Sun-transit Outage

A Sun-transit outage occurs due to the particularly strong interference that results when the geometry of an orbit is such that the beam of an Earth station antenna is pointed directly at the Sun. The days on which maximum solar interference occurs varies according to the latitude of the Earth station; the time of day on which the interference occurs depends on the longitude of the Earth station. Noticeable interference may be experienced for as long as ten minutes a day for several days, during which time the receiving Earth station can do nothing except wait for the Sun to move out of the antenna’s main lobe. Although the time lost may seem insignificant (approximately 0.01% of the year), Sun-transit outages always occur in the daytime during peak traffic loads.