Technologies


Personnel Screening Device for the Detection of Non-metallic Concealed Contraband Using Microwave Backscatter

Reference#: P02003


Current security scanning procedures at commercial airlines may reasonably fail to detect nonmetallic objects (i.e., plastic explosives such as C4 and ceramic devices) concealed under a person's clothing. Passive infrared receivers that measure thermal emissions have proven to be ineffective due to the small temperature difference for objects next to the body and the thermal diffusion due to clothing. Although volatile explosives (e.g. TNT) produce a detectable vapor signal, plastic explosives have vapor pressures well below current detection thresholds.

Using a low-power radio frequency (RF) transmitter/receiver (Tx/Rx) the Johns Hopkins University Applied Physics Lab has developed a method to detect nonmetallic materials concealed under clothing. This device may detect prohibited materials by virtue of its variable localized field of view, down to small body surface areas, and the predictable reflected wave scattering differences produced by materials with widely dissimilar relative electric permittivities. Required radiation power can be sufficiently below commonly encountered environmental levels (e.g., door openers, motion detectors, and police radar) due to the very short operational range required (i.e. 12 inches), thus eliminating any reasonable health/liability concerns. Since no imaging is performed, privacy issues are moot. An entry point sensor system, based on this technology could potentially be inexpensive to produce and maintain.

CONTACT:
Mr. K. Chao
Phone: (443) 778-7927
ott-techmanager6@jhuapl.edu