Public spaces such as mass transit systems, stadiums, and large arenas face the potential for high-impact security incidents because of heavy foot traffic and the ease with which pedestrians could conceal threat items. Real-time imaging technology that detects threat items hidden under clothing or in bags can serve as a powerful tool in securing these vulnerable environments.

Microwave imaging, unlike x-ray sensing, is well-suited to screening humans because it uses safe, non-ionizing signals (similar to that of cellular phones or wireless routers). Furthermore, it offers far superior material penetration than either terahertz or infrared sensing. The public safety uses of this technology are nearly unlimited.

Microwave imaging systems have been successfully used in safeguarding air terminals. However, those systems require a screened subject to stop and pose for several seconds. In high foot traffic environments, this disruption is unacceptable, highlighting a need for a higher throughput solution.

MIT Lincoln Laboratory (MIT LL) has developed a microwave imaging system that can operate at video rate (~10 Hz) to handle a constant stream of subjects. The system employs sparse multi-static array sampling for a low-cost realization of its required electrically large aperture, a fast imaging technique for video-rate image formation, and a modular design for flexible implementation. These aspects are critical to the system’s operation, and were central to the technology transfer efforts.

This product aims to unobtrusively enhance security in high foot traffic environments by assessing subjects via microwave imaging.

Critical technology for the realization of this system was transferred to Liberty Defense Technologies (LDT), which intends to commercialize the transferred technology via its product, the Hexwave. This product aims to unobtrusively enhance security in high foot traffic environments by assessing subjects via microwave imaging.

The system will form a 3D microwave image of the subject, revealing items that are concealed under clothing or in bags. The image will be processed using artificial intelligence (AI) techniques to identify potential items of interest and ensure that no personally sensitive image is presented to an operator.

Overall, this partnership has greatly accelerated movement of a federally developed technology investment into industry. Almost one year after its founding, LDT has grown to a sizeable organization, building a product that is based on a federally funded prototype. MIT LL’s close interaction with LDT has facilitated very efficient transfer of some of the core research and development, and practical developments realized under the federally funded effort.

Contact: David Pronchick, (781) 981-3027, [email protected]