at different observation angles

Fig. 16. Synthetic IR images of target in different bands