Some good news for those like me who have an occasional nightmare about a radiological dirty bomb set off in an American city.
Cell phone sensors detect radiation to thwart nuclear terrorism
Researchers at Purdue University are working with the state of Indiana to develop a system that would use a network of cell phones to detect and track radiation to help prevent terrorist attacks with radiological "dirty bombs" and nuclear weapons.
Such a system could blanket the nation with millions of cell phones equipped with radiation sensors able to detect even light residues of radioactive material. Because cell phones already contain global positioning locators, the network of phones would serve as a tracking system, said physics professor Ephraim Fischbach.
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Long before the sensors would detect significant radiation, the system would send data to a receiving center.
"The sensors don't really perform the detection task individually," Fischbach said. "The collective action of the sensors, combined with the software analysis, detects the source. The system would transmit signals to a data center, and the data center would transmit information to authorities without alerting the person carrying the phone. Say a car is transporting radioactive material for a bomb, and that car is driving down Meridian Street in Indianapolis or Fifth Avenue in New York. As the car passes people, their cell phones individually would send signals to a command center, allowing authorities to track the source."
The signal grows weaker with increasing distance from the source, and the software is able to use the data from many cell phones to pinpoint the location of the radiation source.