116 



300* 



«r 



Mcr 



ISO* 



270* 



24<r 



810* 



380* 



ISO* 



Fig. 3A, 10-foot Line Hydrophone 

 with Compensator at 2.5 kc. 



Fig. 3B. 10 -foot Line Hydrophone 

 with Compensator at 2.5 kc. 



S4cr 



120* 



Fig. 3C, 10-foot Line Hydrophone 

 with Compensator at 2.5 kc. 



Fig. 3D. 10 -foot Line Hydrophone 

 with Comepnsator at 2.5 kc. 



rotating the array. Because of the physical symmetry, the full three-dimen- 

 sional patterns are obtained by rotation of the plane pattern about the 0° - 180° 

 axis. 



In application the line array is suspended and weighed so that it hangs 

 vertically in the water. Directional patterns are then plotted by means of a 

 polar recorder synchronized with the rotation of the compensator. 



Figures 4a and 4b are compensator patterns taken in the field. In figure 

 4a the sound source is a projector and single frequency generator, While in fig- 



