FOREWORD 



The work on acoustic scattering from the small inhomogeneities of 

 the ocean suffers from a lack of cohesion. There are many diverse and appar- 

 ently unrelated papers and experimental results which are nowhere treated from 

 a common point of view or even in a consistent notation. 



As a result, this survey of the field has become a compromise between 

 a compendium of miscellaneous material, a critique of the current state of knowl- 

 edge, and a textbook . We have tried to incorporate the more mathematical ma- 

 terial in the body of the report, since much of theprogress in this field has been 

 essentially mathematical. K the reader is primarily interested in obtaining a 

 physical understanding of the subject, however, he should feel free to skim the 

 mathematical detail unabashedly. We hope that the text contains sufficient con- 

 tinuity without the mathematics . 



The authors wish to acknowledge here the very helpful survey by 

 E. Skudrzyk covering the scattering by weak inhomogeneities. This is one sub- 

 stantial portion of the subject matter which we found to be well summarized. 



Znhnr Ji.lLittU.3nt. 



S-7001-0307 



