TM No. 377 



CONTENTS 



Page 



CHAPTER I . INTRODUCTION 1 



Historical Background 3 



In Situ Measurements ■ k 



Laboratory Experiments 6 



Studies of Atmospheric Turbulence 8 



Spectral Analys is 9 



Formulation of the Problem 9 



Categories of Wave Motion 10 



Parameters to be Measured 11 



Aims of Wave Motion Study 13 



CHAPTER II . DEVELOPMENT OF THE WAVE METER Ik 



Choice of an Instrument 18 



Orthogonally Mounted Ducted Meter - OMDUM I. 21 



Design Characteristics , 21 



Dynamic Characteristics and Calibration 23 



Modified Orthogonally Mounted Ducted Meter ( OMDUM II) .... 25 



Design Characteristics 25 



Calibration and Response Studies 25 



Small-Scale Ducted Meters (OMDUM III and LIMDUM I ) 31A 



Design Characteristics 32 



Calibration. 33 



Towing Tank and Associated Equipment 33 



Calibration of Individual Ducted Meters . . . 35 



Instrument Response to Off -Angle Flow 36 



Calibration of the OMDUM III System. 37 



Error Correction for OMDUM III 38 



Estimation of Response Time 39 



Amplitude of Induced Voltage as an Analog of Flow kl 



Summary of Dynamic Characteristics of the Wave Meters k2 



CHAPTER III . DATA PROCESSING AND ANALYSIS . kk 



Processing of Wave Particle Velocity Observations kk 



Rax/ Data Preparat ion kk 



Analog Velocity Conversion Program. U5 



Linear Interpolation Program. k^ 



Correction Program for OMDUM III Data k6 



Data from the Free Surface Elevation Wave Staff System k6 



Data from Horizontal Current Observations ^7 



Statistical Analysis of Processed Data kj 



Basic Assumptions for Time Series Analysis k9 



Planning Data Sampling for Spectral Measurements 50 



Classical Equations and Definitions 5^- 



Single Time Series Analysis « 5^ 



Paired Time Series Analysis 56 



VI 



