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Satellite location for TV and radio
transmissions.
Every satellite is positioned in an orbit
around the equator at a distance of about 36,000km from the
Earth
Each satellite is in a fixed and well
defined position on this orbit, shown in degrees in relation
to Greenwich meridian. The Astra 1 satellites are all positioned
at 19.2° east of Greenwich. The Eutelsat and Hotbird satellites
are all positioned at 13° East of Greenwich. The Atlantic
Bird 3 (A-Bird3) satellite is positioned 5° to the west
of the prime (greenwich) meridian.
Sky digital broadcasts are on the Astra
28E (not shown).
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Satellite reception
area (Footprint)
Since the satellites are fed exclusively
by solar panels, the power available for transmitting to the
ground is very low. They are therefore forced to concentrate
all their transmitting energy in a very small area of the
Earth, so the signals can be received by parabolic antennas
which are relatively small. The effect of the signal transmission
is like the light beam of a car: more powerful at the centre
of the beam, weaker and weaker towards the edges. These areas,
where one can receive the signals delivered from the satellite,
are called Foot-Prints, and each satellite has a different
Foot-Print depending on its power. For example, "older"
satellites have a smaller transmission power, and hence a
smaller Foot-Print. TELECO has chosen for its whole range
of satellite receiving systems three dish dimentions: 50cm,
65cm and 85cm.
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and Radio signals broadcast by the 3 groups of satellites
is guaranteed with the darker Foot-Print areas. It should
be remembered that signals become weaker when the sky is overcast
or rainy, and this could lead to images with black and white
dots, or the images could even disappear. When choosing the
satellite system to be installed on your vehicle, make sure
the dimensions of the parabola are suited for receiving the
satellite signals in your viewing area.
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How to align the parabola
to the Satellite
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1. Ensure
your location in is inside the Foot-Print for your parabola
50cm, 65cm, or 85cm. |
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2.
Make sure the sky towards the South is not screened by nearby
obstacles (trees, houses, etc.) which would prevent the signal
being received. Since all the main satellites (Astra, Hotbird,
Telecom) are positioned on an orbit over the plane of the equator,
the parabola must be pointed in that direction, i.e.
towards the south. |
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Scandinavia |
3. Set
the exact elevation of the parabola; remember that the satellite
is always fixed on the equator. As you move from North to South
on the globe, the parabola must be angled more. For example,
in Scandinavia, the parabola must be angled at 15° to point
to the satellite, whereas in Morocco it must be angled at 50° |
Morocco |
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With TELECO's systems you
won't run out of patience attempting a set-up
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 Aligning
the antenna with a satellite situated at 36,000km above the
earth, without any help, certainly calls for a good deal of
patience and a stroke of luck. Teleco has made this operation
very simple and quick. With the Voyager Plus and Voyager
Matic systems, you can set elevation in no time: just
check the supplied map to determine the angle that the dish
should have for your current location, then turn the crank
to reach the required setting. Once the elevation has been
set, turn the parabola (already pointing South) a little (15°
- 20°) to the right a little to the left, and images will
appear on your TV screen immediately.
 Should
you have chosen one of the automatic Magic Sat Digital
systems, all the operations described above will be performed
automatically just by pressing a remote control key.
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