THE MEASUREMENT OF STRATOSPHERIC DENSITY DISTRIBUTION WITH THE SEARCHLIGHT TECHNIQUE.
Abstract
An investigation of light scattering from a beam projected into the atmosphere over New Mexico was made by means of the searchlight technique. Modulation of the searchlight beam was necessary in order to differentiate the scattered light from the light of the night sky. Therefore, a modulating technique using a rotating beam is first developed and evaluated, as is the shutter method of modulation used for acquisition of final upper-altitude data. A 60-in. parabolic mirror and photomultiplier tube mounted at its focus comprised the sensing device. A narrow-band tunable amplifier then selected the desired signal component from the photomultiplier output. Absolute values of atmospheric densities were obtained by assuming Rayleigh scattering and matching the measured response at 15 km with the densities obtained from radiosonde measurements at the same height. Eight vertical density distributions to 61.8 km so determined were in good agreement with the Rand distribution for a model atmosphere. A seasonal trend for densities at high altitudes was evident. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1951
- Accession Number
- AD0638151
Entities
People
- L. Elterman
Organizations
- Air Force Cambridge Research Laboratories