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Reference
Troubleshooting
Chart
If the ‘No Differential GPS
Position’ message is displayed
on your GPS receiver,
correction data may not be
available. This may be due to a
missing or weak beacon signal,
not enough GPS satellites or
bad wiring connection between
the GBR 23 and GPS.
7) Beacon signal weak
or not received.
Interference from ship’s
electrical system, thunderstorm
activity, or another source is
inhibiting signal lock on.
Also refer to Troubleshooting
problems 5 and 6.
8) Accuracy not as
expected
Poor satellite geometry
coverage exists.
Interference to GPS antenna
and/or beacon antenna exists.
Portable antenna being used
on GPS unit. Use remote
antenna.
Multipath signals being
received by GPS unit.
Too far from DGPS transmitter
or not tuned to closest station.
6) GPS interface
status screen displays
“None” or “No Status”
GBR 23 not wired properly with
GPS unit. Check wiring.
No power to GBR 23. See
Troubleshooting problem 1.
Possible damage to the with
DGPS antenna.
Baud rates do not match.
Beacon transmitter out of range.
Try a different station.
Possible Cause
If either ‘No Status’, ‘None’, or
‘Check Wiring’ messages
appear (depending upon model
of GPS) see Troubleshooting
problem number 7.
Problem
9) Distance from
DGPS station is blank
or zero on GPS unit
The distance reading to the
beacon is dependent upon
reception of the RTCM
message transmitted from the
DGPS broadcast site. This
message is infrequently
broadcast and may vary from
station to station.
GBR 23 Manual.p65
5/23/00, 1:28 PM
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