Characterization of penetrable dielectric slab affixed to the human body using focused CW mm-waves

Abstract

Long security lines are frustrating for airline passengers who must undergo pat downs when when currently deployed mm-wave imaging system falsely alarm innocent objects. Faster and more efficient security checkpoints are required to effectively prevent airplane terrorist attacks while minimizing the inconvenience of long security lines. The goal of this work is to build an algorithmic approach to determine the dielectric constant of concealed objects, and rule out non-explosive dielectric objects, to speed Advanced Imaging Technology (AIT) scanning. VS model which is an intuitive ray-based forward model for characterization of weak dielectric objects (like slabs of explosive threats) on the surface of a highly conducting ground plane (modeling the body skin), for focused Continuous Wave (CW) sensing applications is presented with its inversion. This simple model is well suited for focused beam, near-field mm-wave sensing of body-worn explosives for person scanning security systems. VS model inversion algorithm is using two observable probe parameters by considering expected small variation of dielectric slab thickness over its surface. The presented ray analysis is experimentally-validated and the determination works reasonably well with both simulated and measured dielectric covered conductive ground plane as a representation of body worn explosives. xi

Automatic characterization of low-loss low-permittivity body-born threats using wideband millimeter-wave radar

“…In [31,32,33,34,35], thickness and dielectric constant of body-born concealed objects have been determined for the continuous wave (CW) radar images. Our study focuses on determining the same properties of the potential threats automatically and by using wideband radar images with high range resolution.…”