Modeling of 830 nm FSO Link Attenuation in Fog or Wind Turbulence

Abstract

This study is focused on the experimental research of the atmosphere impact on FSO link attenuation. Experiment is performed on a mountain observatory Milesovka of severe weather conditions. The empirical relationships on 830 nm only between FSO attenuation A on one hand and atmospheric visibility V or wind turbulent energy ET on the other hand are presented and discussed. In the fog case it was found A= 401.4V-0.5738- 1.462 dB/60m (V in meters) while for the attenuation due to the wind turbulence ET it holds A = 2.112 - 2.213 exp(-0.2867ET) dB/60m (ET in m2s-2, it was derived for 830 nm wave length). A discussion concerning problems of the “clear air attenuation,” atmospheric turbulences and sun shine impact, which was observed as a maximum 2 dB attenuation for a few minutes with a period of 24 hours is added.

Keywords

• Free Space Optics propagation
• fog attenuation
• wind turbulence attenuation
• turbulent energy