Last week, a suicide bomber attacked Moscow’s busiest airport, killing 35. Carey Rappaport, professor of <b >electrical and computer engineering and associate director of both the <b >ALERT (Awareness and Localization of Explosive-Related Threats) Center and <b >Gordon-CenSSIS (Bernard M. Gordon Center for Subsurface Sensing and Imaging Systems), describes some of Northeatern’s technological advances in explosives detection and homeland security, as well as some of the nontechnical challenges researchers need to consider.

What research is ALERT conducting in the area of suicide bombing prevention?

Our research in ALERT looks at a variety of sensors to try to identify potential suicide bombers, including standoff and portal-based millimeter-wave radar and X-ray backscatter to identify suspicious shapes of concealed objects, IR and Terahertz standoff spectroscopy for trace-explosive detection, video surveillance to look for unusual behavior, and electronic sensing to detect hidden triggering devices. Some of the advanced technology is mature but being brought to bear for new situations, and some is brand-new basic research that would provide novel detection features.

<b >What must researchers keep in mind when developing new bomb- imaging techniques so that travelers still feel at ease?

As with all practical technology development, we must put ourselves into the shoes of those who will experience the technology. Health, privacy, dignity, expense, and time are important aspects that cannot be overlooked. Of course, there are some health and engineering problems that are so tough to solve that they require extreme measures (like chemotherapy or the Big Dig), but we should always be asking ourselves if there’s a better way to detect without being too intrusive. If terrorists hide things in embarrassing places, security officers will have to search in embarrassing places. But it would be best if the searching could be done using technology instead of humans.

<b >How do airport security measures differ internationally?

Airport security is constantly in a state of flux, with policies changing sometimes between one’s vacation arrival and departure. I’ve noticed in Europe and Asia that security doesn’t make you take off your shoes, but does require that belts, jewelry and wallets be removed. In some countries there is more emphasis on interviewing travelers as they go through security. It is interesting that the Department of Homeland Security rarely shares details about security technology development internationally, but we expect other countries to scrutinize travelers as well as the U.S. does.