KVH Industries TracPhone F55, Installation Manual

Page: 34 / 157

Chapter 3: Placing the Antenna
12 Interference
3.3.3 Interference
At distances further away than “d min.” given above the radar might still be
able to degrade the performance of the Fleet system.
The presence of one or more X-band radars within a radius up to around
100 m could cause a minor degradation of the signal to noise ratio during high
speed and data calls. The degradation will be most significant at high radar
pulse repetition rates.
As long as receiving conditions are favorable, this limited degradation is
without importance. However, if receiving conditions are poor – e.g. due to
objects blocking the signal path, heavy precipitation or icing, low satellite
elevation and violent ship movements – the small extra degradation due to the
radar(s) could cause poor call quality. A speech call might become noisy and
perhaps fail while a data connection might decrease in speed and
performance.
The presences of S-band radar(s) are unlikely to cause any performance
degradation – as long as the minimum distances (d min.) listed above are
applied.
It is strongly recommended that interference free operation is verified
experimentally before the installation is finalized.
3.3.4 Other Inmarsat systems
Recommended minimum safe distance to other Inmarsat antennas is 10 m.
3.3.5 GPS receivers
Good quality GPS receivers will work properly very close to the ADU - typically
down to one meter outside the main beam, and down to a few meters inside
Warning! The ADU must never be installed closer to a radar than
“d min.” - even if experiments show that interference free operation
can be obtained at shorter distances than “d min.” given above.