TABLE OF CONTENTS (Continued) 



D. Program Operation Notes . . „ 50 



1 . Introduction 50 



2. Input and Screening of Data 52 



3. Conversion from Voltage to Pressure Signals. ... 52 

 k. Instrument Tilt Approximation 53 



5. Tide Calculation 55 



6. Development of Curvature Terms 56 



7. Significance of the Signals in Linear Theory ... 56 



8. FFT and Conversion to Water Surface Terms 5? 



9. Failure of the Absolute Channel 59 



10. Failure of 3 Differential Channels 62 



11. Effective Period 63 



12. The Directional Fourier Coefficients 63 



13. Block -averaging 64 



14. Frequency Bands of Greatest Energy ........ 65 



E. DPG Simulation and Error 66 



CHAPTER V: LABORATORY DEVELOPMENT, CALIBRATION, AND 



TESTING OF THE INSTRUMENT 76 



A. Introduction 76 



B. Fluid Back-Filling the Sensors 



(System Modifics-tions) 76 



C. Bench Calibration. ...... °5 



1. The Calibration Technique 85 



2. Testing for Air Bubbles 88 



3. Static Calibration Results 90 



4. Power Supply Sensitivity 92 



5. Transducer Drift ^ . . . . 92 



6. Temperature Effect 93 



7. Absolute Sensor Back-Fill Pressure 9^ 



D. CERC Wave Tank Tests 9^ 



1 . Introduction 9^ 



2. Installation 95 



3. Tests and Results 97 



E. The Second DPG Prototype IO5 



CHAPTER VI: FIELD INSTALLATION AND EVALUATION 107 



A. Installation at the FRF IO7 



B. Instrument Orientation 113 



C. First Month's Inspection 118 



