Site preparation
3-4
Chapter 3: Installation
98-150471-A02
3.2.2
Obstructions (ADU shadowing)
Place the ADU so that it has as much free line-of-sight as possible without any structures in
the beam through one full 360 degrees turn of the vessel. Do not place the ADU close to
large objects that may block the signal. To avoid obstruction elevate the ADU by mounting
it on a mast or on a mounting pedestal on a deck or deck house top.
The ADU is stabilized in 3-axis (plus skew) and can be used in environments with elevations
of -25° to + 125° to allow for continuous pointing even in heavy sea conditions.
The ADU beam is approximately 1 m in diameter for the first 30 m from the ADU. Beyond
30 m the beam gradually widens so that it is approximately 5 m in diameter at 100 m
distance. This beam expansion continues with increasing distance.
Any obstructions, such as masts, funnels, bridge house etc. within this field can cause signal
degradation or signal loss.
Figure 3-1: Signal degradation because of obstructing objects
Note
Note that due to the short wavelength at Ku band and the
narrow beam width of the ADU even a
6 mm steel wire
placed within 50 m
inside the beam can causes signal
degradation.
SAILOR900HP.book Page 4 Monday, July 18, 2016 12:44 PM
