Characterization of hydrometeor scattering effects and experimental measurements using near-infrared free-space urban links

Abstract

The improvements of the instrumentation available within the free space optics (FSO) link set up in the Roman area (Italy) is illustrated together with FSO channel physical modelling activity. The wireless optical link at 1550 nm is 1.650 km long and has a transmission rate up to 1.5 Gbps. This link is intended to be, in the next future, the trunk sector of a convergent passive optical network (G-PON). Among particle scattering effects affecting the capacity of the optical channel, a focus is placed on raindrop and fog droplets. An evaluation of these atmospheric effects is illustrated and a comparison with measurements is carried out for some case studies of moderate and heavy rainfall. This becomes fundamental to evaluate the feasibility of such an approach in real telecommunications access scenarios, where the quality of service (QoS) and the quality of experience (QoE) must be always guaranteed. © 2012 IEEE

Modeling scintillation effects on free space optical links using radiosounding profile data

“…A range between 10-20 and 10-13 m-2 / 3 are observed with higher values during summer. FSO system and path parameters are derived from the NTR link at 155 0 run in Rome (Italy), about 20 km far from the RAOB site [10]. Statistical results in terms of Rytov variance (I� and power scintillation index (If; are shown in Fig.…”

“…Il.B (see (10) and (12)), we have carried out the evaluation ofNTR (If; for a slant link with an elevation angle u=45° and maximum height H=12000 m during day and night.…”

Clear-air turbulence effects modeling on terrestrial and satellite free-space optical channels

“…II, we have evaluated the statistics of for terrestrial link path (see (6) and (9)). In this first analysis FSO system and path parameters are derived from the NIR (Near Infrared) link at 1550 nm in Rome (Italy) with L=800 m, a link about 20 km far from the nearest RAOB site in Pratica di Mare [10]. RAOB data of 2013 have been collected for this purpose.…”

“…FSO links are very sensitive to the presence of atmospheric droplets within the beam such as fog and hydrometeors [4], [6]- [10]. Tropospheric turbulence, due to small temperature variations of atmopsheric masses, can be responsible of beam power losses due to the beam spot spreading and of space-time fluctuations of the laser beam intensity, better known as scintillation [6].…”

Hydrometeor scattering and stochastic modeling for free-space optical channel characterization

“…Within this project an experimental set up has been realized in the Roman area (Italy). The link is operating at 1550 nm, and the instrumental devices include the fSONA SONAbeam® 1250-E optical transceiver, located at three channel heads (triangular configuration), a meteorological station, a particle disdrometer, a visibilimeter, an AXIS P1344-E video camera for visibility analysis [7]. Data collected within the set up will allow the parameter refinement and validation of the models developed within the joint project.…”