By Zack Sampson, News Staff
Backscatter X-ray units are used primarily in airports to provide high-quality images of passengers’ bodies, but the US Department of Homeland Security has joined with multiple research institutions, including Northeastern University, to test the use of such security technology in a mobile platform.
According to documents recently published by the Electronic Privacy Information Center (EPIC), Northeastern was contracted for $1,305,181 by the Department of Homeland Security to research the development of a transportable explosive sensor system in July 2006.
“Our idea is a mobile platform with a collection of sensors that work at different ranges … [to] try to get a sense of people who might have something suspicious beneath their clothing,” Carey Rappaport, a professor of computer and electrical engineering at Northeastern and principal investigator on the project, said.
Rappaport said the initiative is still going on in some forms, but will remain inactive until the Department of Homeland Security can allocate more funding for the studies.
Researchers worked on the “BomDetec Wide – Area Surveillance and Suicide Bomber Detection” program. It was a collaborative effort between multiple organizations including Raytheon, American Science & Engineering, Inc., Rensselaer Polytechnic Institute and the Siemens Foundation.
Rappaport said Northeastern was the “principal organizing entity” while the project was active. He said some students at the university were involved in algorithm-based work, and no experimentation with radar hardware occurred on-campus.
The BomDetec program centered on the development of an integrated system which could use data from four sensor types: intelligent video, radar, X-ray Backscatter and Terahertz radiation to detect and track potential suicide bombers at distances greater than 10 meters. Government defense institutions sought a final product that could serve foreign and domestic purposes.
The Department of Defense application of such a mobile unit would provide extra security at military checkpoints, Rappaport said.
“The idea was that it would be nice if you had a series of sensors that, in layers, could determine first of all if a person was suspicious, second of all if there might be something dangerous concealed under his clothing, third of all to confirm that there was something suspicious about this person,” he said.
Domestic security officials also planned to use the technology in a mobile form for scenarios such as a parade route passing by a reviewing stand.
“On the homeland side, wouldn’t it be great if you could park a van near the stand to make sure there wasn’t some idiot marching with these guys with a vest full of pipe bombs?” Rappaport said.
Theoretically, researchers hoped to place all sensors in a single hardwired van. Similar retrofitted vans already exist in more basic forms. American Science & Engineering, Inc. markets a Z Backscatter Van that has built-in X-ray equipment.
Rappaport said a van using all four sensors would need to be slightly larger, but still could be easily retrofitted.
“The X-ray was sort of the biggest thing, you could put video cameras on top of a van and nobody would even notice,” he said. “The radar fits into the size of maybe a telephone book … Terahertz is also about the size of a desktop computer.”
Rappaport said, for those moving in front of the Backscatter van, the system would work similar to security cameras at a mall.
“If you looked for it, you probably could find it,” he said. “But you really wouldn’t know about it unless you were looking for it. It’s not as secretive as traffic radar police use to catch speeders; that’s really hidden.”
Some, including members of EPIC, have expressed privacy concerns about mobile use of X-ray surveillance technology.
“This would allow them to take these technologies out of the airport and into other contexts like public streets, special events and ground transit. It’s a clear violation of the fourth amendment that’s very invasive, not necessarily effective and poses all the same radiation risks as the airport scans,” Ginger McCall, an attorney for EPIC, said in a recent Forbes Magazine article.
Rappaport said concerns of radiation risks are not significant.
“Taking pictures with video versus radar versus X-ray versus Terahertz, in no cases does any of it produce any sizable radiation that would have any health effects,” he said.
Rappaport added that the security vans would not necessarily produce the same images as an airport security system.
“[The images] probably wouldn’t be as high resolution as you’d get with an airport scanner because you are not standing right near it with your hands in the air,” he said.
Rappaport compared the actual images that Backscatter X-rays would produce in the mobile platform to looking at a person in a tight leotard or bathing suit like someone would wear at the beach.
“If that’s acceptable in some contexts, then it seems, in the interest of keeping everybody safe, it might be an acceptable compromise,” he said.
Rappaport emphasized that safety was his key motivator for the project.
“It’s satisfying to do this type of security research,” he said. “Everybody has thoughts of what is considered beneficial for society. But, all I have to do is have my device save the life of one nine-year-old girl … that makes a lot of the hard work seem worthwhile.”
