# Towards a Real-Time Description of the Ionosphere:
## 6 Validation Results for _fo_F2 Based on Radio Occultation Observations
\begin{table}
\begin{tabular}{c c c c c c c} \hline
**COSMIC Dataset** & **Model** & \begin{tabular}{c} **Res. Mean** \\ **[MHz]** \\ \end{tabular} & \
\begin{tabular}{c} **RMSE** \\ **[MHz]** \\ \end{tabular} &
\begin{tabular}{c} **NRMSE** \\ **[\%]** \\ \end{tabular} & **R** & **Counts** \\ \hline Daytime & IRI & 0.012 & 1.058 & 14.841 & 0.891 & \\  & IRTAM & 0.048 & 1.127 & 15.801 & 0.875 & 998,544 \\ \hline Nighttime & IRI & 0.126 & 1.076 & 21.781 & 0.856 & \\  & IRTAM & 0.172 & 1.157 & 23.424 & 0.834 & 422,509 \\ \hline Solar terminator & IRI & 0.146 & 1.014 & 17.872 & 0.883 & \\  & IRTAM & 0.136 & 1.059 & 18.672 & 0.871 & 370,549 \\ \hline March Equinox & IRI & 0.332 & 1.157 & 17.291 & 0.911 & \\  & IRTAM & 0.257 & 1.188 & 17.754 & 0.902 & 454,118 \\ \hline June Solstice & IRI & \(-\)0.068 & 0.917 & 15.715 & 0.898 & 439,417 \\  & IRTAM & \(-\)0.021 & 0.985 & 16.870 & 0.881 & 439,417 \\ \hline September Equinox & IRI & \(-\)0.044 & 1.044 & 16.724 & 0.908 & 447,872 \\  & IRTAM & 0.056 & 1.080 & 17.304 & 0.900 & 447,872 \\ \hline December Solstice & IRI & 0.041 & 1.077 & 16.665 & 0.888 & 450,195 \\  & IRTAM & 0.085 & 1.210 & 18.721 & 0.859 & 450,195 \\ \hline LSA & IRI & \(-\)0.085 & 0.899 & 17.064 & 0.879 & 750,993 \\  & IRTAM & \(-\)0.233 & 1.000 & 18.972 & 0.859 & 750,993 \\ \hline MSA & IRI & 0.080 & 1.075 & 16.357 & 0.891 & 608,461 \\  & IRTAM & 0.180 & 1.092 & 16.613 & 0.890 & 608,461 \\ \hline HSA & IRI & 0.312 & 1.252 & 16.142 & 0.891 & 432,148 \\  & IRTAM & 0.547 & 1.337 & 17.237 & 0.890 & 432,148 \\ \hline Quiet magnetic activity & IRI & 0.061 & 1.043 & 16.561 & 0.902 & 1,660,108 \\  & IRTAM & 0.090 & 1.111 & 17.643 & 0.888 & 1,660,108 \\ \hline Moderate magnetic activity & IRI & 0.138 & 1.176 & 18.046 & 0.895 & 129,917 \\  & IRTAM & 0.159 & 1.232 & 18.897 & 0.885 & 129,917 \\ \hline Disturbed magnetic activity & IRI & 0.165 & 1.561 & 21.840 & 0.841 & 1577 \\  & IRTAM & 0.251 & 1.537 & 21.500 & 0.851 & 1577 \\ \hline Low Modip & IRI & \(-\)0.422 & 1.373 & 17.518 & 0.872 & 267,449 \\  & IRTAM & \(-\)0.254 & 1.481 & 18.902 & 0.844 & 267,449 \\ \hline Mid Modip & IRI & 0.139 & 1.036 & 16.496 & 0.903 & 1,230,835 \\  & IRTAM & 0.168 & 1.100 & 17.521 & 0.890 & 1,230,835 \\ \hline High Modip & IRI & 0.208 & 0.746 & 14.746 & 0.861 & 293,318 \\  & IRTAM & 0.107 & 0.766 & 15.129 & 0.842 & 293,318 \\ \hline Full dataset & IRI & 0.067 & 1.053 & 16.688 & 0.901 & \\  & IRTAM & 0.095 & 1.120 & 17.748 & 0.888 & 1,791,602 \\ \hline \end{tabular}
\end{table} 
Table 4: _Res. Mean, RMSE, NRMSE, and \(R\) values calculated for the IRI and IRTAM models on the basis of the _fo_F2 COSMIC observations, for the bins defined in Section 4.2, according to the three levels of solar activity defined in Section 3.1, and for the full dataset (bottom row). The number of counts on which the statistics were calculated is reported in the rightmost column._Figure 20: Maps of binned _RMSPE_ values calculated between _f_oF2 values measured by COSMIC satellites and modeled by (**a**) IRI and (**b**) IRTAM, and (**c**) the corresponding map of differences. Data were binned as a function of the geographic latitude (2.5\({}^{\circ}\)-wide bins) and longitude (5\({}^{\circ}\)-wide bins). Figure 21: Grids of binned _RMSPE_ values calculated between \(f\)0F2 measured by COSMIC satellites and modeled by **(a)** IRI and **(b)** IRTAM, and **(c)** the corresponding grid of differences. Data were binned as a function of the LT (fifteen minute-wide bins) and modify (2.5\({}^{\circ}\)-wide bins). Figure 22: Same as Figure 21 but in this case data were binned as a function of the day of the year (five-day wide bins) and modify (2.5°-wide bins). Figure 23: Same as Figure 21 but in this case data were binned as a function of the F10.7\({}_{81}\) solar activity index (two s.f.u.-wide bins) and modify (2.5\({}^{\circ}\)-wide bins). Figure 20 highlights significant differences between the two models.