A large modified polar nephelometer was constructed for the purpose of making high altitude atmospheric optics measurements. The instrument is balloon-borne and measures the angular volume scattering function from ground to better than 26 km in absolute quantities. The results of the initial flight with the unit are presented and they depict the variability in this parameter over the altitude profile for three scattering angles and four wavelengths. In addition, the polarization and the forward-to-backscatter ratio of the scattered light are shown to be sensitive indicators of the atmosphere's vertical aerosol structure. The import of these preliminary results is, however, in pointing out the capabilities of this instrument, which can provide quantitative information on fundamental optical parameters of the atmosphere without the constraints inherent in other techniques.

A large modified polar nephelometer was constructed for the purpose of making high altitude atmospheric optics measurements. The instrument is balloon-borne and measures the angular volume scattering function from ground to better than 26 km in absolute quantities. The results of the initial flight with the unit are presented and they depict the variability in this parameter over the altitude profile for three scattering angles and four wavelengths. In addition, the polarization and the forward-to-backscatter ratio of the scattered light are shown to be sensitive indicators of the atmosphere's vertical aerosol structure. The import of these preliminary results is, however, in pointing out the capabilities of this instrument, which can provide quantitative information on fundamental optical parameters of the atmosphere without the constraints inherent in other techniques.

The report presents the results of a series of field measurements with a Balloon Borne Polar Nephelometer. This instrument measures the optical scattering from a defined volume of atmosphere through which the instrument is transported by a high altitude balloon. Measurements were made from ground level to an altitude of 90,000 feet. Parameters investigated include scattering angle, polarization, and wavelength. The report includes a brief description of the instrument and summaries for each flight made between November 1967 and November 1969. The optical scattering data is graphically presented in the form of volume scattering function versus altitude for each of the parameters investigated. Tables of the individual measurement values have been submitted separately for future detailed analysis. (Author).

Optical scattering, under very clear atmospheric conditions, was measured in situ and analyzed. The experiments were made with a large balloonborne nephelometer launched from Holloman AFB, New Mexico and flown to 26 km altitude. Profiles of angular scattering and polarization properties of atmospheric aerosols show contrast with aerosol particles encountered in the troposphere and stratosphere. The results are compared with those obtained using particle counters under similar atmospheric conditions.