SOC 
and 
(51) E(z') = 0 
(52) E(z') = $0 - 4" 
(53) E(z'*) = 9 
(54) RA 2 2 4 
E(2'4) = 347 - ob 2 - 3y 
1 
pai ianiae is zero and the coefficient of excess is 
-6y Au - 4,2) 
Estimates of Vo Dn 0 and b, 
From (52) the average of z'(x) is zero and the variance is, 
say, Ug s Oe - He. This is the variance that is estimated by a free sur- 
face wave record. 
Since 
9% 2w dw 
(55) S(k) dk = S(T) ey = S'(w) dw 
= SIU) be 
and since (for example) 
oe 4 £7 
(56) S(k) k™ dk = S'"'"(f) lon —> df 
g 
let us assume that 
iK/ie yee Se 
(57) S'"(£) =| q 
0 otherwise 
From equations (35), (36), (37), (55), (56), and (57), one can 
obtain the result that 
(58) ue -¥,*(Tep) 
2 Wales ai 
(59) == Gos)! : — He | (res) sf 
g n- 3 fo) 1 - (£,/f oa SPD) as. 
u 
and 
