32 ELEMENTS OF AIRBORNE RADAR SYSTEMS DESIGN PROBLEM 



justify the weapons system cost. Thus, although the system design will 

 endeavor to meet the desired goal, some degradation may be acceptable 

 if such degradation can be shown to be unavoidable. 



Unexpected developments in technology or in the long-range strategic 

 situation can cause radical changes in the operational requirement during 

 the design cycle. For this reason, the radar designer must constantly 

 monitor the operational requirement to ensure quick reaction to such 

 changes. 



System Concept. The operational requirement defines a military 

 problem. The next step is to define a system concept which provides bases 

 to presume a weapons system potential capability compatible with the 

 operational requirement. This step usually is implemented in the following 

 way. Various possible systems are postulated. Technical military agencies 

 examine these in the light of available or projected technical capabilities 

 to determine which provides the best foundation for a subsequent develop- 

 ment. Weapons system contractors may assist this study phase by pro- 

 viding new ideas, state-of-the-art evaluations, etc.; however, the basic 

 responsibility for decision and action invariably rests with the military. 



Once a decision is made on the type of system desired, the basic features 

 of the selected system are set forth in the form of technical design objectives 

 These comprise the performance specification of the overall weapons 

 system and 



1. The system effectiveness goal related to the operational require- 

 ment 



2. The basic system philosophy, i.e., mode of operation 



3. The system environment as defined by tactics, logistics, climate, 

 etc. 



4. The characteristics of major system elements 



5. The system design, development, and evaluation program 



6. Fundamental state-of-the-art limitation in various portions of 

 the system 



Unless he has already participated in the definition of the system concept, 

 the radar designer's T^^rj/ task is to become familiar with these conceptual 

 characteristics of the overall weapons system. They define the elements of 

 his problem which are relatively fixed and with which his design must be 

 compatible. 



Technical Analysis. The systems problem and its boundary con- 

 ditions having been defined and understood, the radar designer now is 

 ready for the next step — the construction of a weapons system model that 

 will define the radar problem. This model is used to determine the quan- 



