UNCLASSIFIED 



SECURITY CLASSIFICATION OF THIS PAGE (When Data Entered) 



REPORT DOCUMENTATION PAGE 



READ INSTRUCTIONS 

 BEFORE COMPLETING FORM 



1. REPORT NUMBER 



NORDA REPORT #4 



2. GOVT ACCESSION NO 



3. RECIPIENT'S CATALOG NUMBER 



4. TITLE (and Subtitle) 



A NEW MODEL OF RESONANT ACOUSTIC SCATTERING 

 BY SWIMBLADDER-BEARING FISH 



5. TYPE OF REPORT & PERIOD COVERED 

 FINAL 



6. PERFORMING ORG. REPORT NUMBER 



7. AUTHORfsJ 



8. CONTRACT OR GRANT NUMBERfsJ 



RICHARD H. LOVE 



9. PERFORMING ORGANIZATION NAME AND ADDRESS 



NAVAL OCEAN RESEARCH AND DEVELOPMENT ACTIVITY 

 NSTL STATION, MISSISSIPPI 39529 



10. PROGRAM ELEMENT, PROJECT, TASK 

 AREA 4 WORK UNIT NUMBERS 



62759N/2552/301 



11. CONTROLLING OFFICE NAME AND ADDRESS 



NAVAL OCEAN RESEARCH AND DEVELOPMENT ACTIVITY 

 NSTL STATION, MISSISSIPPI 39529 



12. REPORT DATE 



AUGUST 1977 



13. NUMBER OF PAGES 



14. MONITORING AGENCY NAME & ADDRESSfyf different from Controlling Office) 



IS. SECURITY CLASS, (of thla report) 



UNCLASSIFIED 



15a. DECLASSIFI CATION/ DOWN GRADING 

 SCHEDULE 



16. DISTRIBUTION STATEMENT (of this Report) 



APPROVED FOR PUBLIC RELEASE: DISTRIBUTION UNLIMITED 



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



18. SUPPLEMENTARY NOTES 



19. KEY WORDS (Continue on reverse side It necessary and Identify by block number) 



VOLUME SCATTERING, BIOLOGICAL SCATTERING, ACOUSTIC MODELS, 

 BIOACOUSTIC MODELS, REVERBERATION 



20. ABSTRACT (Continue on reverse side If necessary and Identity by block number) 



The primary -cause of oceanic volume reverberation is resonant scattering by 

 the swimbladders of small fish. A new model of a swimbladder-bearing fish has 

 been developed in order to provide improved predictions of the resonant 

 frequency and acoustic cross section of such a fish. Development of a new 

 model was undertaken because comparisons of the predictions of previous models 

 with experimental data show these models to be inadequate. Primarily, the 

 experimental data indicate that damping in fish tissue is consistently greater 



DD t'j 



FORM 14/3 



EDITION OF 1 NOV 65 IS OBSOLETE 



S/N 0102-014- 6601 I 



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