CAREER: Enabling Non-Line-of-Sight Imaging with Terahertz Holography

标题：使用太赫兹波的非视距成像摘要：这项工作的重点是使用太赫兹波来实现能看到隐藏物体的相机。太赫兹波是极高频率的信号(100 GHz 10太赫兹)，可实现独特的成像功能。除非观察抛光良好的表面，否则人眼和普通相机只能分辨出视线内的物体，因此位于角落里的物体是不可见的。另一方面，太赫兹(THz)波从普通建筑表面表现出强烈的反射。使用太赫兹摄像头，墙壁或门可以像镜子一样出现，从而可以窥探房间和洞穴的内部，否则就不会被直接看到。这种能力将增强第一反应人员和救援人员在无法到达和未知环境中的视野和情景意识。有趣的是，下一代超高速无线通信系统可以利用非视距成像功能。未来的通信系统将配备天线，可以作为摄像头运行并传输数据。太赫兹通信和成像的协同作用将实现不间断的链接和用户移动性。此外，非视距成像将使用户能够以厘米级的精度定位虚拟/增强现实或辅助医疗保健中的应用程序。拟议的项目还将强调培养更广泛的高中、本科生和研究生受众。通过使用增强现实耳机，学生将实现允许在现实世界中可视化太赫兹成像能力的软件。此外，PI将与当地的急救人员和退伍军人合作，通过研讨会向他们介绍新成像技术的能力和机会。这项研究的目标是设计图像重建算法和硬件拓扑，使之能够从单个观察点对视线(LOS)和非视线(NLOS)对象进行实时3D THz成像。这项为期五年的职业发展计划有以下目标：1)分析多路径成像中图像失真的机制，并实施算法来反转过程，以实现准确的图像重建。2)设计非视距太赫兹成像的拓扑结构，了解通信和成像共存的要求。3)实现同时定位和映射的方法以及成像和通信协议之间的协同以实现有效的信道估计。这项工作的智能价值在于了解THz波在多路径和多反射情况下的波前失真，并利用这些知识实现反向散射方法，从后向散射信号中重建图像。这些知识还将帮助我们了解硬件成像要求，以及NLOS成像如何与通信硬件协作实现新的应用。利用周围环境的3D图像，为下一代超高速无线通信提供了一种新的信道估计方法。从长远来看，这项研究将通过在恶劣和未知的环境中实现第一反应、监视和侦察来为国家安全做出贡献，允许在拥挤的空间进行自主导航，并为成像和通信的集成提供一条途径，以实现更快的无线数据传输。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Title: Non-line-of-Sight Imaging Using Terahertz WavesAbstract:This work is focused on using terahertz (THz) waves to implement cameras that see hidden objects. THz waves are extremely high frequency signals (100 GHz 10 THz) that enable unique imaging capabilities. Unless looking into a well-polished surface, human eyes and regular cameras can only discern objects that are in the line of sight, therefore an object located around a corner is not visible. On the other hand, terahertz (THz) waves exhibit strong reflections from common building surfaces. Using THz cameras walls or doors can appear as mirrors, thus allowing to peek inside rooms and cavities otherwise hidden from direct sight. Such capability will augment vision and situational awareness of first responders and rescuers in unreachable and uncharted environments. Interestingly, non-line-sight imaging capabilities could be leveraged from the next generation of ultra-fast wireless communication systems. Future communication systems will be equipped with antennas that can operate as cameras and transfer data. The synergy of THz communications and imaging will enable uninterrupted links and user mobility. Additionally, non-line-of-sight imaging will enable localization of users with centimeter-level accuracy for applications in virtual/augmented reality or assisted healthcare. The proposed project will also emphasize on educating a broader audience of high school, undergraduate, and graduate students. With the use of augmented reality headsets, the students will implement software that allows the visualization of THz imaging capabilities in the real-world. Additionally, the PI will collaborate with local first responders and military veterans to educate them through workshops on the capabilities and opportunities of the new imaging technology.The goal of this research is to design image reconstruction algorithms and hardware topologies that will enable real-time, 3D THz imaging of both line-of-sight (LoS) and non-line-of-sight (NLoS) objects from a single observation point. The five-year career-development plan has the following objectives: 1) Analyze the mechanisms that distort images in multipath imaging and implement algorithms to invert the process for accurate image reconstruction. 2) Design topologies for NLoS THz imaging and understand the requirements for communication and imaging coexistence. 3) Implement methods for simultaneous localization and mapping and synergy between imaging and communication protocols for efficient channel estimation. The intellectual merit of this work is to understand wavefront distortions of THz waves in multipath and multi-reflection scenarios and use this knowledge to implement inverse scattering methods to reconstruct images from backscattered signals. This knowledge will also help us understand the hardware imaging requirements and how NLoS imaging can collaborate with communication hardware for novel applications. Using the 3D images of the surrounding, the proposed research will provide a new approach for channel estimation for the next generation of ultrafast wireless communications. In the long term, this research will contribute to the national security by enabling first response, surveillance and reconnaissance in hostile and uncharted environment, allow autonomous navigation in crowed spaces, and provide a path for the integration of imaging and communications for faster wireless data transmission.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.