- The Science and Technology Directorate (S&T) and Transportation Security Administration (TSA) are collaborating on Advanced Imaging Technology to improve the passenger screening experience.
In 2024, TSA screened three million people in a single day for the very first time. With unprecedented numbers of travelers passing through airports, S&T is focused on improving the airport experience of the future so passengers can move to their destinations with ease. New and retrofitted passenger screening systems are currently being tested at S&T’s Transportation Security Laboratory (TSL) in Atlantic City, New Jersey.
Developing the future of aviation security
The S&T Screening at Speed Program, in collaboration with TSA, is developing new concepts and technologies to help the Department of Homeland Security (DHS) meet the needs of passengers while also fine-tuning detection performance, so TSA continues to stay ahead of evolving threats and keep the traveling public safe. The Screening at Speed Program is working with the Department of Energy’s Pacific Northwest National Laboratory (PNNL) to develop improved detection capabilities and a more user-friendly passenger experience. High Definition-Advanced Imaging Technology (HD-AIT) is the backbone of this development.
What is High Definition-Advanced Imaging Technology?
HD-AIT uses non-harmful radio waves known as millimeter waves that pass through natural and synthetic materials to generate high-resolution data. Millimeter waves can penetrate through fabrics to screen for concealed objects, including non-metallic objects that traditional metal detectors aren’t designed to detect. However, the millimeter waves are completely safe as they are 10,000 times less powerful than cell phone signals and don’t penetrate the skin. This data is not reviewed by a human but processed by an algorithm that protects passenger privacy and provides results on a generic representative human figure for Transportation Security Officers (TSOs) to review. The algorithm will alert the TSO that an anomaly has been detected by presenting identifiers on the generic representative human image, so they can conduct secondary screening as needed.
Integrating HD-AIT into standard airport screening lanes could allow passengers to keep light sweaters, jackets, and even shoes on during screening as well as making the detection and identification of threats easier while reducing false alarms. These enhancements provide an opportunity to improve overall detection while also improving the passenger experience. The more forward-leaning Real-Time AIT may eventually allow standard passengers to be screened at walking speeds, similar to a metal detector.
Designing passenger screening and retrofit-kits
The Screening at Speed Program has worked with PNNL to create two versions of the HD-AIT system, the stand-alone passenger screening system and the passenger screening retrofit-kits.
The passenger screening system operates like existing walk-in, pause-and-pose systems currently operating in airports. The difference is the higher definition data that can identify threats more easily while reducing false alarms, improving screening effectiveness, saving passengers time, and reducing the frequency of pat downs to resolve alarms.
The retrofit-kits consist of the custom electronics developed for the HD-AIT system and package them so they can be installed into systems already in use at airports without having to replace the entire system chassis, saving TSA time and money. PNNL has delivered three retrofit kits in support of evaluation and design for manufacturing efforts. In May 2024, one of these systems was delivered to the TSA Systems Integration Facility in Arlington, Virginia, for evaluation in a near operational environment, which is a critical step in development before demonstrations with real passengers can take place.
Scanning shoes without removing them
A prototype shoe scanner has been developed for potential integration with the HD-AIT, which could support a future screening experience that provides a fast and efficient alternative to current security practices at airports. The shoe scanner operates similarly to the HD-AIT passenger screening system. When a passenger steps onto the shoe scanner, harmless millimeter waves pass through the sole of the shoe and 3D data is sent to a computer for review. The footwear scan takes approximately two seconds and data processing about five seconds. In the future, the shoe scanner could be incorporated in the floor of passenger screening systems so both passengers and their shoes can be screened at the same time.
Real-time AIT is a walk in the…airport
After developing the passenger screening and prototype shoe-scanner systems, the Screening at Speed Program began pursuing more forward leaning on-person screening applications like real-time passenger screening panels. Real-Time Advanced Imaging Technology builds upon the HD-AIT technology, increases its capability, and places it inside modular panel sensors to collect images at video rates as passengers walk-by or move in front of the panels. Real-time screening will enable next generation concepts of operations for aviation security, such as checkpoint-less screening, allowing higher passenger throughput rates and lower pat down rates.
Awards and commercialization
In October 2020, the shoe scanner received the R&D 100 Award for IT and Electrical engineering. In the summer of 2024, the Real-Time AIT system also won an R&D 100 Award in the Software/Services category. The R&D 100 awards are the only science and technology awards that recognize new innovations of significance available for sale or license.
In early 2021, both the HD-AIT passenger screening system and the shoe scanner were commercialized to Liberty Defense Holdings Ltd. of Atlanta, Georgia. The limited license allowed Liberty Defense to demonstrate an HD-AIT retrofit-kit installed in the shell of a passenger screening system already deployed to airports nationwide.
In 2022, the Screening at Speed Program and PNNL also won the Interagency Partnership Award from the Federal Laboratory Consortium for Technology Transfer for their work to commercialize both the HD-AIT passenger screening system and the shoe scanner.
Integrating with an open architecture
Future-proofing new technologies as they are developed is critical to make systems continue to operate at peak performance for years after they are installed. The Screening at Speed Program ensured that the HD-AIT system was built on an open architecture platform to provide DHS flexibility when choosing the best partners to collaborate with and to make updating software and hardware easier.
The HD-AIT systems were built to the joint S&T and TSA Open Platform Software Library (OPSL), a government-owned open architecture developed by Sandia National Laboratories and Stratovan Corporation, which was designed to allow the use of cutting-edge algorithms and detection software developed by the best in the business.
Algorithm challenge harnesses innovation
Screening systems are only as good as the algorithms that sort through the large amount of data collected to detect concealed threats. The better the algorithm, the better the system can determine what is and is not a threat, reducing false alarms and pat downs at the checkpoint. To ensure DHS had access to the best detection algorithms possible, the Screening at Speed Program co-sponsored a Passenger Screening Algorithm Challenge prize competition with the TSA Office of Acquisition Program Management, Passenger Screening Program.
The innovative competition solicited new automated detection algorithms that could be used to improve the speed and accuracy of threat detection during the airport screening process. In 2018, eight competition winners spilt the $1.5 million prize for algorithms that improved the capability of AIT passenger screening systems. In exchange, S&T retained unlimited rights to the top scoring algorithms which have since been further refined and certified for field trials to increase security effectiveness.
Testing and demonstration to improve prototypes
S&T sends new technology to the TSL for testing and demonstration to assess if it meets the needs of TSA and other stakeholders and meets standards provided by TSA. All three AIT prototype systems have been demonstrated to numerous high-level visitors including the U.S. Secretary of Energy, S&T Under Secretary, members of Congress, and DHS and TSA leadership and staff. The systems are currently undergoing evaluation at TSL to further define and characterize their detection capabilities.
When will the public be able to see AIT technologies?
While it may be a few years before passengers will see operational AIT systems at airport checkpoints, plans are in the works to conduct an operational assessment of the HD-AIT passenger screening system much sooner than that. Additionally, TSA plans to bring the shoe scanner to an airport for a limited demonstration within the next few years to gather feedback from TSOs and passengers. Attendees of the 2025 Consumer Electronics Show may be able to see a demonstration of the shoe scanner at the TSA booth to try out the system for themselves.
S&T’s strong partnership with TSA provides a glimpse into what the airport of the future could look like and highlights the hard work, extensive planning, and mutual dedication it takes to improve the air traveler experience and keep the American public safe.
