Modeling of Fog and Smoke Attenuation in Free Space Optical Communications Link Under Controlled Laboratory Conditions

An Experimental Study of FSO Link Performance in Desert Environment

“…However, theoretical approaches require some parameters that may not be available at the installation location such as particle size, particle distribution, refractive index, etc. [6].…”

“…The second method for signal attenuation calculation which is widely used in literature for practical applications depends on experimental observation [6]. In this method, empirical models are developed using the visibility range data to characterize the channel.…”

“…Visibility data can be obtained easily form meteorological stations located close to the installation location. Visibility is defined as the distance to an object where the image distinction drops to a certain percentage of what would be if the object were nearby instead [6]. Image distinction that drops to 2% and 5% is used to be considered in visibility definition.…”

“…Finally, severe dust storm (dense dust) occurs when the visibility becomes less than 0.2 km where large quantity of dust particles is lifted up by very strong winds. The visibility range can be determined from the signal attenuation coefficient α and the visual threshold T th by [6] where T th =0.02 according to Koschmieder law. The signal attenuation coefficient is given by [6] …”

“…Because of the difficulty to predict the occurrence of specific atmospheric effects like fog, rain, smoke, and dust events, and because of the difficulty to repeat the measurements under the same conditions, the authors in [4][5][6][7] made a pioneering but preliminary investigation of the FSO performance using controlled environment (chamber). In particular, the authors in [4] studied the FSO performance using on-off keying (OOK) modulation and pulse position modulation (PPM) schemes.…”