The effect of factors on the deflection of infra-red beam within projectile dome(MgF2)

The aim of this work to study theoretically for variation of the angle of refraction for the passing ray within the homing head magnesium fluoride(MgF2) for the projectile this variation represented by symbol d and the variation in temperature as represented by nT . influents the passing ray inside window when the temperature increases due to high speed for projectile ,approaches 5 mach through the air in this work .Then the spot size place on the detector in the projectile optical system will influents . This will changes the projectile movement .The ray deflection within the dome increases with increase incident angle on the dome for a specified mach , this study it is shown that the deflection is increase with dome temperature and angle of incidence on homing head .this study theoretically was in 4 Km above earth surface and 0.4 m μ wave length .