New airport scanners to speed up security checks

Anastasia Dagaeva
November 27, 2017

American airports are joining those in the rest of the world, starting trials of new bag scanners, using the CT tech common in hospitals, that will give TSA agents a major upgrade over the x-ray scanners they use now, according to Wired

TSA [Transport Security Administration] people will be able to virtually unpack bags and spin objects around in 3-D, eliminating the need for you to unpack — and keeping everyone moving as well as safe. 

On Thanksgiving holiday, the number of long-distance trips goes up 54%. For those flying, security will be extra strict this year, according to TSA guidelines released in July. The passengers are now asked to put any electronics larger than a cell phone into a plastic bin, with nothing on top of or below it, just like laptops have always been scanned. So if you’re carrying a tablet and an e-reader, it’s a bunch of extra unpacking too. Any liquids still have to be the teeny travel-size toiletries, in a clear plastic bag, in their own plastic bin. 

The unpack-shove along a conveyor-repack process is responsible for most of the slowdown in security lanes (and passenger stress too!), but it's also necessary. X-ray scanners give operators a pair of 2-D images: a view from the top and one side. If a bag holds electronics stacked on top of each other, it can be hard to figure out what’s a battery and what might be a bomb.

A CT scan (that's computed tomography a term you probably met a lot while watching the House M.D. show) creates a full 3-D image by rotating a narrow band of x-rays around whatever it's inspecting, and digitally compiling the result into a multicolored image that gives a lot more data. Massachusetts-based Analogic, which makes CT scanners for hospitals, it adapting its tech for the TSA. “We’re using atomic profile, and the density of material, through the CT scan and slices of the bag,” says Mark Laustra, who's leading the rollout of this tech for the company. “It’s just like getting a brain scan at a hospital and looking for a brain tumor.” 

Lorem Ipsum is simply dummy text of the printing and typesetting industry. Lorem Ipsum has been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in the 1960s with the release of Letraset sheets containing Lorem Ipsum passages, and more recently with desktop publishing software like Aldus PageMaker including versions of Lorem Ipsum.

The results are nuanced and detailed, and the screening operator can change the colors or contrast to make certain materials stand out. She can also manipulate the image with pinch and zoom gestures to get a good look from every angle. Analogic’s ConneCT equipment, designed for airport security lanes, looks like a white jet engine, with glowing blue accents that wouldn’t be out of place in the medical bay of a starship. The company has worked to reduce the weight, size, and power draw, over the first generation of CT scanners that airports started using to monitor checked baggage after the September 11 terrorist attacks. Those old units are so bulky and heavy, airports would have to reinforce the floors to move them into the passenger halls. In the US, American Airlines has purchased the first eight devices, and is currently checking them out. The airline is also working with the TSA to test CT tech with another supplier, L3 technologies, at Phoenix Sky Harbor airport. Larger scale trials should get underway next year.

In the airport, under the passenger level, the checked bag flies through its CT at high speed. There, computer algorithms do the scanning automatically, but unlike in carry-on scanners, the machines don’t have to look for guns and knives, just explosives, which have distinctive densities. People are still the best bet for spotting something, like a gun that’s disassembled and packed into multiple bags for example, so humans will continue to monitor these new machines. They will get help from algorithms written to highlight suspicious items, and which should improve through machine learning.

Trials in Europe have shown promise at reducing that checkpoint pinch point. “We’ve seen almost double the throughput from 150 passengers to 300 passengers per hour,” Laustra says. The passengers then become the limiting factor, he says—the machine could process up to 600 bags an hour. The tests also highlighted a few problems. Boxes of spaghetti triggered a lot of false alarms. "We had to train algorithm to recognise and ignore pasta," Laustra says. Of course, change can be slow in an industry that values safety first. Change can also be expensive: Analogic’s machines cost $300,000, versus $150,000 for a modern, multiview x-ray machine.

The IATA survey reported that passengers traditionally underlined airport security and border control as two major stress points when traveling. The top frustration were the personal items removing (60%), the inconvenience of having to unpack electronic devices in carry-on bags (52%) and all sorts of screening procedures at various airports (47%).  

Singapore’s newest Terminal 4 allows not only automatic check-in but proceed with a security screening check as well. The centralised security screening at T4 terminal uses new CT technology so that passengers’ laptops and tablets can now rest inside the bag for a seamless scanning. Using an automated system, trays are presented to two passengers at the same time. The trays are automatically returned to the start of the line after each scanning procedure is done. This feature improves screening efficiency and reduces waiting time in the queue. With these new technologies to be introduced globally, there’s hope now, for a better way.