The satellites relevant for satellite TV and radio reception are positioned in the so-called „Clarke Belt“ in geostationary orbit, at an altitude of 35.803 km directly above the equator.
Objects positioned there move analogously to the earth’s rotation, and appear to be stationary above a specific point on the ground. This is the basis behind the reception of satellite broadcasts using a fixed ground antenna.
Depending on the position of the satellite in this orbit, for example ASTRA at 19,2° East, and the location of the satellite antenna relative to the north/south and east/west direction on can calculate two values that are relevant to allow you to position the satellite antenna correctly for reception of the desired satellite, the “angle of azimuth” and the “angle of elevation”.
Azimuth is the angle for the horizontal positioning of the antenna dish. The angle is stated in degrees. North = 0 degrees, South = 180 degrees.
Elevation is the vertical angle of elevation above the horizon, and is also expressed in degrees. This is the angle by which the antenna must be „tilted“ in relation to the theoretical horizon in order to point directly at the desired satellite.
As you can see from the illustration, parabolic dish antennas can also be installed in locations close to the house (e.g. in the garden, etc.), it is only rarely really necessary to install them on top of the roof. Even where the parabolic antenna cannot be installed in the garden because there is no direct line of sight to the desired satellite from there, it is recommended you investigate whether the parabolic antenna can be mounted on a house or garage wall using a mounting bracket
On the one hand, this simplifies installation, and on the other hand it ensures you have easy access to the parabolic dish. The illustration below shows the outstanding position of the main satellite for direct satellite television reception, namely ASTRA and EUTELSAT.
The orbital positions of these satellites provide extremely favourable elevation angles for reception in Germany. Thus, for example, the elevation angle for the ASTRA satellite at the 19,2° East position in Germany is between approx. 28° (north) and approx. 35° (south), this means that in many cases just a few metres distance between the parabolic antenna and an obstacle are all that is required to ensure an unobstructed line of sight to this satellite.
|incline (relative to a distance of 1 m)|
Source : technisat