Ocean Wave Spectra and Shtp Appltcattons 
The angular resolution illustrated previously can be improved 
if one applies a weighting function to the Fourier coefficients, The 
choice of the weighting function depends on one's taste, as has been 
discussed by Longuet-Higgins 
The separation D was 2.5 feet in the present experiment. 
This separation can be adjusted to improve the long-wave angular 
resolution. The choice of the D depends on the wave frequency range 
in which one is interested. If one is only interested in the long waves 
then one can chose a suitably large D such that—“-D <7 for all 
frequencies in which one is interested. But in this case, the total 
array length will certainly be increased, and the increase in the array 
length can complicate the operations of the detectors. This has to be 
considered in the choice of an optimum D. By moving the probes 
opposite to the direction of the waves, one can also improve the an- 
gular resolution significantly[" | . It is applicable in an open sea 
where the waves are considerably homogenious over a large area, It 
may not be suitable for a model basin unless the basin is large and 
the waves are very homogenious with respect to space. 
The length of the wave records used for the above irregular 
wave calculations are approximately one minute long. The accuracy 
might have been improved if longer wave records had been used. 
ACKNOW LEDGMENTS 
The author is indebt to Dr. Wm. E. Cummins for his sugges- 
tion of the subject and the guidance given during the course of the 
work. Also, the author wishes to thank Mr. Daniel Huminik for his 
assistance with the experiments and many others who helped on the 
manuscript. 
REFERENCES 
[1] PIERSON, J.W. and MOSKOWITZ, L., ''A Proposed Spectral 
Form for Fully Developed Wind Seas Based on the Similarity 
Theory of S.S. Kitaigorodskii", J. Geophys. Res., Vol. 69, 
No, 24, 1964. 
[2] BRETSCHNEIDER, "Wave Variability and Wave Spectra for 
Wave Generated Gravity Waves", Technical Memorandum, 
No. 118, Corps of Engineers, Department of the Army, 1959. 
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