TAPPERT: SELECTED APPLICATIONS OF THE PARABOLIC-EQUATION METHOD IN 

 UNDERWATER ACOUSTICS 



ADVANTAGES 



1. RANGE- DEPENDENT VELOCITY PROFILES INCLUDED 



2. RANGE- AND DEPTH-DEPENDENT LOSSES INCLUDED 



3. VARIABLE BATHYMETRY INCLUDED 



4. EASY TO SOLVE NUMERICALLY BY MARCHING IN RANGE 



DISADVANTAGES 



1. STEEP SLOPES (LARGE ANGLES) CAUSE INACCURACIES 



2. DISCONTINUITIES OF VELOCITY, DENSITY, AND VOLUME LOSS NEED TO 

 BE SMOOTHED 



3. AZIMUTHAL COUPLING NEGLECTED. 



Figure 5. ADVANTAGES AND DISADVANTAGES OF THE 

 PARABOLIC-EQUATION METHOD 



166 



