[Narew]

It's not only fog. Depending on pupil size it can also be rain. But during my thesis 10y ago one of the big limitation on horizontal line of sight laser telecommunication was scintillation due to turbulence. And this phenomenon appear in clear weather condition with heat. So it was limited in clear and sunny weather. I don't know what up time did there expect ? But the bandwidth should fluctuate a lot.

[mmaunder]

Thanks