A full-body scanner is a device that detects objects on or inside a person's body for security screening purposes, without physically removing clothes or making physical contact. Unlike metal detectors, full-body scanners can detect non-metal objects, which became an increasing concern after various airliner bombing attempts in the 2000s. Some scanners can also detect swallowed items or items hidden in the body cavities of a person. Starting in 2007, full-body scanners started supplementing metal detectors at airports and train stations in many countries.
Three distinct technologies have been used in practice: Millimeter wave scanners use non-ionizing electromagnetic radiation similar to that used by wireless data transmitters, in the extremely high frequency (EHF) radio band (which is a lower frequency than visible light). The health risks posed by these machines are still being studied, and the evidence is mixed, though millimeter wave scanners do not generate ionizing radiation. X-ray-based scanners Backscatter X-ray scanners use low dose radiation for detecting suspicious metallic and non-metallic objects hidden under clothing or in shoes and in the cavities of the human body. The dosage of radiation received is usually between 0.05 and 0.1 μSv Considerable debate regarding the safety of this method sparked investigations, ultimately leading multiple countries to ban the usage of them. Transmission X-ray scanners use higher dosage penetrating radiation which passes through the human body and then is captured by a detector or array of detectors. This type of full body scanners allows to detect objects hidden not only under the clothes, but also inside the human body (for example, drugs carried by drug couriers in the stomach) or in natural cavities. The dosage received is usually not higher than 0.25 μSv and is mainly regulated by the American radiation safety standard for personal search systems using gamma or X-ray radiation Infra-red thermal conductivity scanners do not use electromagnetic radiation to penetrate the body or clothing, but instead use slight temperature differences on the surface of clothing to detect the presence of foreign objects. Thermal conductivity relies on the ability of contraband hidden under clothing to heat or cool the surface of the clothing faster than the skin surface. Warm air is used to heat up the surface of the clothing. How fast the clothing cools is dependent, in part, on what is beneath it. Items that cool the clothing faster or slower than the surface of the skin will be identified by a thermal image of the clothing. These scanners are less often used compared to X-ray-based and mmWave-based scanners.
Passengers and advocates have objected to images of their naked bodies being displayed to screening agents or recorded by the government. Critics have called the imaging virtual strip searches without probable cause, and have suggested they are illegal and violate basic human rights. However, current technology is less intrusive and because of privacy issues most people are allowed to refuse this scan and opt for a traditional pat-down. Depending on the technology used, the operator may see an alternate-wavelength image of the person's naked body, merely a cartoon-like representation of the person with an indicator showing where any suspicious items were detected, or full X-ray image of the person. For privacy and security reasons, the display is generally not visible to other passengers, and in some cases is located in a separate room where the operator cannot see the face of the person being screened. Transmission X-ray scanners claim to be more privacy neutral as there is almost no way to distinguish a person but they also have software able to hide privacy issues.
History The first (ultra-low-dose backscatter X-ray) full body security scanner was developed by Dr. Steven W Smith,Hamilton, John (January 14, 2010) New Airport Body Scans Don't Detect All Weapons. National Public Radio who developed the Secure 1000 whole body scanner in 1992. He subsequently sold the device and associated patents to Rapiscan Systems, who now manufacture and distribute the device.
Safety aspects of the Secure 1000 have been assessed in the US by the Food and Drug Administration, the National Council on Radiation Protection and Measurements and other independent sources since the early 1990s.J. L. McCrohan and K. R. Shelton Waters. Response to UCSF regarding their letter of concern , Oct. 2010. RadiationEmittingProductsandProcedures/ SecuritySystems/ucm231857.htm.
In 2000, Dr. Vladimir Linev patented a system for scanning a person based on transmission (penetrating) X-ray technology focused on the search for unwanted objects and contraband, which was later the base for CONPASS body scanner.
The first millimeter-wave full body scanner was developed at the Pacific Northwest National Laboratory (PNNL) in Richland, Washington. The operation is one of the four national laboratories Battelle manages for the U.S. Department of Energy. In the 1990s, they patented their 3-D holographic-imagery technology, with research and development support provided by the TSA and the Federal Aviation Administration (FAA). In 2002, Silicon Valley startup SafeView, Inc. obtained an exclusive license to PNNL's (background) intellectual property, to commercialize their technology. From 2002 to 2006, SafeView developed a production-ready millimeter body scanner system, and software which included scanner control, algorithms for threat detection and object recognition, as well as techniques to conceal raw images in order to resolve privacy concerns. During this time, SafeView developed foreground IP through several patent applications. By 2006, SafeView's body scanning portals had been installed and trialed at various locations around the globe. They were installed at border crossings in Israel, international airports such as Mexico City and Amsterdam's Schiphol, ferry landings in Singapore, railway stations in the UK, government buildings like The Hague, and commercial buildings in Tokyo. They were also employed to secure soldiers and workers in Iraq's Green Zone. In 2006, SafeView was acquired by L-3 Communications. From 2006 and 2020, L-3 Communications (later L3Harris) continued to make incremental enhancements to their scanner systems, while deploying thousands of units worldwide. In 2020, Leidos acquired L3Harris, which included their body scanner business unit.
