Thanks for your reply. I'm clear now, that the longitude of the
geostationary satellite's position (relative to my position)
affects its apparent angle above the horizon.
However, this effect is nil for a satellite that is in a due south
position. I can look out my window and see the neighbor's antennas
pointing due south, and at an angle of only 25 degrees, or less,
above the horizon.
Looking closer, I just realized that the antenna is receiving
signals from a high angle (about 55 degrees) and reflecting them
into a transducer positioned at a low angle (minus 5 degrees),
so it all makes perfect sense, now.
Thanks.
--Bill
--------------<original message>----------------
From: "Jim Shaffer, Jr." <jshaffer@csrlink.net>
Date: Thu, 30 Jul 1998
Subj: Re: Gravity....Push vs. Pull / Geostationary
Yes, you're missing something obvious. The satellites aren't all
located due south of your home. They're all along the celestial
equator (more or less, allowing for parallax, which is why equinox
blackouts don't happen exactly at the equinoxes), but the celestial
equator passes through the east and west points on your horizon as
well as the point due south whose altitude equals the complement of
your latitude. So you could have a dish pointing due east or due
west, though the signal strength would be pretty poor. These days
most commercial TV broadcasts occupy the same one or two
satellites, but in fact there are probably satellites at most of
the allowed orbital positions. (Only a few degrees seperation are
necessary for a large dish. High-power satellites must be further
apart since the small dish doesn't focus as well.)
>
> Maybe I'm missing something obvious, but this has boggled me
> for decades. Why do the common satellite TV antennas that point
> towards geostationary satellites always seem to be inclined at
> about 25 degrees up from the horizon -- at least here in
> Southern California (your latitude may vary) ?
>
> There shouldn't be any geosynchronous satellites out in that
> direction -- they should be about 50 degrees from the horizon,
> or ABOVE the half way point to true vertical. This is easy to
> prove if you can do, or imagine, ordinary technical drafting.