# Development of the User Requirements for the Canadian WildFireSat Satellite Mission
## 1 Introduction  
Global monitoring of wildfire emissions is supported by the network of geo-stationary weather satellites [1]. Finer resolution polar orbiting systems provide further support by correcting for observational biases [2; 3; 4], and are more commonplace in direct wildfire management applications. Even still, the use of satellite data in real-time emergency management decision-making remains rare, partially due to the latency of satellite wildfire data [5; 6; 7]. Furthermore, at high latitudes the geostationary network is challenged by rapidly degrading spatial resolution and atmospheric transmission [1; 4], leavingwildfire-prone northern boreal regions with limited wildfire monitoring capacity from polar-orbiting systems and a heavy reliance on monitoring from aircraft. Efforts to enhance the uptake of satellite data in wildfire management have been pursued through satellite design (e.g., [8; 9; 10]) and purpose-built information systems (e.g., Global Wildfire Information System [GWIS][11]); additionally, various commercial proposals have been proposed. However, to date no system has successfully delivered end-to-end operational support to address the specific needs of fire managers. In part this is a result of the broad range of wildfire management practices globally and the resulting variation in specific regional requirements for wildfire monitoring. Inability to accurately define the requirements of end-users presents a broad reaching barrier to operational implementation. Responses to wildfires vary across Canada [12] and range from a \"Full Response\" (immediate, aggressive initial/sustained attack), to \"Monitored Response\" (observation and periodic reassessment; [13]), guided either by zonation, or wildfire specific conditions termed \"appropriate response\" [14]. In situations with increased wildfire activity, the suppression capacity can be rapidly overwhelmed, resulting in escaped wildfires that may burn very large areas [15; 16]. These larger wildfires represent only 3% of the number of wildfires in Canada, yet they account for 97% of the area burned [12; 17], and require substantially more resources to manage [18; 19]. In many higher risk locations, Canadian wildfire management agencies generally rely on the Initial Attack model where wildfires are detected early and suppressed small. The early detection and suppression of wildfires is critical to successful wildfire control resulting in fewer escaped wildfires, therefore reducing impacts and response costs [20]. Wildfire remote sensing has been recognized for its capacity to detect wildfires (e.g., [21]). However, there is a significant gap between what is required for \"early\" detection (e.g., identifying small sub-canopy wildfires) for wildfires that require suppression and what can be accomplished reliably with satellite remote sensing [22]. Beyond detection, during periods of escalated wildfire activity it is useful to have current intelligence about all ongoing wildfires. Reliable wildfire intelligence is critical for situational awareness and informed decision-making including prioritization and strategic and tactical wildfire response. Wildfires that are threatening communities and critical infrastructure are prioritized for suppression action over remote wildfires where there is more opportunity for the natural ecological role of wildfire on the landscape [23]. Therefore, these wildfires more frequently grow larger and are generally managed through modified tactics (e.g., continuous mapping and monitoring; [14]). Although satellites are not typically helpful for early detection [22], there is an emerging requirement for large wildfire and regional intelligence gathering to maintain situational awareness during periods of escalated wildfire activity. This intelligence requirement can be met through the proper application of satellite technology, and is broadly described as wildfire \"monitoring\" here. Wildfire monitoring is also an essential component of Canada's efforts to track and predict smoke dispersion from active wildfires.