7
Choosing the Mounting Location
For accurate compass readings and a reliable GPS signal, selecting the best
location for the sensor is very important. It can be mounted on a pole, rail, or flat
surface. Choose a location that balances the requirements below.
• The sensor must have a clear view of the sky to the horizon in all directions.
However, the lower it can be mounted, the more stable it will be. It will better
track satellites low on the horizon and give more accurate compass readings by
minimizing pitch and roll.
• Do not mount on top of a sailboat mast. The sway will cause jitter in the data.
• To prevent interference to the magnetic compass, mount the sensor:
- A minimum of 0.3m (1') from other standard and steering compasses.
- Above a metal hull/deck.
- Away from any structures or equipment that contain ferrous metals.
- Away from anything that may create a magnetic field such as: magnetized
material, electric motors and equipment, power/ignition cables, and batteries.
For distances, follow the respective manufacturer’s recommendations.
• To prevent interference to the GPS (Figure 1):
- It must have a clear view of the sky to receive satellite signals. Check for any
obstructions such as buildings or boats.
- Mount it as far as possible from high-powered transmitting antennas to avoid
mutual interference.
- Mount it lower than any on-board INMARSAT communications antenna.
- Mount above or below any radar beam.
Do not mount within a radar beam
.
• Mount reasonably level with the earth’s surface—
not tilted to one side
.
• Do not mount where the sensor could be a tripping hazard or be tread upon.
Note that frozen water spray on the unit may degrade reception.
• Be sure there is access to the underside of the mounting surface.
• Be sure the cable(s) can be routed to reduce electrical interference from other
electrical wiring and any on-board equipment with a strong magnetic field such as
radar equipment, radio transmitters, engines, generators, etc. Separate the cables
by at least 1 m (3').
Figure 1. Minimum distance from sensor
Courtesy of Northstar, Acton, MA
Min. 2m
antenna insulator
metal hull /deck
1.5m
Min.
Min. 2m
GH2183