Measurements of incident radio frequency power levels from the L3 technologies provision body scanner for the national academy of science

Abstract

The Transportation Security Administration is tasked with the job of performing safety screening of millions of air travel passengers annually in a safe and efficient manner. One of the most widely deployed detection systems is the L3 Technologies “Provision” body scanner, which utilizes millimeter wave radio frequencies (RF). Have you ever wondered what type and levels of RF energy are used to execute this routine security screening test? Recently, the Department of Homeland Security, Transportation Security Administration, tasked the National Academies of Science (NAS) to execute an updated safety analysis of the L3 manufactured TSA ProVision Body Scanner units deployed in airports world-wide. In the process of executing their tasking, the NAS realized there was very little peer-reviewed published data on calibrated field incident power within the ProVision scanner itself. While L3 has their own factory acceptance program, the NAS wanted independent measurements executed on operational L3 machines at four randomly selected airports. The NAS contracted with the team of BerrieHill Research and Applied Research Associates to design a specialized field probe system that measures the RF field strength of the Provision Units. This very challenging measurement environment required design ingenuity to fulfill the contract needs, since this system was not allowed to physically connect to any part of the ProVision machine. We had to place a field measurement device inside the unit where the passenger stands, and record all data “over the air” only. This paper will completely describe the BRC/ARA Provision Scanner field probe measurement system, and present calibrated RF field measurements.