UNCLASSIFIED 
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REPORT DOCUMENTATION PAGE BEFORE COMPLETING FORM 
1. REPORT NUMBER 2. GOVT ACCESSION NO 3. RECIPIENT'S CATALOG NUMBER 
CETA 80-5 
4. TITLE (and Subtitle) 5. TYPE OF REPORT & PERIOD COVERED 
Coastal Engineering 
Technical Aid 
PERFORMING ORG. REPORT NUMBER 
INTERPRETATION OF WAVE ENERGY SPECTRA 
6. 
7. AUTHOR(s) 8. CONTRACT OR GRANT NUMBER(s) 
Edward F. Thompson 
10. PROGRAM ELEM 
AREA & WORK U 
A31463 
NT, PROJECT, TASK 
IT NUMBERS 
9. PERFORMING ORGANIZATION NAME AND ADDRESS 
Department of the Army 
Coastal Engineering Research Center (CERRE-CO) 
Kingman Building, Fort Belvoir, Virginia 22060 
E 
N 
12. REPORT DATE 
July 1980 
13. NUMBER OF PAGES 
21 
15. SECURITY CLASS. (of thi report) 
UNCLASSIFIED 
11. CONTROLLING OFFICE NAME AND ADDRESS 
Department of the Army 
Coastal Engineering Research Center 
Kingman Building, Fort Belvoir, Virginia 22060 
14. MONITORING AGENCY NAME & ADDRESS(if different from Controlling Office) 
DECL ASSIFICATION/ DOWNGRADING 
SCHEDULE 
15a, 
16. DISTRIBUTION STATEMENT (of this Report) 
Approved for public release; distribution unlimited. 
17. DISTRIBUTION STATEMENT (of the abetract entered in Block 20, if different from Report) 
18. SUPPLEMENTARY NOTES 
19. KEY WORDS (Continue on reverse side if necessary and identify by block number) 
Spectral analysis Wave gages Wave hindcast 
Wave energy spectra Wave height Wave period 
ABSTRACT (Continue em reverse side if mecessary and identify by block number) 
Guidelines for interpreting nondirectional wave energy spectra are presented. 
A simple method is given for using the spectrum to estimate a significant height 
and period for each major wave train in most sea states. The method allows a 
more detailed and accurate description of ocean surface waves than that given by 
a single significant height and period, yet it eliminates much of the formidable 
detail of a full spectrum. An example problem illustrating application of the 
method is presented. Spectral analysis and display techniques, and the natural 
variation of spectra in space and time, are discussed. 
20. 
FORM 
DD 1 JAN 73 1473 EDITION OF ? NOV 65 IS OBSOLETE UNCLASSIFIED 
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