# The Combined ASTER MODIS Emissivity over Land (CAMEL) Part 2: Uncertainty and Validation
## 3 CAMEL Uncertainty Estimates
### Method
A quality flag is provided for the total uncertainty as defined in Table 2. The quality flag is zero where no CAMEL data is available (over ocean), one where it is determined to be of good \begin{table}
\begin{tabular}{c c c c c c} \hline
**CAMEL** & \multicolumn{2}{c}{**CAMEL**} & \multirow{2}{*}{**UWBF**} & \multirow{2}{*}{**ASTER**} & \multirow{2}{*}{**CAMEL COMBINING METHOD**} & \multirow{2}{*}{**ALGORITHM UNCERTAINTITY**} \\
**Channel** & & & & & & \\
**Number** & **[jum]** & & & & & \\ \hline
1 & 3.6 & Y & - & UWBF1 & Abs(UWBF1 \(\times\) [UVWBF6 \(-\) \\  & & & & & & \\  & & & & & & \\  & & & & & & \\
2 & 4.3 & Y & - & UWBF2 & Abs(UWBF2 \(\times\) [UVWBF6 \(-\) \\  & & & & & & \\
3 & 5.0 & Y & - & UWBF3 & Abs(0)/\(\times\) \\
4 & 5.8 & Y & - & UWBF4 & Abs(0)/\(\times\)/3 \\
5 & 7.6 & Y & - & UWBF5 & 0.01 \(\mu\)m  \\
6 & 8.3 & Y & Y & ASTER 1 + (CAMEL/UWBF, ASTER 2 \(-\) ASTER 2 ) & Abs(UVWBF \(-\) ASTER/1)/\(\times\) \\
7 & 8.6 & Y & Y & Weighted Mean(UWBF, ASTER 2 \(\times\)) & Abs(UVWBF \(-\) ASTER/2)/\(\times\) \\
8 & 9.1 & - & Y & ASTER 3 + (CAMEL/UWBF, ASTER 2 \(\times\)) & AB(UVWBF \(-\) ASTER/3)/\(\times\) \\
9 & 10.6 & - & Y & ASTER 4 & Abs(UVWBF \(-\) ASTER/1)/\(\times\) \\
10 & 10.8 & - & - & Linear Interpolation(ASTER 4, ASTER 5) & Abs(UVWBF \(-\) ASTER/2)/\(\times\) \\
11 & 11.3 & - & Y & ASTERS & Abs(UVWBF8 \(-\) ASTER/3)/\(\times\) \\  & & & & UWBF9 & All(UVWBF9 \(-\) ASTER/5)/\(\times\) \\
12 \({}^{*}\) & 12.1 & Y & - & UWBF9 + diff(CMEL/10, UWBF8) & Abs(UVWBF9 \(-\) ASTER/5)/\(\times\) \\  & & & & UWBF10 & 14.3 & Y & - \\  & & & & & & \\
13 \({}^{*}\) & 14.3 & Y & - & & & CAMEL12 & Abs(UWBF10 \(-\) ASTER/5)/\(\times\) \\ \hline \end{tabular}
\end{table} 
Table 1: Bands, inputs, and methodology for generating the CAMEL (Combined ASTER and MODIS Emissivity over Land, combining the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER)) product and algorithm uncertainty estimates \({}^{*}\). Note University of Wisconsin Baseline-Fit (UW BF) is based on the MODIS emissivity product. quality, and two where it is determined to be unphysical and should not be used. To determine which total uncertainty values are unphysical (i.e., have a 'total_uncertainty_quality_flag' = 2), unphysical uncertainties are first identified in the 3 uncertainty components (i.e., the temporal, spatial, and algorithm uncertainty), though the components' flags are not provided to users due to file size restraints. Spatial and temporal uncertainty values are flagged unphysical if they are located in the 99.9 th percentile, while algorithm uncertainty values are determined as unphysical if the ASTER and BF differences prior to having their absolute values taken are in the 0.1 st or 99.9 th percentiles. Total uncertainty values are then flagged as unphysical if any of the 3 components uncertainties are flagged as unphysical, so that up to 0.4% of the total uncertainty estimates could be marked as unphysical. In addition to the 13 hinge point CAMEL product, the following analyses (illustrated in Figures 3 and 4) show total uncertainty estimates for CAMEL HSR spectra. While a CAMEL HSR uncertainty is not provided with the official product, it is calculated here to illustrate the sensitivity of the HSR algorithm to the 13 hinge point CAMEL product. To obtain the HSR uncertainty, the 13 hinge point total uncertainty is both added to and subtracted from the monthly emissivity and then input into the CAMEL HSR algorithm. The HSR uncertainty is then estimated as half the difference between the HSR emissivity produced by adding and subtracting the 13-hinge point uncertainty from the monthly emissivity value.