Morlet wavelet

The Morlet wavelet, named after Jean Morlet[?], is a symmetric and periodic wavelet that results from the superposition of a sine and a Gaussian. In complex notation this can be written as:

<math>\psi(t) = \pi^{-1/4} \exp(i \omega_0 t - t^2 / 2)</math>

Because of its smoothness and periodicity, the Morlet wavelet is a good choice for data that is varying continuously in time and is periodic or quasi-periodic, for example atmospheric indices, such as the NAO[?] index.