Take heart, cellphone users. All those dropped calls you experience may someday be used for a greater good: to help forecast the weather.
That’s the suggestion of an Israeli electrical engineer, Hagit Messer, who has demonstrated that the ups and downs of signal strength in wireless communications can be used to measure rainfall accurately and continuously over a wide area.
Raindrops and other particles in the atmosphere can weaken electromagnetic signals. Satellite TV viewers who lose the signal when a thunderhead passes know this well. Wireless companies know it too.
“To ensure reliable communications, they need to cope with disturbances caused by weather and other effects,” said Messer, a professor at Tel Aviv University.
Wireless companies constantly analyze signal strength so they know, for example, when to increase the power at their base stations. Messer’s idea, reported in the journal Science, was to analyze those same data to determine the rainfall that is causing the disturbance.
“All we need to do is exploit this information to get better monitoring of environmental conditions,” she said.
Messer used “backhaul” transmissions between base stations, which move calls throughout the network. They have a higher frequency than transmissions from phones and are more prone to environmental interference. They are sent from fixed locations, making the analysis easier. But eventually, she said, it should be possible to use phone transmissions, which would provide more readings over a given area, increasing accuracy.