With this information in hand we can calculate the elevation and azimuth we
should put on the dish to begin our coarse antenna alignment. There are
formulas to do that but some websites are again quite useful. There are also free
mobile applications, as Dish Aligner, which calculates the elevation and azimuth
and also your current location determined by the GPS of the mobile phone. This
one is especially interesting for you can select the satellite you want and then
position yourself on a graphical map:
http://science.nasa.gov/realtime/jtrack/3d/JTrack3D.html/
For example if we take ASTRA (19E position) and select a location somewhere in
Germany:
•
Latitude: 50 degrees North
•
Longitude: 12 degrees East
The required elevation and azimuth for the dish are:
•
Azimuth: 170 degrees
•
Elevation: 31 degrees
Elevation must be measured from the horizontal level (may be using an
inclinometer) and azimuth from magnetic north (with a compass) there are some
applications for smartphones, as mentioned above, that include compass and
inclinometer, although it should be noted that the measurements made by
mobile phone may be affected by interferences from the antenna itself. It is
normally more practical to start with azimuth moving the dish horizontally and
then look for the elevation.
June 2014
Figure A2.7.
4 4
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