基于非视距雷达三维成像的隐藏目标精确重构方法

Precise Reconstruction Method for Hidden Targets Based on Non-line-of-sight Radar 3D Imaging

非视距(NLOS)三维成像雷达是一种利用多径散射回波探测隐藏目标的新技术,但存在多路径回波分离、孔径遮蔽缩减、反射面相位误差等问题,传统视距雷达三维成像方法难以实现非视距隐藏目标的高精度成像。为此,该文提出了一种基于迭代稀疏重构的非视距隐藏目标三维成像雷达精确成像方法(NSIR)。在该方法中,首先构建非视距毫米波雷达三维成像的多径信号模型,利用视距/非视距回波特性,通过模型驱动方法提取非视距隐藏目标的多路径回波,实现视距/非视距回波信号的分离;其次,构建耦合多径反射面相位误差的全变分多约束隐藏目标重构优化问题,利用分裂Bregman全变分(TV)正则化算子和最小均方误差的相位误差估计准则,联合求解多约束最优化问题,实现非视距目标的精确成像及轮廓重构。最后,搭建平面扫描的三维成像雷达试验平台,完成了拐角非视距场景下刀具、铁架等目标的实验验证,验证了非视距毫米波三维成像雷达隐匿目标探测能力及该文方法的有效性。

Non-Line-Of-Sight(NLOS)3D imaging radar is an emerging technology that utilizes multipath scattering echoes to detect hidden targets.However,this technology faces challenges such as the separation of multipath echoes,reduction of aperture occlusion,and phase errors of reflective surfaces,which hinder the high-precision imaging of hidden targets when using traditional Line-Of-Sight(LOS)radar imaging methods.To address these challenges,this paper proposes a precise imaging method for NLOS hidden targets based on Sparse Iterative Reconstruction(NSIR).In this method,we first establish a multipath signal model for NLOS millimeter-wave 3D imaging radar.By exploiting the characteristics of LOS/NLOS echoes,we extract the multipath echoes from hidden targets using a model-driven approach to realize the separation of LOS/NLOS©The Author(s)2024.This is an open access article under the CC-BY 4.0 License(https://creativecommons.org/licenses/by/4.0/)echo signals.Second,we formulate a total variation multiconstraint optimization problem for reconstructing hidden targets,integrating multipath reflective surface phase errors.Using the split Bregman Total Variation(TV)regularization operator and the phase error estimation criterion based on the minimum mean square error,we jointly solve the multiconstraint optimization problem.This approach facilitates precise imaging and contour reconstruction of NLOS targets.Finally,we construct a planar scanning 3D imaging radar experimental platform and conduct experimental verification of targets such as knives and iron racks in a corner NLOS scenario.Results validate the capability of NLOS millimeter-wave 3D imaging radar in detecting hidden targets and the effectiveness of the method proposed in this paper.