It could become an indispensable safety device for outdoor enthusiasts - a cellphone that warns you to take cover if lightning is heading your way.
Lightning can pose a major risk to people taking part in outdoor pursuits, such as golfing. So Nokia proposes a warning system that uses the fact that a lightning bolt is an electric current that emits radio waves. Each bolt produces frequencies between 10 hertz and 5 gigahertz, and the distribution of these signals depends on how far away the lightning is.
— Red Panda, Outdoor Enthusiast, Light Reading