Fig. 1. Schematic diagram of optical system in roll-pitch infrared homing head

Fig. 2. Comparison of MTF at different temperatures. (a) -50 ℃; (b) -20 ℃; (c) 0 ℃; (d) 20 ℃; (e) 50 ℃; (f) 70 ℃

Fig. 3. Refractive index variation of two materials. (a) Germanium; (b) silicon

Fig. 4. Homing head simulation model in LightTools

Fig. 5. Distribution cloud of self-radiation irradiance received by detection surface of the detector at different temperatures, and variation in corresponding self-radiation irradiance with lateral central dimensions of homing head. (a) 473.15 K; (b) 573.15 K; (c) 773.15 K; (d) 1073.15 K

Fig. 6. Imaging simulation of a typical aircraft target at 5 km under different temperatures. (a) Original image; (b) 473.15 K; (c) 573.15 K; (d) 773.15 K; (e) 1073.15 K

Fig. 7. Variation in SNR of the infrared optical system with temperature