Computation of radiative transfer model based on MODIS infrared channel

The infrared radiative transfer equation of earth-atmosphere system was established,and the radiative transfer model based on MODIS infrared channel was computed.The atmosphere transmittance was calculated fast by accurate PFAAST model,the effect of ground reflected atmospheric emission radiance was considered in the radiative transfer calculation,it was showed that the percentage of ground reflected atmospheric emissive radiance in radiative transfer equation increased while the surface emissivity reduced,the MODIS 33rd band was most sensitive to emissivity.The percentage was 7.12% when emissivity was 0.65 in U.S.Standard Atmosphere.So the radiative transfer calculation was not accurate if the ground reflected atmospheric radiance was negligible.The MODIS infrared channel radiance was calculated and compared with that of MODTRAN4.0 calculation,the biggest relative error was only 0.12%.The effect of atmospheric slanting path on the sounding brightness temperature of satellite infrared channel was simulated.