Optical attenuation estimation from measured visibility data in Islamabad, Pakistan

Free-space optics (FSO) is subject of interest for researchers due to its various advantages like high bandwidth, low setup cost, easy installation, license free spectrum and secure communication. Although there are various advantages of using FSO but when it comes to its implementation FSO links are highly affected by various weather factors like fog, rain, snow, smoke and smog. Among all these factors fog is one of the prominent factor causing severe attenuation for FSO link. Department of Meteorology at COMSATS Institute of Information Technology in Islamabad is measuring visibility data due to fog since 2009. In this paper four sample fog events have been selected to estimate optical attenuation using Kim, Kruse and Al Naboulsi model at three different wavelengths of 830 nm, 1550 nm and 10 μm. The results indicate that optical attenuation are reaching upto 110 dB/km.