Abstract:The infrared windows of hypersonic vehicles encounter a rapid increase in temperature due to the aerodynamic heating effect during flight, resulting in intense background radiation that affects the imaging quality of the detection system. To precisely assess the effects of aerodynamic heating on the infrared imaging system, a combined approach of the Monte-Carlo method and ray tracing method is developed and employed to analyze the background radiation and the decrease in transmission of the infrared window caused by temperature rise. Accordingly, a method to improve the signal-to-noise ratio of the imaging system is proposed, resulting in an average improvement of 11.2 in the signal-to-noise ratio under ideal conditions.