476 



AUTOMATIC TRACKING CIRCUITS 



20,000 



20,000 



16,000 12,000 



RANGE (yards) 



20,000 



16,000 12,000 



RANGE (yards) 



<^ 6.0 

 i 4.0 



1 2.0 

 i 



2 -2.0 



16,000 12,000 

 RANGE (yards) 



4000 ^ 20,000 

 Fig. 9-1 Lead-Pursuit Course Inputs. 



16,000 12,000 



RANGE (yards) 



4000 



teristics of the motion which are used to establish angle tracking loop 

 specifications as described in Paragraph 9-6. 



Table 9-1 TYPICAL MAXIMUM ANGULAR RATES AND 

 ACCELERATIONS OF THE SIGHT LINE 



CO mils/sec co mils/sec^ 



Lead Pursuit (Horizontal Target Maneuvers) 46 11.4 



Lead Collision Course" 18.3 2.27 



"At time of firing, 10 seconds to go. (Much more severe at short ranges; see Fig. 2-45.) 



Fig. 9-1 also shows plots of the lead angle and lead angle rate to illustrate 

 how the antenna must be moved with respect to the antenna platform. 

 Space platform disturbances are not included here, but curves such as these 

 help define the necessary antenna gimbal motion and actuator capabilities. 



Figs. 9-1 and 2-45 are typical of the plots needed to define the angle track 

 inputs, and in practice many others would be made during studies of various 

 attack conditions to determine the most severe operating requirements. 



Signal Fades. At long ranges, signal returns from a target are of 

 extremely low power and may be detected only periodically. This variation, 

 of random nature, is referred to as/at^ifiii;. Fading is not a desirable input, 



