378 HAYES— U. S. NAVY MV TYPE OF HYDROPHONE. 



R^= 2D cot e^, 



i?2 = 2D cot (f)2, 



the depth (D) being taken from the chart. It is to be noticed that 

 for ranges ahead the compensator reading, 6, occurs in the equation 

 while for ranges astern the " sounding angle," (j>, is used. 



■c 



A 



-^ 



^./'.Miuua^ 



^ 



\ 



KCY 

 O-Ct-i fonp 



p,-an cote. 



RfiDcofP, 



t -^l '^^"^ 



\ 

 \ 

 ° \ 



\ 



\ '/! 



> / / 



\ / / 



/ \ 



/ \ ' 

 \ / \l 



__ J-/^ Vg 



^^TT- 



in:: 



/ 



\ 





METHOD OF SOUNDING /\ND RANGE FINDING BY M-V HYDROPHONE 



Fig. 4. 



If the depth is not too great, {D) can be determined by the hydro- 

 phone as outlined above and the range formulas become 



R, = L 



R., = L 



Tan$ 

 Tan^i ' 



Tan$ 

 Tan *2 ' 



where (R) is the range to be determined, (L) the distance between 

 the sound-source and hydrophone on the listening vessel, and 6^, 6.-,, 

 and $ are the angles which the reflected sound from the three vessels 

 make with the surface as shown. 



It is evident that the range to which these formulae will give rea- 

 sonably accurate determinations is proportional to the depth of water 

 in which the vessels are operating. 



The equation connecting {D), the depth, and $, the angle which 

 the reflected sound makes with the surface, becomes somewhat com- 



