Characterizing the propagation path in moderate to strong optical turbulence

Area of Science:

• Atmospheric optics and turbulence research.
• Electromagnetic wave propagation in turbulent media.

Background:

• Atmospheric turbulence significantly impacts optical and radio wave propagation.
• Accurate measurement of atmospheric parameters like the refractive index structure constant (C2n) is crucial for system performance.
• Previous methods for inferring turbulence parameters from optical measurements have varying degrees of accuracy.

Purpose of the Study:

• To compare an inferred turbulence parameter scheme with a commercial scintillometer.
• To validate a numerical scheme for inferring atmospheric parameters (C2n, l0, L0) from optical scintillation data.
• To assess the performance of Gaussian beam propagation experiments for turbulence characterization.

Main Methods:

• Conducted a joint atmospheric propagation experiment using a 1500 m horizontal path.
• Propagated a Gaussian beam and measured optical scintillation at three receiver diameters (1, 5, 13 mm).
• Employed scintillation theory and a numerical scheme to infer C2n, inner scale (l0), and outer scale (L0); simultaneously used a commercial scintillometer for C2n measurement.

Main Results:

• Both the inferred scheme and the commercial scintillometer showed similar trends in C2n values.
• The inferred scheme consistently produced slightly lower C2n values than the commercial instrument.
• Optical measurements provided data for inferring turbulence parameters, including inner and outer scales.

Conclusions:

• The numerical scheme based on optical scintillation is a viable method for estimating atmospheric turbulence parameters.
• The inferred scheme shows good agreement with commercial instruments, indicating its potential for atmospheric studies.
• Further investigation may be needed to understand the systematic difference in C2n values between the two methods.