Impact of Background Radiation on the Long Wave Infrared Radiation Characteristics of Aircraft at High Altitude

Abstract

<p class="maintext">Reflected background infrared radiation is an important contributor to the aircraft total infrared radiation. A reverse Monte Carlo ray tracing method to compute the infrared radiation signature of aircraft was introduced. The impact of atmospheric and ground radiation on the long wave infrared radiation signature of aircraft at the altitude of 11 km is analysed. The flight speed is Mach 0.8. The horizontal detection directions, downward detection directions and upward detection directions are considered. The results show that in the horizontal plane, the ratio of reflected background infrared radiation to self infrared radiation is about 10 per cent in summer, and 7 per cent in winter; the ratio values distributed in the front and side of the aircraft are bigger than that in the rear; and the existence of atmospheric and ground infrared radiation makes the apparent radiance temperature of the lower part of the aircraft higher than that of the upper part of the aircraft.</p><p class="maintext"><strong>Defence Science Journal, Vol. 66, No. 1, January 2016, pp. 51-56, DOI: http://dx.doi.org/10.14429/dsj.66.8090</strong></p>