Orolia Spectracom VelaSync 1232, User Manual

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Regarding the selection of a suitable antenna location , the following recommendations
generally apply:
A clear view of the sky down to the horizon in all directions is recommended for
the most optimal satellite reception. The mounting location of the external GNSS
antenna should be free of objects that could obstruct satellite visibility from straight
overhead to within 20 degrees of the horizon in all directions.
To optimize timing accuracy, the GNSS receiver attempts to track satellites that are
spread out as far as possible across the sky. The GNSS receiver must track at least
four satellites in order to obtain time synchronization. Obstructions that block a sig-
nificant portion of the sky result in degraded performance.
GPS antennas need to be separated from surrounding metallic materials . Any
metal in the area changes the shape of the reception pattern of the antenna. Any
buildings or metallic materials close to the antenna can create shadows which can
shield the antenna from receiving in that particular direction.
Separation between multiple antennas : If the antennas are installed too close
together there could potentially be interaction between the antennas and a res-
ulting loss of sensitivity. This could also adversely affect the search pattern of the
antennas, resulting in fewer satellites being tracked.
Ideally, antennas should be separated as much as physically possible, so as to
help isolate them from being simultaneously affected by the same anomaly
(such as a nearby lightning strike or a falling object, for example). The min-
imum GNSS antenna-to-antenna distance is 39 inches (1 meter).
GPS antennas are receive-only antennas which do not intentionally transmit
any signals. Even though this reduces the amount of separation needed
between multiple antennas, a few meters of separation are recommended to
isolate the antennas from each other, in order to limit any possible EMI inter-
ference caused by the active components inside the antennas.
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APPENDIX