## 4 Results  
### Accuracy of Interchangeability of Answers  
We selected low-latitude regions to apply the genetic algorithm. This is because the deviation of the true magnetic field from the WMM is expected to be small. Next, the answers given by the genetic algorithm were applied to other available orbit data of the same satellite. This method was applied to the on-orbit magnetic field data from NepaliSat-1, Uguisu, and Raavana-1. Figure 9 shows the data set used for calibration. The region between Ref 1 and Ref 2 was selected for GA application. The geographic latitude and magnetic latitude are shown in Figure 10. Table 2 shows the range of unknowns used for the GA. The nine parameters were searched to provide the best match with reference to the WMM values, and the calibrated values were calculated using the nine parameters. Table 3 shows the parameters found by applying the GA to the selected region of Data Set 2 of Raavana-1, shown in Figure 9.  
\[\mathrm{e_{m}}=\frac{\Sigma\bigg{(}\frac{\sqrt{\left(\mathrm{Bwmm}-\mathrm{Bm }\right)^{2}}}{\mathrm{Bwmm}}\bigg{)}}{\mathrm{N}} \tag{6}\]  
\[\mathrm{e}=\frac{\Sigma\bigg{(}\frac{\sqrt{\left(\mathrm{Bwmm}-\mathrm{Bt} \right)^{2}}}{\mathrm{Bwmm}}\bigg{)}}{\mathrm{N}} \tag{7}\]  
Figure 9: Data Set 2, Raavana-1, measured on 14 February 2021 at 5:23 a.m. UTC and the selected region for the calibration. The results of the other two satellites' (Uguisu and NepaliSat-1) magnetometer calibrations are shown below. First, the genetic algorithm was applied to the section of Data Set 2 shown between Ref 1 and Ref 2 in Figure 13, where the magnetic latitude is between \(-30.61\) and \(10.28\) degrees for Uguisu. Next, the answers were applied to the whole of Data Set 3. The genetic algorithm was applied to the section shown in Figure 14, where the \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Data Set** & **Equation Used to** & **Error of Selected** & **Error of** & **Error of Data** \\
**Number** & **Calculate the Error** & **Region** & **Whole Orbit** & **Set 3** \\ \hline
2 & \(\mathbf{e}_{\mathrm{m}}\) & 0.19 & 0.16 & \\
2 & \(\mathbf{e}\) & 0.01 & 0.02 & 0.03 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Errors before and after calibration by using the parameters derived from Data Set 2 of Ravana-1. Figure 11: Calibration of Data Set 2, Raavana-1, measured on 14 February 2021 at 5:23 a.m. UTC. Figure 12: Calibration of Data Set 3, Raavana-1, measured on 11 April 2021 at 5:09 a.m. UTC using the values derived from Data Set 2 measured on 14 February 2021. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Data Set** & **Equation Used to** & **Error of Selected** & **Error of** & **Error of Data** \\
**Number** & **Calculate the Error** & **Region** & **Whole Orbit** & **Set 2** \\ \hline
3 & \(\mathbf{e}_{\mathrm{m}}\) & 0.22 & 0.21 & \\
3 & \(\mathbf{e}\) & 0.04 & 0.03 & 0.07 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Errors before and after calibration by using the parameters derived from Data Set 3 of Raavana-1. magnetic latitude is between 12.45 and \(-\)21.97 degrees for Nepalisat-1. Next, the answers were applied to Data Set 2. Table 6 shows the parameters found by applying the GA to the data shown in Figures 13 and 14 using the selected region shown in the figures. Using those parameters, we evaluated the error of other data sets obtained by the same satellites. The results are shown in Tables 7 and 8. According to the results shown above using the on-orbit magnetometer data of Raavana-1, Uguisu, and NepaliSat-1, it is proven that the genetic algorithm can be used to calibrate on-orbit magnetometer data, reducing discrepancies from the WMM.