## 3 Results
### Error Analysis from the TSEB Algorithms
#### 3.1.2 TSEB Data Analysis Separately for LIRF and IIC 2020-2021 Data  
When evaluating the LIRF 2020-2021 data alone, the results were also consistent with the previous combined data from LIRF and IIC regarding both the \(\text{TSEB}_{\text{ser}}\) and \(\text{TSEB}_{\text{par}}\) algorithms. The proximal platform MSR5 (1 m) outperformed all other platforms since it had the smallest NRMSE equal to 10% (\(\text{TSEB}_{\text{par}}\)) and 14% (\(\text{TSEB}_{\text{ser}}\)) see Tables 9 and 10. Underestimation (NMBE) of \(\text{TSEB}_{\text{par}}\) hourly maize \(\text{ET}_{\text{a}}\) predictions ranged from \(-1\) to \(-7\)% for the Landsat-8 TIRS (30 m), Sentinel-2 (10 m), MSR5 (1 m), and UAS (0.03 m). Overestimation of \(\text{TSEB}_{\text{par}}\) maize \(\text{ET}_{\text{a}}\) was observed in the case of RS data used from the Planet CubeSat (3 m) and Landsat-8 IRT platforms, with respective NMBE equal to 4% and 3%. Regarding the \(\text{TSEB}_{\text{ser}}\) RS of the \(\text{ET}_{\text{a}}\) algorithm, similar trends of underestimation and overestimation of hourly maize \(\text{ET}_{\text{a}}\) were observed compared to the \(\text{TSEB}_{\text{par}}\) algorithm. There were 28% and 26% reductions in NRMSE, respectively, for the \(\text{TSEB}_{\text{par}}\) and \(\text{TSEB}_{\text{ser}}\) RS of \(\text{ET}_{\text{a}}\) results when Landsat-8 surface reflectance and IRT \(\text{T}_{\text{s}}\) data were used to estimate hourly maize \(\text{ET}_{\text{a}}\). When evaluating the IIC 2020-2021 data alone, the results were again consistent with the previous analysis regarding LIRF and the combined LIRF-IIC data. Similarly, the MSR5 (1 m) outperformed the spaceborne and airborne platforms/sensors, with an overall error equal to \(-0.03\) (\(-4\)%) \(\pm\) 0.08 (12%) mm/h and \(-0.04\) (\(-6\)%) \(\pm\) 0.09 (14%) for the \(\text{TSEB}_{\text{par}}\) and \(\text{TSEB}_{\text{ser}}\), respectively.  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Site**} & \multirow{2}{*}{**Platform**} & \multirow{2}{*}{
\begin{tabular}{c} **Spatial** \\ **Resolution (m)** \\ \end{tabular} } & \multirow{2}{*}{\(n\)} & \multicolumn{2}{c}{**MBE**} & \multirow{2}{*}{**NMBE (\%)**} & \multirow{2}{*}{**RMSE** **(mm/d)**} & \multirow{2}{*}{**NRMSE (\%)**} & \multirow{2}{*}{**R\({}^{2}\)**} \\  & & & & & & & \\ \hline \multirow{6}{*}{LIRF} & Landsat-8 TIRS & 30 & 14 & \(-0.04\) & \(-7\)\% & 0.13 & 25\% & 0.51 \\ \cline{2-8}  & Landsat-8 IRT & 30 & 14 & 0.02 & 3\% & 0.09 & 18\% & 0.73 \\ \cline{2-8}  & Sentinel-2 & 10 & 35 & \(-0.02\) & \(-4\)\% & 0.09 & 16\% & 0.85 \\ \cline{2-8}  &CubeSat & 3 & 63 & 0.02 & 4\% & 0.10 & 18\% & 0.69 \\ \cline{2-8}  & MSR5 & 1 & 17 & \(-0.01\) & \(-1\)\% & 0.06 & 10\% & 0.91 \\ \cline{2-8}  & UAS & 0.03 & 11 & \(-0.03\) & \(-5\)\% & 0.09 & 15\% & 0.67 \\ \hline \multirow{6}{*}{IIC} & Landsat-8 TIRS & 30 & 12 & \(-0.02\) & \(-3\)\% & 0.18 & 33\% & 0.24 \\ \cline{2-8}  & Landsat-8 IRT & 30 & 12 & 0.03 & 5\% & 0.11 & 21\% & 0.76 \\ \cline{1-1} \cline{2-8}  & Sentinel-2 & 10 & 32 & \(-0.01\) & \(-2\)\% & 0.09 & 15\% & 0.73 \\ \cline{1-1} \cline{2-8}  &CubeSat & 3 & 62 & 0 & 0\% & 0.08 & 14\% & 0.76 \\ \cline{1-1} \cline{2-8}  & MSR5 & 1 & 28 & \(-0.03\) & \(-4\)\% & 0.08 & 12\% & 0.82 \\ \cline{1-1} \cline{2-8}  & UAS & 0.03 & 13 & \(-0.01\) & \(-2\)\% & 0.09 & 14\% & 0.58 \\ \hline \hline \end{tabular}
\end{table}
Table 9. Error analysis from the \(\text{TSEB}_{\text{par}}\) hourly maize \(\text{ET}_{\text{a}}\) evaluation for the LIRF and IIC 2020–2021 data.