Near ground horizontal high resolution Cn2 profiling from Shack-Hartmann slopeand scintillation data

Area of Science:

• Optics
• Atmospheric Science
• Metrology

Background:

• Optical turbulence significantly impacts atmospheric sensing and communication systems.
• Accurate measurement of near-ground refractive index structure constant (Cn2) profiles is crucial for understanding and mitigating turbulence effects.
• Existing metrology techniques have limitations in profiling Cn2 over extended near-ground paths.

Purpose of the Study:

• To provide the first comprehensive description of the Coupled Slope and Scintillation Detection and Ranging (CO-SLIDAR) method for near-ground optical turbulence metrology.
• To detail the physics principles and unsupervised Cn2 profile reconstruction strategy.
• To present an error bar estimation for the reconstructed Cn2 values.

Main Methods:

• Utilizes a mid-IR Shack-Hartmann wavefront sensor coupled to a 0.35 m telescope.
• Employs a CO-SLIDAR technique that exploits both phase and scintillation measurements from two cooperative sources.
• Applies an unsupervised strategy for Cn2 profile reconstruction.

Main Results:

• Successfully demonstrated the CO-SLIDAR method in a heterogeneous rural landscape.
• Achieved Cn2 profiles with a sampling pitch of approximately 220 m over a 2.7 km line of sight.
• Presented retrieved Cn2 profiles and discussed their spatial and temporal variability.

Conclusions:

• CO-SLIDAR is a highly promising technique for metrology of near-ground Cn2 profiles.
• The method allows profiling over the full line of sight between the instrument and sources.
• The study validates the CO-SLIDAR approach with real-world experimental data, showing its capability in diverse environments.