Attenuation of Millimeter Wavelength Radiation by Gaseous Water

Abstract

A theoretical computation and absorption by water vapor of radiation within the millimeter and sub-millimeter region of the electromagnetic spectrum permits the determination of attenuation coefficients for given vapor densities, pressures, and temperatures. The rigid asymmetrical top rotor approximation for all angular momentum quantum numbers J ≤ 12 is used with a line shape derived from kinetic theory and half-widths calculated by Anderson’s theory. An equation is given for extrapolating attenuation coefficients to pressures and temperatures other than those for which calculations were performed.