148
a -;::;- 2.0
I:i:::;
1.5
1.0
0.5
4 How to Determine Wave Parameters
0.0 -+----l\--~IL----\=;'_\__-~_I____jL--____\_\_--_fI_
-0.5
-1.0
-1.5
b -;::;- 1.2
I:i:::;
1.0
0.8
0.6
0.4
0.2
o
5
o
5
10
15
N=20
10
15
20
25
20
25
30
Time (s)
30
Time (s)
Fig. 4.26: Harmonic analysis of a given irregular sea surface variation in time interval
(0, 30 s): a wave type profile, b box-type profile; dashed lines denote given shape,
solid lines denote Fourier series fit to given shape; the parameter N denotes the
number of terms in the Fourier series