Trimble Outdoors 5700 - Manual (Page 115)

5700 GPS Receiver User Guide 9 9
Real-Time Kinematic (RTK) Surveying 8
Appl
icatio
ns
8.3
Extended RTK (eRTK)
By using mobile and satellite communications as the RTK data link
you can survey at operating ranges beyond 10 km.
However, with the increase in distance there is also a greater chance
for error. As the rover moves further from the reference station, the
effects of the atmosphere on the GPS signals received at each station
can degrade RTK performance and initialization times. In areas where
the weather systems fluctuate rapidly, initialization may take longer.
The 5700 receiver firmware detects and measures biases caused by
ionospheric and tropospheric interference, and corrects for significant
biases. However, you should still perform independent checks on your
work.
The need for independent verification increases as the baseline
distance increases. You also need to choose obstruction-free
environments when initializing, if possible.
You can use any of the following techniques to verify RTK results:
• Reoccupy a number of points observed earlier in the day
• Reinitialize and reobserve points
• Reobserve control points in a survey at least two hours after the
initial occupation, when the multipath effects will also be
different
• Perform known point initializations
• Check initializations on previously observed points