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Wi-Fi threatens weather radar images

Wi-Fi threatens weather radar images

Occasionally we see disturbances such as spikes and dots in weather radar images. These are often coming from wireless devices using wrong radio frequencies.

Increasing interference can black out large swaths of weather radar maps, hiding approaching weather systems. International group worried of scientists lead by FMI researchers  published a plea for co-operation to avoid such disturbances.

Weather radars work by sending microwave pulses and receiving a fraction of them reflected by raindrops. This way we get a picture of where it rains and how heavily. When nearby devices transmit at the same frequency, we see the disturbances as dots and spikes in the radar image.

Wireless technology, such as local area telecommunication networks and surveillance cameras, causes severe interference for weather radars because they use the same operational radio frequencies. One or two disturbances can be removed from the radar image, but the number and power of the interfering wireless devices are growing all over the world, threatening that one day the radars could become useless for weather observations.

Use of equipment at radio frequencies is regulated by laws and international agreements. Technologies have been developed for peaceful coexistence. If wireless devices use these technologies to protect weather radars, their data transmission capabilities become limited, so it is tempting to violate the regulations. In Finland, the Finnish meteorological Institute works in close contact with Finnish Communications Regulatory authority, and such disturbances are rare. In an article published in Bulletin of American Meteorological Society the researchers encourage other members of worldwide weather community, even in developing countries,  to involve themselves in the radio frequency management process    to ensure that meteorological interests be duly taken into account in any decision-making process toward the future usage of wireless devices.

More information:

FMI,  Researcher Elena Saltikoff, tel. +358 50 919 5451,

Finnish Communications Regulatory Authority, Specialist Kalle Pikkarainen, tel. +358 295 390 458, kalle.pikkarainen(at)



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