by Andrew James Wardrop
Under the supervision of Professor Edward Ney
- The infrared spectral emission of the clear atmosphere has been calculated from 7 to 14.4 microns and measured from the ground from 4 to 14.4 microns. The calculation used a 12 layer atmospheric model. An efficient line by line calculation procedure was developed for determining atmospheric transmission that permitted a large number of emission spectra to be performed economically, with full correction for pressure broadening and temperature effects. The model used actual radiosonde data to determine atmospheric parameters. The spectra had an intrinsic resolution of 0.02 cm^-1, but were degraded to match the resolution of the radiometer.
- The radiometer used a helium cooled photoconductive detector. The optical system used an unconventional reference radiation source and had a narrow beamwidth (1 mrad). A circular variable filter wheel was used for wavelength selectivity, and gave a resolution of ~ 2%. the accuracy of the radiometer was not limited by detector noise but by systematic errors.
- The comparison of the observed and calculated radiances verified the basic validity of the calculational model, but raised some doubts about the form of the water vapor continuum absorption.