2-20] SUMMARY OF AEW SYSTEM REQUIREMENTS 97 



One important characteristic of a systems problem has been implied by 

 the foregoing discussion; it is worth mentioning explicitly at this point to 

 impress the reader with its importance. In a systems study designed to 

 derive basic system requirements, it is often necessary to make arbitrary 

 decisions on the basis of incomplete quantitative results. The system logic 

 described in Paragraph 2-1 1 for the hypothetical AEW system is an example 

 of such a decision. Many choices could have been made; however, in order 

 to get on with the problem one choice had to be made and then followed to 

 its logical conclusion. Conceivably, it would develop that this was the 

 wrong choice, in which case we should have to repeat the entire process 

 for a more satisfactory initial hypothesis. 



Keeping in mind the provisional nature of a system specification at this 

 stage of the analysis, we may specify the basic parameters of the AEW 

 system as in Table 2-2. The number of the paragraph which discusses 

 each parameter is included for convenience. 



Table 2-2 TENTATIVE AEW RADAR PARAMETERS 



Detection Range 90 per cent probability of detection at 150 n.mi. (Paragraph 



2-12) 



Number of Targets 20 hostile targets, 40 interceptors (Paragraph 2-13) 



Threat Evaluation Range 125-150 n.mi. (Paragraph 2-11) 



Nominal Vectoring Range 75 n.mi. (Paragraph 2-13) 



Azimuth Coverage 360° (Paragraph 2-11) 



Elevation Coverage ..... AS° up, 18.3° down. Operation at 20,000 feet (Para- 

 graph 2-18). 



Range Resolution 1 n.mi. (Paragraph 2-13) 



Angle Resolution 5° maximum (Paragraph 2-13) 



Range Accuracy a a = 0.25 n.mi., rms (Paragraph 2-15) 



Angular Accuracy (Ta = 1-25° rms (Paragraph 2-15) 



Quantization Levels (Paragraph 2-15) 



AEW Azimuth 1.25° 



AEW Range 1 n.mi. 



CIC System 1.0 n.mi. 



Stabilization Errors Less than 10 per cent of measurement error (Para- 

 graph 2-15) 



Time Belay Errors Less than 10 per cent of measurement error (Para- 

 graph 2-15) 



