# Towards a Real-Time Description of the Ionosphere:
## 3 Measured and Modeled Data Used for Validation
### Observations from Ground-Based Ionosondes

Table 1: The ionosonde stations considered for validation along with the corresponding geographic coordinates, QD magnetic latitude, mopł, and time coverage of the dataset. Ionosonde measured _fo_F2 and _hm_F2 values were downloaded from the Digital Ionogram DataBASE [56]. For each station, ionograms were recorded by DPS Digisondes [57], and autoscaled by the Automatic Real-Time Ionogram Scaler with True height analysis (ARTIST) software [58]. ARTIST flags the reliability of autoscaled parameters through the Confidence Score (C-Score) parameter [59] ranging from 0 to 100. For this study, only the most reliable values were considered, namely those with C-Score \(\geq\) 75. _fo_F2 and _hm_F2 time series have a fifteen-minute time sampling (at minutes 0, 15, 30, and 45 of each Universal Time (UT) hour) according to the sounding repetition rate of most of the ionosondes. In \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Number** & **Ionosonde (Country)** & **Geographic** & **Geographic** & **Quasi-Dipole** & **Modip [\({}^{\circ}\)]** & **Years Dataset** \\ \hline
25 & Moscow (Russia) & 55.5\({}^{\circ}\) N & 37.3\({}^{\circ}\) E & 51.5\({}^{\circ}\) N & 58.6\({}^{\circ}\) N & 2008–2019 \\ \hline
26 & Nicosia (Cyprus) & 35.0\({}^{\circ}\) N & 33.2\({}^{\circ}\) E & 29.2\({}^{\circ}\) N & 44.6\({}^{\circ}\) N & 2008–2019 \\ \hline
27 & Nord Greenland (Greenland) & 81.4\({}^{\circ}\) N & 17.5\({}^{\circ}\) W & 81.0\({}^{\circ}\) N & 75.2\({}^{\circ}\) N & 2006–2013 \\ \hline
28 & Norlisk (Russia) & 69.2\({}^{\circ}\) N & 88.0\({}^{\circ}\) E & 64.7\({}^{\circ}\) N & 67.5\({}^{\circ}\) N & 2002–2015 \\ \hline
29 & Point Arguello (USA) & 34.8\({}^{\circ}\) N & 120.5\({}^{\circ}\) W & 40.2\({}^{\circ}\) N & 48.8\({}^{\circ}\) N & 2000–2019 \\ \hline
30 & Port Stanley (Falkland Islands) & 51.6\({}^{\circ}\) S & 57.9\({}^{\circ}\) W & 38.7\({}^{\circ}\) S & 48.3\({}^{\circ}\) S & 2000–2019 \\ \hline
31 & Pruchonie (Czech Republic) & 50.0\({}^{\circ}\) N & 14.6\({}^{\circ}\) E & 45.4\({}^{\circ}\) N & 54.9\({}^{\circ}\) N & 2004–2019 \\ \hline
32 & Ramey (Puerto Rico) & 18.5\({}^{\circ}\) N & 67.1\({}^{\circ}\) W & 27.5\({}^{\circ}\) N & 38.9\({}^{\circ}\) N & 2000–2019 \\ \hline
33 & Rome (Italy) & 41.8\({}^{\circ}\) N & 12.5\({}^{\circ}\) E & 35.9\({}^{\circ}\) N & 49.3\({}^{\circ}\) N & 2000–2019 \\ \hline
34 & Roquetes (Spain) & 40.8\({}^{\circ}\) N & 0.5\({}^{\circ}\) E & 34.7\({}^{\circ}\) N & 48.2\({}^{\circ}\) N & 2000–2019 \\ \hline
35 & San Vito (Italy) & 40.6\({}^{\circ}\) N & 17.8\({}^{\circ}\) E & 34.6\({}^{\circ}\) N & 48.6\({}^{\circ}\) N & 2000–2019 \\ \hline
36 & Sao Luis (Brazil) & 2.6\({}^{\circ}\) S & 44.2\({}^{\circ}\) W & 2.9\({}^{\circ}\) S & 5.0\({}^{\circ}\) S & 2000–2019 \\ \hline
37 & Sondrestrom (Greenland) & 67.0\({}^{\circ}\) N & 50.9\({}^{\circ}\) W & 72.2\({}^{\circ}\) N & 65.8\({}^{\circ}\) N & 2000–2012 \\ \hline
38 & Thule (Greenland) & 77.5\({}^{\circ}\) N & 69.2\({}^{\circ}\) W & 84.5\({}^{\circ}\) N & 72.7\({}^{\circ}\) N & 2000–2014 \\ \hline
39 & Tromso (Norway) & 69.6\({}^{\circ}\) N & 19.2\({}^{\circ}\) E & 66.5\({}^{\circ}\) N & 66.6\({}^{\circ}\) N & 2000–2018 \\ \hline
40 & Wallops Island (USA) & 37.9\({}^{\circ}\) N & 75.5\({}^{\circ}\) W & 47.8\({}^{\circ}\) N & 52.0\({}^{\circ}\) N & 2000–2019 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: _Cont._  
Figure 1: Global view of the ionosonde stations listed in Table 1. The yellow circles depict the ionosonde stations location with the corresponding identification number (Table 1, first column). Blue dashed curves depict the QD magnetic parallels, while red ones depict the modip parallels. Figure 2a, the percentage of available _fo_F2 and _hm_F2 values per year, also considering the applied filtering based on the C-score value, is graphically represented for each ionosonde station. By virtue of the fifteen-minute time sampling, 100% of available values per year correspond to 35,040 (35,136 for a leap year).