page 6
2.
Installation instructions
2.1
Determining installation position
Selection of location for installation of antenna dome
Various factors must be taken into account when selecting the correct installation
location for the antenna dome, these are summarised below:
•
The ideal location will have a free line of sight in all directions.
•
The antenna dome must be installed at the point where the three axes
intersect (roll, pitch and yaw motion).
•
The external unit must be kept away from radar equipment as this can cause
interference; where no other location is possible it is recommended that the
antenna dome be installed a minimum of 1.5 metres below or above the radar
antenna.
•
The substrate on which the antenna dome will be installed must be adequately
resilient and vibration free; in case of doubt we recommend that the substrate
should be reinforced with additional constructions.
Rule of thumb for reception of Astra 1 and 3:
An obstacle which is 3 metres away from the dome may be one
metre higher than the dome.
The rule of thumb assumes a minimal elevation of 20 degrees.
Table 1. Elevation of the dish versus geographical position for Astra 1 (19'2) and Astra 3 (23'5).
