Free-space optical channel characterization and experimental validation in a coastal environment

Area of Science:

• Optical Communications
• Wireless Technologies
• Environmental Sensing

Background:

• Free-space optical (FSO) communication offers high transmission rates but suffers from weather-induced signal degradation.
• Coastal environments present unique challenges for FSO link stability due to varying atmospheric conditions.

Purpose of the Study:

• To develop and validate models for the channel attenuation coefficient (β) in coastal FSO communication.
• To investigate the impact of ambient temperature (T), relative humidity (RH), and dew point (TD) on FSO signal attenuation.

Main Methods:

• Utilized a mobile FSO system (1 Gbps, 70 m, 1310/1550 nm) in a coastal environment.
• Conducted indoor measurements (1.5 m, 1064/1310/1550 nm) for model validation.
• Developed two models: one linking T to β, and another linking β to RH and TD.

Main Results:

• Obtained specific scaling (x) and decaying (c) parameters for different wavelengths (1550, 1310, 1064 nm).
• Validated the attenuation coefficient models against experimental outdoor and indoor data.
• Demonstrated model accuracy across significant temperature and humidity variations.

Conclusions:

• The proposed models accurately predict FSO channel attenuation in coastal and simulated indoor environments.
• Understanding environmental factors is key to enhancing the reliability of high-speed FSO communication systems.
• The validated models provide a valuable tool for FSO system design and deployment in challenging locations.