WiFi can be used to spot weapons and bombs inside stadiums and schools, researchers find
Ordinary WiFi signals could soon become a low-cost security tool for spotting chemicals, bombs and weapons.
A new study from Rutgers UniversityNew Brunswick demonstrates how wireless signals are able to penetrate bags to detect the exact dimensions of dangerous objects or estimate the volume of liquids.
After several trials, the researchers found that the system was at least 95 percent accurate.
The researchers hope that the detection system could help make museums, stadiums, theme parks, schools and other public venues safer.
'This could have a great impact in protecting the public from dangerous objects,' Yingying Chen, one of the study's co-authors, said in a statement. 'There's a growing need for that now.' Compared to traditional security systems, the researchers say their detection method cuts security screening costs, is easy to assemble and avoids invading privacy by having to open and inspect people's personal items.
Existing security screening systems also require more staff and may call for expensive specialized equipment, researchers said.
' In large public areas, it's hard to set up expensive screening infrastructure like what's in airports,' Chen said.
'Manpower is always needed to check bags and we wanted to develop a complementary method to try to reduce manpower.'
Their system uses a WiFi device with two or three antennas - one that transmits signals and one that receives signals.
It works by analyzing what happens when signals penetrate and bounce off objects and materials.
The system can detect and analyze signals from solid objects like weapons, aluminum cans, laptops and batteries.
It can also estimate the volume of liquids like water, acid, alcohol and other chemicals to see if they contain explosives.
It's able to separate the wireless interference caused by 'two influencing factors of objects,' or material and shape, researchers said.
For the study, researchers tested the system with 15 types of objects and six types of bags.
They logged a 99 percent accuracy rate for dangerous objects, 98 percent for metal and 95 percent for liquid.
Typical backpacks showed an accuracy rate of 95 percent, but that dropped slightly to 90 percent when dangerous objects were wrapped with a substance.
It comes as more and more public venues are adopting advanced security technologies to keep patrons safe.
The Transportation Security Administration is now testing checkpoint screening technology that would allow people to use their fingerprint as a form of identification.
It could spell the end of boarding passes, as security agents would compare the scanned fingerprint with one that's already on file.
For now, the technology is only being tested at select airport locations around the US.