18 TRACKER 5100/5100i/5500/5500i Installation and Operation Manual
that can be received by a special receiver on the
boat. Differential beacons are usually only
installed near ports and important waterways,
and each beacon has a limited range. The
accuracy of the corrected GPS position is
typically better than 2 to 5 m (6 to 16 ft).
To use differential beacon DGPS, the TRACKER
must be installed with an external DGPS antenna,
such as the NAVMAN DGPS 1 (see section 15-3).
Each time a GPS receiver is turned on, it normally takes
about 50 seconds before it outputs the first position.
Under some circumstances it will take up to two minutes
The satellite display has information about the GPS
satellites and GPS position.
To go to the satellite display, press DISP and select
7-1 Satellite display
Time & date from GPS
satellites. Time is local time
(UTC (GMT) plus local
offset, see section 13-9).
HDOP: The error in the
GPS position caused by
satellite geometry. A low
value indicates a more
precise fix, a high value a
less precise fix.
Status of GPS antenna, for example Acquiring, GPS fix, No
GPS. If the unit is in Simulate mode it displays Simulate (see
Positions of visible GPS
Outer circle is horizon
Inner circle is 45°
Centre is directly above
North is at top of
If the boat is moving, COG
is a line from centre.
Signal strengths of up to
twelve visible GPS
satellites. The higher the
bar the stronger the signal.
The satellite display shows:
When the TRACKER is turned on, the satellite
display is shown automatically while the GPS
antenna starts up.