4-8] 



AMPLITUDE, ANGLE, AND RANGE NOISE 



199 



1000 



100 



10 



100 



10 ^ 



1 



0.1 



1000 



100 



300 320 



340 



10 20 30 40 50 60 70 

 AZIIVIUTH ANGLE (deg) 



90 100 120 



Fig. 4-21 Plot of Median Echo of B-45 Averaged over 5° of Azimuth. 



characteristics are referred to as target noise (or scintillation) and have an 

 effect similar to noise originating in the tracking system. Target noise is 

 subdivided into amplitude noise, angle noise (or glint), and range noise. 



Amplitude Noise. In a sequential lobing radar, the antenna beam 

 is scanned over a small range of angles, and comparison is made of the 

 signals received with the beam swung to opposite sides of the boresight axis. 

 The difference between these signals is used to drive the antenna toward a 



