天波超视距雷达弹道目标检测判别问题研究

弹道目标（运载火箭、弹道导弹等）助推段的弹体RCS较小，属于高速高机动小目标，天波超视距雷达（Skywave OTHR）很难通过相干积累来检测弹体回波，然而高空中尾焰回波的RCS值比弹体RCS值大1-2个数量级，Skywave OTHR可以通过探测尾焰回波来实现弹道目标检测。为此分析比较了常规目标、流星余迹和弹道目标特别是尾焰回波信号的频域特性，系统归纳了导弹目标尾焰特有的频域特性，提出了二维十字窗S-CFAR检测判别弹道目标的方法。研究结果表明，该方法不但可以抑制噪声，而且可以减小多普勒频率展宽和距离展宽。

Detection and Discrimination of Ballistic Target by Skywave Over-the-horizon Radar

As the ballistic targets （carrier rocket、ballistic missile and so on）whose projectile body has a small RCS over the boost phase belong to a small target with high speed and high maneuvering, it is very hard to detect the projectile body’s echo through the coherent accumulation by the sky wave OTHR. However , the RCS of echo of tail flame high up in the sky has 1-2 order of magnitudes greater than that of the projectile body, the sky wave OTHR can implement the detection of ballistic target by detecting the echo of tail flame. And therefore, this paper analyzes the frequency domain characteristics of echo signals of common targets, meteor trail and ballistic targets, especially the tail flame, concludes the specific frequency domain characteristics of missile target’s tail flame, and presents a scheme of two dimensional cross window S-CFAR for detecting and discriminating the ballistic target. Findings prove that the method proposed can not only suppress the noise, but also reduce Doppler frequency spread and range spread.