INFRARED COLLISION-INDUCED ABSORPTION BY O-2 NEAR 6.4 MU-M FOR ATMOSPHERIC APPLICATIONS - MEASUREMENTS AND EMPIRICAL MODELING

Accurate measurements of collision-induced absorption by O-2 and O-2-N -2 mixtures in the fundamental band near 6.4 mu m have been made. A Fo urier-transform spectrometer was used with a resolution of 0:5 cm(-1). Absorption has been investigated in the O-20-atm and 193-293 K pressu re and temperature ranges, respectively. The current measurements conf irm that the broad O-2 continuum carries small features whose attribut ion is not yet clear. Available experimental data in the 190-360 K tem perature range have been used to build a simple, low cost computer, em pirical model that is well adapted for computation of atmospheric O-2 absorption. Tests show that it is accurate, contrary to predictions of widely used atmospheric transmission codes. (C) 1997 Optical Society of America.