Why do SKY satalite dishes all point the same way?

[Impret-Sir]

The guy who installed ours told me that, "they have to point towards the satalites position in orbit", but surely, considering the height that the satalite orbits at, it cant make any difference what direction the dishes point. If a GPS satnav device can work in a car pointing in any direction, why cant a SKY dish?

[jackthehat]

The GPS uses information from multiple satellites to calculate its location.

The dish receives information from one source.............so it points towards it.

[Sqad]

No idea.....guess?

TV satellites are geo-stationary in that they don´t move and rotate around the earth, WITH the earth.
The other satellites aren't and don't.

LOL

[ChuckFickens]

No, the height the satellite is at means it has to point the correct way more accurately, a few degrees off at ground level will mean it's pointing miles away from the sat at that sort of distance.

GPS receivers use omnidirectional antennas, so they can receive signals from all directions, satellite dishes are directional and also GPS satellites are about half the distance from the earth than the ones sky use. (about 20000KM as opposed to about 40000KM)

[Impret-Sir]

AH, OK, that makes sence re the GPS thing, but still, as the satellite is so high in the sky I still dont get why the SKY dish has to point at it, I think of those satellite pictures of the earth, focusing on a house that then zoom out and out and out untill what you see is the entire planet, at that range the position of a tiny dish on the side of my house looks irrelevant!

[jake-the-peg]

The satellite is in geostationary orbit. That means it goes round the earth once every 24 hours and so stays in the same position in the sky.

There's only one orbit this can happen at and it's 22,000 miles up - that orbit's getting pretty crowded now!

The satellite signal is actually quite weak 5,900 Watts - 1 electric fire bar is 1,000 watts so imagine that at 22,000 miles!

Consequentlt satelltite dishes collect a signal over a big area (compared to a TV ariel) and focus them on a small receiver and to minimise nose from all the other much stronger radio signals the dishs have quite a relatibely narrow "field of view" and so have to point to the position in the sky that the satellite is

[Sqad]

See....I told you....GEO-STATIONARY..........LOL

The others are POLAR....and they do move around the earth.....I think?

[murraymints]

Sqad...and I thought the earth moved around you !....see you make my earth move !!!LOL

[rojash]

The moon is even higher in the sky than than a satellite, so why do we all have to turn towards it if we want to see it?