The wavelength dependent model of extinction in fog and haze for free space optical communication

Abstract

The wavelength dependence of the extinction coefficient in fog and haze is investigated using Mie single scattering theory. It is shown that the effective radius of drop size distribution determines the slope of the log-log dependence of the extinction on wavelengths in the interval between 0.2 and 2 microns. The relation between the atmospheric visibility and the effective radius is derived from the empirical relationship of liquid water content and extinction. Based on these results, the model of the relationship between visibility and the extinction coefficient with different effective radii for fog and for haze conditions is proposed.

Route diversity analyses for free-space optical wireless links within turbulent scenarios

“…Fog is the biggest problem in FSO systems and has been studied extensively in the literature [2,3]. The atmospheric thermal induced turbulence is the next factor that has the high impact on the FSO link performance by affecting the statistics of the received signal [4].…”

Reindeer Vision Explains the Benefits of a Glowing Nose

“…Redder light travels farthest, but the distance that light can travel decreases if the size of the ice crystals or water droplets in the fog is large [6]. If the droplets are above a certain size, then a process called Mie scattering will extinguish all light of any color [7]. Mie scattering happens in most fog types, making most fog very difficult to see through, but a glowing red nose is predicted to outshine any other kind of nose, with red light traveling further in ice fog because the ice crystals in ice fog are smaller than the water droplets in radiation fog [8,9].…”

Analysis of fog and smoke attenuation in a free space optical communication link under controlled laboratory conditions

“…Generally, due to the complexity involved in the physical properties of the fog, like particle size and the non-availability of particle distribution, the fog induced attenuation of the optical signal can be predicted using empirical models [12][13][14]. These models use the visibility data in order to estimate the fog induced attenuation.…”