基于多路径特征融合的非视距目标识别方法
Non-Line-of-Sight Target Recognition Method Based on Multi-Scale Feature Fusion
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摘要: 在获取非视距(non-line-of-sight,NLOS)区域内目标的位置信息后,进一步识别建筑拐角后方的武装人员、无人机等目标类别,对现代城市作战、智能驾驶等场景具有重要研究价值。然而,由于非视距环境中电磁波传播路径复杂,目标的回波信号存在多径边界模糊、信号畸变等问题,使得传统基于几何特征建模或手工特征提取的方法难以获得可靠的分类。因此,本文提出了一种基于多路径特征融合的非视距目标识别网络。该方法首先分析了四类典型目标(即行人、RPG操作者(Rocket-Propelled Grenade,RPG)、四旋翼无人机以及坦克模型)的回波特征差异。其次,针对多路径回波图中路径数量不一、边界模糊等问题,设计了自适应多尺度特征提取模块;具体而言,小尺度卷积核用于捕捉单路径回波中的细小高幅值特征,大尺度卷积核用于提取多路径回波的全局结构信息。随后,引入注意力机制融合多径显著特征与局部散射特征,有效提升了非视距目标类型识别的准确性。最后,利用多径雷达探测系统采集实测数据进行验证,实验结果表明所提网络的目标识别准确率达99.6%,对比实验充分验证了所提算法的有效性与稳定性。Abstract: The accurate classification of targets concealed in non-line-of-sight (NLOS) regions, such as armed personnel or unmanned aerial vehicles behind building corners, holds significant value for modern urban warfare and intelligent driving systems. However, the complexity of electromagnetic wave propagation in NLOS scenarios often introduces multipath interference, blurred path boundaries, and signal distortion in echoes, thereby undermining the reliability of traditional classification methods that rely on geometric modeling or handcrafted features. To address these challenges, this study proposes a multipath feature fusion network for NLOS target classification. First, the echo characteristics of four representative target types were analyzed: pedestrians, soldiers carrying anti-tank weapons, quadrotor drones, and tank models. Given the variability in multipath returns and boundary blurring, an adaptive multi-scale feature extraction module was designed. Specifically, small-scale convolutional kernels were employed to capture fine-grained, high-amplitude features in single-path echoes, whereas large-scale kernels were used to extract global structural information related to multiple propagation paths. Additionally, an attention mechanism was incorporated to effectively fuse salient multipath features with local scattering information, thereby enhancing classification accuracy under NLOS conditions. Finally, real-world measurements collected with a multipath radar sensing system were used for validation. The experimental results demonstrate that the proposed network achieved a target classification accuracy of 99.6%. Comparative experiments confirmed the effectiveness and robustness of the proposed method.
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