## 2 Data and Methods
### Analysis Methods  
For over thirty years, the Geostationary Operational Environmental Satellite (GOES) series from the National Oceanic and Atmospheric Administration (NOAA) has been responsible for measuring meteorological and space weather phenomena. One of the essential components of the GOES-R instrument suite is the EUV and X-Ray Irradiance Sensor System (EXIS), which consists of two instruments designed to monitor solar spectral irradiance: the Extreme Ultraviolet Sensor (EUVS) and the X-Ray Sensor (XRS) [28]. For our study, we utilize data from the GOES 17 satellite to select and analyze six solar flare events that occurred during the years 2021 and 2022 (details provided in Table 2).  
Figure 2 displays the positions of these solar flares on the solar disk, revealing occurrences both in the central region and at the periphery. Recognizing the spatial distribution of these solar eruptions is crucial as it offers pivotal insights into solar activity dynamics. Additionally, it is important to note that, in accordance with the Dst index (Figure 3), the Earth's magnetic field remained calm during this period. This calm magnetic field condition stands as an essential factor for our study, as it ensures that disturbances arising from magnetic field fluctuations are minimal. The data used from the dst index were obtained from the Center for Geomagnetism and Space Magnetism Data Analysis at Kyoto University.  
Figure 1: The figure illustrates the differentiation of each level’s application from 1 to 8 in wavelet algorithms used for solar flare detection. The green rectangle is the solar flare being more distinct in level 7 and 8.  
When investigating the Total Electron Content (TEC) on a per-station basis, we risk overlooking significant insights offered by analyzing TEC data for individual satellites. The computation of TEC for each station mandates the application of diverse filters to counter temporal mean effects that arise as the number of visible satellites observed by the station fluctuates. By individually scrutinizing TEC for each satellite, a more intricate evaluation of TEC conditions becomes achievable. To further enhance our understanding of ionospheric perturbations, we calculated TEC at 5 Hz intervals, allowing us to capture ionospheric fluctuations every 1/5 of a second.  
The deployment of multiple monitoring stations played a pivotal role in mitigating distortions arising solely from the peculiarities of a single station's receiver. Employing wavelet analysis for TEC examination enabled us to distinctly and concisely pinpoint the influence of solar flares on TEC while simultaneously highlighting distinct frequency components evident over time.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Date** & **Day** & **Start Time** & **Peak Time** & **End Time** & **Flare** \\  & **GPS** & **(UT)** & **(UT)** & **(UT)** & **Class** \\ \hline
03 July 2021 & 184 & 14:18 & 14:29 & 14:34 & X1.5 \\
28 October 2021 & 301 & 15:17 & 15:35 & 15:48 & X1 \\
30 March 2022 & 89 & 17:21 & 17:37 & 17:46 & X1.3 \\
30 April 2022 & 120 & 13:37 & 13:47 & 13:52 & X1.1 \\
10 May 2022 & 130 & 13:50 & 13:55 & 13:59 & X1.5 \\
2 October 2022 & 275 & 19:53 & 20:25 & 20:34 & X1.0 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Event Features.  
Figure 2: Location of the solar flare on the solar disk.