Patent ID: 7433806

Claim:
A band model method for determining individual atomic and molecular species spectral transmittances through a gaseous medium, the method comprising the steps of: providing atomic and molecular transition data for a given spectral range and atmospheric conditions; selecting a spectral region to be considered; dividing the spectral region into a number of spectral bins that determine a spectral resolution, each bin having a width of about 0.1 cm −1 or less; calculating atomic and molecular species line center absorption from at least an equivalent width of the atomic and molecular transitions centered within each spectral bin; calculating line tail absorption within each spectral bin from atomic and molecular transitions not centered within the bin; determining atomic and molecular species spectral transmittances for each spectral bin, the spectral transmittance having a value which is a function of at least the calculated line center absorptions and the calculated line tail absorptions; and outputting the determined spectral transmittances.