An Examination Of Higher-Order Treatments Of Boundary Condition In Split-Step Fourier Parabolic Equa - Video Portal
An Examination Of Higher-Order Treatments Of Boundary Condition In Split-Step Fourier Parabolic Equa
LTJG, Savas ERDIM, Turkish Navy
Abstract: The Monterey Miami Parabolic Equation (MMPE) model is used to predict underwater sound propagation in deep and shallow water environments. Previous studies have shown that MMPE is very accurate in shallow water when there is no density discontinuity between the water column and the sediment, but less effective in the presence of realistic density discontinuities due to phase errors that accumulate after a few km. In this thesis, the standard density smoothing approach and an alternative hybrid split-step/finite difference method are compared. The goal is to decrease the phase errors and increase the model’s long range accuracy. Different depth meshes and range step sizes are implemented in the algorithm to find the optimum results for both approaches. It will be shown that the density smoothing method provides better results with small range step sizes while the hybrid method is more effective using longer range step sizes. More detailed examination of the density smoothing approach suggests good accuracy for a few km, while hybrid method provides almost excellent agreement with a benchmark solution at longer ranges.