Researchers at North­eastern are inves­ti­gating ways to make our nation safer from ter­rorist threats through the devel­op­ment of cutting-​​edge imaging tech­nolo­gies. The work is focused within the Bernard M. Gordon Center for Sub­sur­face Sensing and Imaging Sys­tems (Gordon-​​CenSSIS) and the Aware­ness and Local­iza­tion of Explosives-​​related Threats center (ALERT), funded by the National Sci­ence Foun­da­tion and the Depart­ment of Home­land Secu­rity, respec­tively. Pro­fessor of Elec­trical and Com­puter Engi­neering Michael Sile­vitch, who leads Gordon-​​CenSSIS and co-​​directs ALERT, talks about “below-​​the-​​surface” imaging tech­niques and his work with the Depart­ment of Home­land Security.

Given the events of the past month, it is under­stand­able that air­line pas­sen­gers might feel wary about flying. Are our air­ports and air­lines any less safe than they were a year ago? Five years ago?
No, in fact, I believe that the air­ports are in gen­eral safer today com­pared to five years ago. That being said, there are existing tech­nolo­gies that can be more widely deployed to make air­port screening even more reli­able. Exam­ples include dual energy X-​​ray screening for bag­gage and whole-​​body imaging scanners.

Where do you see imaging tech­niques moving in the near future? Will metal detec­tors become a thing of the past?
Multi-​​mode detec­tors (the use of two dif­ferent and com­ple­men­tary screening tech­niques) are being exam­ined for reli­a­bility. For example, X-​​ray tech­nology can scan the con­tents inside of a bag and infrared chem­ical detec­tors can detect traces of chemicals.

I think that cur­rent tech­nolo­gies, like metal detec­tors, will always have a role in screening because they are easy to deploy and inter­pret. More­over, their sig­nals can be used to indi­cate the need for more in-​​depth sec­ondary screening.

What do you con­sider the most impor­tant part of ramping up our home­land secu­rity efforts to keep the nation safe?
One impor­tant area would be to create seam­less ways for var­ious sec­tors and orga­ni­za­tions to work together more effec­tively. There would be tremen­dous value in cre­ating col­lab­o­ra­tions between the aca­d­emic com­mu­nity and our U.S. national laboratories.

The Depart­ment of Home­land Security’s (DHS) Office of Sci­ence and Tech­nology has begun working towards this by estab­lishing aca­d­emic Cen­ters of Excel­lence, including ALERT. It is these non­tra­di­tional part­ner­ships that will bear impor­tant fruit in terms of new approaches on how to make our nation more secure.

How are you working to deter the acts of poten­tial sui­cide bombers before they strike?
The ALERT center has sev­eral ongoing projects to deal with sui­cide bombers. One involves the use of radar tech­nology to detect sig­na­tures of hidden metallic objects under clothing. Another involves using video tech­niques to look at the motion of people in a crowd and dis­cern abnormal behavior. These two com­ple­men­tary tech­nolo­gies could help detect poten­tial sui­cide bomber threats.

What steps are you taking at ALERT that will help thwart future ter­rorist attacks in the United States?
ALERT has hosted a number of counter-​​IED (impro­vised explo­sive device) and imaging work­shops to iden­tify the gaps in our cur­rent knowl­edge and tech­nology base. Based on these work­shops, we can pro­vide more strategic guid­ance to the DHS and advise them where to focus future efforts to ensure progress in com­bating these sig­nif­i­cant threats.

What is the most intriguing part of your research?
The theme of my research is “finding hidden things,” whether they are hidden under­ground, inside the human body, such as a tumor, under the water or within a bio­log­ical organism. It was a nat­ural exten­sion to look for hidden things that were related to explo­sive threats.

The intriguing part is that we hope to extend the use of these ana­lyt­ical tools to address the detec­tion of hidden objects in other places. Showing the gen­er­ality of our approach will lead to the cre­ation of a new field of engi­neering study to deal with dif­fi­cult detec­tion prob­lems. This is my ulti­mate goal.