Satellite Sun Interference

How Does the Sun Cause Interference to my Satellite Reception?

Geostationary satellites are stationed at approximately 22,300 miles (36,000 kilometers) from Earth and located directly over the equator. Given the equator is offset by 22.5 degrees, the sun aligns directly with satellites and receiving earth stations twice a year—once in the spring and once in the autumn (Figure 1). This event is called a sun outage, and is also known as sun fade or sun transit.


A sun outage occurs because the earth station cannot distinguish between the energy from the sun and its intended communication signal. This is similar to when one is listening to a person talk immediately adjacent to them and a loud noise suddenly drowns out the voice of the person speaking, such that all that can be heard is that loud noise, until the noise either stops or moves far enough away to again hear the speaking person’s voice.

Solar eclipse
Figure 1/Figure 2: The sun’s thermal noise overpowers the signal coming from the satellite.





Access our Sun Interference Calculator to calculate predicted interference times based on satellite, antenna location and frequency band. Customers may access the version on MyIntelsat, our customer portal, which provides batch analysis as well. If you do not have a MyIntelsat account, you may apply for access. Applications are processed within two business days.