## 3 Results and Discussion
### RTK Approach--Dynamic Tests
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multicolumn{8}{c}{**NVS (Garmin Antenna, only GPS)**} \\ \hline  & **\#E [m]** & **\#N [m]** & **\#h [m]** & **\#E [m]** & **\#N [m]** & **\#h [m]** & **\% of Epochs** \\ \hline FIX & \(-\)0.094 & 0.110 & 0.474 & 0.124 & 0.176 & 0.490 & 72\% \\ FLOAT & \(-\)0.752 & \(-\)0.166 & 0.554 & 0.217 & 0.125 & 0.726 & 25\% \\ \hline \multicolumn{8}{c}{**u-blox (LEIAR10 Antenna, only GPS)**} \\ \hline  & **\#E [m]** & **\#N [m]** & **\#h [m]** & **\#E [m]** & **\#N [m]** & **\#h [m]** & **\% of Epochs** \\ \hline FIX & \(-\)0.008 & 0.009 & 0.054 & 0.051 & 0.039 & 0.070 & 86\% \\ FLOAT & \(-\)0.019 & \(-\)0.219 & 0.244 & 0.109 & 0.414 & 0.283 & 9\% \\ \hline \hline \end{tabular}
\end{table} 
Table 19: Difference between estimated and reference positioning considering the LEIAR10 antenna splitted and the only GPS constellation. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multicolumn{8}{c}{**NVS (Garmin Antenna, GPS + GLOASS)**} \\ \hline  & **\#E [m]** & **\#N [m]** & **\#h [m]** & **\#E [m]** & **\#N [m]** & **\#h [m]** & **\% of epochs** \\ \hline FIX & \(-\)0.020 & \(-\)0.034 & 0.052 & 0.041 & 0.034 & 0.069 & 78\% \\ FLOAT & \(-\)0.612 & 0.182 & \(-\)0.263 & 0.045 & 0.219 & 0.271 & 19\% \\ \hline \hline \end{tabular}
\end{table} 
Table 20: Difference between estimated and reference positioning considering the Garmin antenna splitted and the GPS + GLONASS constellations. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multicolumn{8}{c}{**NVS (Garmin Antenna, only GPS)**} \\ \hline  & **\#E [m]** & **\#N [m]** & **\#h [m]** & **\#E [m]** & **\#N [m]** & **\#h [m]** & **\% of Epochs** \\ \hline FIX & \(-\)0.094 & 0.110 & 0.474 & 0.124 & 0.176 & 0.490 & 72\% \\ FLOAT & \(-\)0.752 & \(-\)0.166 & 0.554 & 0.217 & 0.125 & 0.726 & 25\% \\ \hline \multicolumn{8}{c}{**u-blox (LEIAR10 Antenna, only GPS)**} \\ \hline  & **\#E [m]** & **\#N [m]** & **\#h [m]** & **\#E [m]** & **\#N [m]** & **\#h [m]** & **\% of Epochs** \\ \hline FIX & \(-\)0.008 & 0.009 & 0.054 & 0.051 & 0.039 & 0.070 & 86\% \\ FLOAT & \(-\)0.019 & \(-\)0.219 & 0.244 & 0.109 & 0.414 & 0.283 & 9\% \\ \hline \hline \end{tabular}
\end{table} 
Table 19: Difference between estimated and reference positioning considering the LEIAR10 antenna splitted and the only GPS constellation. The same results can be obtained if the Garmin antenna is used (Table 20): considering the NVS receiver, it is possible to obtain some epochs with fixed phase ambiguity only if the GPS constellation is used (Table 21); despite that, the precision and accuracy of NVS receiver is less than the u-blox one, also in this case. In this context, we must to take into account the different modeling of the clock errors in the GPS and GLONASS satellites. This means that the processing software can model these errors in a less accurate way if single-frequency receivers are considered in real-time. Therefore, it is easier to obtain a good fixing of the phase ambiguity with a receiver that uses only a Code Division Multiple Access (CDMA) constellation with respect to one that uses a mixed CDMA and Frequency Division Multiple Access (FDMA) constellations, especially if single-frequency receivers are considered