A British firm is aiming to capitalise on travellers' body issues with a security scanner that does not produce an image, yet can identify a wide range of concealed explosives.
Following Umar Farouk Abdul Mutallab's failed attempt to blow up a transatlantic airliner over Detroit, body scanners are firmly on the security agenda. Gordon Brown took to the TV studios to suggest they will be installed across the British airport network soon, backed by the biggest operator, BAA.
The current generation, one example of which was on trial at Manchester Airport before the on Christmas day attack, use either millimetre waves or backscatter X-rays to produce images of travellers in the ghostly altogether. Thus, the official line goes, hiding explosives in your pants, out of the reach of a pat-down, isn't possible any more.
This has raised concerns from privacy, civil liberties and child protection groups over who will see the images and how they will be stored. The Manchester Airport trial quickly ran into trouble over consent and the making of indecent images of children, first reported here.
TeraView, based in Cambridge, says it can satisfy both sides of the debate. It claims to be furthest along developing terahertz body scanners, which use light from upper end of the infra-red spectrum, with a wavelength between 0.1 and 1mm.
The firm's scanners don't produce an image but a "fingerprint". Rather than blurry pictures of naked tourists, a TeraView scanner would return absorbance data that could be automatically analysed to approve travellers or alert airport staff to investigate further.
The "fingerprints" identify textiles, skin underneath, metals, and crucially varieties of explosives, including PETN - Mutallab's weapon of choice. Semtex, TNT and RDX all have their own terahertz signature, too.
"We detect with higher sensitivity and lower false alarm rate than with images," said Dr Don Arnone, TeraView's CEO.
"The advantages outweigh the disadvantages and nobody we've spoken to has suggested they need images," he added. The firm has held talks with the Home Office and Department of Transport, and sold testing kit to the US Navy.
This more discreet approach to airport screening requires significant work, however. TeraView, which span out of Toshiba Research Europe in 2001, is seeking funding to incorporate the technology into a unit for airports, which Arnone estimates will take 12 months.
It also has competition pushing the body scanners of the future. Among the gaggle of body scanner firms gaining publicity in the wake of the failed Christmas day attack was Advanced Photonix, another terahertz outfit, based up the road from the target, in Ann Arbor, Michigan.
Arnone believes his firm's early start and patents put it in the lead against terahertz rivals.
Even so, the more advanced technologies are backed by some of the giants of public security. Rapiscan, part of OSI Systems, is responsible for X-raying travellers at Manchester Airport. Qinetiq, formerly part of the MoD, is meanwhile pushing a millimetre wave scanner which does not produce an image, but was forced to admit it would not have detected Mutallab's
exploding incendiary pants.
Arnone said he has received several calls since Christmas from authorities seeking confirmation that TeraView could detect PETN.
If terhertz scanners ever make it into airports, public health compaigners may cast more obstacles. A study in Physics Letters A in October suggested that the radiation could damage DNA, despite its non-ionising properties. More work is needed, advocates admit, but set against the very well known risks of ionising X-ray radiation and the fact that travellers are already being irradiated for security purposes, the threat to terahertz scanners from the finding seems minimal.
The advantage of terahertz technology in resolving the privacy debate over body scanners seems in little doubt. What remains unproven are the benefits of body scanners themselves for counter-terrorism*.
As has been explained here and in other enlightened places, the reaction to Mutallab means no self-respecting terrorist will attempt the exploding pants ploy where he knows body scanners are in use. He'll simply try something else, and air travel will still be very safe but not risk-free. ®
*Detection of contraband is the other obvious and much more frequent use of body scanners.