ATMOSPHERIC TRANSMITTANCE OF AN ABSORBING GAS .5. IMPROVEMENTS TO THEOPTRAN APPROACH

Improvements to a fast and accurate transmittance-calculation procedur e, Optical Path TRANsmittance (OPTRAN), are described. The previous ve rsion computed a transmittance ratio for an absorbing layer. It requir ed special attention to the interpolation methodology. The new approac h reported here computes the absorption coefficient for an absorbing l ayer. This modified approach is not only simpler but also runs in one twentieth the time of the original OPTRAN approach with the same accur acy. (C) 1995 Optical Society of America