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

摘要

The convension of igital Counts (DC) to surface temperautre, for Thermal Infrared wavelengths in TIROS-NOAA satelites, requires three steps: 1) calibration; 2) conversion of radiance to true temeprature; 3) soil temeprature after atmospheric and emissivity correction. The transformation o DC to radiance of the scene depends on the blackbody internal temperature and the representative cold space view sensed with the platinum resistnace 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 hte inverse of Planck's radiation equaiton. The non-linearity in the calibration is accounted for through the addition of a correction term to the brightness temperature of scene. From rue brightness temperature, the split-window algorithm, determiens the surface temeprature. This methodology is applied to a group of images dated before, during and after a fire in Aznalcollar (Spain) for a temporal evolution analysis.