Estimating the time-evolving refractivity of a turbulent medium using optical beam measurements: a data assimilation...

Area of Science:

• Optical physics
• Wave propagation
• Atmospheric science

Background:

• Free-space optical communication signals degrade due to atmospheric turbulence.
• Characterizing spatial variations of turbulence is crucial for signal recovery but often limited.
• Existing methods lack detailed information on turbulence state and evolution.

Purpose of the Study:

• Investigate data assimilation for characterizing turbulent media.
• Improve signal recovery in free-space optical communication.
• Enhance understanding of spatial and temporal turbulence dynamics.

Main Methods:

• Utilized the paraxial wave equation in a computational setting.
• Employed the extended Kalman filter for data assimilation with intensity measurements.
• Modeled turbulent medium evolution as a stochastic process with limited Fourier wavelengths.

Main Results:

• Successfully recovered spatial and temporal variations of the turbulent medium in many scenarios.
• Demonstrated accurate characterization of turbulence state and evolution.
• Identified specific time windows with larger recovery errors.

Conclusions:

• Data assimilation effectively characterizes turbulent media for optical applications.
• Spatial variation information aids in signal and beam source recovery.
• Further research can refine recovery accuracy and address error sources.