Translator Disclaimer
Paper
11 November 2004 Atmospheric refraction and its impact on free-space optic communication systems
Author Affiliations +
Abstract
Atmospheric refraction bends optical beams and lets objects appear in positions they not really are. This phenomenon is very important in astronomy. However, astronomical refraction formulas can only be used if the light source is at a very far distance from the observer. Then, atmospheric refraction mainly depends on meteorological conditions on ground. In case of optical free-space communications, the distances are comparatively short and well-known formulas for astronomical refraction are no longer sufficient. An exact knowledge of the structure of the whole atmosphere is required to assess refraction in this case. Due to the complexity of the atmosphere, analytical solutions are not possible. Hence, a numerical simulation model based on spherical symmetry, atmospheric shell modeling and standard atmosphere models was used instead. Three different categories of refraction were examined: 1) the observer is situated on ground and the object is at an altitude of at least 25 km, 2) both object and observer are below 25 km and the link path is mainly vertical and 3) both object and observer are in the stratosphere and ray paths are mainly horizontal. The results presented in this work are useful for applications like laser beam pointing and satellite tracking, UAV (Unmanned Aerial Vehicle) and HAP (High Altitude Platform) downlinks or long-haul cross-links through the atmosphere, e.g. HAP-HAP or UAV-satellite.
© (2004) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Karin Hedman and Florian David "Atmospheric refraction and its impact on free-space optic communication systems", Proc. SPIE 5572, Optics in Atmospheric Propagation and Adaptive Systems VII, (11 November 2004); https://doi.org/10.1117/12.565475
PROCEEDINGS
12 PAGES


SHARE
Advertisement
Advertisement
RELATED CONTENT


Back to Top