Despite an advance alert, it wasn’t government, but crew and passengers that thwarted an apparent terrorist attack on Northwest flight 253, notes a Wall Street Journal opinion piece. AnalysisOnline examines the topic of explosives detection technology and factors that hinder keeping up with terrorists’ ever-changing strategies.
A major reversal of the Administration’s characterization of the attack occurred after Homeland Security chief Janet Napolitano first described the Christmas Day attack as an illustration of the system working; subsequently, of course, she admitted it was an example of the system’s failure (see New York Times, December 28, 2009).
At the height of holiday travel season, millions of Americans who endure long lines, cumbersome security scans, and more rules and restrictions than ever, may wonder how such an incident could happen given increased security processes since 9-11.
While official reviews will investigate where gaps may have occurred in this particular attack attempt, a broader answer be tied to how rapidly terrorists can alter their game plans and hide increasingly powerful explosives – faster perhaps than government can put new detection technologies into place in the nation’s 400 major commercial airports, create standards, hire and train security personnel, and gain public acceptance of scanning capabilities that are ever more invasive by some standards.
“A Primer in PETN” in the Wall Street Journal today describes the power of the explosive involved in the Northwest flight: “a white powder than can deliver powerful blasts in quantities as small as tenths or hundredths of a pound,” but difficult to set off.
PETN, also the explosive used in 2001 by Richard Reid, the so-called shoe bomber, has legal uses in the military, mining, and manufacturing. Purchase of this and other explosives is regulated by the federal Bureau of Alcohol, Tobacco, and Firearms.
In a 2008 Department of Homeland Security report on a multi-year research and development program (through 2013) into explosive countermeasures to prevent explosive attacks on the public, six technologies are described:
1) Passive Millimeter Wave (MMW) Imaging: Detects the presence of concealed objects on a person’s body; it can be used to scan crowds
2) Passive Terahertz Imaging: Like Passive Millimeter Wave Imaging, it can detect anomalies in a crowd that indicate presence of a concealed weapon; there is a slight shift to measure electromagnetic energy naturally emitted by human bodies
3) Passive and Active MMW Sensors: Similar to the previous two, except this time, the scans can be automated and a threshold reading can be set for the general environment
4) Infrared Thermography: Using infrared energy, this technology relies on the operator’s ability to identify anomalies indicating the presence of a concealed weapon
5) Intelligent Video Systems: These can be used to detect anomalies in human behavior or objects left behind at a scene, and this technology can be automated. Basically, the software used by the system detects the anomalies
6) Standard Video Surveillance Cameras: This is off-the-shelf technology and is most useful to scan a wider area and be used in conjunction with other technologies (which tend to focus on a more limited range)
All of these technologies provide a video image, but the first five are footnoted as not providing an identifiable face to the operator of the device through the imaging technology. (Thus, as the New York Times article and sidebar feature note, the MMW technology that provides an imagine of what lies beneath a person’s clothes – and could have been helpful in stopping the alleged terrorist on the Northwest Airlines flight – is not supposed to give an identifiable image of the person with the imaging in use, although it may during the R&D process.)
An earlier study, the Rail Security Project, is available at this link.
Possible Obstacles for Americans
In considering a news story like the failed terrorist attempt on Christmas Day in Detroit, the American public, as well as policy makers, are called upon to honestly assess what kinds of tradeoffs they are willing to make to achieve (hopefully) a greater threshold of security on commercial flights.
Some of the key challenges are:
• perceived impingement on privacy and civil liberties;
• the need to develop standards for operation, conduct training, and hire adequate numbers of personnel as operators;
• the likelihood/possibility of false readings – for example, any legal ramifications of false positives, as well as the loss-of-life implications conceivably of false negatives;
• and the ability of terrorists to quickly reform methods and use explosives that may not be among the known and detectable explosive agents
In a 2007 Congressional Research Service report for Congress (“Detection of Explosives on Airline Passengers: Recommendation of the 9/11 Commission and Related Issues”), the National Commission on Terrorist Attacks upon the United States examined each of these considerations
The report stated:
“Passenger explosives screening technologies have been under development for several years and are now being deployed in selected airports. Their technical capabilities are not fully established and operational and policy issues have not yet been resolved. Critical factors for implementation in airports include reliability, passenger throughput, and passenger privacy concerns. Presuming the successful development and deployment of this technology, certification standards, operational policy, and screening procedures for federal use will need to be established. The commission recommended that Congress and the Transportation Safety Administration give priority attention to improving the ability of screening checkpoints to detect explosives on passengers.”
It’s impossible to provide a figure for how much a more extensive effort would cost because it depends on the technologies deployed, the amount of air traffic, the requirements for minimizing passenger delays, the possible need for additional trained operators, and more.
An idea of the costs is hinted at in an August 11, 2009 article in the government trade publication, Government Security News. Stimulus funds totaling $42 million were provided to just three airports for new technology to detect explosives – Sacramento International Airport, Honolulu International Airport, and Kahului Airport.
Among the systems receiving funding, some are targeted to improving the processes passengers go through, while others seek to enhance detection of explosives.
One provider of airport security imaging technology also provides imaging technology for disease detection in healthcare; Guardian Technologies International distributed this news release about its products in November.
Beyond detecting the image of a hidden weapon or dangerous substance, technology is also advancing on detection of trace amounts of explosives and narcotics.
Some of the considerations of these technologies are:
• Effectiveness in detecting a certain compound and distinguishing it from other compounds
• Practicality, or the ability to use the technology with crowds of people nearby and outside the confines of the laboratory
• High reliability and performance traits and minimal degradation of function over time
A General Electric white paper in 2006 examined three trace technologies and provided a matrix of comparison on five criteria: sensitivity; selectivity; range of compounds detected; logistics; and reliability and maintenance.
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