为了得到不同海拔地区的大气透过率, 探索大气透过率随海拔高度的变化规律, 利用数值模拟、软件计算和实地测量方法分别对阿里(5 km)、德令哈(3 km)和怀柔(0 km)3个不同海拔地区在4605~4755 μm波段25 km以下的大气透过率进行了计算和测量。结果表明: 红外大气透过率随海拔高度增加而增加; 采用数值模拟计算得到3个地方的大气透过率分别为0709、0572和0555; 采用软件计算得到的透过率分别为0849、0766和0596; 采用实测方法得到的透过率分别为0805、0.766和0.673; 阿里地区海拔较高, 相对湿度较低, 能见度高, 大气透过率最好。该结论对国内天文红外观测及空间红外目标辐射特性测量具有重要的借鉴意义。

In order to obtain atmospheric transmittance and study its variation with different altitudes, using methods of mathematical models, software simulations, and actual measurement, we calculate and measure the atmospheric transmittance in the range of 4605~4755 μm wavelengths at Ali(5 km), Delingha(3 km) and Huairou(0 km), three different altitudes below 25 km. Results indicate that the infrared atmospheric transmittance increases with altitude. With mathematical model the calculated atmospheric transmittances are 0709, 0572 and 0555, respectively. With software simulations the calculated atmospheric transmittances are 0849, 0766 and 0596, respectively. With actual measurement the obtained atmospheric transmittances are 0805, 0766 and 0673. Due to higher altitude, lower relative humidity, high visibility, the atmospheric transmittance at Ali is the highest one. This conclusion has important reference significance for domestic astronomical infrared observation and spatial infrared target radiation characteristics measurement.