The Truth About Body Scanners

On the left, a raw present-day Millimetre-wave image. However, if successful, systems currently under development will end any fears about privacy issues. The next generation of scanners will show fully-clothed images like the one seen here on the right. It shows an explosives disk found with an auto detect functionality superimposed on the fully-clothed body. A first version of this system will be lab tested by the responsible authorities in the months ahead. (Smiths Detection)

Rory Doyle from Smiths Detection answers some of the many misconceptions about the introduction of the latest airport security systems.


On the left, a raw present-day Millimetre-wave image. However, if successful, systems currently under development will end any fears about privacy issues. The next generation of scanners will show fully-clothed images like the one seen here on the right. It shows an explosives disk found with an auto detect functionality superimposed on the fully-clothed body. A first version of this system will be lab tested by the responsible authorities in the months ahead. (Smiths Detection)

In a world of ever-increasing travel, the likelihood of further alleged terror attempts such as the Christmas Day plot over Detroit is also likely to rise.  Such incidents are no longer perceived mainly as a threat to professionals with frequent flyer status.  Consequently, all air travellers eventually will have to become accustomed to new screening methods at security checkpoints, as authorities across the globe move to improve efficiency by deploying full body scanners.  Numerous airports are already trialing these scanners.
In the aftermath of the Christmas Day incident, in which a passenger allegedly attempted to ignite explosives in his underwear, security experts and the general public have become more aware of full body scanning technologies and are becoming better informed of the pros and cons involved.  Manufacturers have done a significant amount of work to educate the public about their systems’ capabilities and their potential for preventing any repeat of the recent terror incident.  However, there are still many misconceptions and rumours spread about people-screening systems and the way they handle personal data.  Of course, the machines on the market are not all based on the same technology platform.  There are a number of technical approaches employed and several products are available to fulfil different objectives but, basically, body scanners work by imaging the person in either the millimetre-wave or the X-Ray part of the spectrum.  The corresponding imagery is produced as stills or full motion video.
One of the most controversial aspects about body scanning is the individual’s privacy or rather the challenge to ensure minimal intrusion.  In order to give a concise overview on full body scanning it is crucial to understand the related security applications, the way those systems work, and how the personal rights of the screened individual can be fully protected.
Full body scanners screen people as they pass through a controlled security checkpoint, to determine if they are concealing contraband items under their clothing.  Contraband categories relate to life safety (prohibiting weapons, explosives or other threat items that could be used in a life threatening manner), criminal substances (drugs and illicit narcotics), contraband goods (smuggled items whose movement is controlled), and other substances.  In short, anything that is not removed from an individual’s clothing or body when prompted by security assistants at the checkpoint.
 
How does Millimetre-wave work?
Different materials exhibit differing properties when interacting with electromagnetic energy (emission, reflection, absorption, etc).  These properties vary with the temperature, density and the molecular composition of the matter.  Smith’s eqo (pronounced echo) system operates like a sonar or radar device, hence the product’s eqo name referring to the system’s technological approach of sending out and analyzing the signal information as reflected by the human body.  Using non-ionizing energy, eqo scans the passenger’s body.  Reflections from any concealed objects are different to those from a person’s body and this variation is detected by eqo’s sensors.  Those reflected signals are sent into a high-speed image processing computer which produces privacy filtered, three-dimensional image data models in real-time.  These video-style images can be displayed as rotatable images or can be further analyzed electronically.
 
Health & safety
Aside from public misconceptions about full body scanning technologies and their individual applications and capabilities, there is also a great deal of misinformation about health and safety compliance.  Smiths Detection’s eqo uses inherently safe millimetre waves.  These appear in the electromagnetic spectrum in a frequency range between infrared and radio waves (sometimes the term Terahertz is also used − eqo uses a frequency range slightly below Terahertz).  As Millimetre waves are non-ionising there are absolutely no health issues even with multiple uses of eqo.  Smiths Detection has tested its millimetre-wave imagers using third party independent facilities and the system has passed all international standards associated with the use of this energy band.  The test results have demonstrated that the equipment has a margin of safety far above the allowed thresholds.
 
