Beam-displacement ray-mode theory of sound propagation in shallow water

A normal mode method for propagation modeling in common horizontally strati fied shallow water, which is called beam-displacement ray-mode (BDRM) theor y, is introduced. The peculiarity of this method is that the boundary effec ts on the sound field can be expressed by the equivalent boundary reflectio n coefficient, so BDRM theory can be extended to elastic bottom easily. The oretical calculations of shallow-water sound field show that BDRM has high accuracy and fast speed. The pulse propagation in shallow water is also cal culated by BDRM, and the calculated waveforms are in good agreement with th e measured waveforms.