UNCLASSIFIED 



SECURITY CLASSIFICATION OF THIS PAGE (When Data Entered) 



REPORT DOCUMENTATION PAGE 



READ INSTRUCTIONS 

 BEFORE COMPLETING FORM 



1. REPORT NUMBER 



NOSC Technical Report 393 (TR 393) 



2, GOVT ACCESSION NO 



3. RECIPIENT'S CATALOG NUMBER 



4. TITLE (and Subtitle) 



UNDERWATER SOUND PROPAGATION-LOSS PROGRAM 



Computation by normal modes for layered oceans and sediments 



5. TYPE OF REPORT & PERIOD COVERED 



Final Report for Period 

 1976-1978 



6. PERFORMING ORG. REPORT NUMBER 



7. AUTHORfs; 



DF Gordon 



8. CONTRACT OR GRANT NUMBERfsJ 



9. PERFORMING ORGANIZATION NAME AND ADDRESS 



Naval Ocean Systems Center 

 San Diego CA 92152 



10. PROGRAM ELEMENT. PROJECT, TASK 

 AREA a WORK UNIT NUMBERS 



NSEA 06H1 



SF52-552-602 



724-SUlO 



n. CONTROLLING OFFICE NAME AND ADDRESS 



Naval Sea Systems Command (NSEA 63R-23) 

 Washington DC 20362 



12. REPORT DATE 



17 May 1979 



13. NUMBER OF PAGES 

 100 



14. MONITORING AGENCY NAME & ADDRESSr" d'«efenf from Controltlne Olllce) 



15. SECURITY CLASS, (ol this report) 



Unclassified 



16. DISTRIBUTION STATEMENT (of this Report) 



Approved for public release; distribution unlimited 



17. DISTRIBUTION STATEMENT (ol the abstract entered In Block 20, If different from Report) 



18. SUPPLEMENTARY NOTES 



19. KEY WORDS (Continue on reverse aide If neceasery and Identify by block nimiber) 



Ducts Computer programs 



Propagation Numerical analysis 



Acoustics Continued fractions 



Layers Iterations 



20. ABSTRACT (Continue on reverae aide It neceaaery and Identity by block number) 



A normal-mode program for a sound-speed profile of an arbitrary number of layers has been constructed. 

 It has been used extensively and successfully for 12 years to compute sound propagation in idealized underwater 

 acoustic ducts. Documentation is contained for those who wish to use or modify this program. The FORTRAN 

 statements are given for both the normal-mode and a mode-follower program. The numerical analysis necessary 

 for computing modified Hankel functions of order 1/3 is given. The analysis includes a continued fraction 

 technique. 



EDITION OF 1 NOV 65 IS OBSOLETE 



S/N 0102-LF-014-6601 



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