一种大基线分布雷达近场相参探测技术

Study on a Near-Field Coherent Detection Technology for Long-Baseline Distributed Radar

大基线分布式孔径雷达探测近场目标时,由于各孔径对目标的观测角差异较大,雷达接收到的目标散射回波间的相参性差,难以对回波进行相参积累。本文首先研究了目标回波相参性与回波角度和雷达距离分辨率之间的关系;随后,在大基线分布式孔径雷达近场下,通过分辨单元精细刻画,将大散射点目标变为由若干个强散射点组成的“多目标”,进而分别对各强散射点回波进行相参积累;最后,进行仿真分析和试验。结果表明,目标散射回波在大观测角下的相参性得到有效改善,提高了检测信噪比得益,从而验证了本方法的正确性。

The coherence of the echoes from different apertures of long-baseline distributed radar when detecting the targets in the near-field area is often poor because of the difference of the apertures’observation angles,which makes it hard to do coherent integration.This paper firstly studies the relations between the cohe-rences of the echoes and the scattering direction as well as the range resolution.Secondly,based on the near-field detection of the long baseline distributed radar,the large target made up of single scattering point is divided into“multiple targets”which contain multiple scattering points via intensive range segmentation,the echoes of each scattering point are integrated individually.The simulation is conducted and the results show that the coherence of the echoes from apertures with different observation angles is significantly improved,the signal-noise-ratio of the radar also increases remarkably.