Research On The Method Of Single Scattering Approximation In Parabolic Equation

The oceans surrounding our motherland are mostly shallow water, and have multi-layeredocean bottom. So to construct sound field models of low frequency sound wave in ocean withmulti-layered sea bottom is of great significance. Based on the elastic parabolic equation theory, thesingle scattering approximation method is used to deal with the irregular elastic-elastic boundaryconditions in this paper, and combined with the coordinate mapping method, the propagation modelof low frequency sound field in a layered elastic bottom is given, and the distribution of theunderwater displacement field is also shown.Different ocean conditions with various environmental parameters are treated by theconstructed model in this paper, and the results are compared with those given by existing maturesound field prediction models. It is shown that the single scattering approximation method has goodvalidity and accuracy in dealing with slope elastic-elastic boundary conditions; compared to theenergy conservation method, it is shown that the single scattering approximation method can notonly handle the energy coupling problem between the compressive wave and the shear wave, butalso has broader applications than the energy conservation method.This paper focuses on the discussion of the sound field distribution law in the environmentwith layered elastic ocean bottom and low-frequency condition. The distribution of low frequencyunderwater sound fields are simulated for diverse bottom parameters, and underwater displacementfields are also given for some cases; the effects on sound field distribution induced by differentsource depths, different sound frequency, and different bottom slopes have been researched.