Non-Markov character of the phase fluctuations for sound propagation over relatively small ranges in the turbulent atmosphere

2019 ◽  
Vol 145 (6) ◽  
pp. 3359-3369
Author(s):  
Vladimir E. Ostashev ◽  
D. Keith Wilson
Keyword(s):  
Turbulent Atmosphere ◽  
Sound Propagation ◽  
Phase Fluctuations

Cooled Stacked-Actuator Deformable Mirror for Compensation for Phase Fluctuations in a Turbulent Atmosphere

2020 ◽  
Vol 33 (6) ◽  
pp. 584-590
Author(s):  
V. V. Toporovsky ◽  
A. V. Kudryashov ◽  
V. V. Samarkin ◽  
A. L. Rukosuev ◽  
A. N. Nikitin ◽  
...  
Keyword(s):  
Turbulent Atmosphere ◽  
Deformable Mirror ◽  
Phase Fluctuations

Phase fluctuations when focusing light in a turbulent atmosphere

1983 ◽  
Vol 26 (12) ◽  
pp. 1096-1101 ◽  
Author(s):  
M. S. Belen'kii ◽  
A. P. Shelekhov
Keyword(s):  
Turbulent Atmosphere ◽  
Phase Fluctuations

Interferometric Study of Phase Fluctuations of a Laser Beam Through the Turbulent Atmosphere

1968 ◽  
Vol 7 (11) ◽  
pp. 2246 ◽  
Author(s):  
M. Bertolotti ◽  
M. Carnevale ◽  
L. Muzii ◽  
D. Sette
Keyword(s):  
Laser Beam ◽  
Turbulent Atmosphere ◽  
Phase Fluctuations ◽  
Interferometric Study

scholarly journals Vertical and slanted sound propagation in the near-ground atmosphere : amplitude and phase fluctuations

2021 ◽  
Author(s):  
Matthew Kamrath ◽  
Vladimir Ostashev ◽  
D. Wilson ◽  
Michael White ◽  
Carl Hart ◽  
...  
Keyword(s):  
Large Scale ◽  
Sound Propagation ◽  
Microphone Arrays ◽  
Small Scale ◽  
Sound Sources ◽  
Phase Fluctuations ◽  
Turbulent Eddies ◽  
Low Altitude ◽  
Detection And Localization ◽  
Large Eddies

Sound propagation along vertical and slanted paths through the near-ground atmosphere impacts detection and localization of low-altitude sound sources, such as small unmanned aerial vehicles, from ground-based microphone arrays. This article experimentally investigates the amplitude and phase fluctuations of acoustic signals propagating along such paths. The experiment involved nine microphones on three horizontal booms mounted at different heights to a 135-m meteorological tower at the National Wind Technology Center (Boulder, CO). A ground-based loudspeaker was placed at the base of the tower for vertical propagation or 56m from the base of the tower for slanted propagation. Phasor scatterplots qualitatively characterize the amplitude and phase fluctuations of the received signals during different meteorological regimes. The measurements are also compared to a theory describing the log-amplitude and phase variances based on the spectrum of shear and buoyancy driven turbulence near the ground. Generally, the theory correctly predicts the measured log-amplitude variances, which are affected primarily by small-scale, isotropic turbulent eddies. However, the theory overpredicts the measured phase variances, which are affected primarily by large-scale, anisotropic, buoyantly driven eddies. Ground blocking of these large eddies likely explains the overprediction.

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