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29 October 2007 The impact of boundary layer turbulence on optical propagation
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The performance of an optical sensor may be affected by small-scale fluctuations of the atmosphere, quantified through the refractive index structure parameter Cn2. The values of Cn2 along the optical path are modulated by large eddy fluctuations of the atmospheric fields. The resulting variations in the optical propagation have been scarcely documented due to the difficulty in measuring them. In this study, we use a micro-meteorological model to diagnose Cn2 in 3D+time in the case of a convective boundary layer. The regions of high Cn2 match with the convective plumes that drive the boundary layer dynamics. The variability of Cn2 is larger in the bulk boundary layer, where the mean Cn2 is low; it decreases in the surface layer and in the inversion, where the mean Cn2 is large. The impact of this distribution on horizontal optical propagation is analyzed, based on well-known analytical solutions of wave propagation through turbulence. Despite the optical path averaging, a large variability remains for the wave coherence length and the scintillation rate. Implications in terms of optical applications are given. In conclusion, the challenges in extending our modelling approach to present-day weather prediction are discussed.
© (2007) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
S. Cheinet and A. P. Siebesma "The impact of boundary layer turbulence on optical propagation", Proc. SPIE 6747, Optics in Atmospheric Propagation and Adaptive Systems X, 67470A (29 October 2007);

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