The influence of boundary effects and type of environment on turbulence profiles
Abstract
Light or laser beams propagating through the atmosphere can get severely distorted by optical turbulence. When light propagates over a horizontal path over homogeneous terrain, the strength of the atmospheric turbulence, is often assumed to be constant. This assumption cannot be made for vertical or slant propagation paths, since it is known that the strength of atmospheric turbulence varies with height above the ground. Several models exist which predict the variation of atmospheric turbulence with height above the ground. Measurements show a good agreement with these predictions of atmospheric turbulence profiles for higher altitudes. The prediction is not very good in the first 30 - 50 m of the surface layer, i.e. close to the ground. It is known that a surface, in this case the ground, causes boundary effects. It is also known that the surface roughness of the surface (ground) influences how turbulence behaves. Both effects are included in the measurements, since one is always performing an experiment in a certain environment. However, these effects are not included in the models and they will predict the same behavior whether it is for a city, a forest, a field of grass, or the ocean. A better understanding of the behavior of the turbulence (profiles) in the atmospheric surface layer in general and specifically the role that boundary effects play in these turbulence profiles and the effects that the type of environment has on the turbulence profiles will be investigated. This is important for multiple applications, like free space optical communication, directed energy, and remote sensing, in which light or a laser beam propagates along a slant or vertical path through the atmosphere. A more realistic prediction of the turbulence profile will lead to better understanding and performance of these applications in different environments.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 07, 2024
- Source ID
- FA95502310610
Entities
People
- Miranda van Iersel
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Dayton