Canines Are Still Top Dog When it Comes to Finding Explosives
Backscatter radiation, millimeter and terahertz waves are among the costly and exotic sensors that have either been tested, or are in use at airports, stadiums and train stations.
The most practical solution may be one that has been employed for years: bomb-sniffing dogs, said the Government Accountability Office.
Congress has allocated $2.5 million to the watchdog agency to produce a new series of “technology assessments.” The first of these reports examined the difficult problem of detecting explosives in passenger rail systems such as inter-city trains and subways. GAO investigators did extensive field research and provided a detailed overview of all the technologies that are in the development, or already in use.
Explosive detection canines “are considered a mature technology,” the unclassified version of the report said. (Why dogs are defined as a “technology” is not explained.)
Science does not completely understand how dogs use their sense of smell to detect the chemical compounds found in bombs, nevertheless, “operators also viewed canines as the most effective method currently available for detecting explosives in the rail environment because of their detection capability as well as the deterrent effect that they provide,” the report stated.
Dogs aren’t perfect. Unlike a machine, they must take frequent breaks, and they usually only spend about three to four hours per day on the job. They generally complete training at about age two and retire at age nine, giving them about seven years of “operational life,” as the GAO calls it.
Unlike some of the intrusive sensors that can reveal body parts underneath clothing, the general public generally accepts canines in public areas, those who employ the dogs in their rail systems told investigators. The dog normally signals suspicious odors by sitting down. Having a handler who understands the animal’s subtle signals is key to the team’s success, the report noted. There has been a good deal of research in recent years into fine tuning the training of dogs and handlers, as well as understanding their limitations and how the teams interact.
Meanwhile, a new method of using dogs to sniff out explosives in crowds is emerging, and mimics some of the technologies that are intended to passively find bombs as passengers stream through a checkpoint.
Instead of walking up to individuals or suitcases to take of whiff of their contents, “vapor wake canines” stand in one spot as they sniff the air for the chemicals used to make explosives. If the dog smells something suspicious, the handler lets it follow the trail to its source. The Department of Homeland Security’s science and technology directorate tested the concept in the Metropolitan Atlanta Rapid Transit Authority system in 2006 with “generally positive results,” and experiments into this concept are ongoing, the report said.