Post by Eric Johnston on Sep 14th, 2010 at 10:42am
Sun outages last only a few minutes. Your site will get sun outages on your receive path. Your hub site will get sun outages on its receive path at different times to you.
If you are getting much longer outages at regular times, every day or half day this may be due to the inclination of the satellite increasing so that at times of day the satellite moves out of the beam of your fixed pointing antenna.
Satellites are normally kept +/- 0.15 deg north south and they remain within the beam of small fixed pointing antennas. If the inclination is much larger e.g. +/- 0.8 deg, or you have a large hub dish, then you need a trackling antenna, that repoints itself every 10 minutes or so.
This image shows the result of having a badly pointed dish, whose beamwidth does not include the whole of the daily satellite movement range. It does not work all day, even though the satellite is well within its box. Outages occur daily when the satellite is towards the upper left.
AMOS 5i is due to soon run out of fuel for north south stationkeeping but as of now its inclination is only 0.0816 deg. It has not yet run out of fuel. The inclination gradually increases (about 0.8 deg per year) and every few weeks north-south stationkeeping fuel is used to reverse the drift. Think of it as gradually increasing from -0.1 to +0.1 and then being pushed back to -0.1 using the thrusters. Longer term gradual adjustment is also possible using lower thrust ion thrusters.
Recent 2-line orbit elements:
AMOS 5I
1 23723U 95064A 10256.80216159 .00000089 00000-0 10000-3 0 3262
2 23723 0.0816 78.0600 0002460 85.5602 134.8296 1.00270992 54184
Regarding alternative satellites for East Africa please say where in East Africa are your customers and where is the teleport hub. What is your preferred frequency band and polarisation type (based on your existing hardware).
Best regards, Eric.
If you are getting much longer outages at regular times, every day or half day this may be due to the inclination of the satellite increasing so that at times of day the satellite moves out of the beam of your fixed pointing antenna.
Satellites are normally kept +/- 0.15 deg north south and they remain within the beam of small fixed pointing antennas. If the inclination is much larger e.g. +/- 0.8 deg, or you have a large hub dish, then you need a trackling antenna, that repoints itself every 10 minutes or so.
This image shows the result of having a badly pointed dish, whose beamwidth does not include the whole of the daily satellite movement range. It does not work all day, even though the satellite is well within its box. Outages occur daily when the satellite is towards the upper left.
AMOS 5i is due to soon run out of fuel for north south stationkeeping but as of now its inclination is only 0.0816 deg. It has not yet run out of fuel. The inclination gradually increases (about 0.8 deg per year) and every few weeks north-south stationkeeping fuel is used to reverse the drift. Think of it as gradually increasing from -0.1 to +0.1 and then being pushed back to -0.1 using the thrusters. Longer term gradual adjustment is also possible using lower thrust ion thrusters.
Recent 2-line orbit elements:
AMOS 5I
1 23723U 95064A 10256.80216159 .00000089 00000-0 10000-3 0 3262
2 23723 0.0816 78.0600 0002460 85.5602 134.8296 1.00270992 54184
Regarding alternative satellites for East Africa please say where in East Africa are your customers and where is the teleport hub. What is your preferred frequency band and polarisation type (based on your existing hardware).
Best regards, Eric.