Using a tunable source of monochromatic radiation (BWO) and a pneumatic detector, the field and laboratory investigations have been performed to obtain spectral distribution of atmospheric water vapor absorption coefficient in transparent windows centered at the wavelengths of 0.88 and 0.73 mm.
Field measurements have been made of atmospheric absorption in the wavenumber range (4-15)/cm, using a 200-m horizontal transmission path at a resolution of 0.2/cm. The results are compared with theoretical spectra based on water-vapor monomer absorption, and anomalous absorption spectra are presented. There is support from some preliminary laboratory work. A binding energy of between 0.4 and 0.8 electron volts per molecule is derived for the water-vapor complex responsible for the absorption.