x Abu Dhabi, UAEMonday 22 January 2018

High-stakes hide and seek

New scanning technologies are bringing increased transparency to everything from long-haul cargo to carry-on luggage.

A new crop of X-ray scanners produce several images of an object, including a backscatter X-ray (top) and a high-penetration transmission X-ray (bottom), for a more complete view.
A new crop of X-ray scanners produce several images of an object, including a backscatter X-ray (top) and a high-penetration transmission X-ray (bottom), for a more complete view.

When it comes to the business of airport and cargo security, Chip Starns says the complex physics, patents and millions spent on research all boil down to one question: "Who can build a better mousetrap?" Just as a sly mouse can often have his cheese and live to eat it too, a determined criminal can slip weapons, drugs and explosives past hi-tech scanners at any airport or border. "None of us are going to get it perfect," says Mr Starns, the vice president of ScanTech Sciences, a relatively new and small technology firm that recently landed a large contract with the Abu Dhabi police.

"You can bring explosives in any possible shape, and it's easy to hide them," says Stefan Aust, the director of product management for Smiths Detection, one of the oldest and largest X-ray technology firms. Smiths and ScanTech are helping the UAE to provide its airports and border checkpoints with state-of-the-art equipment. While scanners may not catch every threat, Bruce Schneier, the chief security technology officer of the BT group, says they are one of the best assets available to authorities - an automated version of bomb-sniffing dogs. "There are a lot of stupid things in airport security; baggage scanning isn't one of them," he said.

Last month, Sheikh Mohammed bin Zayed, the Crown Prince of Abu Dhabi, initiated a five-year plan to improve security. Since then, Abu Dhabi police have reached a deal with ScanTech, and Abu Dhabi Customs bought US$55 million (Dh202m) worth of equipment from American Science and Engineering (AS&E). Meanwhile, Smiths has been outfitting Dubai airport's new Terminal 3 with 70 scanners for hold-stowed luggage and 200 units for carry-on bags. Smiths will also provide scanners to Jebel Ali airport.

The changing nature of security fears, triggered by international incidents such as Sept 11, have spurred the development of scanning technology. The first airport X-ray equipment was installed after terrorists began targeting air travel in the late 1960s. The German company Heimann, which was bought by Smiths Group in 2003 and named Smith Detection, sold its first machines in the mid-to-late 1970s. Primitive compared with today's systems, bags were placed in a box and then shot with radiation. The result was a black and white printout that outlined the shape of the bag's contents - similar to a medical X-ray.

The first Smiths scanner, which slid luggage on a conveyor belt, was installed at the Manchester and Athens airports between 1981 and 1982. These machines used transmission X-ray technology, the basic science that remains in use: an X-ray beam is shot through the baggage; different items inside absorb the radiation at different rates, and a detector determines how much of the beam makes it through the luggage, then generates simple images on a filter. "They were looking for clock faces with wires sticking out and connecting to TNT," says Brian Mayo, the president of the X-ray technology firm Xstream Systems.

For the most part, these scanners deterred and prevented hijackings, the main concern of airlines at the time, Mr Aust says. Bomb attacks, such as the one on board Air India in 1985, which killed all 329 people on board when it exploded over the Atlantic Ocean, increased urgency to develop stowed baggage scanners that recognised the density of materials. The new technology determined whether an item was organic - made of carbon, hydrogen, nitrogen and oxygen - or not. While current scanners are good at recognising conventional threats such as guns and knives, Mr Mayo says they still have trouble with materials, mistakenly identifying harmless items such as modelling clay as threats.

Mr Aust says these false alarms are a by-product of how secure an airport or border checkpoint chooses to be. On one side, authorities want a machine to flag any potential threat. On the other, airports and airlines do not want flights held for hours while the chocolate is separated from the C4 explosive. "You can adjust the same machine to say, 'My major concern is detections', so the machine alarm is very sensitive," he said. "Because under [any] circumstances you don't want to miss a threat. But then you have to deal with a large false alarm rate."

That rate can be cut down by ensuring operators are experienced, says Joe Reiss, the vice president of marketing for AS&E. "Trained analysts are pretty good at finding strange looking things." Still, all three companies have tried to take the burden off the operator by creating a picture that is not a fuzzy mess of shapes, but a detailed, three-dimensional diagram of a bag's contents. ScanTech, Smiths and AS&E are now marketing technology that Mr Aust sees as the next innovation in airport security.

AS&E uses backscatter X-rays which, instead of examining how a beam passes through an object, looks at how the X-ray bounced off the object. Low-density materials - such as drugs, bombs, cigarettes and other threats - tend to scatter more than high-density items. "[Backscatter] will tend to highlight the organic material inside that object," Mr Reiss says. In a photo of a lorry that passed through an unidentified customs checkpoint, an AS&E backscatter image revealed the cargo - 267 bottles of vodka - and the driver who had not declared them. Another image showed the outline of a stowaway on the floor of a van.

Mr Starns explains that ScanTech is able to produce three-dimensional images by analysing cargo from many angles. The scanner itself looks at all four sides of an object. The operator then manipulates the image to look closer at suspicious items. Eventually, Mr Starns says, officers will be able to drag the screen back and forth with their finger. "It's almost like the iPhone." ScanTech's accelerators, what Mr Starns calls "the secret sauce", make this possible. The accelerator in an X-ray machine speeds up electrons that hit an atom and release the X-ray photon. For 10 years, ScanTech has been improving the technology. Unlike older systems, ScanTech's scanners shoot multiple X-ray beams in a matter of milliseconds. Each beam has a different energy level, which provides more data.

"We can really eliminate the false positives," Mr Starns says, adding that eventually there is only one substance that is comprised of the analysed atoms. "C4 you can only make so many ways; it's like a cake." While Mr Mayo believes all these technologies will increase security in the UAE, he says they remain flawed. However, he says, his firm has developed a technology that is 99 per cent accurate. Originally used to find cracks in concrete, Xstream's energy-dispersive X-ray diffraction technology analyses objects at a molecular level. The Department of Homeland Security and the Transportation Security Administration in the United States asked Mr Mayo and his brother, who is an X-ray expert at Rutgers University, to develop the science in the wake of Sept 11. By determining the space between atoms, which Mr Mayo calls an object's "unique fingerprint", there is no mistaking or missing threats. In fact, he says, as demand for detection products increases, the traps available to airports and customs agents will continue to improve. "I think you're going to see in five to 10 years' time some impressive solutions in technology." @Email:jmather@thenational.ae