Millions of phones create most complete map ever of the ionosphere

Data from millions of phones has helped produce the most complete map ever made of the ionosphere, part of Earth’s upper atmosphere. This could help us understand disturbances caused by geomagnetic storms and perhaps even improve GPS.

“Smartphone-based measurements cover twice as much of the ionosphere as traditional scientific monitoring stations,” says Brian Williams at Google Research. “It’s like there is a scientific monitoring station in every city where there are phones.”

Williams and his colleagues analysed data…