Page 



PART VIII: PEAK DIRECTION AND SPREAD AT THE FREQUENCY LEVEL 88 



Peak Direction 88 



Directional Spread 91 



PART IX: SHAPES OF DIRECTIONAL DISTRIBUTIONS 95 



Data Reduction 95 



Resulting Shapes 102 



Applicability of the Model of Longuet-Higgins , Cartwright, and 



Smith (1963) 118 



Summary 122 



PART X: CONCLUSION 123 



REFERENCES 128 



APPENDIX A: LINEAR ARRAYS - THEORY AND APPLICATION Al 



Introduction Al 



Wave Information from Bottom-Mounted Pressure Sensors Al 



Estimating Propagation Direction of a Single Plane Wave with Two 



Pressure Sensors A2 



Requirements for More than Two Sensors A5 



Linear Array with Four Sensors A7 



Directional Spectra from Longshore Wave Number Estimates A12 



Linear Array with Nine Pressure Sensors A13 



APPENDIX B: NOTATION Bl 



