OBSERVATION OF ATMOSPHERIC ABSORPTION USING SUBMILLIMETRE MASER SOURCES

Using five submillimetre maser emission lines the absorption of the atmosphere and of pure water vapour have been experimentally determined ; the latter as a function of pressure. These results have been compared with values derived from a complete theoretical analysis based on monomeric water vapour only. This comparison leads to the conclusions that atmospheric absorption in the spectral region 32 - 100 cm-1 may be effectively computed using a theoretical model which considers monomeric water vapour alone; and that for absorption by pure water vapour a small deviation exists which is consistent with the theoretically evaluated spectrum of the water vapour dimer. © 1969.