## 3 Results and Discussion  
The trajectories obtained by using the tested GNSS receivers are shown together with the reference one, i.e., Stonex S7-G, in Figure 4.  
The summary statistics of the data are shown in Table 2, while the results of the related Analysis of Variance is shown in Table 3.  
Figure 4: Plot of the trajectories obtained using the four satellite receivers together with the reference one (test A). The S7 receiver, used in tests B, C and D, recorded an error with a larger relative dispersion in test C, i.e., without RTK differential correction and with external antenna, with a coefficient of variation equal to 63.62% and with a positioning error between 0.06 and 1.06 m. The S5 receiver, used in tests E, F, G and H, provided a positioning error with a larger relative dispersion in test E (coefficient of variation equal to 64.68%) and error values between 0 and 0.59 m. The receiver that showed the highest relative dispersion was the TMMP in test I with a coefficient of variation of 90.44% and error values between 0.03 and 1.77 m. The cheapest receiver, QLV2, used in test M, recorded a coefficient of variation equal to 69.59% and a positioning error ranging from 0 to 1.28 m. Test G, carried out by using the S5 receiver with external antenna without differential correction, provided the lowest relative dispersion, with a positioning error between 0.58 and 1.18 m.  
The ANOVA table decomposes the variance of the data into two components: a between-group component and a within-group component. The F-ratio, which in this case equals 56.4953, is a ratio of the between-group estimate to the within-group estimate. Since the \(p\)-value of the F-test is lower than 0.05, there is a statistically significant difference between the means of the 11 variables at the 5% significance level. Table 4 shows the results of a multiple comparison procedure application able to determine which means are significantly different from which others. Seven homogenous groups were identified using columns of Xs. The levels containing Xs form a group of means within which there are no statistically significant differences. The method currently being used to discriminate among the means is [PERSON]'s Honestly Significant Difference (HSD) procedure. With this method, there is a 5.0% risk of calling one or more pairs significantly different when their actual difference equals 0 (Figure 5). Table 5 shows the estimated difference between each pair of means. An asterisk has been placed next to 38 pairs, indicating that these pairs show statistically significant differences at a 95.0% confidence level. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Id. Test** & **Count** & **Average** & \begin{tabular}{c} **Coefficient** \\ **of Variation** \\ **[\%]** \\ \end{tabular} & \
\begin{tabular}{c} **Minimum** \\ **[m]** \\ \end{tabular} &
\begin{tabular}{c} **Maximum** \\ **[m]** \\ \end{tabular} \\ \hline A & 50 & 0.000 & - & 0.000 & 0.000 \\ B & 50 & 0.071 & 77.992 & 0.000 & 0.201 \\ C & 50 & 0.532 & 63.616 & 0.061 & 1.062 \\ D & 50 & 0.469 & 39.337 & 0.033 & 0.749 \\ E & 50 & 0.221 & 64.683 & 0.000 & 0.594 \\ F & 50 & 0.358 & 59.167 & 0.014 & 0.715 \\ G & 50 & 0.962 & 17.177 & 0.580 & 1.183 \\ H & 50 & 1.368 & 46.904 & 0.103 & 2.352 \\ I & 50 & 0.715 & 90.444 & 0.032 & 1.768 \\ L & 50 & 1.439 & 70.331 & 0.172 & 3.434 \\ M & 50 & 0.550 & 69.592 & 0.000 & 1.278 \\ Total & 550 & 0.608 & 105.418 & 0.000 & 3.431 \\ \hline \hline \end{tabular}  
* Tests A, B, C and D were carried out with the S7 receiver, tests E, F, G and H with the Stonex S5 (S5) receiver, tests I and L with the Thales MobileMapper Pro (TMMP) receiver and test M with the Quanum GPS Logger V2 (QLV2) receiver.  
\end{table} 
Table 2: Summary statistics for distance 1.