Passive Millimeter-wave Sensors Research Articles

Portable Passive Millimeter-Wave Sensor for Detecting Concealed Weapons and Explosives Hidden on a Human Body

This paper describes a portable passive millimeter-wave sensor designed for remote detection of both metallic and non-metallic objects hidden on a human body under cloth. The sensor is based on a directly detection and analyses of the energy emitted by a human body. The algorithm of detection estimates unimodality features of traces recorded in the process of a manual scan. The sensor demonstrates a detection probability in the laboratory environment close to 100% at a distance of up to 3 m for the tested samples of explosives and metal objects hidden under cloth.

Measured comparison of contrast and crossover periods for passive millimeter-wave polarimetric imagery

Several targets are set-up outside and imaged by a passive millimeter-wave sensor over a 24 hour period. The sensor is capable of measuring two linear polarization states simultaneously and the contrasts of the targets are compared for the different polarizations. The choice of polarization is shown to have an impact on the contrast of different targets throughout the day. In an extreme case the contrast of a target experiences a crossover event and disappears for one polarization while it presents a strong contrast (9 K) with the other polarization. Experimental results are shown along with a simulation of the scene using a ray tracing program.

New Technology and Applications on Passive Millimeter-Wave Sensors

Some new technology and applications on passive millimeter wave (pmmW) sensors are reviewed. The development of passive millimeter wave imaging sensors, operating at W band, that are currently being manufactured for commercial markets using standard automated assembly processes. is described. The focus was to adapt the night vision passive thermal infrared imager performance models and apply them to pmmW imaging systems for prediction of field performance for the task of small watercraft and boat identification. A novel method of human presence detection using pmmW sensors is presented. The method focuses on detecting a standing human from a moving platform in a cluttered outdoor environment using pmmW radiometry. Finally the research and development in passive millimeter wave imaging and performance improvements is discussed. The future passive millimeter wave sensors are expected.