SIMBAD references

A type of the relatively new time-frequency method, the wavelet analysis is studied. Some results of testing this method are presented. The test data series were defined so that they show similarities with the light variations of variable stars. The effects of observational noise and irregularities in data sampling are pointed out. The wavelet analysis seems to be a suitable method for detecting the local behaviour of the light curves, e.g. phase jump or mode switching. The investigation of time-dependent phenomena, e.g. amplitude or frequency modulation, is more available than in the case of standard Fourier analysis. In order to interpret the real wavelet maps of variable stars it is necessary to take into account the properties of the method presented by similar tests.