/o 



^^.^' '"'■'sj — —~ 



^ 1 





^^^^"' 



■^■^^^VT^:;^^ ^ . LANDS END 



80 



\. NORTH SEA 

 \ STRAIT of JUAN de FUCA 





90 



WINTER PROFILES 

 50 km RANGE 

 25 m SOURCE 



/ ^ EAST OF SINGAPORE 



100 



1 111 



1 1 1 1 1 1 1 1 1 



300 500 700 



FREQUENCY, Hz 



Figure 4.20. Comparison of propagation loss for optimum receiver deptli vs frequency results 

 for four sites and the 50 km range; source depth 25 m (winter profiles). 



^ 100 



110 — 



120 — 



130 





^~~^ 





' ^ ^ ^ ^ NORTH SEA 



^^-- 



^_/____^>^ 





\ STRAIT of 

 JUAN de FUCA 



lANDS END >r^ 



^ \ 



\ 



\ 







EAST of SINGAPORE \^ / 





SUMMER PROFILES 



^\^^X^ 





50 km RANGE 



z' 





25 m SOURCE 



1 



/ ^ 



1 1 1 1 1 1 /l 1 II 1 



100 



300 500 



FREQUENCY, Hz 



700 



1000 



4000 



Figure 4.21. Comparison of propagation loss for optimum receiver depth vs frequency results 

 for four sites and the 50 km range; source depth 25 m (summer profiles). 



56 



