Chapter 13. EXAMPLES OF PRESSURE AND WAVE RECORD ANALYSES 
Introduction 
In this chapter, a detailed and highly informative analysis of 
a pressure record will be carried out according to the procedures 
devised by Tukey and Hamming [1949]. The pressure power spectrum 
will then be corrected for the effect of depth thus obtaining the 
power spectrum of the free surface. The 10% to 25% error of the sig- 
nificant height and period method will then be explained. Various 
features of the free surface will be deduced. 
The analyses of wave record correlograms carried out by Tukey 
and Hamming will be discussed and interpreted in the light of some 
of the papers published by Seiwell [1949, 1950]. A refutation of 
the conclusion that wave records have one or more "discrete" periods 
(or cyclic components) will be given by showing that such components 
have not been proved to exist and that the available evidence cor- 
rectly interpreted indicates the contrary. 
The design criteria for wave analyzers as described by Tukey 
and Hamming will be applied to known wave analyzers and their perform- 
ance will be interpreted in the light of these design criteria. 
A detailed analysis of a pressure record* 
The twenty-five minute pressure record which was sampled in Chap- 
ter 7 to see if it was Gaussian and which was taken on 18 December 
1951 starting at 2258 EST can be analyzed and studied in great detail 
* See also a paper to be published by Pierson and Marks [1952] in the 
A.G.U. Mr. Wilbur Marks has done all of the numerical work for this 
section and has written up the details of the procedures employed 
in the A.G.U. paper. 
lis 
