ashtech Reliance FS/2, Operation Manual

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16 Reliance with FS/2 Field Operations Manual
• While logging a point feature, keep the GPS antenna as motionless as
possible.
• Record at least thirty minutes of data in each session. Even if only a few
minutes of feature data are logged, let the receiver collect at least thirty
minutes of data for more accurate post-processing.
• Use Mission Planning, included with the office software, to find the best
time to collect data at obstructed sites that have poor satellite visibility.
While GPS can not be used in every possible site, proper planning allows
you to achieve optimum accuracy at many obstructed sites.
Tips for Maximizing Centimeter Accuracy
• Set minimum number of satellites to 6.
• Keep baseline distances less than 10 kilometers to ensure centimeter
accuracy can be achieved.
• Use mission planning and obstruction modeling to verify that the number of
satellites available above 10º will be greater than six and PDOP less than
3.5.
• Make sure to minimize any error in antenna height or antenna centering.
Errors of this type translate directly to the position accuracy of the surveyed
point.
• Minimize errors in the base coordinates. Errors in the base positions directly
translate to the accuracy of the surveyed point.
Tips for Maximizing Decimeter Accuracy
• Use mission planning to identify favorable periods for data collection.
• Minimize antenna centering error. Use a stable mount when performing
decimeter surveys.
• Maintain lock on five or more satellites at all times for at least 30 minutes.
• Do not jerk or move the antenna unnecessarily during the survey.
• Baselines longer than ten kilometers may degrade decimeter results.
Tips for Maximizing Submeter Accuracy
• Use mission planning to identify favorable periods for data collection.
• Maintain lock on five or more satellites at all times for at least 15 minutes.
• Do not jerk or move the antenna unnecessarily during the survey.
Tips for Maximizing Accuracy When Using LRFs
• Minimize the distance between the LRF and GPS antenna.
• When lasing thin objects, a reflector or opaque target may be needed to
ensure making the desired measurement.