Contribution of new water vapor absorption lines to the atmospheric transmission in the transparency window 8-12 µm

The evaluation of the contribution of numerous H2O absorption lines to the atmospheric transmission in the 8-12 μm transparency window is presented based on different spectroscopic databases of water vapor absorption lines, including the new theoretical data sets POKAZATEL and VoTe, as well as the H2O data from the popular spectroscopic databases HITRAN and GEISA. Comparison of the atmospheric transmittance calculated using different databases is presented. The contribution of the weak lines is investigated and shown to be important for very long absorption paths