Many users had asked why the transmission of some satellite images in the Global-Local function was recently disturbed.
This is why:
Occasionally (especially during the time of the eclipses in spring and autumn) some satellite images experience degradation due to the intrusion of sunlight into the radiometer. This occurs mainly when the Sun is not in complete eclipse, so that at least a part of the Sun is visible from the satellite behind the northern or southern hemisphere of the Earth.
The light spots detected in the visible image are caused by double reflections (secondary reflection straylight) due to the optical design of the satellite radiometer. Direct sunlight reaches the satellite and is reflected and diffused by the mechanical structure of the radiometer, so that reflected light enters the radiometer field of view and reaches the detectors to create the anomalous intense spots in some images. This effect is observed particularly around midnight and especially during the time of the eclipses in spring and autumn.