Refractive index of humid air in the infrared: model fits

The theory of summation of electromagnetic line transitions is summarized in terms of the Taylor expansion of the refractive index of humid air as a function of the basic independent parameters ( temperature, pressure, humidity, wavelength) in five separate infrared regions from the H to the Q band at a fixed percentage of carbon dioxide. These are least-squares fits to raw, highly resolved spectra for a set of temperatures from 10 to 25 degrees C, a set of pressures from 500 to 1023 hPa and a set of relative humidities from 5 to 60%. These choices reflect the prospective application to characterize ambient air at mountain altitudes of astronomical telescopes.