Thales Z-Max Operation And Application Manual page 291

estimates (HRMS, VRMS) do not meet expected values, use this feature to examine
the current DOP values.
DOP values not too high
Go to step 4 below.
DOP values too high
1. Look for a satellite window with more suitable DOP values to perform the
survey.
a. Use the Mission Planning software to examine expected DOP values for
periods during which you would like to perform your survey.
b. Avoid surveying during periods where DOP values are above 4.
c. For the highest level of accuracy, limit surveying to periods where DOP
values are between 1 and 2.
d. Remember that obstructions to line-of-sight between the GPS receiver
antenna and the satellites will block out satellite signals. Every time a
satellite is lost due to obstructions, DOP values will be adversely affected.
An obstructed area may not be suitable to meet your precision needs due
to the adverse effect on satellite geometry.
Step 4. Precision requirements too stringent for RTK?
If the RTK system is not delivering the precision requirements you need for your
specific task, it is possible that your precision requirements are too stringent for the
RTK system. Review your system documentation to determine the precision
specifications for the RTK system.
Precision not beyond capability
Go to step 5 below
Precision beyond capability
Your precision requirements are not attainable through RTK surveying. You will
need to find some other measurement system to perform your survey.
Step 5. Your rover receiver may be malfunctioning
Contact your local dealer or Thales Navigation technical support for assistance.
This concludes the troubleshooting section. If the tips given here did not help you to
resolve your problem with your Z-Max System, please call your local dealer or Thales
Navigation technical support for assistance.
268 Z-Max Surveying System Operation and Applications Manual