Far Infrared and Submillimeter Scattering
I. The Optical Constants of Water — A Survey
ResearchPublished 1974
I. The Optical Constants of Water — A Survey
ResearchPublished 1974
To estimate correctly the atmospheric attenuation of far infrared and submillimeter radiation due to scattering by hydrometeors, the corresponding optical constants of water must be accurately known. These constants are highly dependent on wavelength, and until very recently could not be accurately measured. This report surveys the most recent literature critically and shows that for liquid water at room temperature, good data are available for radiation of 16 to 1000 micrometers. The most reliable sets of optical constants for water and ice are presented graphically by means of convenient plots and curves on a single figure, allowing interpolation for any wavelength with reasonable accuracy. A selected set of optical constants based on these data can be used in computations of cloud and rain attenuation at atmospheric temperatures without introducing serious error. For ice, however, data are scant and are based on measurements at temperatures too low to be usable.
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