# Effects of the 12 May 2021 Geomagnetic Storm on Georeferencing Precision
## 3 Results
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \multirow{2}{*}{**Station**} & \multirow{2}{*}{**DoYs**} & \multicolumn{3}{c}{**RMS [cm]**} & \multicolumn{3}{c}{**MAX [cm]**} & \multicolumn{3}{c}{**DVTEC**} & \multicolumn{1}{c}{**\%DVTEC**} & \multicolumn{1}{c}{**ROTI**} \\  & **[Season]** & **E** & **N** & **U** & **3D** & **E** & **N** & **U** & **3D** & **[TECu]** & **[\%]** & **[\(\frac{TECa}{\text{min}}\)]** \\ \hline \multirow{6}{*}{**madr**} & QD2017 & 0.4 & 0.5 & 1.0 & 1.1 & 1.6 & 2.0 & 5.5 & 5.7 & & & \\  & DoY 86 & 0.6 & 0.5 & 1.2 & 1.4 & 2.2 & 1.5 & 4.4 & 4.5 & 9.9 & 110 & 0.1 \\  & [Spring] & & & & & & & & & & & \\ \cline{2-10}  & QD2019 & 0.6 & 0.5 & 1.5 & 1.7 & 2.7 & 2.2 & 6.2 & 6.3 & & & \\  & DoY 217 & 1.0 & 0.9 & 2.8 & 2.8 & 3.1 & 2.6 & 11.6 & 11.7 & 12.0 & 153 & 0.52 \\  & [Summer] & & & & & & & & & & & \\ \cline{2-10}  & QD2021 & 0.7 & 0.6 & 1.7 & 1.9 & 2.4 & 2.7 & 8.7 & 8.8 & & & \\  & DoY 132 & 1.2 & 1.1 & 3.5 & 3.7 & 3.9 & 4.1 & 15.4 & 17.0 & 11.9 & 120 & 0.3 \\  & [Spring] & & & & & & & & & & & \\ \hline \multirow{6}{*}{**vzch**} & QD2017 & & & & & & & & & & & & \\ \cline{2-10}  & DoY 86 & & & & & & & & & & & & \\ \cline{2-10}  & [Fall] & & & & & & & & & & & & \\ \cline{2-10}  & [Q2019 & 0.6 & 0.5 & 1.5 & 1.7 & 5.2 & 3.7 & 15.4 & 15.4 & & & \\ \cline{2-10}  & DoY 217 & 0.9 & 0.7 & 2.2 & 2.5 & 6.0 & 3.5 & 15.0 & 15.1 & 4.1 & 62 & 0.11 \\  & [Winter] & & & & & & & & & & & \\ \cline{2-10}  & QD2021 & 0.6 & 0.5 & 1.6 & 1.8 & 7.0 & 6.8 & 18.7 & 18.9 & & & \\ \cline{2-10}  & DoY 132 & 1.5 & 1.4 & 3.8 & 4.4 & 52.4 & 52.9 & 58.8 & 82.5 & 5.3 & 56 & 0.08 \\  & [Fall] & & & & & & & & & & & \\ \hline \multirow{6}{*}{**vita**} & QD2017 & 0.6 & 0.6 & 1.8 & 2.0 & 2.9 & 3.1 & 8.4 & 8.4 & & & \\ \cline{2-10}  & DoY 86 & 1.0 & 1.1 & 2.8 & 3.2 & 3.5 & 3.0 & 10.0 & 10.0 & 23.5 & 150 & 0.09 \\ \cline{2-10}  & [Fall] & & & & & & & & & & & & \\ \cline{2-10}  & [Q2019 & & & & & & & & & & & \\ \cline{2-10}  & DoY 217 & & & & & & & & & & & & \\ \cline{2-10}  & [Winter] & & & & & & & & & & & & \\ \hline \multirow{6}{*}{**vita**} & QD2021 & 0.6 & 0.6 & 1.7 & 1.9 & 11.1 & 11.6 & 26.8 & 30.3 & & & \\ \cline{2-10}  & DoY 132 & 1.7 & 1.2 & 4.3 & 4.8 & 52.5 & 25.0 & 41.9 & 61.2 & 5.1 & 51 & 0.13 \\ \cline{2-10}  & [Fall] & & & & & & & & & & & & \\ \hline \end{tabular}
\end{table} 
Table 4: The root mean square (RMS), the maximum values (MAX), DVTEC, %DVTEC, and ROTI of the Madrid (madr, 40.43\({}^{\circ}\)N, 4.25\({}^{\circ}\)W), Las Vizcachas (vzch, 33.6\({}^{\circ}\)S, 70.51\({}^{\circ}\)W), Vegas de Itata (36.42\({}^{\circ}\)S, 72.86\({}^{\circ}\)W) stations, during the geomagnetic storms of 27 March 2017 (DoY 86), 5 August 2019 (DoY 217) and 12 May 2021 (DoY 132). DoYs 83, 84, 85 are the quiet DoYs of reference for the 27 March 2017 storm (QD-2017), DoYs 214, 215, and 216 are the quiet DoYs of reference for the August 2019 storm (QD-2019), and DoYs 129, 130, and 131 are the quiet DoYs of reference for the storm of May 2021 (QD-2021). Figure 7: The positioning errors of each component and the different TEC variations-related indexes (VTEC, DVTEC, and %DVTEC). The **(left panels)** show the effects of the 5 August 2019 storm. The **(right panels)** show the effects of the 12 May 2021 storm. The **(top panels)** and **(bottom panels)** present the Madrid (madr, 40.43\({}^{\circ}\)N, 4.25\({}^{\circ}\)W) and Las Vizcachas (vzch, 33.6\({}^{\circ}\)S, 70.51\({}^{\circ}\)W) stations, respectively. On displays representing VTEC, the orange line represents VTEC mean calculated with the reference days. We plotted the VTEC mean in all the studied days to compare it with the VTEC of each of the days (blue line).