scholarly journals The active-passive continuous-wave terahertz imaging system

2016 ◽  
Vol 735 ◽  
pp. 012075 ◽  
Author(s):  
Irina N Dolganova ◽  
Kirill I Zaytsev ◽  
Anna A. Metelkina ◽  
Stanislav O Yurchenko
Keyword(s):  
Continuous Wave ◽  
Imaging System ◽  
Terahertz Imaging

Improvement of continuous-wave terahertz imaging system for cellulose acetate membrane electrophoresis

2012 ◽  
Vol 7 (S1) ◽  
pp. S126-S131 ◽  
Author(s):  
Hongbing Zhang ◽  
Kazutaka Mitobe ◽  
Mahmudul Kabir ◽  
Masafumi Suzuki ◽  
Yoko Mitobe ◽  
...  
Keyword(s):  
Cellulose Acetate ◽  
Continuous Wave ◽  
Imaging System ◽  
Terahertz Imaging ◽  
Cellulose Acetate Membrane

A hybrid continuous-wave terahertz imaging system

2015 ◽  
Vol 86 (11) ◽  
pp. 113704 ◽  
Author(s):  
Irina N. Dolganova ◽  
Kirill I. Zaytsev ◽  
Anna A. Metelkina ◽  
Valeriy E. Karasik ◽  
Stanislav O. Yurchenko
Keyword(s):  
Continuous Wave ◽  
Imaging System ◽  
Terahertz Imaging

scholarly journals Towards Practical Terahertz Imaging System with Compact Continuous Wave Transceiver

2021 ◽  
pp. 1-1
Author(s):  
Li Yi ◽  
Yosuke Nishida ◽  
Tomoki Sagisaka ◽  
Ryohei Kaname ◽  
Ryoko Mizuno ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Imaging System ◽  
Terahertz Imaging

scholarly journals Comparison of digital beamforming algorithms for 3-D terahertz imaging with sparse multistatic line arrays

2017 ◽  
Vol 15 ◽  
pp. 283-292 ◽  
Author(s):  
Bessem Baccouche ◽  
Patrick Agostini ◽  
Falco Schneider ◽  
Wolfgang Sauer-Greff ◽  
Ralph Urbansky ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Imaging System ◽  
Near Field ◽  
Terahertz Imaging ◽  
Projection Algorithm ◽  
Back Projection ◽  
Digital Beamforming ◽  
Linear Movement ◽  
Range Migration ◽  
Continuous Wave Signal

Abstract. In this contribution we compare the back-projection algorithm with our recently developed modified range migration algorithm for 3-D terahertz imaging using sparse multistatic line arrays. A 2-D planar sampling scheme is generated using the array's aperture in combination with an orthogonal synthetic aperture obtained through linear movement of the object under test. A stepped frequency continuous wave signal modulation is used for range focusing. Comparisons of the focusing quality show that results using the modified range migration algorithm reflect these of the back-projection algorithm except for some degradation along the array's axis due to the operation in the array's near-field. Nevertheless the highest computational efficiency is obtained from the modified range migration algorithm, which is better than the numerically optimized version of the back-projection algorithm. Measurements have been performed by using an imaging system operating in the W frequency band to verify the theoretical results.

scholarly journals Fast FMCW Terahertz Imaging for In-Process Defect Detection in Press Sleeves for the Paper Industry and Image Evaluation with a Machine Learning Approach

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6569
Author(s):  
Maris Bauer ◽  
Raphael Hussung ◽  
Carsten Matheis ◽  
Hermann Reichert ◽  
Peter Weichenberger ◽  
...  
Keyword(s):  
Machine Learning ◽  
Continuous Wave ◽  
Imaging System ◽  
Early Stage ◽  
Paper Industry ◽  
Terahertz Imaging ◽  
Image Resolution ◽  
Structural Defects ◽  
Learning Approach ◽  
Machine Learning Approach

We present a rotational terahertz imaging system for inline nondestructive testing (NDT) of press sleeves for the paper industry during fabrication. Press sleeves often consist of polyurethane (PU) which is deposited by rotational molding on metal barrels and its outer surface mechanically processed in several milling steps afterwards. Due to a stabilizing polyester fiber mesh inlay, small defects can form on the sleeve’s backside already during the initial molding, however, they cannot be visually inspected until the whole production processes is completed. We have developed a fast-scanning frequenc-modulated continuous wave (FMCW) terahertz imaging system, which can be integrated into the manufacturing process to yield high resolution images of the press sleeves and therefore can help to visualize hidden structural defects at an early stage of fabrication. This can save valuable time and resources during the production process. Our terahertz system can record images at 0.3 and 0.5 THz and we achieve data acquisition rates of at least 20 kHz, exploiting the fast rotational speed of the barrels during production to yield sub-millimeter image resolution. The potential of automated defect recognition by a simple machine learning approach for anomaly detection is also demonstrated and discussed.

The Experiment Research of Continuous-Wave Terahertz Imaging System

2018 ◽  
Vol 103 (1) ◽  
pp. 247-254
Author(s):  
Yan Deng ◽  
Wenjun Li ◽  
Pengbo Tong ◽  
Shiqin Liu ◽  
Weiwen Liang ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Imaging System ◽  
Terahertz Imaging ◽  
Experiment Research

Continuous Wave 2D Terahertz Imaging System

2012 ◽  
Author(s):  
Jyotirmayee Dash ◽  
Shaumik Ray ◽  
Bala Pesala
Keyword(s):  
Continuous Wave ◽  
Imaging System ◽  
Terahertz Imaging
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