Research

The ALERT research program is derived from a top-down understanding of societal issues related to explosive detection, mitigation, and response. These issues can be crystallized by considering a set of "Grand Challenges". These challenges in turn inform and drive the ALERT research program through an organizing three-level strategy which includes four core fundamental science research thrusts: Explosives Characterization (F1), Explosives Sensors (F2), Explosive Sensor Systems (F3), and Blast Mitigation (F4).

In the following sections, we will present a sample scenario, the Grand Challenges, the three-level ALERT strategic structure and details of the proposed research program.

The importance of a top down approach:
"Deployment of Previously Unknown Explosive Compounds" - sample scenario

Background: A recent bombing utilized new explosives which were not detectable with current technology. Trace analysis showed only that the explosives were perchlorates. In addition, the detonator used appeared to be thermite-based. A house in Somerville, MA is suspected to be a facility for producing explosives. There is no credible evidence that there are explosives in the house, and swipes for traditional explosives have come up negative for any trace of nitrates or amines on surfaces around the house. No forced entry to the house will occur until a suitable understanding and quantity of the explosives and detonators are known due to its proximity to highly populated areas.

Detection: New methodologies of stand-off and close-in detection for unknown explosives will clearly have to be developed through a series of steps: (1) The actual (or potential) explosive will have to be identified; (2) properties of the energetic material must be characterized (vapor pressure, density, x-ray signatures, UV/Vis/IR spectra, mechanical properties) to determine the most effective detection method; (3) synthetic pathways will need to be deduced so that precursors of synthesis can be included in potential signatures; (4) blast properties will be determined via actual detonations; and (5) testing of materials will be performed to determine sensitivity and potential countermeasures. Sensors will be developed based on non-traditional signatures of the explosives, precursors, initiators, and detonators. Methodology for sample collection will also need to be investigated (e.g. waste water sampling or vapor phase sampling) and detection limits understood. The main method of preventing future use of these novel explosives will be by early detection of precursors, as purchases of significant quantities of the precursors would suggest further investigation. The mechanical properties of the explosive will also be verified (e.g. solid, liquid, polymer) which will lead to probable methods of packaging the energetic materials into a device.

Mitigation: Once the properties of the new explosives are determined and potential quantities are estimated, blast effects can be predicted via advanced modeling. These predictions can then be used to establish a safe perimeter, to determine the effects on surrounding structures, and to select appropriate protective equipment for personnel conducting a forced entry. Response: An understanding of the characteristics of the new explosives (e.g. impact sensitivity, potential triggering methods, and probable packaging methods) will assist responders in locating and neutralizing explosive devices during a forced entry. Response will also focus on ways of chemically destroying energetic materials where large area contamination or densely populated areas do not allow for in-place destruction of the explosives. In the event that terrorists succeed in detonating the explosives and causing significant casualties/damage, there is a critical need to manage the response (medical, fire-fighting, police, bomb squad, investigators, etc.) to prevent chaos, evacuate wounded, and limit additional casualties. Technologies that can support this phase include: planning/modeling tools, airborne surveillance systems, communication systems, tagging/tracking and visualization technologies, and forensics for attribution/prosecution purposes.

Grand Challenges that drive the ALERT research program

The ALERT team uses scenarios like the one above, to define several "Grand Challenges" facing DHS and society. We present these challenges as overarching themes followed by specific examples of challenge questions. Each of these challenges has important attributes in common: fast/rapid, reliable/low-false-alarm-rate, unobtrusive, and in many cases stand-off.

Ultra-Reliable Screening

• Can we handle large crowds, e.g., at sports events, in subways, nightclubs and churches?
• Can we improve the speed and reliability of passenger and luggage screening?
• Can we non-invasively identify explosives in cargo containers in transit?

Greater than 50 meter Stand-Off Discovery and Assessment

• Can we reliably pinpoint explosives in left behind packages or vehicles?
• Can we recognize potential suicide bombers?
• Can we find explosives in urban traffic?

Unequivocal Pre- and Post-Blast Mitigation

• Can we render inactive an explosive material (shockless mitigation)?
• Is there an optimal strategy to protect critical assets from an explosion?

Rapid and Thorough Preparedness and Response

• Can we classify and understand unknown explosive materials in real time?
• How can we quickly both learn from and educate first-responder teams?
• Can we accurately develop and gain insight from realistic scenario simulations?

Addressing the Challenges: The Three-Level ALERT Strategy

ALERT's organizing and operational strategy is described through a three-level strategy, tying real-world Grand Challenges and the fundamental research together and keeping them synchronized but able to adapt as societal and DHS needs change. This top-down approach has proved exceedingly successful within the National Science Foundation Engineering Research Center program that strives for breakthrough transformational research in areas of societal importance. The three-level approach helps to identify research barriers that prevent the achievement of the Grand Challenges, keeps resources focused on objectives, and assists in solving management issues. The three-level structure is illustrated below.

The Grand Challenge Level (top level-red) contains the challenges that need to be addressed in order to achieve a high level of protection from explosives-related threats. Within each broad challenge area there are subsets that will lead toward next-generation explosives detection and mitigation engineered systems, enabling an order-of-magnitude improvement in performance over present technologies. The first versions of these systems will begin to emerge from the ALERT COE in approximately four years. The Enabling Technology Level (middle level-green) contains testbeds needed to validate fundamental research results and to enable these research breakthroughs to play a role in addressing the grand challenges. Initial versions of these testbeds will emerge in about two years. The Fundamental Research Level (bottom level-blue) contains the basic research areas and associated projects needed to overcome barriers that prevent achievement of the grand challenges.