Satellite Position Notation

[lari]

I am trying to set up a dish for receiving satellite television. I had assumed that I understood the meaning of, for example, 28.2 degrees East. I assumed that this meant 28.2 degrees east of north. Or possibly 28.2 degrees past east. But then, what can 122.2 degrees East mean ? I have hunted for an explanation but it seems to be regarded as being self-evident. Unfortunately, it is not self-evident to me. I would be grateful for elucidation from anyone.

[visionset]

Yes

No

122.2 degrees East of North! or 32.2 degrees East of East if you must.

[Michael Chare]

28.2 degrees is the position of the satellite in its orbit relative to the Greenwich Meridian.

The angle you have to point your dish at depends where you are.

See

is a more appropriate ng or uk.tech.tv.sky

[Andy Dingley]

Not for geosynchronous satellite positions it doesn't. The numbers refer to lines of longitude (through the poles) and they're relative to Greenwich.

28.2=B0E is on a meridian somewhere towards the far end of the Med. I'm guessing an Arabic station? Obviously the satellites are all near the Equator in terms of lattitude.

Assuming that you're in the UK your dish needs to point somewhat "leftwards" of a locally vertical meridian plane, but it's still mainly southwards. Stick it on a southern-facing wall, not eastern-facing.

[Terry]

28.2=B0E is the position of the Astra 2A, 2B & 2D satellites used by Astra and the satellites have to be directly over the equator.

If they were not, they would wander north and south of the equator over a 24 hour period and need a sophisticated steerable dish to track them.

The dish needs to point to a spot in the sky which is 28.2=B0E of the Greenwich meridian and 35,786 kilometers (22,236 miles) above the equator - finding this point is the clever bit!

This link will work out the correct details for you:

[Terry]

28.2=B0E is the position of the Astra 2A, 2B & 2D satellites used by Astra ...

Whoops! That should have said "used by Sky"!

Terry

[adder1969]

One is looking south for the satellites, towards the equator. 28.2E is then more or less 28.2 degrees east (left) of south. You should be able to find more information than you need by googling etc. I recently set up a dish from scratch, pointed in roughly in the same direction as the neighbours dishes then used the digibox to get to the right satellite.

[Andy Burns]

Sounds a bit hit-and-miss, aiming something smaller than a dustbin lid, at something about the size of a people-carrier which is more than twice as far away as Sydney is from London.

[Dave Fawthrop]

|Andy Dingley wrote: | |>

|> 28.2?E is on a meridian somewhere towards the far end of the Med. I'm |> guessing an Arabic station? Obviously the satellites are all near the |> Equator in terms of lattitude. |>

| |28.2?E is the position of the Astra 2A, 2B & 2D satellites used by |Astra and the satellites have to be directly over the equator. | |If they were not, they would wander north and south of the equator over |a 24 hour period and need a sophisticated steerable dish to track them. | |The dish needs to point to a spot in the sky which is 28.2?E of the |Greenwich meridian and 35,786 kilometers (22,236 miles) above the |equator - finding this point is the clever bit!

Quite easy really

the complex maths has been done for you.

[Dave Liquorice]

No, 28.2 is the Astra constellation of satellites used for Sky etc

There is enough adjustment in a minidish mount to go on either. As a rough guide the direction to face the dish is the same as the sun at about 1020 GMT so anywhere that is well illuminated by direct sunlight around that time can be a site for a dish. Note that this is only the horizontal direction and is on bearing around 145 degrees. The elevation= (up/down) to the satellites is about 30 degrees.

[Andy Dingley]

You can still use them with a static dish if they're geosynchronous, even if they're wobbling in the figure-8 you describe. Maybe not for TV, but certainly for some data services where a lower signal strength at the LNB is acceptable.

As older satellites run low on station keeping fuel they often end up in such orbits, pensioned off to less obvious VSAT services.

[adder1969]

Well it might be but I got mine done in about 5 minutes. The sky signal is very strong and you use the digibox to fine tune it.