Smile, you’re being spied on!

Video surveillance of Madrid’s Plaza Major. A series of cameras allow control staff to simultaneously view several 3D images and to alert the appropriate agencies (police, fire service, ambulance) should a particular situation present itself. © Courtesy Indra
Video surveillance of Madrid’s Plaza Major. A series of cameras allow control staff to simultaneously view several 3D images and to alert the appropriate agencies (police, fire service, ambulance) should a particular situation present itself. © Courtesy Indra

With security all the rage, science and its applications are being called on to play their part. The latest paraphernalia on sale is stuffed with a long list of technological innovations: electronic chips, movement sensors, biometric recognition. But how do these devices that can monitor our smallest deeds and gestures work excatly?

In 2007, 1.7 billion RFID - Radio Frequency Identification Device – chips were sold around the world, in a sector that has grown by 330% in three years. These ‘marker’ chips are designed to transmit information engraved in them, by radio frequency, to any emitter-receiver station which activates them in their immediate environment. Encapsulated in an adhesive support, each silicon chip is linked to an antenna wound round it. The whole device is no more than 1 millimetre thick, small enough therefore to pass unnoticed in packaging and in identity documents, and to be hidden in clothes or even under the skin.

Operating in autonomous mode, an RFID chip generally takes its energy from the waves emitted by the emitter-receiver which gathers the data contained on it. Its possibilities depend on the frequencies at which it operates. The higher the frequencies, the more information can be sent. Between 125 and 135 kHz, the chip contains a simple code used to trace goods, identify animals, or as an electronic key for lock-less systems, with a detectability range of 150 cm. At a higher frequency, around 13.56 MHz, biometric data can also be stored, to permit double verification. This type of RFID is found in access badges to sensitive installations. Finally, high frequency RFIDs – up to 3 GHz – can carry several tens or even hundreds of metres, making it possible to locate the product or person carrying it, and to follow them around. On the other hand, energy autonomy is more difficult to achieve.

Who’s who?

For identification purposes, the device of course works only if it is inseparable from its support – the object, animal or person one wants to authenticate. This was pointed out already in the report published in 2007 by the European group CERP – Cluster of European Research Projects – tasked with identifying the potential applications of RFIDs. As Jean-Marie Willigens, co-author of the report and representing Lufthansa at the time of publication, explains, it is difficult to identify a person reliably on the basis of an RFID. “At one time we were talking of air tickets fitted with RFID chips containing the passenger data. But given the possibility of people holding substitute tickets, this technology was judged to be much less effective than biometric analysis. On the other hand, if each baggage item carried an RFID chip, airlines would have an effective tool for checking that each embarked suitcase corresponds to a duly encoded traveler. This process will probably be introduced, but later rather than sooner, bearing in mind that certain airports have still not recouped the cost of introducing the present adhesive barcode system.

To identify persons, the chip would have to be implanted directly in the person, as is already done in animals. “We can project ourselves into the future”, Jean-Marie Willigens continues, “and predict that all newly-born children will be fitted with a chip from birth. RFIDs would in this way become a particularly well-performing identity technique. But are European citizens ready for this to guarantee their security? One can doubt it. Until now, only members of certain very ‘in’ night clubs accept to be marked like cattle. In this way they spend less time paying for their drinks at the bar.

Optical ‘sniffer dog’

However, major investments in security in Europe are motivated much more by a concern for global protection against terrorist threats than in a desire to trail every individual citizen. Currently, over 60% of terrorist attacks involve improvised explosive devices. What do we do with an abandoned and unidentified parcel?

The Optix project that the 7th Framework Programme is financing is seeking to develop an instrument that can supply police and armed forces with a concrete response on the risk of explosion. Carlos de Miguel, project head at the security systems department of Indra (ES) and project coordinator, explains the technical constraints of such a machine: “The system needs to be compact, transportable and able to detect, at 20 metres’ distance, the presence of explosives in the package, and where explosives exist, to precisely identify them. This tour de force will be possible by combining three complementary optical technologies: LIBS – Laser Induced Breakdown Spectroscopy –, Raman and infrared absorption. These three spectroscopic processes are sufficiently similar to be implanted in a single platform with a common data acquisition and processing system.

The principle of spectroscopy is simple: beams of known wavelength are transmitted through the sample to be analysed. These undergo specific changes as a function of the molecular composition of the matter they pass through, thus providing a genuine spectral signature of the target. With a source of 1064 nm(1), the laser impulse given by the LIBS excites the atoms which then emit photons with a characteristic energy. Based on the scattering of the photons emitted in this way – 266 nm – the Raman technology informs us of the vibrational modes of the molecules of the compound. Finally, the infrared absorption spectrum – 1064 nm – provides information on other fundamental vibrations, the frequencies of which depend on the nature of the atomic and molecular links.

“These technologies permit effective identification of solid, liquid or gaseous samples”, Carlos de Miguel continues. “With the technological improvements we are developing right now, the prototype, with its fully-automated ‘decision’ system, will provide the operator with a clear answer on the degree of danger of the product. Before the project ends in 2012, the new product will be tested with the help of the Spanish Guardia Civil, which is tasked with developing realistic experimental scenarios.

Big(ger) brother

Still at the novelty stage, researchers in the European Probant project are working – discreetly (editor’s note) – on a prototype which would make it possible, by wave emission(2), to visualise the movements of a suspect in an adjoining room. Long-distance biometric measurements would even help them determine the individual’s state of nervousness.

Work is also in hand on coastal protection. The perpetrators of the terrorist attacks at Mumbai, India last November, are believed to have arrived clandestinely in fishing boats. It is to prevent this problem, but in particular that of illegal immigration, that the Amass – Autonomous Maritime Surveillance System – has come into being. “Maritime areas are too vast to be monitored by coastal patrols only”, explains Thomas Anderson, project coordinator at Carl Zeiss Optronics (DE). “We are therefore developing a system that can detect small and medium-sized boats and inform the competent authorities of any illegal activity in territorial waters.”

For this, a series of technically and energetically autonomous platforms are anchored up to 20 km offshore. On board are 6 metre high cameras, able to detect any movement day and night in a 360° radius. 25 metres below water level, hydrophones register every sound and compare them continuously with a data base of all suspect frequencies. In the case of detection, a signal is radioed to the onshore control base. Triangulation will permit the precise localisation of the zone, allowing a patrol to be sent out if necessary “Such surveillance platforms will be able to operate in all weathers, 24/7”, Thomas Anderson adds. “Amass will also help coastal agencies protect their employees, and save the lives of hundred of immigrants trusting to fortune in often unseaworthy vessels.”

Marie-Françoise Lefèvre

  1. nm = nanometre, or 10-9 metres.
  2. See also ‘Teaching corner’


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