## 3 Results
### Validation
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Site** & **Site ID** & \begin{tabular}{c} **Mean of** \\ **Flux Tower** \\ \end{tabular} & \begin{tabular}{c} **Std. Dev. of** \\ **Flux Tower** \\ \end{tabular} & \begin{tabular}{c} **Mean of** \\ **Estimated** \\ \end{tabular} & \begin{tabular}{c} **Std. Dev. of** \\ **Estimated** \\ \end{tabular} & \
\begin{tabular}{c} **RMSE** \\ **RMSE** \\ \end{tabular} &
\begin{tabular}{c} **MAD** \\ **Rank** \\ \end{tabular} \\ \hline \multicolumn{8}{c}{**Cropland**} \\ \hline Lamont ARM Main & 1 & 0.11 & 1.73 & \(-\)0.33 & 2.63 & 2.58 & 1.71 & 1 \\ Bondville & 2 & na & na & na & na & na & \\ Batavia & 3 & na & na & na & na & na & na & \\ Brooks Field-10 & 4 & 0.15 & 2.85 & 0.22 & 2.73 & 1.81 & 1.00 & 6 \\ Curtis Ranch & 5 & \(-\)0.03 & 0.64 & \(-\)0.80 & 0.90 & 1.41 & 1.00 & 7 \\ Fermi Agricultural & 6 & na & na & na & na & na & na & \\ Haller & 7 & na & na & na & na & na & na & \\ Kellogg Biological Station & 8 & na & na & na & na & na & \\ Lennox & 9 & 0.41 & 2.95 & 0.59 & 2.93 & 1.21 & 0.85 & 9 \\ Mandan & 10 & 0.69 & 2.00 & 0.13 & 1.36 & 1.79 & 1.39 & 2 \\ Mead Irrigated Continuous & 11 & 0.37 & 3.66 & 0.16 & 2.43 & 1.73 & 1.01 & 5 \\ Mead Rainted & 12 & 1.13 & 4.51 & 0.61 & 2.97 & 2.46 & 1.22 & 3 \\ Mead Irrigated Rotation & 13 & \(-\)0.08 & 1.99 & \(-\)0.15 & 2.12 & 1.07 & 0.70 & 10 \\ Rosenount Conventional & 14 & 0.42 & 2.98 & 0.41 & 2.03 & 1.62 & 1.00 & 8 \\ Rosenount G19 & 15 & 0.19 & 1.97 & \(-\)0.21 & 1.13 & 1.95 & 1.14 & 4 \\ \hline \multicolumn{8}{c}{**Mean**} \\ \hline
**Mean** & & & & & & 1.76 & 1.10 & \\ \hline
**Grasland** & & & & & & & \\ \hline Batavia & 16 & 0.7 & 2.33 & na & na & na & \\ Letbridge & 17 & 0.3 & 1.36 & na & na & na & \\ Fort Peck & 18 & \(-\)0.21 & 1.12 & 0.26 & 1.05 & 1.61 & 1.08 & 1 \\ Mandan & 19 & 0.25 & 0.89 & 0.1 & 0.74 & 1.06 & 0.77 & 7 \\ Miles City & 20 & \(-\)0.21 & 0.77 & \(-\)0.51 & 0.41 & 0.9 & 0.67 & 13 \\ Brookings & 21 & 0.08 & 1.3 & 0.36 & 0.97 & 1.2 & 0.9 & 4 \\ Cottonwood & 22 & \(-\)0.08 & 0.91 & 0.14 & 0.97 & 0.98 & 0.62 & 9 \\ Gudmundsen Ranch & 23 & \(-\)0.07 & 0.99 & \(-\)0.04 & 0.44 & 0.92 & 0.7 & 12 \\ CPER & 24 & 0.18 & 1.13 & 0.33 & 0.68 & 0.96 & 0.7 & 10 \\ CRP ungrazed & 25 & \(-\)0.43 & 0.81 & \(-\)0.45 & 0.57 & 0.94 & 0.7 & 11 \\ Ramnelsk Ranch & 26 & 0.45 & 1.88 & 0.17 & 0.88 & 1.47 & 1 & 2 \\ Walnut River & 27 & 0.14 & 1.15 & 0.01 & 0.76 & 0.99 & 0.73 & 8 \\ Woodward & 28 & 0.24 & 1.15 & 0.01 & 1.12 & 1.1 & 0.89 & 6 \\ Fort Reno & 29 & 0.16 & 1.63 & 0.62 & 1.08 & 1.14 & 0.91 & 5 \\ Freeman Ranch & 30 & 0.14 & 0.93 & \(-\)0.9 & 0.78 & 1.35 & 1.09 & 3 \\ \hline Mean & & & & & 1.12 & 0.83 & \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Leave-one-out flux tower site cross validation for crops and grasslands (g C\(\cdot\)m\({}^{-2}\cdot\)day\({}^{-1}\)). Figure 3: Crop mapping model randomized test and training variations in mean (of nine replications) MAD as a function of the size of the training dataset. \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Year**} & \multicolumn{2}{c}{**Mean of**} & \multicolumn{2}{c}{**Std. Dev. of**} & \multicolumn{2}{c}{**Mean of**} & \multicolumn{2}{c}{**Std. Dev. of**} & \multirow{2}{*}{**RMSE**} & \multirow{2}{*}{**MAD**} & \multicolumn{2}{c}{**Influence**} \\  & \multicolumn{2}{c}{**Flux Tower**} & \multicolumn{2}{c}{**Flux Tower**} & \multicolumn{2}{c}{**Estimated**} & \multicolumn{2}{c}{**Estimated**} & \multicolumn{2}{c}{**Estimated**} & \multicolumn{2}{c}{**Rank**} \\ \hline \multicolumn{8}{c}{**Cropland**} \\ \hline
2000 & \(-0.22\) & 2.45 & 1.19 & 3.43 & 0.93 & 2.02 & 1.42 & 3 \\
2001 & \(1.08\) & 4.13 & 0.26 & 2.6