Cellular rain gauges

Knowing where and how hard rain is falling is important not only for deciding whether to take an umbrella, but also for managing water resources, improving precipitation models, anticipating floods, and assessing climate. Yet many parts of the globe lack good data, whether from weather radar or from rain gauges. (Gauge prevalence is less than half what it was a decade or two ago.) Meanwhile, the world is being increasingly covered by cellular communications networks, and radio signals broadcast between cell towers have been proposed as a new means of monitoring rainfall: At common communications frequencies (roughly 7–40 GHz), the attenuation of signals transmitted from one cell tower to another is mainly due to absorption and scattering by raindrops along the path. Such attenuation data are typically gathered by cellular companies every 15 minutes or so to monitor the stability of their networks. Armed with attenuation data from a Dutch...