Hemisphere GPS V104s, User Manual

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V104s GPS Compass User Guide
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No SBAS lock • Verify the V104s has a clear view of the sky
• Verify the lock status of SBAS satellites (this can be
done with PocketMax - monitor BER value)
• Set SBAS mode to automatic with the
$JWAASPRN,AUTO command
Note: SBAS lock is only possible if you are in an
appropriate SBAS region; currently, there is limited
SBAS availability in the southern hemisphere.
No heading or incorrect
heading value • Check CSEP value is fairly constant without varying
more than 1 cm (0.39 in)—larger variations may
indicate a high multipath environment and require
moving the receiver location
• Recalibrate the tilt sensor with $JATT,TILTCAL
command if heading is calculated then lost at
consistent time intervals
• Heading is from primary GPS antenna to secondary
GPS antenna, so the arrow on the underside of the
V104s should be directed to the bow side
• $JATT,SEARCH command forces the V104s to
acquire a new heading solution (unless gyro is
enabled)
• Enable GYROAID to provide heading for up to three
minutes during GPS signal loss
• Enable TILTAID to reduce heading search times
• Monitor the number of satellites and SNR values
for both antennas within PocketMax—at least four
satellites should have strong SNR values
• Potentially, the volume of data requested to be
output by the V104s could be higher than the
current baud rate supports (try using 19200 as the
baud rate for all devices or reduce the amount of
data being output)
•
Intermittent issues potentially caused by an incorrect
HBIAS.
Table A-1: Troubleshooting ( continued)
Symptom Possible Solution