An efficient method combined the Douglas operator scheme to split-step Pade approximation of higher-order parabolic equation

In this paper, three numerical techniques based on the PE method and results are presented for ocean acoustic propagation problems. First, the derivation of an efficient method combined the Douglas operator scheme to Parabolic Equation based on the Pade approximation is given for the shallow water model in frequency domain. Secondly, a new time-domain PE method based on the slow-varying envelope approximation is given for the analysis of forward wave propagation, diffraction and reflection and applied for short pulse propagation problems. Lastly, the acoustic characteristics of an underwater acoustic lens for a real-time image sonar system are studied by using 2D/3D PE method.