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December 27, 2011

APL Shapes Future Explosive Detection Systems

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APL is working with the Department of Homeland Security (DHS) Science and Technology Directorate to combat terrorism by developing requirements for explosive detection systems for subways and other modes of mass transit. The goal is to prevent tragedies in the United States like the 2005 London subway bomb attacks that killed 52 people and injured 700 mass transit passengers.

A team from the Homeland Protection Business Area's Transportation Security Systems Program (TSSP) leads an effort to develop tools that increase security for subway and light rail passengers, starting with research of more than 130 train stations nationwide over the past year. This group of APL scientists, engineers, and mathematicians aims to characterize passenger flow, physical constraints, and environmental parameters at these locations and develop requirements that DHS will use to develop state-of-the-art detection systems.

"We are tackling the very complex problem of securing the mass transit environment to ultimately prevent terrorist attacks, and we began by studying subway systems in Seattle, Chicago, Philadelphia, San Francisco, Los Angeles, and Baltimore," says Emily Stoll, TSSP manager. "Our project will eventually expand to other surface transportation venues such as ferry boats and buses."

Securing the mass transit environment is a challenge; subways for example, are designed to be open and allow people to move freely from street level to the railcars below. "In some of our country's larger mass transit systems, you see hundreds of thousands, if not millions, of passengers in a given day," says Jacob Boon, TSSP project manager. "Not only do you have many people moving through a confined space very quickly, but subway stations typically have different access points. The challenge is developing technology that fits well and works effectively within that environment."

Many aviation security systems were developed after 9/ 11, but they aren't easily transferred to the mass transit environment. A big reason for this is staffing and passenger flow. Baggage X-ray and other devices in use at airport checkpoints require at least one operator, and mass transit systems don't have the resources for additional staff, yet must deal with much higher passenger flow. "We are looking for automated ways that don't require a human operator to make the detections," says Stoll.

To establish the requirements for such technologies, APL is taking measurements in the field to determine how passengers flow through a given area. An APL-developed modeling and simulation component of the project, called STRATAM (for Surface Transportation Technology Assessment Model), simulates the process of people moving through a transit system and helps translate raw measurements into performance requirements for sensors. DHS can then determine how much of a passenger load a given sensor can handle and how fast it must scan a crowd moving through a transportation system. STRATAM also enables APL to optimize the placement of sensors within a station and explore layered detection concepts.

Homeland Protection Business Area Executive Jose Latimer says the Laboratory's integrated systems engineering approach brings all of the data and information together for the sponsor, allowing APL to make recommendations and DHS to make sound investments in technologies that increase mass transit security. "The TSSP program is a great example of how APL expertise in systems engineering and modeling and simulation can combine to support our sponsors with reliable information," he adds. "As we tackle this challenging problem, we are playing a significant role developing the right technology to enhance our national security."