Multiple Scattering in Rain and Fog on Free-Space Optical Links

Author

Grabner, Martin ; Kvicera, Vaclav

Author_Institution

Dept. of Freq. Eng., Czech Metrol. Inst., Prague, Czech Republic

Volume

32

Issue

3

fYear

2014

fDate

Feb.1, 2014

Firstpage

513

Lastpage

520

Abstract

The multiple scattering effects of light propagation in rain and fog are investigated by means of numerical Monte Carlo photon propagation simulations. Rain and fog consisting of water droplets are described by realistic drop size distributions with parameters related to physical parameters of hydrometeors such as rain intensity, liquid water content, effective droplet radius of fog and atmospheric visibility. Simulations show that optical attenuation due to rain is about two times lower than predicted by single scattering approach. Fog attenuation is also reduced for the lowest visibilities. An impulse response of optical channel in rain and fog is obtained and the explicit models for the delay spread dependence are provided. Under realistic conditions, the RMS delay spread due to rain on 1 km long free space optics (FSO) path is limited below 10 ps. Moderate and dense fog can cause the delay spread about 50 ps or more. Frequency characteristics of the FSO channel impaired by rain and fog are given.

Keywords

Monte Carlo methods; fog; light propagation; light scattering; optical communication; optical delay lines; optical links; rain; FSO channel frequency characteristics; RMS delay spreading; atmospheric visibility; distance 1 km; drop size distributions; fog attenuation; free space optics path; free-space optical links; hydrometeors; impulse response; light propagation; liquid water content; multiple scattering effects; numerical Monte Carlo photon propagation simulations; optical attenuation; rain intensity; single scattering approach; time 50 ps; water droplets; Atmospheric modeling; Attenuation; Optical attenuators; Optical scattering; Photonics; Rain; Attenuation; Monte Carlo (MC); delay spread; fog; free space optics (FSO); impulse response; propagation; rain;

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/JLT.2013.2294356

Filename

6679219