CONTENTS 



Page 

 CONVERSION FACTORS, U.S. CUSTOMARY TO METRIC (SI) .... 6 



I INTRODUCTION 7 



1. The System 10 



2. Data Collection 14 



II FIELD DATA ANALYSIS 14 



1. Computation of Wave Direction 18 



2. Simulated Data Analysis 20 



3. Identification of Wave Trains from the High- 



Resolution Spectrum 28 



4. Spectra and Direction of Wave Propagation for 



Field Data 28 



5. Conclusions 31 



LITEPvATURE CITED 32 



APPENDIX 



A DERIVATION OF THE EXPRESSION FOR WAVE DIRECTION 35 



B COMPUTER OUTPUT FOR CROSS-SPECTRA COMPUTATIONS 36 



C FOURIER COEFFICIENTS FOR A MIXTURE OF THREE SINUSOIDS . . 48 



D SPECTRA PLOTS MD COMPUTER OUTPUT FOR SIMULATED 



OBSERVATIONS 54 



E HIGH-RESOLUTION SPECTRA FOR FIELD WAVE DATA 79 



TABLES 



1 Percent of observations where the largest departure of the 



standard deviations from the mean in the observations was 



as indicated (871 observations in 1970) 16 



2 Directional results with 0.01 hertz resolution for two 



observations 21 



3 Characteristics of simulated wave trains 24 



4 Computational results at closest spectral frequencies for 



simulated wave trains 26 



5 Directional results of high-resolution spectral computations 



for 8-second wave 27 



6 Average spread in computed directions for 280 wave trains 



identified in the high-resolution spectra of 44 field wave 

 observations 30 



4 



