During recent months passengers randomly selected for additional screening at Phoenix's Sky Harbor International Airport have had the option of a typical pat down by security personnel or a one-minute, full body scan from a new type of x-ray machine that allows screeners to see through clothes. The US federal government is testing so-called backscatter x-ray machines there, which can detect potentially threatening objects under a person's clothes by picking up x-rays scattered by materials. (Traditional x-ray machines pick up signals that pass through or are absorbed.)"It's using edge detection to detect anomalies," says Joe Reiss, vice president of marketing at American Science and Engineering (AS&E), the Boston-based manufacturer of the SmartCheck machine. "If you are a suicide bomber and have a vest on, that would appear as clear as day in an image."
The system can operate in full scan mode, or can be configured to obscure the details from certain, more sensitive, body areas. Security specialists argue that in the latter mode the system is ineffective.
Similar trials have taken place in the UK, Russia and elsewhere.
