What conditions cause outage of freespace optical systems?

The effects of weather on the operational performance of freespace optical systems vary with the severity of the weather condition encountered. Specific weather conditions such as rain, snow, fog, mist, etc. can impair visibility and thus reduce the effective range of freespace optical transmission. Such effects are transient, yet common seasonal trends are determined by the climate zone, the latitude and other known geographic parameters of the area where the installation is to be located. PAV publish effective fade margins for each type of system and can supply a software tool to assist in the availability calculation for differing scenarios using the international weather table as reference.