SONA (Automatic Cloudiness Detection System)

Above: SONA, external unit

Why our system?

Cloud monitoring and cloud prediction are crucial for air traffic and weather forecast. Clouds play a key role in solar radiation balance. Absorption, scattering and reflection caused by clouds can reduce significantly the solar radiation at ground. Clouds also absorb Earth’s infrared radiation.

Cloudiness or cloud fraction is a meteorological observation traditionally performed by observers. They look at the sky and estimate the cloud cover in Oktas. These observations are expensive and not accurate enough because of human subjectivity. The same atmospheric situation could be assessed by different observers with no similar results, depending on their mood, perception or fatigue.


Sieltec Canarias S.L. have successfully developed SONA (Automatic Cloud Observation System) in collaboration with the Izaña Atmospheric Research Center managed by the Meteorological State Agency of Spain in the Canary Islands. This system provides, with high resolution in space and time, hemispherical images of the sky which are processed and analyzed in real time providing an objective and accurate value of cloudiness percentage.


Traditional observation

SONA: analyzed image and original one

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