Global atmospheric turbulence forecasting for free-space optical communications

The optical turbulence in the Earth's atmosphere is a major limitation to free-space optical communications. It is therefore critical that we are able to model and forecast realistic atmospheric optical turbulence conditions for site selection, instrument development, instrument performance validation and network switching. Here, we present global maps of optical turbulence strength and associated parameters (Fried parameter, isoplanatic angle, coherence time and Rytov variance), from a turbulence forecasting tool. These maps can be used by the community to understand the expected performance of free-space optical systems anywhere in the world, day and night. These maps also demonstrate that optical turbulence can be modelled and visualised in the same manner as other aspects of the Earth's weather system such as wind, rain or temperature, opening the door for more advanced turbulence forecasting functionality. We show global averages, examples of temporal sequences and more detailed analysis from some example sites.