signal strengh throughout the day

its to do with the rotation of the earth as rfar as i know! the angle to the sat changes slightly on the horizon? (could be totally wrong but remember reading when i was trying to get 0.8 and 4.8 nordic)

A TV satellite usually has a geostationary orbit so therefore it is in a fixed position from an observer's point of view, so the earth's curvature should have no influence in the fluctuation of a satellite signal. Only if the orbit was inclined (not orbiting at 0 degrees to the equatorial plain) would this be a factor. From what I understand, it is more to do with the difference in the composition of the ionosphere and other layers of the earth's atmospere at certain points of the day, heavily influenced by the sun. Basically, the sun and atmospheric conditions do not remain constant, and this affects the journey of the microwaves as they pass through the layers of the earth's atmosphere.

i beg to differ musogeek ¬
a satellite cannot be parked absolutely STILL in space that's why they end up in what is referred to as InCLINED orbits - I have found that fringe areas in the footprint can get different signal levels throughout the day and night and this level change can be tracked ¬ For example last time i set up my 1.5meter dish i could recieve 4.8 bot not all the channells without break up however during a select period of 6-7 hours certain channels wouldn't break up and that time spot changed through out the Rotation sequence - Funny it should be the same satellite in the beggining of this thread !

Rik

As far as I understand, a satellite eventually enters an inclined orbit towards the end of its life, as it has spent most of its fuel. As you rightly say Rik the orbit isn't completely stable, and that is why it needs fuel, to keep the orbit as stable as possible, however, I am not so sure that this has the biggest effect on the signal strength, obviously if this slight instability caused the satellite to dip below the horizon and then reappear, then it would be noticed, but there is a lot more going on.

One should only notice it on the Edge of the footprint ¬ Such as with 4.8e and 26e !

Nice Thread

below is a good site for tracking a satellite's position - the link is for TV satellites.

http://www.n2yo.com/satellites/?c=34

Maybe it would be interesting to take note of the signal strengths in relation to the position of the satellite and the times of day etc to see what causes the fluctuations. Nothing like experimenting (so I used to say in my late teensjoint10)

this is only too true for BBc2 viewers in some well known "blackspots" in southern Spain... it goes " out of range"
for wanting of a better wording in the afternoon fom 374pm until about 7pm
but meanwhile only 1 km distance there´s no problem at all 24/7 ......