The creators of the popular OpenSignal Android app have figured out a way to crowdsource real-time weather information from the batteries of smartphones.
The OpenSignal app collects all sorts of phone information from voluntary users in order to build maps of cellphone coverage and WiFi access spots and has about 700,000 users. The developers of the app realized that the information coming from the temperature sensors in users' smartphones batteries, which helps to make sure the battery doesn't overheat, could be used to make weather predictions for the area they were in.
Using data from users in London, Los Angeles, Paris, Mexico City, Moscow, Rome, San Paulo and Buenos Aires, Argentina, they estimated daily average temperatures within 1.5 degrees Celsius after some calibration.American Geophysical Union reports, "While each of the cities already has established weather stations, according to the new method’s creators it could one day make predictions possible at a much finer scale of time and space than is currently feasible. Whereas today, weather reports typically provide one temperature for an entire city and a handful of readings expected throughout a day, the technique could lead to continuously updated weather predictions at a city block resolution."
"The ultimate end is to be able to do things we’ve never been able to do before in meteorology and give those really short-term and localized predictions,” said James Robinson, co-founder of OpenSignal. “In London you can go from bright and sunny to cloudy in just a matter of minutes. We’d hope someone would be able to decide when to leave their office to get the best weather for their lunch break.”
The key to this type of weather forecasting is to have a large number of users to account for people in a range of temperatures in the same place (inside in the air conditioning versus outside in direct sunlight). With a large crowd supplying data, the real conditions of an area start to emerge and that information can be mapped and used to make predictions that can be drilled down to a small area or to provide more accurate weather forecasts for people living farther away from weather stations.
The creators have also developed an app called WeatherSignal that takes advantage of more recent phones that come with built in environmental sensors for air temperature, humidity and pressure.