Prediction of atmospheric turbulence by means of WRF model for optical communications

Abstract

Free Space Optical (FSO) communication is an excellent tool for high-speed information transmission across a wide range of applications. It is now a key technology to overcome the rapidly increasing bandwidth limitations for space communications. However, FSO is directly affected by atmospheric propagation factors, such as meteorological conditions (cloud, fog, rain, etc.) and atmospheric turbulence conditions. A major challenge among these factors is atmospheric turbulence, which can lead to a phase distortion of the wavefront and to serious degradation of system performance. It is therefore crucial to overcome the effects of atmospheric turbulence in order to reliably monitor, assess the whole performance of the optical system and to fully exploit the potential of the FSO. Forecasts of meteorological and atmospheric turbulence conditions is of interest for optical link optimization because it can contribute to the efficient selection of the optical ground station network. It can also help to identify favorable time periods for laser optical links. In this study, numerical approach by Weather and Research Forecasting (WRF) model coupled with different turbulence models had been used. We compare the vertical profile of meteorological parameters (temperature, relative humidity, wind speed and wind direction) as well as the optical turbulence ( 2 ) conditions from the forecast model with the in-situ measurements, balloon-borne radiosoundings launched above Cerro Pachon Observatory in Chile. A new approach to estimate the outer scale ( 0 ) of turbulence is also presented and discussed.

Experimental Machine Learning Approach for Optical Turbulence and FSO Outage Performance Modeling

“…R for a spherical wave (10) From Equations ( 9) and (10) it is seen that shorter wavelengths experience smaller irradiance fluctuations. It is of significant importance to be able to model those fluctuations.…”

“…The performance of the link under turbulence, precipitation, dust and flying objects is studied with a focus on water particles effects. Rafalimanana et al used a numerical approach by weather and research forecasting (WRF) modeling coupled with different turbulence models in order to forecast the vertical profiles of meteorological parameters and C 2 n [10]. Finally, alternative FSO geometries studied to include satellite laser communications [11] and drone-to-ground FSO links [12].…”

Generation of kinetic energy of the pulsating component of the wind speed in the atmospheric boundary layer

“…WRF model is successfully used to describe optical turbulence. [17][18][19] The WRF model is a collaborative work of many scientific organizations led by the US National Center for Atmospheric Research (NCAR) and represents a whole family of numerical models that are successfully used both for operational weather forecasting and for research purposes. The results of numerical simulation make it possible to obtain physically substantiated meteorological fields of high spatial resolution, which is important from the point of view of determining and short-term forecasting of optical turbulence parameters.…”

The 24hSHIMM: a continuous day and night turbulence monitor for optical communications

“…They also enhance operation scheduling through proving both real-time information on site conditions and data for assimilation into turbulence forecasting models. 19,20 However, a key difference to astronomy is that FSOC and SST systems will need to work 24-hours a day in a wide variety of turbulence strengths and in locations with sub-optimal turbulence conditions such as cities. To support these emerging technologies, we have developed the 24-hour Shack-Hartmann Image Motion Monitor (24hSHIMM) 21 -the first truly continuous day and night turbulence monitor.…”