An Optical Apparatus to Determine the Effect of Turbulence on the Modulation Transfer Function of the Atmosphere

An Optical Apparatus to Determine the Effect of Turbulence on the Modulation Transfer Function of the Atmosphere
Author: Wayne Thompson Hildebrand
Publisher:
Total Pages: 43
Release: 1972
Genre: Physics
ISBN:

An apparatus was designed and constructed to determine the effect of atmospheric turbulence on the modulation transfer function (MTF) of the atmosphere. A reflecting telescope and reticle system provided optical information in the visible region to a silicon photodiode detector which was responsive from .35 micron to 1.1 microns. The output of the detector was processed to measure irradiance modulation from a target of known spatial frequency. The modulation transfer function of the atmospheric transmission medium and the optical system was measured under calm conditions and conditions of turbulence on a 270 meter round trip path through a building corridor. The optical apparatus described was capable of detecting, in the visible range, the degrading effect of turbulence on MTF. All reflective optics were used so that the visual through 10 micrometers range can be covered with use of different detectors. (Author).

Effects of Atmospheric Turbulence on Optical Instrumentation

Effects of Atmospheric Turbulence on Optical Instrumentation
Author: Randolph A. Becker
Publisher:
Total Pages: 17
Release: 1961
Genre:
ISBN:

The results of research on optical turbulence at White Sands Missile Range are presented. It has been shown that elevating camera stations 33 feet above ground level can yield nearly a threefold increase in optical resolution during periods of atmospheric turbulence. Early research postulated the existence of thermal-induced air-lenses as the cause of optical turbulence effects. Recent research has shown that air-lenses can account for most of the observed effects. The 'prism' concept of turbulence appears to be unnecessary for explaining trubulence -induced image motion. The dependence of the optical effects of turbulence upon exposure time and aperture size is discussed qualitatively. The source of optical turbulence in the atmosphere and a method of measuring the trubulence-generating potential of various terrain surfaces are described on the basis of micrometerology. This research has been limited to an investigation of optical turbulence during the period from sunrise to sunset. However, many of the results apply to the nighttime turbulence encountered by astronomers. (Author).

Astronomical Optics

Astronomical Optics
Author: Daniel J. Schroeder
Publisher: Elsevier
Total Pages: 367
Release: 2012-12-02
Genre: Science
ISBN: 032313856X

Written by a recognized expert in the field, this clearly presented, well-illustrated book provides both advanced level students and professionals with an authoritative, thorough presentation of the characteristics, including advantages and limitations, of telescopes and spectrographic instruments used by astronomers of today. Written by a recognized expert in the field Provides both advanced level students and professionals with an authoritative, thorough presentation of the characteristics, including advantages and limitations, of telescopes and spectrographic instruments used by astronomers of today

Effects of Atmospheric Turbulence on Optical Propagation

Effects of Atmospheric Turbulence on Optical Propagation
Author: R. S. Lawrence
Publisher:
Total Pages: 8
Release: 1984
Genre:
ISBN:

The optical refractive index of the atmosphere depends on temperature, pressure, and humidity. Naturally occurring variations of these quantities, with scales of a few centimeters and associated with atmospheric turbulence, cause optical scintillation, image distortion, and laser beam broadening. I review the meteorological conditions that influence the occurrence of this optical turbulence, discuss the optical significance of turbulence at various heights in the atmosphere, and point out the differences between these optical effects and the corresponding phenomena at radio wavelengths. While beam broadening increases indefinitely with the strength of optical turbulence, scintillation saturates and eventually decreases with increasing turbulence.