3-D acoustic scattering from 2-D rough surfaces using a parabolic equation model
Helmy, Ahmed M.
Smith, Kevin B.
MetadataShow full item record
Rough surface scattering plays a crucial role in the statistics of acoustic propagation signals, especially at mid-frequencies and higher (e.g., acoustic communications systems). For many years, the effects of rough surface scattering were computed using simple models that were applied in two dimensions (2-D) only. A prescribed method of computing 2-D rough surface scattering directly in a parabolic equation model based on the Split-Step Fourier algorithm was introduced by Tappert and Nghiem-Phu in the mid-1980s. This method has been successfully implemented in various 2-D parabolic equation models, including the Monterey Miami Parabolic Equation model. However, some scientific research of more formal scattering predictions have suggested that out-of-plane, three dimensional (3-D) scattering may lead to significant disparities in the scattered field statistics. Introducing a hybrid implementation for the scattering effect in the field transformation equations using a tri-diagonal solution with the Pad approximant to obtain a system of equations for azimuthal corrections will support predictions of the effect of surface scattering on 3-D propagation, which is critical in evaluating the variability in underwater acoustic propagation. Results of the 3-D scattering calculations obtained are compared with the output of basic 2-D interface perturbations utilizing the standard 2-D approach.
Approved for public release; distribution is unlimited.
Showing items related by title, author, creator and subject.
Predicting the effects of sea surface scatter on broad band pulse propagation with an ocean acoustic parabolic equation model Ead, Richard M. (Monterey, California. Naval Postgraduate School, 2004-06);Littoral waters when compared to the open ocean create an environment of greater reverberation with acoustic energy scattering from the sea surface, bottom, topographic features, and regions that lack homogeneity within ...
Higher-order boundary and rough surface treatment of the MMPE model in the evaluation of scattering effects Tan, Yi Ling; Leigh, Gonzalo H. Veran (Monterey, California: Naval Postgraduate School, 2018-03);This research aims to improve the Monterey-Miami Parabolic Equation model (MMPE) by incorporating a higher-order hybrid boundary treatment and Fred D. Tappert’s field transformational model to add surface scattering to the ...
Li, Lit Siew. (Monterey, California. Naval Postgraduate School, 2000-09);A reverberation model based on the parabolic approximation is developed that includes sediment interface and volume perturbations. A multiple forward/single backscatter approximation is made, and the structure of the ...