A. IlffRODTICTION 



Since January 195ii3 the Navy Hydrographic Office has been engaged 

 in the qualitative and quantitative analysis of wave and pressure data 

 collected in 30 to 1^0 feet of water off the east coast of the United 

 States. The analysis of these data is fundamental in that it has afforded 

 an opportunity to initiate prediction techniques for determining various 

 characteristics of bottom pressures. In some instances, the full signifi- 

 cance of these properties have not been determined » 



Many of the features of surface waves have been explained by Pierson 

 (1952) and Neumann (19?3) on the su.pposition that a wave record as a func- 

 tion of time is Gaussian. Employing the techniques of Tukey (I9ll9) and 

 Tukey and Hamming (I9h9) t the theory has been further developed to explain 

 the methods of wave analysis for estimating the power spectrum of the 

 steady-state sea surface. 



Various theories based on the analysis of noise, advanced by Rice 

 (I9U4. and 19ii?)j have been applied to surface waves. None of these theories 

 have been carried completely or satisfactorily to the point of explaining 

 how the surface waves are attempted with depth. Yet the need for con- 

 venient and efficient methods of predicting properties of pressure vraves 

 has made itself increasingly felt in research and development in fields 

 where background pressure ( the variation in pressvire on the ocean 

 bottom as a result of the wave action at the sxirface ) is important in 

 determining an index of effectiveness for pressure gear. 



