Abstract

Waves propagating through a medium having three-dimensional turbulence with inner scale have been simulated using the SDSC Cray supercomputer. Simulations of point source and plane wave initial conditions are substantially differeny, and these differences are amplified when an inner scale is introduced into the turbulent spectrum. The results are in reasonable agreement with the results of laser propagation over kilometer-length paths in the atmosphere. The intensity patterns of the waves emerging from a turbulent medium with large inner scale show striking networks of caustics. If the small-scale tail of the turbulence spectrum is present, the large-scale caustic networks are diffused and are less clear, but they are still present. The long tail of the probability density function at high intensity is precisely determined in the simulations, up to 50 times the mean intensity. Physical explanations for this long tail will be discussed. It will be suggested that simulating impulse response (pulse propagation), rather than single-frequency propagation, will elucidate some fundamental characteristics of waves through turbulent media.

© 1990 Optical Society of America