Image simulation for airborne star tracker under strong background radiance

Airborne star tracker is an attitude measurement instrument of the aircraft. Unlike applications in space, the operational environment of airborne star tracker is mainly influenced by factors such as sky background radiance, atmospheric refraction, aerodynamic effects, etc. In order to carry on the research, simulation is an efficient way. This paper presents a procedure of image simulation for airborne star tracker with a focus on the impact of sky background radiance, taking into account the radiance intensities at different heights, in different spectral wavebands and under different observing conditions. Several experiments are carried out to calculate the equivalent magnitude of sky background radiance and to determine the detectable limiting magnitude during daytime with a given signal to noise contrast. With these analyses the background noise of star image can be determined. Numerical star images are simulated to confirm the above discussion, which formed a basis for further study.