A team led by the US Air Force's Phillips Laboratory at Kirtland AFB, New Mexico, is developing a walk-through security device able to indicate when a metallic object is a security risk, such as a firearm, rather than a harmless object such as a key or a coin.

The joint industry-government team was formed by the Phillips Laboratory in September with Farr Research of Alburquerque, New Mexico and EG&G Astrophysics of Long Beach, California, with funding under the federal defence-laboratory diversification programme.

The Metal Object Identification System should cut down on inconvenience for airline passengers who now have to put metal objects into a basket before stepping through the arch, or are searched manually if they trigger the detector. As well as comparing object "signatures" to a database of objects such as guns and knives, the system can indicate the position of a concealed weapon.

The technique upon which the system relies was developed by Dr Carl Baum of Phillips Laboratory's Advanced Weapons and Survivability Directorate. He established that low-frequency magnetic fields return a distinctive signature for a particular object, and used the method to build up a computer database which could then be referred to when scanning any object for a match.

Source: Flight International