Nominal pixel scale
The VIIRS I-band active-fire product has a nominal 375 m pixel dimension at nadir. The MODIS active-fire product is approximately 1 km. Pixel geometry varies with viewing conditions; neither number describes fire area.
Confidence is not one shared probability
VIIRS reports categorical confidence such as low, nominal, or high. MODIS reports a numerical confidence field that is grouped for filtering. These values come from different algorithms and must not be compared as identical probabilities.
Why both remain visible
Separate orbits, instruments, resolution, and processing can produce different observations. ThermalGlobe removes repeated same-product pixel observations but never collapses independent NOAA-20, NOAA-21, and MODIS measurements into a false single record.
How to compare two observations responsibly
First compare observation time, product and footprint before comparing point locations or FRP. A later VIIRS point near an earlier MODIS point may add evidence of persistent heat, but it does not prove that both coordinates belong to one incident. Different overpass geometry can shift the apparent centre of the observed pixel.
Use repeated observations as context, then verify any incident interpretation with responsible public authorities. ThermalGlobe does not rank one sensor as the official account of conditions on the ground.