Signal structure outside the underwater sound channel: Wave effects

Potentialities of ray and wave theories are investigated in the context of estimating the duration of broadband signals under the condition that the correspondent points are located outside an underwater sound channel with prominent boundaries formed by high vertical gradients of sound velocity las it is the case in the northwestern Pacific). It is shown that the ray theory may cause considerable errors (up to 0.45 s at a distance of 100 km), while the wave theory appropriately describes all features of measured signals.