Perfectly correlated phase screen realization using sparse spectrum harmonic augmentation.

Area of Science:

• Physics
• Atmospheric Science
• Wave Propagation

Background:

• The split-step Fourier method is standard for simulating radiation propagation in turbulent atmospheres using 2D phase screens.
• Existing methods struggle to achieve isotropy of the structure function, particularly along the propagation axis.
• Limitations exist in achievable frequencies and time development with current approaches.

Purpose of the Study:

• To introduce the sparse spectrum harmonic augmentation method to overcome limitations in current wave propagation simulations.
• To address the lack of isotropy along the propagation axis in phase screens.
• To enable the inclusion of low frequencies, which contain significant energy, in simulations.

Main Methods:

• Development of the sparse spectrum harmonic augmentation method.
• Generation of transversely endless phase screens.
• Ensuring perfect correlation along the propagation axis.

Main Results:

• The new method produces phase screens that are transversely endless and perfectly correlated along the propagation axis.
• Achieves desired spectral content, including previously neglected low frequencies.
• Overcomes limitations in isotropy and frequency range inherent in existing methodologies.

Conclusions:

• The sparse spectrum harmonic augmentation method significantly improves the simulation of wave propagation in random media.
• This technique is applicable to diverse fields including atmospheric propagation, underwater acoustics, and ionospheric radio wave propagation.
• The method offers enhanced accuracy and broader applicability for modeling complex wave phenomena.