Wildfire data field guide
Fire Radiative Power vs Fireline Intensity: what is the difference?
FRP is a satellite-derived radiative-power estimate integrated over a detected pixel. Fireline intensity is heat release per unit length of fire front. Their units, spatial meaning and measurement methods are different.
Core distinction
MW per detected pixel vs kW per metre of fire front.
NASA FIRMS defines Fire Radiative Power (FRP) as pixel-integrated fire radiative power, reported in megawatts. NWCG defines fireline intensity as heat release per unit time per unit length of fire front.
Remote-sensing quantity tied to a satellite detection footprint and observation time. Units: MW.
Fire-behavior quantity tied to the flaming front. Units commonly kW/m or Btu/(ft·s).
Why they cannot be converted directly
The geometry is different.
FRP integrates radiative output from active burning within a satellite pixel. Fireline intensity normalizes heat release by the length of the active fire edge. Without information about the active flaming length, combustion phase, sensor response and other assumptions, there is no simple one-step conversion between the two.
What FRP is good for
Comparing satellite-observed radiative activity.
- Characterizing relative radiative activity among detections.
- Supporting biomass-combustion and emissions research.
- Tracking changes in satellite-observed thermal output over time.
- Adding an independent evidence layer to incident chronology.
Sensor resolution, saturation, viewing geometry and observation timing can affect FRP estimates.
Connect the tools
Keep satellite radiometry and fire behavior separate.
Sources
NASA FIRMS and NWCG.
NASA FIRMS — VIIRS active-fire attributes and FRP ↗
Published 21 September 2026.