Emulating and mitigating atmospheric effects in free-space OAM-based communication links

2016 ◽  
Author(s):  
Alan E. Willner
Keyword(s):  
Free Space ◽  
Atmospheric Effects ◽  
Communication Links

scholarly journals Analysis of visibility effects on free space earth-to-satellite optical link based on measurement data in Nigeria

2020 ◽  
Vol 9 (1) ◽  
pp. 41-45
Author(s):  
S.E. Falodun ◽  
J.S. Ojo ◽  
O.L. Ojo
Keyword(s):  
Free Space ◽  
Measurement Data ◽  
Optical Systems ◽  
Atmospheric Effects ◽  
Signal Loss ◽  
Free Space Optical ◽  
Specific Attenuation ◽  
Port Harcourt ◽  
Link Margin ◽  
Communication Links

The effect of atmospheric variables on signals propagating from earth to space are of concern in the design and performance of wireless  communications systems. Since atmospheric effects which led to atmospheric losses (attenuations, fading and scintillation) are location-dependent, climatological phenomena such as fog, snow, rain, and haze has much effect on Free Space Optical (FSO) and can cause reduction in the link availability. This paper analysed the effect of fog on FSO communication links from earth to satellite links over five selected locations (Ikeja, Akure, Enugu, Jos and Port-Harcourt) in Nigeria. One year (2012) visibility data obtained at Nigeria Meteorological Agency (NIMET) have been used to estimate the specific attenuation caused by fog on FSO communication links in the selected locations. Link margin was deduced in all the five locations. The estimated specific attenuation caused by fog was based on operating frequencies associated with a typical commercial FSO. The result shows that at 352 THz frequency, Ikeja recorded the highest value of about 38.60 dB/km for the specific attenuation due to fog on FSO link followed by Akure with value of about 30.33 dB/km. Enugu recorded the least estimated attenuation of about 14.19 dB/km . The implication of the result is that Ikeja and Akure will suffer more signal loss, while Enugu will suffer less signal loss. Result on link margin performed on FSO link also showed that Ikeja has the highest link margin of -109.79 dB, Port-Harcourt with link margin value of -91.99 dB while Jos experienced lowest link  margin of about -37.48 dB. Keywords: Free space optical systems; Fog induced specific attenuation; Earth-space links; Link margin

Normal Incidence Free Space Optical Data Porting to Embedded Communication Links

2008 ◽  
Vol 31 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Michael E. Teitelbaum ◽  
Shridhar Yarlagadda ◽  
Daniel J. O'Brien ◽  
Eric D. Wetzel ◽  
Keith W. Goossen
Keyword(s):  
Free Space ◽  
Normal Incidence ◽  
Optical Data ◽  
Free Space Optical ◽  
Communication Links

Angle discrimination based pointing and tracking for free-space communication links

2004 ◽  
Author(s):  
Narasimha S. Prasad ◽  
Patrick T. Kratovil ◽  
Charles Bjork ◽  
Neil J. Vallestero
Keyword(s):  
Free Space ◽  
Space Communication ◽  
Communication Links ◽  
Angle Discrimination ◽  
Free Space Communication
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