106 THE DEVELOPMENT OF WEAPONS SYSTEM REQUIREMENTS 



enjoys approximately a normal dis- 

 tribution about some mean heading 

 as indicated. If the transition from 

 the vectoring phase to the tracking 

 phase is made at this point (AI radar 

 lock-on), this distribution defines the 

 range of initial conditions for the 

 conversion phase. In addition, for 

 any point in space the distribution 

 defines the likely angular positions of 

 the target with respect to the inter- 

 ceptor flight path. The maximum 

 look-angle required for the AI radar 

 is largely determined by this consid- 

 eration coupled with the viewing 

 probability requirement. For exam- 

 ple, if the interceptor heading in Fig. 



2-28 were along line OA, a look-angle of approximately 90° would be required 



for the AI radar to "see" the target. 



Fig. 2-28 Distribution of Interceptor 

 Headings Due to Vectoring Errors. 



2-25 



ANALYSIS OF THE VECTORING PHASE OF 

 INTERCEPTOR SYSTEM OPERATION 



Analysis of the vectoring phase must yield the following information: 



(1) The distributions of aircraft headings as functions of lock-on range 

 and angle off the target's nose 



(2) The AI radar characteristics required for compatability with the 

 operation of the vectoring phase; i.e. display requirements, 

 stabilization requirements, look-angle requirements. 



Vectoring System Logic. The flow of information and allocation of 

 function for the vectoring system are shown in Fig. 2-29. This diagram 

 expresses the system logic outlined in Paragraph 2-11 for the assumed 

 AEW/CIC system. 



System Configuration Parameters. The basic factors governing the 

 operation of the vectoring system may be ascertained from preceding 

 definitions of target inputs and fixed parameters and the design objectives 

 established for the vectoring system. These factors are summarized in 

 Table 2-2 and Paragraph 2-21. 



Collision vectoring was specified to minimize the average target penetra- 

 tion. The equation defining this vectoring method was derived as 



sin Ld = {VtIVf) smd (2-4) 



