Achievable Positioning Accuracies in a Network of GNSS Reference Stations - Global Navigation Satellite Systems: Signal,Theory and Applications - page 212

It should also be noted that increasing the measurement time from 10 to 20 minutes does not
entail a real improvement in the positioning accuracy, that reaches values from about 2-3
cms (“red” network) to 7 cms (“green” network) at the 90% of reliability.
As before, a better accuracy can be obtained using VRS RINEX files generated by the
network software. The analysis of the positioning accuracy, shown in Fig. 18, confirms the
expected behaviour, already seen for geodetic receivers.
A reduction of the maximum planimetric and altimetric error for “red” and “green”
networks is observed (few centimetres at 90% of reliability).
The percentage of measurement sessions with fixed ambiguities, goes from 68% (“red”
network) to 48% (“green” network) and only to 31% (“blue” network). These percentages do
not appreciably changes when 20 minutes long files are considered.
Fig. 18. Positioning quality of a GIS receiver after the post-processing with the VRS file. CDF
of the planimetric (left) and altimetric (right) error using static time sessions of 10 (top) and
20 (bottom) minutes
The combined use of single frequency instruments and virtual data is very useful only for
the “red” network, while the virtual data generated by the “green” and the “blue” networks
significantly increase the errors, as clearly shown in Fig. 18.