Future Nokia phones may double as lightning detectors

Stephen Withers
Friday, 25 May 2007 03:23

Your IT - Mobility

Your mobile phone is already a music player, a camera, a games console and an Internet access device, so why not make it a lightning detector too? That's the plan set out in a Nokia patent application.

The idea relies on the way lighting generates electromagnetic noise across a very wide range of frequencies (10Hz to 5GHz) that can be received at distances of 30km or more.

Having detected that noise in both the channel used by the phone and another band (eg, FM radio, RFID, Wi-Fi or Bluetooth), software in the phone could calculate how far away the strike had occurred and warn the user.

It would even be possible to use the different receivers in a tri-band phone to cover a sufficiently broad range of frequencies,

Such a capability could be useful for outdoor workers, golfers and others spending a lot of time outside in areas prone to thunderstorms.
 
An interesting aspect of the patent application is the idea of using a low-power receiver (eg RFID) to wake up the next stage of the circuit when it detects signals that could be lightning. This monitoring mode would consume more energy, but would give accurate lightning detection. Finally, when the device is confident that a strike has been detected, it switches to full operation allowing the most accurate measurements. Nokia engineers suggest that a simpler implementation could go straight from the initial monitoring mode to full measurement.