Smartphones could provide weather data in poor nations

Laura Garcia in SciDev.net: Smartphones can now be used to collect weather data such as air temperatures through WeatherSignal, a crowdsourcing app developed by UK start-up OpenSignal.   This helps crowdsource real-time weather forecasts and could one day help collect climate data in areas without weather stations, its developers say.

Once installed, the app automatically collects data and periodically uploads them to a server. The app's ability to record air temperature is based upon the discovery that the temperature of a smartphone battery correlates closely to the surrounding air temperature, published in Geophysical Research Letters this month (13 August).

"Lithium ion batteries have temperature sensors to prevent damage caused by attempts to charge them when the battery is too hot," the paper says. But these sensors do not provide a direct air temperature measurement — due to heat being emitted by both the smartphone and its user. So the researchers used a model that estimates the outside temperature based on smartphone readings. The fact that battery temperature correlates with ambient air temperature was discovered by accident, James Robinson, one of the authors of the paper and co-founder of OpenSignal, tells SciDev.Net. 

The team was researching energy consumption in relation to poor mobile network signal, a condition that is known to reduce battery performance. "We started playing with the data and decided to look at average battery temperature versus historic weather temperature, and we found a really strong correlation," says Robinson....

An Ubuntu smartphone (in an attempt not to be outdated), shot by Cartmanland, Wikimedia Commons, under the Creative Commons Attribution 3.0 Unported license