-27] 



SEARCH STABILIZATION EQUATIONS 441 



(cos E5 COS A5 sin B - sin £5 cos d) 





= Aircraft Roll Angle 

 : Aircraft Pitch Angle 

 £(., Ar = Search Command in Space 



L 1 Resolver for 

 I each Angle 



sinE^= sinAj cos £5 sin</)-(cos A5 cos Ej sin 6 - sin £5 cos 6) cos 

 sinA^ cosE^=sinA5 cos £5 cos^ + icos A5 cos £5 sin 9 -sin £3 cos 6) sin <^ 



Fig. 8-28 Exact Coordinate Conversion Mechanization for a Two-Gimbal An- 

 tenna Search Pattern. 



creates very little significant error (in the command signals for search angles 



within 50 deg) is expressed by the following equations: 



Ea = As sin cf) - (d - Es) cos 4> (8-30) 



Ja = As cos <p - (d - Es) sin (8-31) 



These equations are shown mechanized in Fig. 8-29. 



Elevation 



Antenna 

 Position 



Antenna Search Loops 



4> = Aircraft Roll Angle \ ^ ^^^^^^^^ 

 e = Aircraft Pitch Angle ) 



A=As cos</)- (d-Es) sin0 

 Fig. 8-29 Approximate Coordinate Conversion Mechanization. 



