Thursday, October 31, 2013

How does satellite tv work
How does satellite tv work
There isn’t just a single “Sky” satellite out there orbiting our blue planet, there is a cluster of them. New satellites are continually being launched to replace tired and old ones.At any one time there are between 4 & 5 satellites orbiting the planet. These satellites are close together. Close as in space terms is that they occupy an area in orbit of approx 100km squared. These satellites have the ability to adjust their position so that they will stay in their position. They have small rocket boosters to help, but eventually they run out of fuel and have to be replaced.
The satellites which send down to us the sky & Freesat broadcasts are owned by a company called “SES-Astra”. That’s why when we engineers are looking for those satellites our meters will read “Astra-1” as this is the correct one in space to lock on to. The satellites receive the Tv broadcasts from Luxemburg. There is a huge dished beaming up the data every day. That then is beamed down to your dish. The signal is decoded by your receiver or digi box and converted into pictures and sound.
The group of satellites are always in the same area of orbit ensuring that the signal being beamed to your sky dish is constant. If the satellites were to move out of “geostationary orbit” then you would lose your signal and stop receiving your Sky or Freesat Tv. This means that even though the earth rotates , the satellite cluster always stays in the same position over that particular part of our planet. That is why we can fix a sky dish on a wall or fixed position and get the signal all the time.
The group of satellites are around 24,ooo miles above the earth. That is why it takes experts to lock a satellite dish onto the signal of the correct group of satellites in orbit, so as to get you either Freesat or Sky Tv. The dish has to be aligned perfectly so as to receive all the Tv broadcasts without it getting glichy or dropping out altogether.

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