DARPA tests anti-terrorist radiation detection network

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In an experiment testing a technology designed to detect the radiation from a terrorist-deployed small nuclear bomb, DARPA in October deployed more than a thousand volunteers in Washington DC to test a detector that can be carried in a backpack.

Recently, a geneticist was mysteriously abducted in Washington DC, leading to the US government deploying a small army of detectives to foil a dirty bomb plot. At least, that was the fictional scenario of a DARPA field test that saw a thousand volunteers equipped with smartphone-sized radiation detectors fan out over the National Mall in a radioactive scavenger hunt to test the progress of the agency’s SIGMA project, which is tasked with developing technology to combat nuclear terrorism.

Nuclear terrorism is one of the top nightmares of security services. Not only is the prospect of a dirty bomb involving radioactive materials dispersed by conventional explosives alarming, but tracking down illegal nuclear materials in an urban setting requires covering far too large an area for fixed sensors. Since 2014, DARPA has been working on how to produce a portable sensor array based on low-cost, high-efficiency, radiation sensors networked by smartphone networks to detect gamma and neutron radiation and evaluate the information in real time

According to DARPA, the SIGMA array was first tested in New York and New Jersey using 100 sensors. For the Washington test, 1,000 sensors were carried in backpacks by hundreds of ROTC cadets from the universities in the National Capital Region, midshipmen from the US Naval Academy, and DARPA personnel coordinated by the University of Maryland’s National Consortium for the Study of Terrorism and Responses to Terrorism (START).

Developing technology that can find and catch a terrorist who is trying to deploy a nuclear bomb in an urban area is certainly a good thing. I can’t help worry, however, about some larger philosophical concerns. Putting aside the specific technology being tested, the infrastructure being developed here that will make it easy for the government to deploy thousands of volunteers to hunt down an individual makes me a bit uncomfortable.



  • Steve Earle

    “…tracking down illegal nuclear materials in an urban setting requires covering far too large an area for fixed sensors…”

    I disagree, this tech makes sense for a one-off specific scenario where there is some advance info on the threat. It doesn’t really help the more likely scenario of a random Ryder-Rental Truck bomb that drives in to one or more cities and immediately detonates.

    I can see where a small sensitive device could come in handy once you know there is a threat to search a particular area, but it seems like fixed sensors that monitor traffic of all kinds would be more useful as a standing early warning system.

  • Garry

    My understanding is that sensors are deployed along busy highways, bridges, etc. I know that when patients are given certain treatments that leave behind residual radiation for a few days, they are given doctors’ notes in case they are stopped by police responding to radiation detectors.

    I get the feeling that there are a lot of things deployed that the public isn’t aware of, including ways to look into our computer activities.

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