超视距雷达探测高超声速飞行器可行性分析

在前期开展再入飞行器RCS（雷达散射截面）特性试验和理论研究的基础上，对典型临近空间高超声速飞行器RCS特性开展了研究，分析了绕流和尾迹对飞行器本体RCS特性的影响。研究表明等离子体流场在头身部绕流、近尾尾迹和部分远尾尾迹的最大电子密度将远高于电离层最高电子密度，更高于典型天波超视距雷达工作频段对应的临界电子密度。因而等离子体尾迹将会对3~30 MHz频段电磁波产生较强的散射，使得等离子体尾迹的RCS远远大于飞行器本体的RCS。利用临近空间高超声速飞行器尾迹RCS的这一特点，有可能实现对临近空间高超声速飞行器的超视距探测。

Feasibility Analysis on Hypersonic Vehicle Detection by Over the Horizon Radar

The scattering characteristics of a hypersonic near space vehicle are studied in this paper. The research takes into account the effect of the surrounding flow and wake on the radar cross section (RCS) of the near space hypersonic vehicle. The results show that the maximal plasma density of the surrounding flow, near wake and part of the far wake is higher than the critical plasma density of the ionosphere and much higher than the critical plasma density of the over-the-horizon radar whose frequency ranges from 3 MHz to 30 MHz. The plasma wake may be seen as conducting observation when the radar frequency is lower than the plasma frequency. So the RCS of the plasma wake is even larger than the hypersonic vehicle. On the basis of the numerical analysis, we suggest to detect the near space hypersonic vehicle by an over-the-horizon radar, which may provide longer reaction time for a radar warning system.