Monday, June 25, 2018

Abstract-Three-Dimensional Terahertz Coded-Aperture Imaging in Space Domain

Bin Deng, Cheng-Gao Luo, Hong-Qiana Wang, Long Peng, Shuo Chen, Zhao-Wen Zhaung,

As a promising radar imaging technique, terahertz coded-aperture imaging (TCAI) can achieve high-resolution, forward-looking and staring imaging by producing spatiotemporal independent signals with coded apertures. However, traditional three-dimensional (3D) TCAI working in time domain, has two problems, tkhat is, heavy computational burden caused by large-scale reference-signal matrix, and poor resolving ability under low signal-to-noise ratio (SNR). Frequency-domain (FD)-TCAI (FD-TCAI) is able to reduce the two problems only in a limited degree. Therefore, this paper first proposes a spacedomain (SD)-TCAI (SD-TCAI) method, which achieves more effective and efficient 3D imaging than FDTCAI under low SNR. With correlation operation, SD-TCAI transforms the echo signals from frequency domain to space domain, where spike pulses appear in the target positions. According to different spike pulses, the 3D imaging areas can be divided and reconstructed in parallel, and finally synthesized together to obtain the whole 3D target. In this way, the computational burden is further reduced, leading to an improved SNR. In this paper, we build and present the imaging models and procedures of TD-TCAI, FDTCAI, and SD-TCAI, respectively. The experimental results demonstrate that SD-TCAI has overwhelming superiority over TD-TCAI and FD-TCAI. Therefore, SD-TCAI has great potential in applications such as security screening, nondestructive detection, medical diagnosis, etc. 

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