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June 2003

Companies Vie for Airport Security Contracts

Market for explosive-detector systems largely dominated by two firms

by Christian B. Sheehy

The business of installing explosive-detection systems at airports in the United States has been captured, for the most part, by two companies that traditionally have focused on military and defense programs.

L-3 Communications and InVision Technologies have developed screening devices designed to more accurately recognize chemical and physical properties of scanned objects—something the current X-ray equipment fails to do, according to industry experts.

The U.S. Transportation and Security Administration, last year, awarded InVision Technologies and L-3 Communications initial contracts of $512.9 million and $355 million, respectively, to deliver two types of explosive detection systems—the 625 CTX and the 425 eXaminer 3DXTM.

These two explosive detectors are the only ones that have been certified for further testing, out of 19 others currently in prototype development stages. The InVision systems sold to TSA include the CTX 5500 DS—at $1 million each—and the CTX 9000 Dsi, a more advanced system that costs $1.5 million. L-3’s detector runs about $800,000 per unit.

At the core of the CTX and eXaminer systems is a commonly used medical technology called computerized tomography (CT), which scans the interior of a person’s body. CT uses two- and three-dimensional images to create virtual cross-sectioned slices, or tomographs, of specific areas.

“Simple X-ray analysis is no longer enough to make the kinds of timely, decisive conclusions necessary to achieve the safety and efficiency demands of today’s airline industry,” said David M. Pillor, InVision’s senior vice president. “The challenge, in meeting FAA requirements, was to create a single system with a high degree of speed and accuracy, capable of minimizing false alarm frequency while simultaneously maximizing detection precision.”

Using standard electromagnetic imaging, the CTX and eXaminer systems present three-dimensional properties of explosives in cluttered passenger bags. In a full 360-degree rotation, images are taken from all angles as streams of light intersect throughout the bag.

With CTX, the density, mass and volume of materials are obtained and analyzed using computations that match findings against a database with already known values.

“The most difficult task confronting an EDS system is distinguishing potential explosives from harmless objects” that may have similar traits, said Joe Paresi, president of L-3 Security and Detection Systems Division.

“Not only do certain electronic items have parts that look suspiciously like bomb parts, but they are often hidden under layers of other items. The result is a complex, two-dimensional image that requires computer analysis to correctly identify.”

CTX technology examines the unique density signatures produced when electromagnetic radiation passes through different substances. The medium-frequency light waves (X-rays) react differently depending on the material’s density.

A cross-section, or CT slice, of an item can then be constructed, using mathematical algorithms that are pre-programmed into system software.

“Three-dimensional, cross-sectional analysis turns suspicion into near certainty,” Pillor noted. “With a virtual reconstruction of an object’s internal structure, fewer false leads are encountered, allowing passengers to pass more quickly.”

CTX hardware comprises a conveyor gantry, X-ray tube chamber, CT scan chamber and an operator control station. Once through the X-ray chamber, baggage moves into the CT chamber, where processors use the X-ray data to compute findings into CT slices.

CT scanning reveals specific object densities and volumes that enable computation of item mass. Concealed items do not affect processing since only the objects with specific X-ray signatures are selected for further analysis.

After entering the CT chamber, a bag is divided virtually into three-dimensional units called “voxels.” Based on their similarities, certain voxels are grouped together as volumes of the same objects within a bag, so that the density of the scanned object can be determined.

Based on density and volume, CTX and eXaminer software automatically correlate the mass characteristics of luggage contents to those of potential explosives. If the system finds a match, it alerts the operator, by highlighting suspect areas within the CT slice.

“Like most detection technologies, CT scanning only provides an operator with a positive or negative assessment,” stated Paresi. “The ultimate decision as to whether an object needs further examination remains the operator’s to make.”

At average weights between 7,000 and 11,000 pounds and a size of about 6 feet long by 5 feet high, the CTX and eXaminer systems can be integrated with existing airport X-ray equipment or can be used as stand-alone systems. Both technologies are able to process an average of 300-500 bags per hour depending on the number of positive identifications.

According to Pillor, the systems are supposed to eliminate the false alarms that happen with X-ray scanning, which can take about three to five minutes to resolve.

L-3 has projected EDS sales for 2003 at approximately $175 million, a portion of which will come from an order with Singapore for airport security systems and EDS products. Meanwhile, InVision projects EDS 2003 revenues from sales and services to reach $400 million. That number also includes current product orders with Spain and Israel.

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