T-Ray Camera Sees Through Clothes, Preserves Privacy

Quite a few readers are sending in stories about ThruVision's products, slated to be demonstrated in Britain next week, that are claimed to use Terahertz radiation ("T-rays") to detect foreign objects under clothing, without revealing body details, from a distance of 25 meters and while the subject is in motion. T-rays lie on the electromagnetic spectrum between infrared and microwaves, and are the subject of lively research efforts worldwide. ThruVision says it developed its products in cooperation with the European Space Agency.

Schiphol Amsterdam using same kind of technology

[Tjeerd]

Last year they installed a device at Airport Schiphol in Amsterdam, that can also scan through your clothes to see what's beneath it. Read the article [url=http://www.dutchamsterdam.nl/174-amsterdam-airport-body-scanning]here[/url]. Some articles on the internet claim that "The Security Scan scanner is based on a technology that uses millimeterwaves. The waves will persist over clothing, and are reflected by the skin. Also other materials, such as plastic, metal, wood, iron, ceramics, etc. reflect the waves. This will help to detect suspicious objects." More information can also be found here [safeviewinc.com].

Re:Don't be silly

[iNaya]

Stupid things getting confiscated happens a lot. I've accidentally brought scissors onto a plane while my girlfriend had make-up and beauty cream stolen from her. (It wasn't in the mandatory plastic bag (don't see how a plastic bag makes make-up less dangerous though)). By focussing on too many things, security actually drops because it allows more error for more dangerous things to get on. They wasted so much time arguing with my girlfriend they didn't actually catch what was in my jacket as it went through the scanner.

T-ray

[Wilson_6500]

It's a really unfortunate choice of names, this "T-ray." Inevitably, it wants to make a person associate these waves with x-rays. Photons are photons, but as far as these guys go healthwise, it's pretty certain they'll have more in common with radio or microwaves than x-rays. Heck, the reason they call them x-rays and gamma rays in the first place is because they're in the regime where it makes sense to talk about photons as particles, rather than waves. And they call them "radio waves" and "microwaves" because THEY are down in the more wave-like regime. Just call it "millimeter wave" and be done with it, before we get people claiming they're getting ARS from T-ray devices.

(Let us not forget that a single terahertz-range photon carries about 4meV of energy. That's little-m milli, not big-M mega. These guys might cause some heating, but they're not going to be ionizing many atoms in your body.)

Re:Don't be silly

[malsdavis]

People taking their own drinks on planes is a real threat ...to the profits of Airport Operators who make A LOT of money selling duty-free retail space.

Re:Schiphol Amsterdam using same kind of technolog

[billsf]

Schiphol has had this technology for a few years now. The 'technicians' watch the show in a curtained box some distance from the gates and relay findings to security. When I asked if it was a 'sub-millimeter' system, I was told so, with a smile. They also have infrared that can spot people with a fever, who cannot fly. This system is passive. This device operates at about 10uM or 30THz.

BTW, 1mm = 300GHz and a true 'T-ray' is at about 1000GHz or 1/3mm.

Re:Preserves privacy

[robably]

That's an aweful lot of disgusting bodies to look at for just a few good looking ones!

If I remember correctly, I think that's part of Operant Conditioning [wikipedia.org] - producing a reward only occasionally is more effective at reinforcing a behaviour than rewarding the behaviour every time. After you've conditioned the rat to press the bar to receive a food pellet you reduce the frequency of the reward and it ends up pressing the food bar manically in the hope of receiving another. Thus in this case, hot chicks stand out from fat birds and the operator is stimulated to continue looking to find another.

Re:Judging by this picture

[Loconut1389]

Or this one
http://www.iancavalier.com/spiralnotepad/images/2007/millimeter-wave-backscatter.jpg [iancavalier.com]
from when this first hit slashdot.

Follow the money

[bytesex]

Lots of people look at your bits with your permission; doctors, correction facility officers, the military, visitation people at airports. You could get around the awkwardness easily by establishing a code of conduct, and special procedures (like, I only want to be seen by a woman - ok, get in this special line here). But it would be expensive, and it would add a notch to the paycheck of the otherwise menial job of airport security officer. This technology is only being developed to avert payrises. Because T-ray /will/ be there at some point.

The amazing strip-search scanner

[dark-br]

Link with pictures here [thznetwork.org]

Re:Don't be silly

[grrrl]

The plastic bag is simply so they can eyeball all your liquids/gels at once, easily.

Re:Don't be silly

[TerribleNews]

I maintain that this is all part of a plan to get people used to obeying rules that don't make any sense and keeping people afraid so they'll be docile and do what they're told. Imagine combining the Milgram experiment (http://en.wikipedia.org/wiki/Milgram_experiment [wikipedia.org]) with a multi-generational desensitization towards following orders you don't agree with. You know, start small, like forcing people to split their fluids up into 3 oz containers on airplanes. Eventually , I bet you could get people to do pretty much anything.

Re:Preserves privacy

[Anonymous Coward]

At airports where these systems are under trial (Heathrow is an example), policies are in place to prevent some of these issues. Basically, the screeners looking at the output from these systems are separated physically from the location where the passengers are being scanned. They do not have visual/optical access to the individuals, only the monitor on which the processed image/video is displayed.

I say "processed" because certain systems that have exceptional resolution also have privacy controls, which de-resolve specific bodily areas. Those systems are x-ray backscatter, however, not passive terahertz. Passive terahertz (Thruvision, and ones such as this [nationalgeographic.com]) do not have this problem, as the article states. Think about it: f = 100 GHz to 1 or 2 THz. What's the wavelength? What's the best possible resolution (Rayleigh criterion, diffraction limited optics with a reasonable aperture not larger than 0.5 m, etc.)?

Disclaimer: this is my Ph.D. thesis topic.