@inproceedings{dbfefa33440540b6a704928821a0f92b,
title = "A controlled laboratory environment to study EO signal degradation due to underwater turbulence",
abstract = "Temperature microstructure in the ocean can lead to localized changes in the index of refraction and can distort underwater electro-optical (EO) signal transmission. A similar phenomenon is well-known from atmospheric optics and generally referred to as 'optical turbulence'. Though turbulent fluctuations in the ocean distort EO signal transmission and can impact various underwater applications, from diver visibility to active and passive remote sensing, there have been few studies investigating the subject. To provide a test bed for the study of impacts from turbulent flows on underwater EO signal transmission, and to examine and mitigate turbulence effects, we set up a laboratory turbulence environment allowing the variation of turbulence intensity. Convective turbulence is generated in a large Rayleigh- B{\'e}nard tank and the turbulent flow is quantified using high-resolution Acoustic Doppler Velocimeter profilers and fast thermistor probes. The turbulence measurements are complemented by computational fluid dynamics simulations of convective turbulence emulating the tank environment. These numerical simulations supplement the sparse laboratory measurements. The numerical data compared well to the laboratory data and both conformed to the Kolmogorov spectrum of turbulence and the Batchelor spectrum of temperature fluctuations. The controlled turbulence environment can be used to assess optical image degradation in the tank in relation to turbulence intensity, as well as to apply adaptive optics techniques. This innovative approach that combines optical techniques, turbulence measurements and numerical simulations can help understand how to mitigate the effects of turbulence impacts on underwater optical signal transmission, as well as advance optical techniques to probe oceanic processes.",
keywords = "Optical turbulence, Rayleigh-B{\'e}nard tank, computational fluid dynamics, numerical simulation, oceanic optics, temperature measurements, turbulence measurements",
author = "Silvia Matt and Weilin Hou and Wesley Goode and Guigen Liu and Ming Han and Andrey Kanaev and Sergio Restaino",
note = "Publisher Copyright: {\textcopyright} 2015 SPIE.; Ocean Sensing and Monitoring VII ; Conference date: 21-04-2015 Through 22-04-2015",
year = "2015",
doi = "10.1117/12.2177028",
language = "English (US)",
series = "Proceedings of SPIE - The International Society for Optical Engineering",
publisher = "SPIE",
editor = "Arnone, {Robert A.} and Hou, {Weilin W.}",
booktitle = "Ocean Sensing and Monitoring VII",
}