Concealed object enhancement using multi-polarization information for passive millimeter and terahertz wave security screening

Abstract

Passive millimeter and terahertz wave imaging has become a significant potential technique for human security check and scene monitoring. Due to the small difference of the brightness temperatures between human body and concealed objects, the temperature sensitivity and spatial resolution of radiometers are always the key performance indexes which are difficult to improve. Therefore, when the hardware performance is given, improving detectivity becomes a pressing need. In this paper, a physically-based concealed object enhancement method using multi-polarization information is presented. The polarization model and polarization property of human body and concealed objects have been analyzed. By fusing multiple polarization images, we can obtain a complete polarization image in which the contrast between human body and concealed objects is enhanced and stable. The experimental results of simulation and measurement demonstrate the enhancement performance, and Differential Signal Noise Ratio (DSNR) is obviously improved by using the proposed method.

Series Photothermoelectric Coupling Between Two Composite Materials for a Freely Attachable Broadband Imaging Sheet

“…The presented findings and technologies can potentially be used for highly functional active sensing/imaging applications and further developments in blackbody radiation (BBR)‐based passive photomonitoring techniques, simultaneously. Although the current range of BBR‐based applications [ 39–41 ] is limited, due to a weaker intensity than that of external photo sources, [ 42 ] passive photomonitoring techniques have received significant attention for their unique advantageous characteristics: photo‐sourceless compact setup and wideband‐available frequency regions (MMW–IR). In particular, the use of human/animal bodies as BBR sources could contribute to noninvasive passive healthcare photomonitoring.…”

An Infrared DoLP Model Considering the Radiation Coupling Effect

“…In 2017, based on a three-component as sumption, Liu [22] established the pBRDF model of the coating, and used satellite coatin samples sr107 and s781 as examples to simulate and measure the polarization character istics. In 2020, Chen [23] analyzed polarization models and polarization properties of hu man bodies and transparent objects. Zhang [24] investigated the optical polarization char acteristics of low-earth-orbit space targets; Su [25] and Tuo [26] studied the ship targe detection method based on polarization characteristics.…”

AC‐SDBSCAN: Toward concealed object detection of passive terahertz images

“…Some studies have focused on the object detection in passive THz images in recent years [6–12]. Haworth et al.…”

“…Some studies have focused on the object detection in passive THz images in recent years [6][7][8][9][10][11][12]. Haworth et al [13] used k-means algorithm to segment the targets in passive millimeterwave images (PMMWIs).…”