临近空间高超声速目标RCS模拟技术研究

针对雷达探测临近空间高超声速目标模拟试验中的雷达散射截面(radar cross section,RCS)逼真模拟问题,提出了一种适用于临近空间高超声速飞行器等离子体鞘套下目标RCS衰减模拟方法.首先利用不同高度、不同速度对应的等离子体频率和电子碰撞频率的相关数据,拟合得出不同速度、不同高度对应的等离子体频率和电子碰撞频率关系表;其次,实时查表得到给定雷达频率情况下不同目标高度与速度对应的等离子体频率和电子碰撞频率,建立目标等离子体包覆模型和电磁波传输模型,计算雷达电磁波的衰减系数和反射系数;最后,通过雷达电磁波的衰减系数和反射系数模拟出目标RCS衰减.通过与有关实测数据比对,证明了方法的合理性.仿真分析可知,利用高频率雷达探测临近空间高超声速飞行器将更容易得到连续的航迹,产生雷达"黑障"的时间更短.

RCS simulation technology for near space hypersonic target

In order to solve the problem of radar cross section(RCS) simulation in the simulation test of radar detection of hypersonic target in near space, a target RCS reduction simulation method suitable for near space hypersonic vehicle under plasma sheath is proposed. Firstly, based on the relevant data of plasma frequency and electron collision frequency corresponding to different altitude and velocity, the relationship table of plasma frequency and electron collision frequency corresponding to different velocity and altitude was fitted. Secondly, the plasma frequency and electronic collision frequency corresponding to different target altitude and velocity are obtained by real-time table lookup under given radar frequency. The target plasma coating model and electromagnetic wave transmission model are established, and the attenuation coefficient and reflection coefficient of radar electromagnetic wave are calculated. Finally, the RCS reduction of target can be simulated by the attenuation coefficient and reflection coefficient of radar electromagnetic wave. By comparing with the concerned real data, the rationality of the method is proved. The simulation analysis shows that it is easier to obtain continuous tracks and shorter time to generate radar "black-out" by using high-frequency radar to detect near space hypersonic vehicle.