What lies beneath
Technologies forcing air passengers to ‘bare all' have proved an effective way to detect concealed objects.
The system, which was first piloted by the TSA at Phoenix Airport in 2007, can detect illegal objects very effectively.
"What we're doing is generating a very small ray of x-rays which we refer to as a pencil beam. Using this mechanical scanning technology we basically create an x-ray beam that can move back and forth and up and down to scan an area," says Joe Reiss, vice president of marketing, AS&E.
"We're collecting the scatter off the object we're scanning, in this case a person, so we can look at the signal of the reflected x-rays. We use those scattered x-rays to generate the images. Different types of material will scatter different rays, making it easy for security officials to detect explosives or narcotics."
Though concerns about radiation exposure have been expressed, medical scientists have dismissed the risk as "trivial".
Even for frequent travellers, the effects are so minimal they pose no real health threat. A person would have to be scanned hundreds of thousands of times for the issue to even merit discussion.
As Reiss points out, people are exposed to radiation on a daily basis, and particularly so during air travel.
"When you're flying in an aeroplane you receive the same amount of radiation in two minutes that you do by undergoing one scan by one of these SmartCheck systems," he says.
In addition the technology is very simple to use. Training sessions are very short and analysts quickly become accustomed to recognising objects displayed on the images.
Reiss says: "Security officials are trained to position passengers. The machine itself is very simple, you just press a button to start. A lot of the training is just having people become familiar with looking at and interpreting images."
According to AS&E, officials are often capable of detecting anomalies after only a few hours of training.
Despite the detection success rates of these technologies, the images they produce have caused considerable controversy.
While privacy advocates argue that the anatomical detail present on some of the images is invasive and unnecessary, system developers insist they are doing everything they can to protect passengers.