Abstract
The use of autonomous underwater vehicles (AUVs) is highly desirable for collecting data from seafloor sensor platforms within a close range. With the recent innovations in underwater wireless optical communication (UWOC) for deep-sea exploration, UWOC could be used in conjunction with AUVs for high-speed data uploads near the surface. In addition to absorption and scattering effects, UWOC undergoes scintillation induced by temperature- and salinity-related turbulence. However, studies on scintillation have been limited to emulating channels with uniform temperature and salinity gradients, rather than incorporating the effects of turbulent motion. Such turbulent flow results in an ocean mixing process that degrades optical communication. This study presents a turbulent model for investigating the impact of vehicle-motion-induced turbulence via the turbulent kinetic energy dissipation rate. This scintillation-related parameter offers a representation of the change in the refractive index due to the turbulent flow and ocean mixing. Monte Carlo simulations are carried out to validate the impact of turbulent flow on optical scintillation. In experimental measurements, the scintillation index (SI) and signal-to-noise ratio (SNR) are similar with (SI = 0.4824; SNR = 5.56) and without (SI = 0.4823; SNR = 5.87) water mixing under uniform temperature channels. By introducing a temperature gradient of 4 °C, SI (SNR) with and without turbulent flow changed to 0.5417 (5.06) and 0.8790 (3.40), respectively. The experimental results show a similar trend to the simulation results. Thus, turbulent flow was shown to significantly impact underwater optical communications.
Highlights
U NDERSEA exploration is highly attractive for both general research and military applications
This paper investigated the relationship between turbulentflow-induced mixing process and scintillation in underwater wireless optical communication (UWOC) because communication quality is crucia when underwater vehicles equipped with wireless optical systems are used to collect data from seafloor platforms
We considered the modelling of the influence of turbulent-flow induced mixing process on scintillation of underwater optical links
Summary
U NDERSEA exploration is highly attractive for both general research and military applications. Color versions of one or more of the figures in this paper are available online at http://ieeexplore.ieee.org. Retrieving sensor data is rarely achieved due to limited bandwidth and interference of the acoustic channel To this end, the data mule method, shown, utilizes autonomous underwater vehicles (AUVs) to collect data from seafloor platforms using a close-range wireless optical link before returning to surface for data upload. This research suggests that channel characterization in deep water is profoundly influenced by the emergence of underwater vehicle motion, accompanied by an increase in the TKE dissipation rate and ocean mixing. Turbulent flow induced by AUV affects optical links The results of this investigation will expand the applications of underwater vehicles and UWOC in deep-sea exploration.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
