0.35 



0.30 -1.3 



0.25 



y. o.20 



>- 



u 



| 0.15 

 a 



LU 

 Qi 



U_ 



0.10 

 0.05 



- 1.6 



0.00 



1.5 



•1.5 



1.1 



1.3 1.4 



2.5 • • 



1.5 



1.6 



1.4 



1.5 



1.4 1.5i 



• 1.9 



1.9 



1.3 1 



i.i; 



— i 



1.2 * 



1.4 



1.2. 



•1.1 



1.4 



1.3 



1.3 1 1.2- -1-3 



Hl " 31 - 1.5 



1.2 



I L 



1.4 



1.2 



1.4- ' 

 1.6 



•1.4 1.2 



'•1.3 



..14 "1-2 



1-7 < .1.2 



1.3 • .1.4 '1-5 



1.4" '1.2 1 ' 1 '- 1.6 



L4.':, 3 , ,2 -j4 



1.1 1.5- 



1.2 



.1.3 



1.4 ■ 1.6 



1-3 '1.2 



1.2! 



1.2' 



1.4 



1-5 .'1.7 

 1-2. 1.3 



12 - ; - 1.6 



1.2 -1.4 



1.4- 



1.3' 



1.3 



.1-4 

 '•1.2 



1.3 



1.3 



1.2 



1.5 • 

 • 1.3 



■1.3- -1-5 



1.2- 



•1.5 



1.1 1.8 il-4 2.2 • 

 • - r 1.6 1. 



1.3 



1 -6!l.4 



1-2 i.i 

 1.3 -1.3 



1.6 i o 1.1 1.5 

 '..15" 

 1.9. 171" 1-4 -1.3 



1.3 

 1.2* 1.6 



1.2 



1.4 ( 1.6 

 1.4' 



1.61 



1.5 

 ••1.3 '■'* 1.3 _ 

 1.3-1-4 -2.2 



1.4 



•1.4 

 •1.3 1-2- H 



1.5 



45 90 135 180 225 270 



DIRECTION OF TOW (DEGREES) 



315 



1.4 



360 



Figure 28. Summary of direction of row distributions of power spectrum from success; 

 half-minute readings of isotherm depth in the main thermocl ine (shallower isotherm). 

 Circled are the more significant ratios. 



In both graphs, the values were arranged with reference to 

 direction of tow and frequency. 



The ordinate is frequency (cycles per minute) and the 

 abscissa is direction of tow. If the tow direction creates a 

 Doppler effect, the dominant frequencies would shift with the 

 direction of tow. All the peak-to-background power spectrum 

 values of the shallow isotherm (fig. 28) that were derived from 

 the power spectrum plots are entered. Each peak ratio is 

 numerically identified, and peak zones of high values are con- 

 nected with a dashed line. Some sample sections have nearly the 

 same direction of tow and are thus plotted near each other. The 

 highest values (over 1. 6) are circled to emphasize the most 

 important and to more easily relate them to direction and fre- 

 quency. Values greater than 1.6 are considered significant in 



57 



