DUST DETECTION USING THERMAL INFRARED CHANNEL

The thermal infrared temperature difference ΔT(T_11μm-T_12μm) is investigated as a possible method for detecting dust outbreaks. Based on radiative properties of the winter dust aerosol defined by Almeida, this paper calculated the thermal infrared temperature difference ΔT(T_11μm-T_12μm) as a function of optic thickness of dust aerosol. The result of atmospheric radiation calculations indicates that the temperature difference △T over and surface will decline when optic thickness of dust aerosol increases. Similarly, atmospheric transmittance calculations of thermal infrared channel as a function of optic thickness of dust aerosol also indicate that 11μm atmospheric transmittance is bigger that 12μm atmospheric transmittance when optic thickness of dust aerosol increases. Sensitive test of △T (T_11μm-T_12μm) to surface temperature (ST) and water vapor (W) is also illustrated. It indicates that W remarkably affects △T. △T can be used to detect heavy dust when W is big; however, △T can be used to detect light dust when W is small. The sensitive test indicates that △T is not sensitive to the change of ST. Furthermore, the feasibility of dust detection using this technology is demonstrated by comparing satellite observations and surface observations of meteorological stations. The validation of three dust detection indicates that dust using remote sensing coincides with observed dust.