XM Satellite Sun Outage Page

Twice a year satellite downlink sites in the Northern Hemisphere experience reception interruptions due to the transition of the sun. Close to the Spring and Fall Equinox all Geostationary satellites experience a period of approximately ten days when sun interference will affect the ability of earth stations to receive programming.

This interference is the result of the sun aligning directly above the satellite and the downlink antenna. Radiation from the sun overpowers the signal of the satellite, decreasing the signal level received by the earth station antenna. Sun outage interference gradually increases through the transit time period, peaks, and then subsides as the transit period ends.

It is important to note that XM satellites' downlink power (signal strength) is significantly higher than most satellites, therefore it is possible subscribers may notice little or no signal degradation which occurs with other common satellite signals.

The start and end dates of the sun outage cycle for your geographical location determines the severity of the interference on any given day.

SOLAR TRANSIT DAY LINES

FALL

SPRING

solarmap.gif (15435 bytes)
  KEY WORST DAY   KEY WORST DAY
1. OCT. 6 - 16  OCT. 11 10. FEB. 25 - MAR. 7  MAR. 2
2. OCT. 5 - 15  OCT. 10 11. FEB. 26 - MAR. 8 MAR. 3
3. OCT. 4 - 14  OCT. 8 & 9 12. FEB. 28 - MAR. 9 MAR. 4 & 5
4. OCT. 3 - 12  OCT. 7 13. MAR. 1 - 10 MAR. 6
5. OCT. 2 - 11  OCT. 6 14. MAR. 2 - 11 MAR. 7
6. OCT. 1 - 10  OCT. 5 15. MAR. 4 - 12 MAR. 8
7. SEPT. 30 - OCT. 8  OCT. 4 16. MAR. 5 - 13 MAR. 9
8. OCT. 8 - 18  OCT. 13 17. FEB. 23 - MAR. 4 FEB. 28
9. SEPT. 29 - OCT. 3  OCT. 1 18. MAR. 10 - 13 MAR. 12

USING THE TIME ZONE MAP AND TIME ZONE TABLE

According to the spring dates on the time zone map, recievers in the vicinities of Seattle, Great Falls (MT), Duluth (MN), and Quebec City, Canada, will see short interference periods beginning February 25 and lasting for perhaps 10 days, until March 7. The worst day will most probably be March 2 for these places. This also applies to other places on or near the map's February 25 - March 7 Transit Day Line. 

 

PREDICTED INTERFERENCE LOCAL TIMES ON WORST DAYS

SATELLITES

SPRING (Standard Times)

EAST TO WEST

Eastern

Central

Mountain

Pacific

E. Alaska

Hawaii
XM Roll (85.0)
XM Rock (115.0)

12:58 PM
3:11 PM

11:50 AM
2:04 PM

10:42 AM
12:57 PM

9:37 AM
11:51 AM

8:40 AM
10:47 AM

7:20 AM
9:27 AM

 

PREDICTED INTERFERENCE LOCAL TIMES ON WORST DAYS

SATELLITES

FALL (Daylight Savings Times, except Hawaii*)

EAST TO WEST

Eastern

Central

Mountain

Pacific

E. Alaska

Hawaii
XM Roll (85.0)
XM Rock (115.0)

1:33 PM
3:48 PM

12:26 PM
2:41 PM

11:19 AM
1:34 PM

10:13 AM
12:27 PM

9:14 AM
11:20 AM

7:00 AM
9:08 AM

*Note: Hawaii does not participate in Daylight Savings Time.