The sound field frequency-range interference patterns in deep water：theory and experiment

The sound field frequency-range interference patterns in deep water are discussed based on ray theory when the source and the receiver are near the sea surface. Approximate formulae of the sound field frequency-range interference patterns in the direct arrival zone and the shadow zone are provided. In the direct arrival zone, the sound intensity periodical structure is caused by the interference between the direct arrival wave and the surface-reflected wave, and the interference cycle is closely related with the arrival time difference between waves. In the shadow zone, the sound intensity periodical structure is caused by the interference among the bottom-reflected wave, the bottom-reflected-surface-reflected wave, the surface-reflected-bottom-reflected wave and the surface-reflected- bottom-reflected-surface-reflected wave, and the interference cycles are closely related with the depth of the source and the receiver. This method is verified by the numerical simulation and sea experiment data.