Visibility and attenuation due to hydrometeors at 850 nm mEASURED on an 850 m path

Results on a propagation study carried out on a free space optical link at 850 nm on an 850 m long path over a one-year period are given. All recorded individual attenuation events were compared with the concurrent meteorological conditions and were identified according to the types of individual hydrometeors. Cumulative distributions of attenuation due to individual hydrometeors and the cumulative distributions of visibility due to individual hydrometeors were obtained. The influence of individual hydrometeors on both attenuation and visibility was assessed. The measured dependence of specific attenuation on visibility for fog was compared with the calculated dependences in accordance with four models.