Calculation of upper atmospheric transmittance and radiation in mid-infrared region

The mid-infrared atmospheric transmittance and radiation were calculated with four different HITRAN databases using LBL software. Results show that atmospheric transmittance is increases with the transmission path decreases. Radiation decreases with the transmission path decreases. The transmittance average absolute deviation of HITRAN96, HITRAN2k and HITRAN04 is small in the three downlink propagation. But the transmittance absolute deviation is larger in some bands, such as the maximum absolute deviation of HITRAN2k up to 0.81 in transmission path from 100 to 10 km. The radiation average absolute deviation level of HITRAN96, HITRAN2k and HITRAN04 is 10-6 in the three downlink propagation. The deviation caused by old versions of the database should be considered for calculating infrared atmospheric transmittance and radiation. The difference caused by different versions of the database should be considered.