Three-Dimensional Terahertz Coded-Aperture Imaging Based on Geometric Measures.

Area of Science:

• Radar imaging technology
• Electromagnetic wave applications

Background:

• Synthetic aperture radar faces limitations in high-resolution forward-looking and staring imaging.
• Terahertz coded-aperture imaging (TCAI) offers a solution but struggles with computational burden and low SNR resolution in 3D.
• Existing methods face challenges in detecting scattering information at extremely low SNRs.

Purpose of the Study:

• To propose a novel 3D TCAI method using geometric measures (GMs) to address computational complexity and low SNR imaging.
• To enhance signal detection and noise suppression for improved target resolution.
• To reduce computational complexity for efficient 3D image reconstruction.

Main Methods:

• Development of a GM-based TCAI (GM-TCAI) model derived from the conventional TCAI (C-TCAI) model.
• Utilizing GMs to enhance useful signals and suppress noise in range profiles, overcoming limitations at extremely low SNRs.
• Simultaneous reconstruction of target information by extracting data from range profiles, enabling efficient 3D image generation from 2D results.

Main Results:

• The proposed GM-TCAI method effectively reduces computational burden compared to C-TCAI.
• GM-TCAI demonstrates superior high-resolution imaging capabilities, particularly for targets with low signal-to-noise ratios.
• Experimental results validate the enhanced performance in imaging ability and efficiency of GM-TCAI.

Conclusions:

• GM-TCAI offers a significant improvement over conventional TCAI for 3D imaging.
• The method is effective in overcoming challenges associated with low SNR and high computational load.
• GM-TCAI shows broad applicability in close-range imaging fields such as medical diagnosis, nondestructive testing, and security screening.