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FOREWORD 



The advent of the nuclear submarine with Its unlimited 

 cruising range has increased the urgency of acquiring and an- 

 alyzing data required to assess the ocean environment. This 

 report presents one example of the type of analysis required 

 to understand some of the characteristics of random-type data. 

 Such data are exemplified by continuous recordings of sub- 

 marine motions and relative flow across the deck of the 

 hovering or slowly moving submarine, and digital recordings 

 of the height of the sea surface above the submarine. The 

 fact that so many interrelated variables can be sensed and 

 recorded simultaneously is an indication of the submarine's 

 potential as an oceanographic research platform. In addition, 

 such simultaneous recording procedures make the data amenable 

 to even more sophisticated analysis; namely, the estimation of 

 cross-spectral densities connecting two continuously distributed 

 random variables. 



E. C. STEPF 



Rear Admiral, U.S. Navy 



Hydrographer 



