APPENDIX A 



Insonif ication of the ocean is strongly dependent on the structure 

 of the velocity profile. Figures A-l, A-2 , A-3 show three velocity 

 profiles (VP-1, VP-2, VP-3) and associated ray plots for a source at 

 15 feet below the surface. A semilogarithmic depth scale was used on 

 the ray plots to emphasize the shallow depths. Rays were terminated 

 after a maximum of nine surface bounces. VP-1 has an initial positive 

 gradient, the velocity is 5022.0 ft/sec at the surface, and 5024.5 ft/sec 

 at 100 feet. VP-3 has an initial gradient that is the negative reflection 

 of VP-1, i.e., it has a velocity of 5026.0 ft/sec at the surface and 

 5024.5 ft/sec at 100 feet. VP-2 has an iso-velocity layer down to 

 approximately 400 feet with a velocity of 5024.5 ft/sec. 



Figure A-4, A-5 shows ray plots of convergence zones. The first 

 and second convergence zone are shown for VP-1; the first convergence 

 zone is shown for VP-3. Rays were allowed a maximum of three surface 

 bounces and two bottom bounces before termination. The structure of the 

 layer depth is relatively insignificant when considering zone operation. 



A-l 



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