Simrad HS52, Instruction Manual

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Simrad HS52 GPS compass and DGPS navigator
12
20222360 / E
3.4 Sensor Unit
Location of the Unit
The Sensor unit is the most important part of the HS52 system,
and great care should be taken when deciding the mounting
location.
The space above the Sensor unit has to be free of obstructions of
any kind. A GPS compass is more sensitive for blocking and
reflections (multipath) of GPS signals than GPS sensors that are
only used for calculating position. This since HS52 also utilizes
carrier phase measurements for heading determination, and both
GPS antennas need to see at least two common satellites at the
same time.
The unit should be protected from direct illumination of radar
beams and other transmitting antennas such as Inmarsat
antennas.
The Sensor unit has to be mounted horizontally in the mast or
directly on deck, with 5° maximum allowed deviation angle
from the horizontal plane. If mounted in the mast, the distance
from the unit to the nearest deck should be as large as possible
to reduce problem due to the multipath effect.
The unit should also be mounted parallel to the vessel’s
centerline with the bow arrow pointing forward. The heading
offset feature will however compensate for a heading offset
caused by the orientation of the Sensor unit. An eventual offset
correction is performed after the calibration as described in
Head Offset on page 36.