Influence of Beam Distribution on the Quality of Compressed Sensing-Based THz Imaging

Li Zhang,Xuemei Hu,Zeqi Zhu,Xiaoli Ji,Feng Yan

doi:10.1109/access.2020.3023442

Li Zhang, Xuemei Hu + Show 3 more

Open Access

https://doi.org/10.1109/access.2020.3023442

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Abstract

This paper investigates the impact of incident beam inhomogeneity on the quality of THz imaging based on the compressed sensing (CS) method. Image sampling and reconstructions under point and Gaussian beams with various geometric parameters are compared with the standard one. The simulation results show that the geometric parameters of beams strongly affect the peak signal-to-noise ratio (PSNR) of the reconstructed images. Especially for the Gaussian one, expanding the beam size at the position of the mask (BZPM) dramatically increases the PSNR. To achieve high sensitivity and resolution, new measurement matrices correlating to the incident beam distribution are proposed and the simulation results are demonstrated. Experiments under VDI THz source reveal that by using the new matrices, the PSNR of CS-based imaging at 100 GHz is evidently improved from 6 dB to 13 dB, informing the new measurement matrices are highly efficient and accurate in removing the beam effect on CS-based THz imaging. Our results may provide a new way for the high-quality CS-based THz imaging for target recognition.

Highlights

The recent developments of Terahertz (THz) imaging technology have shown broad application prospects in various areas such as security, material analysis, and biomedical research [1]
EXPERIMENT AND RESULTS On the basis of the above simulation results, the experiments for compressed sensing (CS)-based THz imaging are performed to certify the effects of our proposed method on imaging denoising
The random patterned mask is made of aluminum tape on a transparent quartz plate, where the opaque area accounts for half of the mask

Summary

Introduction

The recent developments of Terahertz (THz) imaging technology have shown broad application prospects in various areas such as security, material analysis, and biomedical research [1]. Provided that the distance between the source and the Lens1 is fixed in all the simulations, the incident beam is collimated by Lens 1, passing through the object and masks, and focusing on the single-pixel detector by Lens 2.

Results

Conclusion