Northwestel and Telesat are reminding customers that we are entering sun transit time again. The natural phenomena which occurs every spring and fall causes the loss of the satellite communication signal due to the high level of noise generated by the sun passing directly behind the satellite spacecraft.
Sun transit for this fall began October 7 and will end October 19, with customers possibly experiencing noise or service interruptions between 19:00 and 19:30 MDT.
"Sun transits occur when the sun crosses the earth's equatorial plane during the spring and fall equinoxes. At these times, the sun aligns directly behind the satellites for a few minutes each day. When the sun moves directly behind the satellite to your receive antenna, the satellite 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,” states Northwestel in a public service it released.
The number of outages, outage duration and the time of outage depend on the radio emission activity of the sun, the movement of the earth with respect to the sun, the pointing and location of receive antenna, and characteristics of the communication system. Those characteristics, in turn, include the operating receive radio frequency, the receive antenna gain pattern, the clear sky operating carrier-to-noise ratio (C/N), the clear sky equivalent system noise temperature and the minimum acceptable C/N.
When the sun transits occur, the antenna noise temperature varies depending on the antenna size, the elevation angle, location and environment.
