scholarly journals Extended sources near-field processing of experimental aperture synthesis data and application of the Gerchberg method for enhancing radiometric three-dimensional millimetre-wave images in security screening portals

2017 ◽  
Author(s):  
Neil A. Salmon
Keyword(s):  
Near Field ◽  
Three Dimensional ◽  
Aperture Synthesis ◽  
Millimetre Wave ◽  
Security Screening ◽  
Extended Sources

First imagery generated by near-field real-time aperture synthesis passive millimetre wave imagers at 94 GHz and 183 GHz

2010 ◽  
Author(s):  
Neil A. Salmon ◽  
Ian Mason ◽  
Peter Wilkinson ◽  
Chris Taylor ◽  
Peter Scicluna
Keyword(s):  
Real Time ◽  
Near Field ◽  
Aperture Synthesis ◽  
Millimetre Wave

An efficient design method for LED surface sources in three-dimensional rotational geometry using projected angle difference  An efficient design method for LED surface sources

2018 ◽  
Vol 51 (3) ◽  
pp. 457-464 ◽  
Author(s):  
X Li ◽  
P Ge ◽  
H Wang
Keyword(s):  
Design Method ◽  
Near Field ◽  
Three Dimensional ◽  
Optical Systems ◽  
Two Dimensional ◽  
Efficient Design ◽  
Angle Difference ◽  
Extended Sources ◽  
The Relationship ◽  
Better Than

An efficient method is proposed for the design of prescribed rotational illumination on the far or near field using the edge-ray principle. By this method, the prescribed illuminance on the prescribed location can be determined by projected angle difference in a two-dimensional design process for LED extended sources. Profiles of the lens with two initial curves on the centre can be calculated based on the relationship between the illuminance and the projected angle difference. The initial optical systems we calculated are close to the prescribed illumination despite the influence of skew rays. More importantly, a prescribed illumination on the near field can be achieved accurately and quickly by using this method, which is better than the usual luminous intensity distribution design methods for LED extended sources.

scholarly journals Imaging of bi-anisotropic periodic structures from electromagnetic near-field data

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Dinh-Liem Nguyen ◽  
Trung Truong
Keyword(s):  
Inverse Scattering ◽  
Maxwell Equations ◽  
Field Data ◽  
Periodic Structures ◽  
Near Field ◽  
Scattering Problem ◽  
Three Dimensional ◽  
Inverse Scattering Problem ◽  
Factorization Method ◽  
Unique Determination

AbstractThis paper is concerned with the inverse scattering problem for the three-dimensional Maxwell equations in bi-anisotropic periodic structures. The inverse scattering problem aims to determine the shape of bi-anisotropic periodic scatterers from electromagnetic near-field data at a fixed frequency. The factorization method is studied as an analytical and numerical tool for solving the inverse problem. We provide a rigorous justification of the factorization method which results in the unique determination and a fast imaging algorithm for the periodic scatterer. Numerical examples for imaging three-dimensional periodic structures are presented to examine the efficiency of the method.

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