SECT. 4] 



SOUND SCATTERING BY MARINE ORGANISMS 

 330° 340° 350° 0° 10° 20° 30° 



527 



DIRECTIVITY PATTERN 



OBG 



27.5 kc/s 



(b) 



FREQUENCY (kc/s) 



(C) 



Fig. 15. (a) Directivity pattern of the QBG transducer at 5 kc/s. 



(b) Directivity pattern of the QBG transducer at 27.5 kc/s. 



(c) Broad-band receiving response of the QBG along its principal axis. 



