The Effects of Sloping Bottoms on the Vertical Correlation

Abstract

Using the parabolic equation code RAM, the sound field vertical correlations are studied as functions of vertical spans and ranges in sloping bottom environments. The wedge mode theory is used to explain the numerical results. It is shown that there is significant difference of the sound field vertical correlation between the upslope propagation and the downslope propagation. In comparison to the vertical correlation in flat bottom environments, downslope propagation increases the vertical coherence and upslope propagation decreases the vertical coherence. An oscillating phenomenon of the vertical correlations caused by the interference between effective modes is observed. For upslope propagation and downslope propagation, the radius of the oscillation decrease or increase, respectively.