Demonstrating 24-hour continuous vertical monitoring of atmospheric optical turbulence

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

Abstract

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.

Citation

Griffiths, R., Osborn, J., Farley, O., Butterley, T., Townson, M. J., & Wilson, R. (2023). Demonstrating 24-hour continuous vertical monitoring of atmospheric optical turbulence. Optics Express, 31(4), 6730-6740. https://doi.org/10.1364/oe.479544

• Journal Article Type: Article
• Acceptance Date: Jan 15, 2023
• Online Publication Date: Feb 9, 2023
• Publication Date: 2023
• Deposit Date: Feb 14, 2023
• Publicly Available Date: Feb 20, 2023
• Journal: Optics Express
• Electronic ISSN: 1094-4087
• Publisher: Optica
• Peer Reviewed: Peer Reviewed
• Volume: 31
• Issue: 4
• Pages: 6730-6740
• DOI: https://doi.org/10.1364/oe.479544
• Public URL: https://durham-repository.worktribe.com/output/1183088
• Related Public URLs: https://arxiv.org/abs/2301.07612