# Development of the User Requirements for the Canadian WildFireSat Satellite Mission
## 3 Definition of the User Requirements
### Precision Requirements
#### 3.3.2 Co-Registration Requirements  
Multi-spectral analysis is essential to the delivery of all of the active- and post-fire products required for the mission. Band-to-band co-registration requirements are defined to minimize band remapping requirements prior to data processing (Table 6), helping to facilitate NRT data delivery under FMF-6. Particularly strong co-registration requirements are imposed on the MWIR and LWIR bands due to their use in bi-spectral sub-pixel analysis [73], which is known to be highly sensitive to band mis-registration errors [87]. Although FRP calculations no longer require the use of the Dozier method [32], the sub-pixel descriptors it produces are required for complete wildfire behavior analysis. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Type** & **URD Parent Reference** & **Requirement** \\ \hline \multirow{8}{*}{Noise} & CWFM-URD-0207 & The VIS/NIR noise SHALL be: \\  & CWFM-URD-0207 & \(\bullet\) SNR \(>30\) over the full dynamic range (Table 5; CFWM-URD-0200) for the VIS bands \\  & \(\bullet\) SNR \(>40\) over the full dynamic range (Table 5; CFWM-URD-0200) for the NIR band \\  & CWFM-URD-0208 & The LWIR band SHALL have NESR \(<0.12\) (W m\({}^{-2}\) sr\({}^{-1}\) um\({}^{-1}\)) when computed for a TOA scene at 300 K \\  & CWFM-URD-0209 & The MWIR band SHALL have NESR \(<0.22\) (W m\({}^{-2}\) sr\({}^{-1}\) um\({}^{-1}\)) when computed for a TOA scene at 300 K \\  & The band noise SHOUTD be: \\  & CWFM-URD-0210 & \(\bullet\) SNR \(>90\) over the full dynamic range (Table 5; CFWM-URD-0200) for the VIS bands \\  & \(\bullet\) SNR \(>110\) over the full dynamic range (Table 5; CFWM-URD-0200) for the NIR bands \\  & \(\bullet\) LWIR and MWIR NESR should be minimized \\ \hline \multirow{8}{*}{Sensitivity} & CWFM-URD-0220/30 & The design SHALL be capable of measuring the background temperature in the MWIR and LWIR channels with a \(2\sigma\) uncertainty of no more than 5\(\%\) at TOA for the sub-satellite pixel \\  & The design SHOUTD be capable of measuring the background temperature in the MWIR and LWIR channels with a \(2\sigma\) uncertainty of no more than 3\(\%\) at TOA for the sub-satellite pixel \\ \cline{2-3}  & CWFM-URD-0240 & Minimum FRP detectable SHOUTD be 5 MW at radiat and 40 MW at edge of swath (up to 45 degree off-radiar) \\  & CWFM-URD-0250 & The uncertainty of the FRP of the center pixel when mid-pointing SHALL be less than 15\(\%\) of the FRP, or less than 5 MW (whichever value is larger). \\  & CWFM-URD-0251 & The uncertainty of the FRP of pixels at edge of swath (45 degree off-radiar) when radar-pointing SHOUTD be less than 15\(\%\) of the FRP, or less than 5 MW (whichever value is larger). \\ \hline \multirow{8}{*}{Co-registration} & CWFM-URD-0260 & Co-registration between MWIR and LWIR bands SHALL be provided within 1/3 MWIR pixel accuracy for all pixels in each of the bands \\  & CWFM-URD-0270/71 & Co-registration between LWIR band and VIS/NIR bands SHALL be provided within 1 LWIR pixel accuracy for all pixels in each of the bands, and SHOUTD be within 0.5 LWIR pixel accuracy \\  & CWFM-URD-0272/73 & Co-registration between MWIR band and VIS/NIR bands SHALL be provided within 1 3 MWIR pixel accuracy for all pixels in each of the bands, and SHOUTD be within 0.5 MWIR pixel accuracy \\ \cline{2-3}  & CWFM-URD-0280 & Co-registration between NIR and VIS bands SHOUTD be provided within 1-pixel accuracy of either the VIS or NIR band \\ \cline{2-3}  & CWFM-URD-0290 & The Modulation Transfer Function for all bands SHOUTD be \(>\)0.3 for all frequencies below the Nyquist frequency \\ \hline \multirow{2}{*}{Geo-location} & CWFM-URD-300 & Data provided to the users SHALL be tagged with geo-referencing information accurate to within 0.5-pixel resolution \\ \cline{2-3}  & \multicolumn{1}{c}{} & \\ \end{tabular}
\end{table} 
Table 6: Summary of key Precision Requirements as outlined in the User Requirements Document (URD), and refined in the Mission Requirements for WildFineSat.