London arrests should prompt interest in fluoroscopic detection system
In tests conducted in spring 2004, TSA found that, compared with X-ray machine systems, screeners using the fluoroscopic system from Golan Group were more likely to detect IEDs — especially those “artfully concealed”; it is time to consider to act on the study’s conclusions
The arrest in Britain two weeks ago of twenty suspected terrorists on suspicions that they were plotting to smuggle liquids on board U.S.-bound planes and then mix the binary chemicals to create explosives, raised serious questions about the adequacy of various scanning and screening technologies now used in airports around the world.
The questions raised may be serious, but they are not new. Two years ago, in May 2004, the Transportation Security Administration (TSA) conducted a detectability study to examine the effectiveness of different screening technologies. The study used a double blind, within-subjects factorial experimental design to evaluate the ability of 16 screeners to detect 29 threat bags randomly distributed among 150 total bags. Each screener received four hours of classroom training and four hours of hands-on training.
Now to the interesting news. The study found that compared with the X-ray machine system, screeners using the fluoroscopic system from the Boca Raton, Florida-based Golan Group were more likely to detect IEDs especially artfully concealed when present. These screeners were also less likely to claim an IED was present when it was not (a false alarm). This result was found to be statistically significant and in most cases superior. Note that this increase in detection performance comes at a cost: It takes screeners using the fluoroscopic system almost twice as long — twenty-four seconds on average — to decide whether a bag contains a threat relative to the X-ray system, which took fourteen seconds on average. Screeners found that conducting a search with the fluoroscopic device may have taken longer, but all highly concealed items, which were usually missed with the standard inspection devices, were found.
The TSA study concluded that, overall, screeners detect IEDs and other concealed items better with the fluoroscopic X-ray machine than with a traditional dual energy X-ray machine. The study notes that although statistically significant, the absolute difference in threats detected was not great owing in part to the overall high level of performance on both machines. The TSA called for further laboratory studies incorporating a more difficult threat set of artfully concealed IEDs in cluttered bags in order to verify, and better quantify, the detection superiority of the fluoroscopic equipment. These additional studies, the authors of the report said, would support a tradeoff analysis between the superior performance and the additional cost and other disadvantages of the fluoroscopic equipment.
The problem: Golan Group’s Xpose 2000 X-ray device finds liquids and creams because it uses fluoroscopic X-ray. Liquids are seen in 3D and in real time by the screeners. Although TSA found that fluoroscopic screening was superior to digital screening, the company did not hear back from TSA until a year and a half later. The company used the time to make some ergonomic changes and improvements to the device, and then, during the 2005 Christmas Holidays, entered discussions with TSA over the system. In January 2006 the discussions stalled, and have not resumed since. Perhaps the London arrests would spur the agency to move more energetically on the company’s fluoroscopic system.
-read more about the system at company Web site
