TABLE OF CONTENTS 



ACKNOWLEDGEMENTS iv 



LIST OF FIGUEES AND TABLES viii 



LIST OF SYMBOLS 



CHAPTER I: INTRODUCTION 



CHAPTER II: CONCEPTS OF A DIFFERENTIAL PRESSURE GAUGE SYSTEM. 



A . DPG Response to Surface Waves . = ' 



B. The Differential Pressure Gauge Directional 



Wave Monitor - ^2 



C. Selection of Transducers and Gage Length J-5 



CHAPTER III: DPG HARDWARE 20 



A. Instrument, Service Box, and Cradle 20 



1 . Introduction 20 



The Instrument Fuselage and Arms 24 



The Transducers 25 



The Isolation Sensor Diaphragms 26 



The Water-Tlght Instrumentation Cylinder 32 



The Cable and Service Box 32 



The Electrical System 33 



The Instrument Cradle 35 



Blofoullng and Corrosion Protection 36 



B . rata Retrieval* 37 



C. Some Considerations of the Hardware Design 37 



1. Fuselage Isolation Diaphragms 37 



2. Height of Sensors 38 



D. Cost 39 



CHAPTER IV: DPG SOFTWARE ^0 



A. Introduction ^'^ 



B . Theory of Analysis ^ ^1 



C. Correction for Centering of Measurements ^7 



