x/v 



WAFI TR-ll+ifO 



ABSTRACT 



This report examines three methods for maximizing the output 

 signal-to-noise ratio of a conventional passive detection system con- 

 sisting of a fixed array, non-adaptive beam forming, and square-law de- 

 tection. The performance of a non-optimal system is compared to each of 

 the three optimum configurations, and the results suggest how an unsophis- 

 ticated, sub-optimal system, which has only marginally poorer performance 

 than the optimum systems, can be designed. 



The specification of such a sub-optimal system depends greatly 

 upon having intelligent estimates of the frequency domain behavior of the 

 received signal; however, this information appears only implicitly in 

 the solution, not explicitly as in the specification of an Eckart filter. 

 Thus, one avoids the essentially insurmountable practical problems of 

 attempting to build a system matched to the signal characteristics (the 

 Eckart filter), while at the same time utilizing the expected variation 

 in signal spectra to specify a realizable system whose performance is 

 only slightly inferior to an Eckart system. 



Prepared by: KcfVM-f /]. (Ar'^^Q-^L OC 



Approved by: 



5ERT H. BEGEMAN 

 Special Components Branch, Chief 



tviax...^' 



\ A. MARASCO 

 Experimental Research Division 



i rH 



i CD 



; D 



t CD 



