## 4 Results and Discussion
### Case D--Area with Vegetation by the Roadside  
The last case D involved a section of the trajectory that was kept flat, with some vegetation barriers near the roadway, which were less leafy due to it being winter. The measurement took place on the outskirts of the city, on the karst plateau, mostly at an altitude of about 300 m above sea level. Figure 15 shows that all the receivers except the ZED-F9R were able to determine the position in most of the section. As in the previous cases, the quality of position determination with the Xiaomi Mi8 was significantly worse than that of the other receivers (Tables 13 and 14, Figure 16). Figure 13: Case C: performance of: (**a**) Septentrio AsteRx-U, (**b**) Xiaomi Mi8, (**c**) u-blox ZED-F9P, and (**d**) u-blox ZED-F9R. \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multicolumn{5}{c}{**Type of GNSS Device**} \\ \hline \multirow{2}{*}{**Parameters**} & **Septentrio** & **u-blox** & **u-blox** & **Smartphone** \\  & **AsteRx-U** & **ZED-F9P** & **ZED-F9R** & **Xiaomi Miß** \\ \hline GPS solutions & 426 (88.6\%) & 285 (59.3\%) & 279 (58.0\%) & 326 (67.8\%) \\ Fixed ambiguities & 257 (60.3\%) & 0 (0\%) & 0 (0\%) & 0 (0\%) \\ \hline \(\textit{dev\_d2D}<1\) m & 424 (88.2\%) & 278 (57.8\%) & 265 (55.1\%) & 157 (32.6\%) \\ \(\textit{dev\_d2D}<30\) cm & 389 (80.9\%) & 118 (24.5\%) & 184 (38.3\%) & 43 (8.9\%) \\ \(\textit{dev\_d2D}<10\) cm & 251 (52.2\%) & 47 (9.8\%) & 65 (13.5\%) & 2 (0.4\%) \\ \hline \(\textit{dev\_d3D}<1\) m & 392 (81.5\%) & 265 (55.1\%) & 149 (31.0\%) & 38 (7.9\%) \\ \(\textit{dev\_d3D}<30\) cm & 389 (80.9\%) & 118 (24.5\%) & 84 (17.5\%) & 37 (7.9\%) \\ \(\textit{dev\_d3D}<10\) cm & 251 (52.2\%) & 47 (9.8\%) & 65 (13.5\%) & 2 (0.4\%) \\ \hline \hline \end{tabular}
\end{table} 
Table 11: GPS solutions, solutions with fixed ambiguities, and deviation of distances below the given threshold. Situation: Case C—serpentines (no. of total solutions: 481). Figure 14: Percentage of solutions for Case C for (**a**) GPS solutions; (**b**) GNSS solutions. Each bar in a group shows: available solutions (1 st bar), percentage of fixed solutions (2 nd bar), deviation at horizontal distances (3 rd bar, where light blue is for thresholds less than 10 cm, green is for thresholds less than 30 cm, and brown is for thresholds less than 1 m), and 4 th bar shows deviation at spatial distances (yellow, green, and dark red for 10 cm, 30 cm, and 1 m thresholds, respectively). \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multicolumn{5}{c}{**Type of GNSS Device**} \\ \hline \multirow{2}{*}{**Parameters**} & **Septentrio** & **u-blox** & **u-blox** & **Smartphone** \\  & **AsteRx-U** & **ZED-F9P** & **ZED-F9R** & **Xiaomi Miß** \\ \hline GNSS solutions & 481 (100\%) & 405 (84.2\%) & 384 (79.8\%) & 469 (97.5\%) \\ Fixed ambiguities & 146 (30.3\%) & 30 (7.4\%) & 48 (12.5\%) & 5 (1.1\%) \\ \hline \(\textit{dev\_d2D}<1\) m & 481 (100\%) & 404 (84.0\%) & 380 (79.0\%) & 353 (73.4\%) \\ \(\textit{dev\_d2D}<30\) cm & 385 (80.0\%) & 145 (30.2\%) & 222 (46.2\%) & 121 (25.2\%) \\ \(\textit{dev\_d2D}<10\) cm & 134 (37.9\%) & 81 (16.8\%) & 76 (15.8\%) & 27 (5.6\%) \\ \hline \hline \end{tabular}
\end{table} 
Table 12: GNSS solutions, solutions with fixed ambiguities, and deviation of distances below the given threshold. threshold Situation: Case C—serpentines (no. of total solutions: 481). In addition, in terms of possible positioning and in situations with fixed ambiguities, the results using the GNSS are much better than with the GPS only. Again, with the Xiaomi Mi8 smartphone, it was not possible to define the ambiguities as fixed. The geodetic receiver also performed much better in this case than the other receivers in terms of the quality of the position determination. Interestingly, fixed solutions have prevailed in GSS processing with respect to GPS, especially for ZED-F9P and ZED-F9R. The deviation of the calculated horizontal distances from the reference distances was less than 10 cm in 91.9% of the total epochs.