Strip search that spares your blushes

Share this article

PIONEERING research by Scots scientists is set to unleash a powerful weapon in the war on terrorists and drugs barons.

Last year a powerful scanner which can detect plastic explosives and illicit drugs was installed and tested at London’s Gatwick Airport as part of a pilot programme.

But the scanner has been sitting idle because its remarkable technology allows it to use a special wavelength of light literally to see through clothing. This, for obvious reasons, infringes civil liberties and means the machine cannot be used.

So scientists at Heriot-Watt University in Edinburgh have been called in by the Home Office to work on a solution which could see the scanner deployed across the globe.

They are developing remarkable software which takes the ‘naked’ image of the person in front of the scanner and replaces it with a computer-generated dummy.

At the same time, the machine can detect suspicious packages or objects under the clothing. Ingeniously, the software then superimposes the real image of the item causing concern on the computer-generated dummy. Crucially, the target’s privacy will still be maintained.

Dr Yvan Petillot, of Heriot-Watt’s School of Engineering and Physical Science, said he was confident his team’s development would mean the powerful scanners would be in use soon at airports.

He said: "The tests were carried out at Gatwick Airport last year, and while the airport authorities were impressed, it is now our job to make the scanner more private to become a mainstream solution to security.

"The problem with the scanner is you effectively see people naked, so although the technology is available and getting better all the time, you can’t use it for privacy reasons.

"We are developing a form of automatic detection and identification tools so you don’t need to have anyone looking at the ‘raw’ images where you see people naked.

"We want to cut and paste the part of the real image where things seem to be wrong on to a mannequin of a person.

"The operators then know where to check manually to see if the person is carrying something they shouldn’t."

The powerful scanner, which was developed by American scientists, uses millimetre waves to see through clothes. It works because the fibres in clothes are less than a millimetre across, allowing the light waves to pass right through them.

A special camera using the waves can see through clothes as easily as we can see through glass. And the picture it creates can be seen on a screen so operators can see not just if a person is carrying arms, but also drugs and plastic explosives. Non-metallic illegal substances like these are not picked up by normal airport scanners.

Petillot explained: "The system would compare around 50 different images produced by the cameras in just two seconds.

"People move differently if they have things attached to them.

The computer will be able to pick up on this to identify things which shouldn’t be there."

He added: "Current X-ray technology only allows operators to see metal weapons like guns and knives, but this scanner detects plastic explosives and drugs as well."

The scanner could eventually be used not just in airports and train stations but in all public places.

Petillot explained: "At the moment there is no real way of checking fans coming into a football stadium or pupils going into a school to see if they are carrying knives.

"The millimetre wave technology needs people to pause for a second at the moment. But it’s possible that when the scanning software is developed it could get quick enough to scan crowds passing through turnstiles into a football match."

Another advantage of millimetre wave scanners over current technology is they do not interfere with pacemakers.

Petillot said: "The camera just receives the rays a person emits, rather than sending out waves itself. So it doesn’t interfere with pacemakers and there are no risks involved in people going through the scanner."

And Petillot believes similar technology could be used to scan lorries and trains crossing borders for illegal immigrants.

Petillot’s team has received 200,000 funding with assistance from the Home Office to complete the new software, which should be available for use in the next two years. His team believe machines could be sold for 100,000.

A spokesman for the Department of Transport said they were monitoring the new research with interest.

"We are aware of the technology but without the further research being carried out at Heriot Watt, the scanner was not mature enough for use at airports," he said.

"We actually enabled Heriot-Watt to achieve part of the funding for the further research.

"We will continue to keep abreast of the new technologies available, which will hopefully provide new weapons in the fight against terrorism."