# Development of the User Requirements for the Canadian WildFireSat Satellite Mission
## 3 Definition of the User Requirements
### Measurement Requirements
#### 3.2.1 MWIR and LWIR Band Requirements
 } & \multirow{8}{*}{CWFM-URD-0180} & Brightness temperatures retrieved in the MWIR band(s) SHALL be in the range of at least 300 to 720 K at 200 m spatial resolution, or 300 to 635 K at 400 m, at surface level \\ \cline{1-1}  & & \(\bullet\) 800 (MWIR: (0.8–0.9 \(\upmu\)m) \\ \cline{1-1}  & & \(\bullet\) 800 (MWIR: (0.6–0.7 \(\upmu\)m; red), (0.5–0.6 \(\upmu\)m; green), AND (0.4–0.5 \(\upmu\)m; blue) \\ \hline \multirow{8}{*}{ \begin{tabular}{} \end{tabular}  } & \multirow{8}{*}{CWFM-URD-0200} & Brightness temperatures retrieved in the MWIR band(s) SHALL be in the range of at least 300 to 720 K at 200 m spatial resolution, or 300 to 635 K at 400 m, at surface level \\ \cline{1-1}  & & \(\bullet\) 800 (MWIR: (0.8–0.9 \(\upmu\)m) \\ \cline{1-1}  & & \(\bullet\) 800 (MWIR: (0.6–0.7 \(\upmu\)m; red), (0.5–0.6 \(\upmu\)m; green), AND (0.4–0.5 \(\upmu\)m; blue) \\ \hline \multirow{8}{*}{ \begin{tabular}{} \end{tabular}  } & \multirow{8}{*}{CWFM-URD-0180} & Brightness temperatures retrieved in the MWIR band(s) SHALL be in the range of at least 300 to 720 K at 200 m spatial resolution, or 300 to 635 K at 400 m, at surface level \\ \cline{1-1}  & & \(\bullet\) 800 (MWIR: (0.6–0.7 \(\upmu\)m; green), AND (0.4–0.5 \(\upmu\)m; blue) \\ \cline{1-1}  & & \(\bullet\) 800 (MWIR: (0.6–0.7 \(\upmu\)m; red), (0.5–0.6 \(\upmu\)m; green), AND (0.4–0.5 \(\upmu\)m; blue) \\ \hline \multirow{8}{*}{\ \begin{tabular}{} \end{tabular}  } & \multirow{8}{*}{CWFM-URD-0180} & Brightness temperatures retrieved in the MWIR band(s) SHALL be in the range of at least 300 to 720 K at 200 m spatial resolution, or 300 to 635 K at 400 m, at surface level \\ \cline{1-1}  & & \(\bullet\) 800 (MWIR: (0.6–0.7 \(\upmu\)m; green), AND (0.4–0.5 \(\upmu\)m; blue) \\ \cline{1-1}  & & \(\bullet\) 800 (MWIR: (0.6–0.7 \(\upmu\)m; red), (0.5–0.6 \(\upmu\)m; green), AND (0.4–0.5 \(\upmu\)m; blue) \\ \cline{1-1}  & & \(\bullet\) 800 (MWIR: (0.6–0.7 \(\upmu\)m; red), (0.5–0.6 \(\upmu\)m; green), AND (0.4–0.5 \(\upmu\)m; blue) \\ \cline{1-1}  & & \(\bullet\) 800 (MWIR: (0.6–0.7 \(\upmu\)m; green), AND (0.4–0.5 \(\upmu\)m; blue) \\ \cline{1-1}  & & \(\bullet\) 800 (MWIR: (0.6–0.7 \(\upmu\)m; red), (0.5–0.6 \(\upmu\)m; green), AND (0.4–0.5 \(\upmu\)m; blue) \\ \hline \multirow{8}{*}{ \begin{tabular}{} \end{tabular}  } & \multirow{8}{*}{CWFM-URD-0180} & Brightness temperatures retrieved in the MWIR band(s) SHALL be in the range of at least 300 to 720 K at 200 m spatial achieved with single band measurements in the MWIR [32]. However, the LWIR remains essential in the detection of wildfire pixels for FRP analysis as well as in interrogating sub-pixel characteristics of wildfire pixels (e.g., effective wildfire temperature and area; [73]). Optimal MWIR band placement for wildfire detection and FRP measurement is a narrow window of observation centred at 3.9 \(\upmu\)m (e.g., MODIS, Band 21). Wider spectral bands have also been demonstrated to be effective (e.g., SLSTR, Figure 1), provided that they enter into the CO\({}_{2}\) band at 4.2 \(\upmu\)m, and avoid encroaching significantly below 3.5 \(\upmu\)m where solar reflection becomes a stronger contributor. These parameters are reflected in the MWIR spectral band requirements in Table 5. The LWIR band's function of supporting contextual detection analysis and sub-pixel analysis affords more freedom in precise band placement. The LWIR band is specified to ensure that it falls within an atmospheric window in the 8-14 \(\upmu\)m range (Table 5), providing sufficient spectral separation for MWIR-LWIR differential analysis. FRP measurement and sub-pixel characterization also requires measurement over the full dynamic range of the scene. Dynamic ranges for the MWIR and LWIR bands (Table 5) were defined in Brightness Temperatures (BT; K) at surface level (i.e., without atmospheric attenuation) as the precise spectral bands are not yet specified. Both bands are required to make ambient (\(\sim\)300 K) surface temperature measurements.