Demonstrating 24-hour continuous vertical monitoring of atmospheric optical turbulence

Ryan Griffiths*, James Osborn, Ollie Farley, Tim Butterley, Matthew J. Townson, Richard Wilson

*Corresponding author for this work

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16 Citations (Scopus)
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We report what is believed to be the first example of fully continuous, 24-hour vertical monitoring of atmospheric optical turbulence. This is achieved using a novel instrument, the 24-hour Shack-Hartmann Image Motion Monitor (24hSHIMM). Optical turbulence is a fundamental limitation for applications such as free-space optical communications, where it limits the achievable bandwidth, and ground-based optical astronomy, restricting the observational precision. Knowledge of the turbulence enables us to select the best sites, design optical instrumentation and optimise the operation of ground-based optical systems. The 24hSHIMM estimates the vertical optical turbulence coherence length, time, angle and Rytov variance from the measurement of a four-layer vertical turbulence profile and a wind speed profile retrieved from meteorological forecasts. To illustrate our advance we show the values of these parameters recorded during a 36-hour, continuous demonstration of the instrument. Due to its portability and ability to work in stronger turbulence, the 24hSHIMM can also operate in urban locations, providing the field with a truly continuous, versatile turbulence monitor for all but the most demanding of applications.
Original languageEnglish
Pages (from-to)6730-6740
Number of pages11
JournalOptics Express
Issue number4
Early online date9 Feb 2023
Publication statusPublished - 13 Feb 2023
Externally publishedYes

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