appears in Appendix C . Accordingly, it has been decided to omit further dis- 

 cussion of these experimental results, although the data are presented for com- 

 pleteness in Curves 37-54. 



2.2 Point by Point Data Analysis . A principal objective of the experimental 

 program was to permit comparison of the acoustical transmission conditions 

 in two different ocean areas. The averaging technique, described in the pre- 

 ceding paragraph, was useful in determining the general validity of the data 

 for overall comparison with the theoretical transmission losses; it did not 

 permit a sufficiently detailed comparison of corresponding transmission loss 

 curves in the two areas. Accordingly 11 transmission loss curves were anal- 

 yzed point by point. They appear as Curves 55-65, selected on the basis of 

 reliability of experimental data and of theoretical importance . 



2 .3 Signal Fluctuation Analysis . As the point by point analysis reveals in 

 Curves 55-65 (and on the expanded scale of Curve 55A) the signal undergoes 

 large fluctuations on either side of a mean curve . The extent of these fluctua- 

 tions is important operationally and scientifically. From the former point of 

 view they affect sonar performance; in the scientific context of this experiment 

 the dependence of the fluctuations on locality, frequency and acoustic transmis- 

 sion paths may provide information on their origin. The quantities 



A l H a n " a n-l 

 A 2 - ^ " aii-2 

 A 3 = On " 011-3 



were calculated from the experimental and theoretical data where o^ = trans- 

 mission loss at the nth data point. The theoretical data were provided by the 

 computer print-out at 100 yard increments corresponding closely to the range 

 intervals between experimental points . Histograms of Aj, A2, and A3 are 

 shown in Figures 2 and 3 . Figure 2 presents the results of analyzing Curves 

 58 and 62, the transmission loss curves at 3000 cps in Areas I and II, between 

 an intermediate depth receiver and an intermediate depth source . Figure 3 

 presents data analogous to that from Curve 62 at frequencies of 700 and 1300 

 cps. The standard deviations of the distributions presented in the histograms 

 are tabulated in Table 1 . 



artftur 2D.HittIe,3nr. 



