双波段协同的建筑拐角多径利用雷达遮蔽目标成像方法

    Dual-band Collaborative Multipath Exploitation Radar Imaging Method for Occluded Targets in Building Corners

    • 摘要: 现有的非视距目标成像方法通常会受到多路径混叠导致的鬼影问题的干扰。为此,文中提出了一种基于双波段协同分离多路径回波信号的多径利用雷达遮蔽目标成像方法。首先,以L型建筑场景为例,建立了主体L波段雷达与辅助毫米波雷达的多路径传播模型,并针对后向投影(BP)及非相干叠加处理得到的L波段目标成像结果,详细分析了鬼影形成的原因;然后,基于L波段雷达与毫米波雷达在多路径传播上的差异性,提出了一种双波段协同的多路径匹配分离策略,通过定义匹配因子定量评估了双波段路径传播时延的相似程度,并进一步设计了路径分离函数,根据双波段匹配结果实现了对主体L波段多路径回波信号的有效分离;接着,利用BP算法对分离后各个路径的L波段回波信号进行独立处理,形成了多个单路径图像,从而避免了多个路径回波信号混叠形成的鬼影干扰;最后,通过非相干叠加将多个单路径图像融合,形成了高质量的遮蔽目标图像。实验结果表明,本文所提方法能有效抑制鬼影干扰,明显提升遮蔽目标图像成像质量。

       

      Abstract: Existing non-line-of-sight target imaging methods often suffer from ghost artifacts caused by multipath aliasing. To address this issue, a multipath exploitation radar imaging method is proposed in this paper for occluded targets based on dual-band collaborative separation of multipath echo signals. First, taking a L-shaped building scenario as a case study, a multipath propagation model is established for the main L-band radar and the auxiliary millimeter-wave radar. The causes of ghost artifacts are analyzed in detail based on the L-band target imaging results obtained by back projection (BP) and incoherent superposition processing. Next, according to the differences in multipath propagation characteristics between the L-band and millimeter-wave radar, a dual-band collaborative multipath matching and separation strategy is proposed. A matching factor is defined to quantitatively evaluate the similarity of propagation delays between dual-band paths. Furthermore, a path separation function is designed to achieve effective separation of the main L-band multipath echo signals based on the dual-band matching results. Then, the BP algorithm is applied to independently process the L-band echo signals of each separated path to construct multiple single-path images, thereby avoiding ghost interference caused by the aliasing of multipath echo signals. Finally, multiple single-path images are fused through incoherent superposition to form high-quality images of occluded targets. Experimental results demonstrate that the proposed method can effectively suppress ghost interference and significantly improve the imaging quality of occluded target images.

       

    /

    返回文章
    返回