Temperature maps obtained from satellite images for a forest wildfire temporal evolution analysis

The conversion of Digital Counts (DC) to surface temperature, for Thermal Infrared wave-lengths in TIROS-NOAA satellites, requires three steps: 1) calibration; 2) conversion of radiance to true temperature; 3) soil temperature after atmospheric and emissivity correction. The transformation of DC to radiance of the scene depends on the blackbody internal temperature and the representative cold space view sensed with the platinum resistance thermomethers. Header words 18, 19 and 20 each contain those measures and header words 23 to 52 provide ten internal target data each for Infra Red channels 3, 4 and 5. The conversion to brightness temperature from radiance is performed using the inverse of Planck's radiation equation. The non-linearity in the calibration is accounted for through the addition of a correction term to the brightness temperature of scene. From true brightness temperature, the split-window algorithm, determines the surface temperature. This methodology is applied to a group of images dated before, during and after a fire in Aznal-collar (Spain) for a temporal evolution analysis.