4 
Ee) ex 
fox AREA UNDER SOLID LINE 
EQUALS 601.5 CM.? 
IN CM2- SEC. 
if 
612 13) 14 156? BS 20 at 22 0623 624 25 26 h 
Sree Te et Te ee ee i, a = 
625 24 23 + IN SEC 
= 4846 T SEC. 
r( 8 9 10 
ub uk fue SB) 
3.8 3.5 
™ 7 a 
12 
AUTOCORRELATION FUNCTION PLOTTED IN TERMS OF [Apy(#)]? Vs. 
TRUE SPECTRUM LIES BETWEEN DASHED BOUNORIES 90% OF THE TIME. 
4000 [4 1° 
fe) a 
IN CM.2—SEC. os 
| a 
3444 ! \ 
| \ 
i] \ 
i ‘ 
3000 | \ AREA UNDER SOLID LINE 
i a EQUALS 1263 CM2 
I 
IN SEC.’ 
46 43 4 
e 60 30 20 15 
2 10 86 75 6.7 
POWER SPECTRUM OF THE FREE SURFACE, [Atz2]? 
Fig 39. Quantitative Power Spectra of the Pressure Record and the Free Surface 
