Influence of background radiation on space target detection in the long wave infrared range

Abstract

Aiming at the space target and two dominant background sources including the sun and earth-atmosphere system, their radiation models are established, and the background influence on the space target detection for the space-based infrared imaging system are discussed in the long wave infrared (8 to 14 μm) range. From the numerical calculation and analysis, we find that the earth-atmosphere system is the strongest background interference source and will form a big detection blind zone, followed by the sun, whose irradiance is about 1.6% of that from the earth-atmosphere system. Compared with these two intense radiations, the space target radiation acting on the space-based infrared detector is so weak that it may be submerged once the target appears in the earth-atmosphere or solar backgrounds. Thus, in order to reduce the influence of the background interferences, necessary measures must be taken to control the space-based infrared detector and its host platform in real time, such as adjusting the flight attitude, changing the detection angle, transferring operating orbit, and so on.