DID YOU KNOW? DTIC has over 3.5 million final reports on DoD funded research, development, test, and evaluation activities available to our registered users. Click
HERE to register or log in.
Accession Number:
ADA063158
Title:
Optical Resolution in the Turbulent Atmosphere of the Marine Boundary Layer.
Descriptive Note:
Final rept. 1 Jul 73-30 Sep 77,
Corporate Author:
NAVAL POSTGRADUATE SCHOOL MONTEREY CALIF
Report Date:
1978-02-24
Pagination or Media Count:
201.0
Abstract:
The effects of turbulence on the performance of imagers or on beam forming optical systems are well expressed by the optical transfer function or its essential equivalents, the modulation transfer function or the mutual coherence function for the atmosphere. These quantities can be adequately expressed in terms of the Fried model by means of a single number, the turbulence structure constant for optical index, C sub n squared, provided that a properly path-weighted value is obtained. The behavior as a function of wavelength and range is also well understood. The quantity C sub n squared, which varies with the micrometeorology, can be determined in its properly path-weighted form with a slit-scanning telescope system developed at NPS. A portable system is available which includes an on-line data processing system that gives immediate numerical and graphical results for the properties of the atmosphere, together with performance prediction for a given optical system. The direct optical measurement of weighted C sub n squared for the path avoids the necessity of making a large number of measurements of C sub t squared at points along the path. Measurement of C sub n squared by the slit-scanner method also obtains a direct result independent of assumptions as to the statistical form of the turbulence.
Distribution Statement:
APPROVED FOR PUBLIC RELEASE
