
74 ◾ Lionel R. Watkins
ω
0
≥ π (2/ln2)
1/2
≈ 5.34, a value suggested by Daubechies [1,2]. Many
experimentalists choose ω
0
= 6, which is the value that has been used
in Figure3.2. e Morlet wavelet has an additional parameter σ that
enables us to control the width of the Gaussian envelope and hence the
number of periods, a feature that is useful experimentally because this
can be done independently of the oscillation frequency ω
0
.
Until now, we have treated t as a continuous variable, but our fringe
pattern is discretized with t (or x) taking integer values from 1 to 512.
If we use the Morlet wavelet with a = 1, the result is a very sharp ...