Rain effects analysis on image transmission through free space optical communication system

Abstract Free Space optics (FSO) has gained significant interest in recent years due to its ability to provide a more secure communication connection than conventional radio links, being relatively inexpensive compared to other wireless systems, and the fact that it operates without any interference from other wireless devices. FSO also has a downside in its susceptibility to certain environmental conditions, which can degrade the quality of the connection by absorbing, scattering, and refracting the optical beams. This paper discusses the rain attenuation effect on RGB image transmission through an FSO communication system. The study uses different metrics to analyze system performance and suggests increasing transmission power to improve performance during heavy rainfall. The findings suggest that for medium and heavy rain, an improvement in maximum link distances of 490 m and 340 m, respectively, is obtained as the transmission power increases to 15 mW. The paper also proposes a spatial domain image restoration technique to enhance image quality at the receiver using the median and wiener filters. Results show that the proposed solutions increase the communication range of the FSO link by 320 m and 205 m for moderate and heavy rain, respectively, when the transmitting power is about 10 mW.