passive sonar detection problem. Besides the simplified spectral 

 characteristics, no mention has been made about determining f i , basic- 

 ally, specifying the location of the operating band. Such a specifi- 

 cation is strongly dependent upon the basic sonar inputs of Figure 2 -- 

 the target, noise, and propagation characteristics -- as well as physical 

 limitations upon the array size and available equipment space for 

 beamforming and processing, Tlie consideration of all these factors 

 would lead to a total system design, which is well beyond the scope and 

 intent of this article; however, some further general comments about 

 the influence of these quantities upon system bandwidth specification 

 will be made in the concluding section. 



17 



