Troubleshooting & Operating Tips
ProMARK X
8-11
Search and Acquisition Errors
.
Under the following conditions, the unit
may be unable to obtain a position fix:
•
Initialization was not done correctly.
•
Poor signal environment.
•
Insufficient number of satellites.
•
Unit searches constantly.
Initialization Errors.
An initialization error occurs when:
•
The initial position entered in SETUP or during initialization was
incorrect by 300 miles (482.7 km) or more.
•
The unit has been moved 300 miles (482.7 km) or more from
its last position fix or initial position.
Either condition can cause the unit to be unable to find the satellites it looks
for. Since the unit searches for satellites based on where it thinks it is, an
initial position or last position fix that is 300 miles (482.7 km) or more away
from the unit’s current position may cause the unit to search for satellites that
are not available at the unit’s true location.
Either condition can also cause the unit to calculate a position fix that is 300
miles (482.7 km) or more from its initial position or the last position fix
calculated. The unit regards this position fix as an error, and tries three more
times to obtain a position fix that it can accept.
After the fourth attempt to obtain an acceptable position fix, the unit
discards the initial position or last fix and assumes that an initialization error
has occurred. The unit then re-initializes itself, using the satellites that it has
already acquired. This takes between 10 and 60 seconds.
Sometimes, the initial position is so far off from the present position that the
unit is unable to locate enough satellites to obtain a fix. When this happens,
the unit searches until it has enough satellites to obtain a fix. You will notice
the PRNs on the receiver status screen change periodically.
If the unit does not have a new position fix after about 20 minutes, either re-
initialize the unit or initiate Almanac Collect with AUX 9 to collect a new
almanac.
The Signal Environment.
The signal environment refers to the physical
conditions in which the unit is being operated. A poor signal environment
limits the receiver’s ability to locate and track satellite signals.
Summary of Contents for GPS PROMARK X
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Page 14: ...Introduction ProMARK X 1 4...
Page 92: ...Attributes ProMARK X 6 8...
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