Availability and reliability of FSO links estimation from measured fog parameters

This work is focused on last mile system called FSO (Free Space Optics). Availability and reliability are estimated from measured fog parameters. In FSO system, the propagation media is air. The FSO systems working in free environment are very popular and establishing of connection is very easy. But on the other hand a number of phenomena in the atmosphere such as scattering, absorption and turbulence cause a large variation of receiving optical power. The influence of absorption and turbulence can be significantly reduced by an appropriate design of FSO link. The visibility has the main influence on quality of the transmission channel. Thus, in typical continental area where rain, snow and fog occur is important to know their values. This article gives us a detail description of the instrument for measuring weather conditions such as the density of fog, humidity and temperature. From the measured data is possible to calculate a visibility which is the main factor for estimation the availability and reliability of FSO link.