Multistatic Terahertz Imaging Using the Radon Transform

Abstract

We present a novel imaging method for compact low-profile imagers in millimeter wave (mmW) and terahertz (THz) frequencies. The method borrows the principles of computerized tomography to generate 2-D or 3-D high-resolution images using simplified RF front ends. To perform imaging, the proposed scheme implements the projection-slice theorem. Specifically, it records the Radon transform (RT) of the desired field-of-view (FOV) and reconstructs the image using the Fourier slice theorem. To achieve the illumination of the FOV, the proposed imaging configuration uses a rotating linear antenna array that produces a highly directive fan beam. The antenna elements are further reduced using multistatic sparse array techniques without compromising the image reconstruction process. By dramatically reducing the number of active elements, the new method could allow high-resolution mmW/THz imaging systems to be embedded in low profile and lightweight platforms, including unmanned aerial vehicles or CubeSats. In this paper, we present the basic concept of the novel imaging scheme and simulation results verifying the proof of concept. Finally, we present a modified imaging antenna array that alleviates interference from objects and sources outside the FOV.