A THEORETICAL APPROACH TO THE PREDICTION 

 OF SIGNAL FLUCTUATIONS 

 DUE TO ROUGH-SURFACE SCATTERING 



F. M. Labianca and E. Y. Harper 

 Bell Telephone Laboratories, Inc. 



A research program, the purpose of which is the rational 

 prediction of signal fluctuations in a physically realistic 

 ocean environment, has been initiated. An initial scatter- 

 ing model is adopted which accounts for fluctuations on the 

 time scale of the random ocean surface. Some applications 

 of this model to current problems in signal processing 

 are presented. 



A perturbation procedure is presented which allows for a 

 fully three-dimensional treatment of the scatterixig from 

 a stochastic ocean surface, and which includes the effects 

 of refraction. 



The perturbation procedure is applied to the problem of 

 scattering in the region of surface-image interference 

 for a deterministic nonrefractive ocean surface. The 

 results, which are original, have a useful ray- theoretic 

 interpretation in terms of multipath effects and energy 

 conservation. The extension of these results to the case 

 of a random ocean surface is discussed. The latter 

 results are relevant to such problems as noise suppression 

 in towed-array operation. 



INTRODUCTION 



Our interest in signal fluctuations and their prediction has 

 been motivated by the need for realistic simulated data to support 

 the signal processing activities at Bell Laboratories. Accordingly, 

 I would like to make a few preliminary remarks before describing 

 our model and what we have been able to achieve with it. Later on, 

 I will describe what research efforts will be needed to develop it 

 further. 



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