雷达导引头跟踪超低空目标时,由于目标镜像多径干扰会引起单脉冲跟踪指示角误差。文中建立了存在镜像目标时的单脉冲差和比模型,推导了单脉冲跟踪指示角误差模型,得到了开环与闭环跟踪模式的指示角解析表达式,仿真分析结果表明,对于开环跟踪,当镜像目标与真实目标相对相位相差180°时,指示角误差最大;对于闭环跟踪,指示角误差偏离程度与弹目距离、目标高度、天线增益、反射系数相关,弹目距离越近,指示角波动幅度越大。

When radar seeker tracks low altitude target, monopulse tracking indication angle error will be caused due to target specular multipath interference. To solve this problem, a difference and ratio model was established under specular multipath interference, a monopulse tracking indication angle error model was deduced, an indication angle analytical expression was derived when radar seeker worked in open-loop and closed-loop tracking mode. Simulation results show that, for open-loop tracking, when the relative phase difference is 180° between specular interference and real target, the indication angle error is maximum: For closed-loop tracking, indication angle error is associated with the distance between target and missile, target height, antenna gain, and reflection coefficient. The closer the distance between target and missile is, the greater the indication angle fluctuations.