Sun Transit

Sun transits occur when the sun crosses the Earth's equatorial plane during the spring and fall equinoxes - late February or early March and September or October. At these times, the sun aligns directly behind the satellites for a few minutes each day. The time of occurrence depends both on the geographic location of the Earth station and the location of the satellites. When the sun moves directly behind the satellite, the signal can be overwhelmed by the enormous amount of thermally generated radio frequency (RF) noise radiated by the sun. This can cause reception interference for a few minutes every day during this occurrence. Degradation of the signal may last for several minutes depending on the antenna size and available link margin, although it is not unusual for the effect to go unnoticed.

To locate specific times for sun transit occurrences or to find out more information please click the link below to go to Telesat's Sun Transit page from which the sun transit calculator can be accessed:

Sun Transit Calculator