Accurate, real-time rainfall measurements can be challenging to obtain in developing economies as traditional rainfall monitoring techniques (rain gauge, satellites, radars) can be costly and weather stations are often sparsely located. This data gap leads to high basis risks of rainfall-based index insurance, which hurts smallholder farmers.

However, in many regions where traditional rainfall data is unavailable, mobile phone service provider networks are widespread. The wireless commercial microwave links (CMLs) used in these networks are widely deployed, and, because rainfall causes attenuation to the radio signals between transmitter and receiver stations in the network, CMLs can be used to draw reliable rainfall estimates based on changes observed in the quality of the signal.

CMLs have the potential to provide quantitative rain estimates with high spatio-temporal resolution as measurements are taken typically every 15 minutes. Furthermore, the project offers a sustainable solution because the implementation cost is minimal; the network infrastructure is in place and the CML data is already collected and logged by many of the cellular operators for quality of assurance needs.

Finally, many of these links are installed in areas where access is difficult such as orographic terrain and complex topography. Therefore, the CML method enables measurements in places that have been hard to access in the past or where rainfall has never been measured before.