## 3 Results
### MSI vs. Oli  
Regarding the comparison of surface reflectance between resampled MSI and OLI pixel values, a reference scatterplot was observed using the training dataset (70%) (Figure 2). The values exhibit a good level of agreement, as indicated by the dashed line representing the ODR slope, whose values (Table 5) are close to 1. The blue band has a higher degree of disagreement (0.8284). Nevertheless, the mean difference values for all bands (Table 5) are statistically significant (\(p\)-value \(<\) 0.05). The RMSD values (Table 2) range from 0.0197 (Green band) to 0.0464 (SWIR2 band). Figure 2: Comparison of pairwise surface reflectance from Sentinel-2 and Landsat-8. In yellow the regions that represent larger numbers of points. The solid line is 1-to-1 relationship, dashed line is the ODR regression slope. Significant differences were identified when adjustment factors found here (Table 6) were compared with those available in the literature by [PERSON] et al. [39] and [PERSON] et al. [40] (Table 7). The coefficients available in the literature and applied to our dataset revealed statistically significant differences (\(p\)-value \(<\) 0.05) (Table 7a) for all comparisons between MSI and OLI bands adjusted, with RMSD values (Table 7b) ranging from 0.0187 (green band) to 0.0480 (NIR band) for [PERSON] et al. (2019) [39] transformation functions, and \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Regression Model** & **Blue** & **Green** & **Red** & **NIR** & **NIRa** & **SWIR1** & **SWIR2** \\ \hline OLS Intercept & 0.0016 & 0.0009 & \(-\)0.0005 & 0.0133 & 0.0204 & 0.02 & 0.0113 \\ OLS Slope & 1.1297 & 1.0518 & 1.0773 & 0.9637 & 0.9677 & 1.0147 & 1.0829 \\ \hline RMA Intercept & \(-\)0.0044 & 0.0041 & 0.0047 & 0.0103 & \(-\)0.0028 & 0.0077 & 0.0035 \\ RMA Slope & 1.2071 & 1.0919 & 1.1032 & 1.0432 & 1.0457 & 1.0544 & 1.1163 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Intercept and slope values obtained by applying both OLS and RMA regression models for each pair of MSI surface reflectance as a function of OLI surface reflectance. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Band** & **OLS** & **RMA** & **Chastain et al. Coeff.** & **HLS Coeff.** \\ \hline Blue & \(-\)2.54 \(\times\) 10\({}^{-5}\) & 2.67 \(\times\) 10\({}^{-5}\) & 0.015 \({}^{*}\) & 0.0055 \({}^{*}\) \\ Green & 2.78 \(\times\) 10\({}^{-5}\) & 6.69 \(\times\) 10\({}^{-6}\) & 0.0043 \({}^{*}\) & 0.0071 \({}^{*}\) \\ Red & 1.73 \(\times\) 10\({}^{-5}\) & \(-\)9.42 \(\times\) 10\({}^{-3}\)\({}^{*}\) & 0.0051 \({}^{*}\) & 0.0104 \({}^{*}\) \\ NIR & 4.81 \(\times\) 10\({}^{-5}\) & \(-\)2.06 \(\times\) 10\({}^{-2}\)\({}^{*}\) & 0.0304 \({}^{*}\) & NA \\ NIRa & \(-\)8.24 \(\times\) 10\({}^{-3}\) & \(-\)8.27 \(\times\) 10\({}^{-3}\) & \(-\)0.0038 \({}^{*}\) & 0.0026 \({}^{*}\) \\ SWIR1 & 8.04 \(\times\) 10\({}^{-7}\) & 1.06 \(\times\) 10\({}^{-6}\) & 0.0165 \({}^{*}\) & 0.0247 \({}^{*}\) \\ SWIR2 & \(-\)8.20 \(\times\) 10\({}^{-2}\)\({}^{*}\) & 4.74 \(\times\) 10\({}^{-6}\) & 0.0261 \({}^{*}\) & 0.0288 \({}^{*}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Statistical differences in surface reflectance between the training set MSI and OLI band values after transformation functions. Mean difference (a) and RMSD values (b) for each pairwise band of the training set subjected to OLS and RMA regression models in this study and to [PERSON] et al. [39] and [PERSON] et al. HLS [40] transformation functions. The asterisk (\({}^{*}\)) indicates the significance of the \(t\)-test, with a \(p\)-value \(<\) 0.05. \"NA\" indicates the absence of a transformation coefficient between band 8 and band 5 of the MSI and OLI sensors, respectively.