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CONTENTS 



I. INTRODUCTION . 1 



II. INSTRUMENTATION AND RECORDING PROCEDURES 



A. Instrumentation .................. 2 



B . Recording Procedure 6 



III . THEORY AND METHOD OF POWER SPECTRUM ANALYSIS 



A. Spectrum Analysis 6 



B . Digital Estimation of Power Spectra 12 



C. Analog Estimation of Power Spectra ............... 16 



D. Some Considerations in Estimating Spectra 



1. Resolution and Statistical Stability ............. 21 



2. Aliasing 21 



3. Comparison of Spectral Estimates . 22 



IV. POWER SPECTRA OF SURFACE WAVE, SUBMARINE, AND FLUID 

 MOTIONS 



A. General ........................... 22 



B . Surface Wave Height Spectra 25 



C. Roll Angle Spectra 25 



D. Transverse Relative Flow Velocity Spectra . "26 



E . Longitudinal Relative. Flow Velocity Spectra 27 



V. SUMMARY OF RESULTS 38 



VI. CONCLUSIONS 39 



VII. FUTURE TESTS AND ANALYSIS PLANS ............... 43 



VIII. ACKNOWLEDGEMENTS ...................... 43 



REFERENCES ........................... 45 



APPENDIX A. Surface Wave Height Data Obtained by The Sonic 



Surface Scanner 47 



APPENDIX B . Power Spectral Estimates of In Situ Pressure Fluctuations . 55 