Popular Myths
Privacy issues have been controversial ever since the first body scanners were deployed.  Despite all efforts to provide accurate and intelligible information on the various measures in place to protect personal rights, blatant spoofs can often unsettle the public and encourage new misconceptions.  Recently, Bollywood actor Rukh Khan, promoting a movie on UK television, claimed that his image taken by a body scanner had been printed and handed over to him for autographing by female airport security assistants.  However, as BAA publicly stated, these scanning machines do not have the facility to print such images, so Mr Khan, as hopefully most of the audience realised at the time, was simply joking.  At the same time, private video forums are swamped with material produced by self-proclaimed ‘security experts’ who allegedly reverse body scan images into ‘normal colour photographs’ using home PC photo imaging software.  These are complete fabrications.  Body-scanning machines installed at airports categorically do not have the ability to save, print or transmit body scan images.  This default privacy measure is a prerequisite and the scanning machines do not have hard drives or printers to facilitate this.  As far as images of semi-naked women with guns in their underwear etc, are concerned, these are nothing but regular camera-taken pictures that have been ‘photo-shopped’ into a negative image, only to be ‘miraculously’ converted back into colour images again.  The giveaway usually is the fact that body features − such as hair − is visible in these supposed body scan images.  Hair and other lightweight materials would not appear in body scan images from a millimeter wave- or backscatter-technology-based system.
 
Respecting people’s privacy
Being committed to and recognizing the importance of balancing security with civil liberties, Smiths Detection fully appreciates the public discussion around protection of privacy and this has helped in the design of a system that addresses these concerns appropriately.
Smiths Detection recognized in the early stages of product development that in order to protect the privacy and dignity of passengers, certain measures had to be adopted within the system design as well as in the operating procedures.  Therefore, eqo has been built and configured with a series of features that ensure the integrity of the screening process.  These features have been informed by the experience of field trials of comparable systems and have been confirmed by independent studies.
A cornerstone of privacy assurance is that no image data is ever retained from a checkpoint screening operation.  Image data that is passed from eqo to the remote station is held only for as long as it takes to analyze and process an individual; the machines cannot store them.  Once the person is cleared through the screening process his or her image data must be erased in order to allow the machine to deal with the next person in the sequence.  The typical lifetime of a single person’s image data is only seconds.  After the person is processed the image data is irrecoverably and automatically deleted.  Prior to delivery the eqo systems are configured so that data cannot be stored or transferred from the screening equipment by printing, copying or any other means of transmission.  All data associated with the image capture is processed and transmitted to the remote analyst station in a proprietary format.  In the remote analyst room no cameras or cell phones are allowed.  This part of the process is out of the manufacturer’s control of course and must be strictly enforced by the airport’s internal procedures.  The operator talks by wireless headset to the security assistant at the checkpoint, clearing the traveller if nothing suspect appears on the image.
Another layer of privacy protection is provided by the Smiths Detection eqo through a range of software level privacy filters.  These filters process the image data to add privacy features such as face blurring that create increased anonymity for the person being screened.  In line with the existing procedures for pat-down searches on people, Smiths Detection can configure eqo so image analysis of male passengers is limited to male screeners and vice versa.  Thus the eqo system allows for a same gender segregation of image data when transferring the image information to the remote stations.  The process ensures that image data of female passengers will only be transferred to analyst workstations operated by females and vice versa.
Smiths Detection is currently working on the development of automatic detection of concealed objects carried by a person.  There are two solutions considered and both will only require a software upgrade with no major modification to the existing hardware.  It will therefore allow customers to upgrade systems they have in use by then.  One approach is to present a red/green traffic light function to the security assistant at the checkpoint, in case an object has been detected, so only passengers with a ‘red’ need to undergo re-inspection.  In order to leave behind all the ‘naked body’ questions, Smiths Detection is also pursuing a software solution represented by a real-time video image (full clothing) with a red frame around areas where the system has detected an object, so the operator can focus inspection directly on the suspicious areas.  This product should be ready for field testing later this year.
However, outside the measures Smiths Detection can take as a supplier of equipment there are a number of concerns related to the deployment of people screening equipment that can only be addressed directly by security authorities or airport operators.  As part of the product deployment process, Smiths Detection offers a series of guidelines to users of the system.  Although not mandatory or enforceable, these guidelines are intended to influence and educate system operators.
In summary, eqo helps security operators screen people for concealed objects at airports and other critical infrastructure to the highest security standards while simultaneously maintaining high passenger throughput.  In combination with other high performance technologies, such as trace detectors and X-ray technology, our customers worldwide can rely on state-of-the-art aviation security products from a single source.