EVERY year, more than 200 million cargo-container shipments transport 90 percent of the world’s cargo. Over 11 million of these shipments arrive in the U.S., carried on ships, trains, planes, and trucks. National security officials view cargo containers as a potential means for terrorists to import a weapon of mass destruction into the U.S.
Several security mechanisms, such as special door locks and electronic seals, have been implemented to protect the integrity of containers during transit. None, however, is as cost-efficient or reliable as SecureBox, a new device developed by Lawrence Livermore in collaboration with Secure Box Corporation of Santa Clara, California, and the National Infrastructure Institute.
The development team, led by systems engineer Kique Romero, received initial funding from Livermore’s Laboratory Directed Research and Development Program and, in 2008, won an R&D
Electromagnetic Security Bubble
SecureBox incorporates the Livermore-developed technology used in GUARDIAN, the general-purpose undetectable autonomous radar detection imaging and notification system. This UWB motion detection system transmits millions of subnanosecond radar pulses and detects changes in echo signals reflected back to the sensor. The GUARDIAN sensor uses precision timing techniques to selectively evaluate echo signals arriving at the sensor from a specific distance.
GUARDIAN turns this invisible ping-pong of electromagnetic pulses into a protective semispherical bubble around the container walls. A bubble-shaped electromagnetic field might seem to be ineffective at protecting a rectangular container. However, an innovative folded-bubble method developed by the Livermore team takes advantage of reflections from the container’s metal walls to precisely time the received echo signals while maintaining sufficient signal energy to trigger the alarm.
Once a container is sealed for transport, any breach of its walls disrupts the radar’s echo pattern and activates an alarm. SecureBox systems also include sensors, such as accelerometers, to help differentiate movement by an intruder from the normal vibrations that occur during shipping.
Sending an Alarm
Commercial UWB communications systems designed for high data rates typically correlate the data pulse with a preset template. This technique does not work well inside ships because they are primarily made of metal. Metal surfaces create a massive number of reflections that distort or stretch the radio-frequency signals emitted by the sensor. Distorted signals are difficult to detect because they do not resemble the template of the transmitted energy.
To counter this issue, the Livermore team used the Laboratory’s transmitted reference modulation technique in designing the communications radio for SecureBox. The radio transmits a pair of pulses, a modulated data pulse closely followed by an unmodulated reference pulse. Each pair has a designated binary value based on the relative polarity of the two pulses. During transmission, both pulses are stretched and distorted identically by the same environment. A reference receiver then correlates the pulses to detect the transmitted data stream. This technique enables the UWB communication system to function in highly metallic environments where traditional communication systems often fail.
A More Secure Future
SecureBox devices are available from Secure Box Corporation, which licensed the Livermore technology in 2007. Thanks to the efforts of the development team, the nation has a more effective way of securing cargo and improving national security.
Key Words: cargo container, GUARDIAN, R&D 100 Award, SecureBox, security, sensor, transmitted reference modulation, transportation, ultrawideband (UWB) communications.
For further information contact Kique Romero (925) 423-2830.
Lawrence Livermore National Laboratory
Privacy & Legal Notice | UCRL-TR-52000-08-11/12 | November 7, 2008