Real-time dynamic optimized band detection method for hypersonic glide vehicle

Abstract

The glide phase is the main time window of detection for a hypersonic glide vehicle (HGV). During a long flight, both skin temperature and background change dynamically, neither of which can be regarded as constant. The traditional fixed band detection can’t adapt to the dynamic changes of target and background infrared radiation characteristics, which not only reduces the tracking and detection efficiency, but also compresses the subsequent countermeasures reaction time. Therefore, based on the real-time infrared characteristics of target and background, this paper presents a real-time dynamic optimized band detection method for the HGV under entire trajectory. Firstly, considering the influence of free-flow conditions, target velocity, angle of attack (AOA), and geometry, we established the heat flux calculation model with a modified reference enthalpy method. Then, the transient temperature of the skin at different trajectory points is obtained by calculating the wall heat flux from convection and thermal radiation. Finally, the detection efficiency of the HGV in different wavebands is simulated by combining different types of backgrounds. Considering the signal-to-noise ratio (SNR) and signal-to-clutter ratio (SCR), a new detection index, comprehensive signal-to-noise ratio (CSNR), is proposed to analyze the optimal band. Research results show that the undetectable time after band optimization can be reduced from 250 s to 70 s compared to the fixed band with CSNRth=10 as the threshold. At 250 s, the detection efficiency of optimized band is 18 times that of fixed band. The band optimization method presented in this work provides a theoretical reference for the defense of hypersonic weapons.