The first passive, non-radiating full body screening camera device was developed by Lockheed Martin through a sponsorship by the National Institute of Justice (NIJ)'s Office of Science and Technology and the United States Air Force Research Laboratory. Proof of concept was conducted in 1995 through the Defense Advanced Research Projects Agency (DARPA). Rights to this technology were subsequently acquired by Brijot Imaging Systems, who further matured a commercial-grade product line and now manufacture, market and support the passive millimeter wave camera devices.
Usage
Schiphol in the Netherlands was the first airport in the world to implement SafeView's millimeter-wave body scanner on a large scale after a test with flight personnel the previous year. On May 15, 2007, two of 17 purchased security scans were installed.
The Italian government had planned to install full-body scanners at all airport and train stations throughout the country, but announced in September 2010 plans to remove the scanners from airports, calling them "slow and ineffective".
The European Union currently allows member states to decide whether to implement full body scanners in their countries:Member States must decide on airport body scanners: EC – EU business news. EUbusiness.com (June 16, 2010). Retrieved on September 26, 2010.
Australia In Australia, the government has decided a no opt-out policy will be enforced in relation to screening at airports. Persons with medical or physical conditions that prevent them from undertaking a body scan will be offered alternative screening methods suitable to their circumstances. Infants and young children under 140 cm will not be selected to undergo a body scan.Airport Body Scanners—Frequently Asked Questions. Australian Department of Infrastructure and Regional Development Body-scanners are being used at eight of Australia's international airports – Adelaide, Brisbane, Cairns, Darwin, Gold Coast, Melbourne, Perth and Sydney.Body scanners. jetstar.com So far only passengers exiting via international flights are affected. Domestic and international passengers departing Newcastle Port Stephens airport have been subject to body scanning since October 2019. Passengers who refuse a scan may be banned from flying.Puhanic, Andrew. Australia Becomes First to Ban Travelers Who Refuse Naked Body Scanners. theglobalistreport.com The scanners proposed to be used in Australia have shown a high rate of error in testing. Public outrage over the nude images created by the body scanners being collected by policy resulted in a lawsuit in 2010 to stop body scanning.
Canada In Canada, 24 airports currently have these scanners in use, using millimeter-wave technology. Transport Canada notes that "Passengers selected for a secondary search can choose between the full body scanner or a physical search."
United States In the U.S. full-body scanners have been installed at train stations, subways, penitentiaries and airports.Advanced Imaging Technology (AIT). tsa.gov In 2012, the United States Department of Homeland Security deployed full body scanners to assist the United States Secret Service.
After having previously used X-ray-based scanners the TSA currently uses Millimeter Wave AIT scanners exclusively, which show no identifying characteristics of the person being scanned. Instead, a generic outline of a person is used.AIT: How it Works. U.S. Transportation Security Administration As of December 2015, "While passengers may generally decline AIT screening in favor of physical screening, TSA may direct mandatory AIT screening for some passengers as warranted by security considerations in order to safeguard transportation security."Vaughan, Jill (December 18, 2015) Privacy Impact Assessment: Update for TSA Advanced Imaging Technology. U.S. Department of Homeland Security
Regarding privacy concerns the Transportation Security Administration (TSA) has stated in 2010 that they "[have] not, will not and the machines cannot store images of passengers at airports". However the TSA later disclosed, in a response to the house chair on homeland security, that its procurement of airport scanners requires manufacturers to include image storage and transmission features but that these features should be disabled before being placed in an airport. The TSA shows 45 individuals have the ability to turn these machines into 'test mode' which enables recording images, but states that they would never do this on a production system.Rossides, Gale D. (February 24, 2010) Letter to Bennie G. Thompson. The US Marshal Service did operate a backscatter machine in a courthouse that records images. However, in a statement, they noted that only individuals involved in a test were recorded. A sample of these images was received and disseminated by Gizmodo in 2010, using a Freedom Of Information Request. It is not clear if the US Marshal service has put these new scanning machines, that have recording capabilities, into production. The analyst is in a different room and is not supposed to be able to see the person being scanned by the Backscatter X-ray AIT, but is in contact with other officials who can halt the scanned person if anything suspicious shows up on the scan.