Effects of Non-Kolmogorov Turbulence and Aerosols on Long-Range, Optical Propagation Through the Atmosphere
Abstract
Optical propagation through the turbulent atmosphere is characterized by turbulent fluctuations of the phase, the propagation direction, and the intensity of the optical wave, collectively referred to as optical turbulence. The modern physics of optical turbulence was pioneered in the 1950s and 1960s and it continues to serve as the scientific backbone for various technologies, such as optical remote sensing, free-space optical communication, optical imaging of terrestrial and extraterres-trial objects and adaptive optics, as well as target-acquisition, beam-control and directed-energy technologies. The objective of this project was to study various controversial aspects of optical turbulence by means of observations, theoretical analysis, and computer simulations. In several field experiments, we deployed digital cameras attached to portable telescopes, a frequency-comb laser system, ultrasonic anemometer-thermometers (sonics), and fine-wire thermometers. Our sonic and fine-wire measurements in the atmospheric surface layer corroborated the validity and use-fulness of the Monin-Obukhov similarity theory of surface-layer turbulence, the Obukhov-Corrsinsimilarity theory (Kolmogorov turbulence), and the Hill-Frehlich model of the Hill bump in the temperature spectrum of fully developed turbulence. While we have seen no evidence of non-Kolmogorov turbulence in the atmospheric surface layer, evidence of non-Gaussian temperature increments has been ubiquitous. To what extentnon-Gaussianity of temperature increments translates to non-Gaussianity of phase increments depends on the number of dominating large eddies along the propagationpath.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 14, 2023
- Accession Number
- AD1230932
Entities
People
- Andreas Muschinski
Organizations
- Northwest Research Associates