Accession Number:

AD0260589

Title:

STUDY OF SHORT TERM VARIATIONS IN THE OPTICAL TRANSMISSION OF THE ATMOSPHERE AT SHORT DISTANCES USING THE SCHLIEREN TECHNIQUE

Descriptive Note:

Corporate Author:

TEXAS TECHNOLOGICAL COLL LUBBOCK

Personal Author(s):

Report Date:

1961-05-31

Pagination or Media Count:

1.0

Abstract:

Motion picture records at 92 frames per second of schlieren observations of the free atmosphere have been made using a variety of schlieren arrangements with path distances of 24 feet to 200 feet, at night and in full daylight. The observations are consistent with a model in which rays traveling as short a distance as 24 feet, 6 feet above the ground, are refracted so as to be deviated by several refractive gradient regions in this distance. These regions are apparently rough surfaces bounding volumes of air larger han the telescope objective area and which are at a temperature different from the surrounding air due to heating or cooling by contact with the ground or with the tube of the telescope. the telescope-induced artifacts can be reduced by use of a sunshade over the entrance of the telescope. Schlieren records give an excellent presentation of the shapes and motions of areas on a telescope objective w ich send light to displaced portions of the image. Data as to intensity of light from a given p rtion of the objective area are complicated by moderately high levels o scattered light which have to be dealt with in a schlieren system operated under outdoor conditions. Te s indicate that color schlieren and an application of the Hartmann test might give data which would make the determination of deviation of flux a more quantitative measure. Author

Subject Categories:

Distribution Statement:

APPROVED FOR PUBLIC RELEASE