Nokia Patents Mobile Lightning Sensor

sNokia's patent for a lightning sensor that would be embedded in mobile phones notes that lightning strikes can actually occur when there are no visible clouds indicating a thunderstorm. Nokia said the most benefit from a mobile lightning sensor would be to outdoor workers whose livelihoods and, often, lives depend on knowing the weather.

The ad campaign could almost write itself. A couple stands under a threatening sky and the woman holds up her phone -- but not to send a text message or call her friends. "You can play music on your cell phone," the voiceover says somberly, "or take pictures, play games, even make phone calls -- and now you can detect lightning."

While that campaign might still be some future fantasy of mobile phone marketing execs, the idea behind it is now owned in a patent by leading cell phone maker Nokia.

Measuring the electromagnetic noise created by lightning, new phones from Nokia might someday not only be able to detect lightning, but also be able to determine how far away a recent lightning strike occurred. This would be done by detecting the electromagnetic signal in both the phone's channel and in another channel, such as FM radio, RFID, Wi-Fi, or Bluetooth.
Lightning Frequencies

Lightning bolts generate frequencies as low as 10 Hz and as high as 5 GHz, with a peak around 500 Hz. The device described in the Nokia patent could actually be any mobile radio-frequency device with "at least two communication channels or frequency bands, whereby at least one of which is normally a telecom channel/frequency range."

Nokia's patent notes that lightning strikes can actually occur when there are no visible clouds indicating a thunderstorm. While anyone could benefit from any amount of advance knowledge and location of a strike, Nokia said the most benefit could be to outdoor workers whose livelihoods and, often, lives depend on knowing the weather.

The patent notes that, on the high end, meteorological and single-band radio-frequency detectors are large and require a specific orientation, making them not well suited for mobile devices. On the low end, Nokia said in the patent, there are existing portable detectors that are susceptible to human-generated electromagnetic signals and, especially near cities or highways, are prone to false alarms.

Beginning of Sensor-Phone?
Gartner analyst Todd Kort said he didn't think a lightning-detection capability in a cell phone "would give much of a competitive advantage, unless you happen to live in an area where there is a lot of lightning."

While calling it an "interesting application," he said he didn't think it would help Nokia sell phones. He also noted that there might be other ways to provide lightning detection, perhaps with more accurate or detailed information, such as a weather service like weather.com providing "lightning alerts" to location-sensing phones.

Kort also noted that there are at least dozens of different sensors being developed to make the cell phone, already a kind of electronic "Swiss Army Knife," into more of a mobile safety detector for a variety of dangers.

"It wouldn't shock me," he said, "if, in 10 or 20 years from now, these kinds of sensors become common." A sensor that uses Bluetooth communication, for example, could alert a pacemaker owner of a problem with the life-critical device.