The apparent temperature of the surface assuming a surface emissivity of 1.0. Setting the emissivity to one is equivalent to assuming the target is a blackbody, so the brightness temperature is defined as the temperature a blackbody would be in order to produce the radiance perceived by the sensor. Brightness Temperature is a descriptive measure of radiation in terms of the temperature of a hypothetical blackbody emitting an identical amount of radiation at the same wavelength. The brightness temperature is obtained by applying the inverse of the Planck function to the measured radiation. Depending on the nature of the source of radiation and any subsequent absorption, the brightness temperature may be independent of, or highly dependent on, the wavelength of the radiation. Units: C
BRIGHTNESS TEMPERATURE
INFRARED WAVELENGTHS