Editor's Note: This is part of IEEE Spectrum's ongoing coverage of Japan's earthquake and nuclear emergency.
A group of device hackers are digitizing Geiger counter readings to monitor radiation levels in real time across Japan.
The data is being aggregated by the platform Pachube (pronounced “patch-bay”), which allows users to upload and share sensor data.
So far, the crowd-sourced effort has produced a range of maps that show radiation levels across Japan. Ed Borden, who manages developer relations at Pachube, told me he foresees more applications for the radiation data, including cell phone programs that could inform the holder of nearby radiation levels. “These visualizations are kind of the first step," he says.
Japan’s Ministry of Education, Culture, Sports, Science & Technology issues periodic updates, indexed here, on radiation levels throughout the country by prefecture.
Pachube’s data is available in real-time, but it is likely not as precise. NPR notes that contamination, poor calibration, and varying levels of background radiation can make it difficult to interpret Geiger counter readings.
Borden says that aggregating radiation data from a number of sensors will allow people to cross-check readings for accuracy and may also inspire a healthy dose of skepticism when it comes to the numbers.
On the face of it, open access to critical environmental information seems like a good thing. The Atlantic's Alexis Madrigal says the crowd-sourced effort could inspire more confidence in official measurements.
I would argue that distributing unofficial radiation readings, particularly uncalibrated ones, may be counterproductive in an emergency. Evacuation planners must grapple with complicating issues, such as voluntary “shadow evacuations” of residents who live outside official evacuation zones. False or hard-to-interpret radiation measurements could encourage that behavior.
With just a few hundred Geiger counter feeds, Pachube’s data is too spotty to paint a clear picture of the radiation environment around the country.
But it will be interesting to see what real-time data the project collects going forward, particularly if the sensor network gets denser. The radiation environment around Fukushima is still changing. On Friday, Japan’s Chief Cabinet Secretary announced a voluntary evacuation for residents living between 20 and 30 kilometers from Fukushima Dai-1 (people living within 20 kilometers of the plant have already been evacuated).
For those interested in digitizing data from decades-old Geiger counters, one Pachube user has posted a tutorial detailing a way to convert analog chirps into data that can be uploaded to the web.