基于全极化超宽带穿墙雷达稀疏快照的建筑物成像方法研究

Mapping the interior structures and layouts of building becomes a hot research topic,but faces great challenges. Its evolution is of great important for the military and civillian fields. Synthetic aperture radar(SAR) imaging approaches are typically for building imaging. However,the generation of SAR images requires movememt of the array aperture along a prescribed path. This is extremely difficult for SAR platforms based upon ground or airborne vehicles , especially in hostile environments.This proposal introduces a portable full polarimetric ultrawideband(UWB) snapshots radar sensing systems as an alternative to SAR.This system avoids SAR deficiencies by not requiring aperture movement along a path when collecting backscatter from multiple location. Instead,a single finite planar antenna aperture is utilized to collect data in random and multiple snapshot locations and to compose building imaging by image fusion techniques. So it has advatage of the attrributes of flexibility and reliability. This proposal investigates building imaging techniques for full polarimetric UWB snapshots radar,especially mapping layouts of building. The main studies will focus on following four aspects:1)to optimize the design of full polarimetric UWB antenna planar array for through-the-wall;2)to analyze scattering mechanisms from buildings;3)to investigate high resolution imaging for full polarization UWB radar in single snapshot location;4)to develop building layout determination and reconstruction visualization enhancement.The research of this project provides new opportunities for enriching and improving through-the-wall radar theory and techniques.

对整座建筑物内部结构布局进行反演成像是国际学术前沿的研究热点与难点，该方面的突破在军民两用领域都具有十分重要意义。建筑结构布局反演成像常采用合成孔径雷达（SAR）体制，它通过机载或车载平台移动天线合成所需的阵列孔径。但是，对于周边地形复杂的敌占建筑侦察、罪犯藏匿建筑和地下结构勘探等特殊环境，使用这些平台就非常困难了。取而代之的是便携式全极化超宽带快照雷达，其使用固定天线阵列在空间位置进行稀疏快照，处理后即可重建建筑布局图像，因而具有很强的灵活性和可操作性，非常适合特殊环境。为此，本项目拟系统地研究基于全极化超宽带穿墙雷达稀疏快照的建筑结构布局反演问题，主要内容包括全极化超宽带雷达天线平面阵列的优化设计、建筑结构布局的散射机理分析、全极化超宽带雷达高分辨成像方法、建筑结构布局图像的重构与可视化增强方法。本项目的研究为丰富和完善穿墙雷达理论和方法提供新的契机。

对于周边地形复杂的敌占建筑、罪犯藏匿建筑和地下结构勘探等特殊环境，难以使用机载或车载平台移动天线合成建筑物成像所需的阵列孔径。取而代之的是使用便携式UWB MIMO稀疏阵列雷达系统在空间位置进行稀疏快照。本项目围绕便携式UWB MIMO稀疏阵列雷达系统综合利用极化、宽带、目标先验信息等重建稀疏快照的建筑物图像面临的技术难题，分析了该雷达在正侧视和斜视时建筑物的电磁散射传播特性，在此基础上研究了建筑物结构的高分辨成像方法、建筑物结构的全景图像重建方法、建筑物结构的属性散射中心提取方法和建筑物内部隐藏目标的高分辨成像方法等，构建了相应的数学模型，探索利用稀疏信号处理等方法提出了相应的算法，解决了MIMO稀疏阵列的栅瓣和旁瓣抑制、off-grid和未知的墙体参数引起成像不聚焦、墙体内部或墙体表面多次反射产生的多径效应形成虚假像以及占据多个网格像素的扩展目标模型引起目标稀疏成像不连续等关键问题。通过仿真和实测数据对相应的模型和算法的有效性进行了验证，结果为提升建筑物透视雷达系统的性能提供理论指导。