470 REGULATORY CIRCUITS 



noted that the gyros are not mounted on the antenna and that the antenna 

 resonant frequencies do not influence the stabilization loop design because 

 relative rate motion between the antenna and aircraft is measured with 

 tachometers and converted to space motion in a coordinate converter. 

 Thus, the difliculty of designing an accurate stabilization loop is transferred 

 to the converter. The three gyros must be more accurate than those usually 

 used for autopilots, the converter must be carefully made, and the various 

 input signals must be phased and combined with precision resolvers to 

 provide the necessary accuracy for the fire-control computer. As indicated 

 in the figure, this method of providing space stabilization does not use 

 the automatic regulation function of a feedback loop. It is primarily a 

 balancing arrangement in which the antenna actuators are moved as 

 directed by a computed signal. In this type of system great accuracy is 

 required of all elements not directly enclosed by a feedback loop. 



By the methods outlined in this chapter, antenna stabilization loops 

 may be designed. Primarily regulating loops, they are not capable of 

 directing the antenna toward a target. Automatically controlled tracking 

 loops are used for this purpose and these loops are discussed in the next 

 chapter. 



