中文摘要：

使用逐线积分（LBL）及四种版本高分辨率分子吸收数据库（HITRAN96、2k、04及08版本）对比计算了中红外2～5μm波段在中纬度夏季（45°N，7月）模式高空大气下行传输的大气分子透过率及热辐射．结果表明：透过率随着下行传输路径减小而增大，热辐射随着传输路径的减小而降低，适当的减小传输路径可以降低高空大气对光电系统应用的影响。96、2k和04版本数据库在三种不同传输路径上透过率的平均绝对偏差均较小，但在某些波段绝对偏差较大，如HITRAN2k在100～10km传输路径上的绝对偏差最大达到了0．81；96、2k和04版本数据库在三种不同传输路径上热辐射的平均绝对偏差的数量级均为10^-6。04版本的平均绝对偏差并非在所有路径中是最小的。计算不同传输路径的大气透过率和热辐射时．采用旧版本的数据库在某些波段可能会产生相当大的误差。

英文摘要：

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.