一种高超声速飞行器雷达测角误差的分析方法

The wavefront distortion caused by the passage of radar echoes through the atmosphere, the external flow field of the aircraft, and the radome has a crucial influence on the angle measurement error of active radar single-pulse. The impact of the refractive index gradient caused by the turbulent structure on the wavefront distortion and the numerical solution accuracy of the weak form of the wave equation were analyzed. The “explicit” gradient term correction approach and the “gradient reconstruction” method of supplementing the small-scale structure of the density field with the turbulent vortex model for the weak form of the electromagnetic wave equation were proposed. Computer numerical simulation was conducted using the finite element method. The simulation results indicate that one of the significant causes of the radar angle measurement error is the electric field distortion induced by small-scale turbulence, and as the scale of the vortex structure decreases and the wavelength lengthens, the electric field distortion intensifies, and the angle measurement error increases.