低空多路径下目标特性参数对PD导引头影响研究

为了得到低空多路径下目标特性参数对脉冲多普勒(pulse Doppler, PD)导引头目标检测的影响，根据导引头、目标空间几何关系,推导了考虑存在多条路径情况下的导引头测量单脉冲比表达式，并指出多普勒频差小于导引头速度门带宽是多径效应对PD导引头产生影响的前提。通过对相位差求取微分的方法，得到了多径回波和目标回波的多普勒频差，给出了多普勒频差与弹目飞行高度、弹目速度、弹目距离关系的解析式，解析式能为导引头末制导阶段的弹道设计提供参考和帮助。

Effect of target parameters on pulse Doppler radar seeker under the conditions of low-ltitude multipath

In order to get the target parameters’ effects on the target detection of the pulse Doppler(PD) radar seeker under the conditions of low-altitude multipath,the expression of monopulse ratio of the seeker under the conditions of multipath is derived according to the geometry relationship between the radar seeker and the target,and the multipath effects on PD radar seeker are analyzed based on the premise that the Doppler frequency difference of the multipath signal and the target signal is less than the radar seeker’s velocity gate.Through the differentiation of the phase difference between the target and the multipath signal,the Doppler frequency difference of the target and the multipath signal is proposed,and the Doppler frequency difference’s fomulas are given based on its relationship with the flight altitude,relative velocity and range between target and seeker.The derived formulas could provide references and help to the design of the radar seeker’s trajectory.