Supervised time-frequency reassignment

A method is proposed for estimating chirp signals em-bedded in nonstationary noise, with the twofold objective of a sharp localization for the chirp components and a re-duced level of statistical fluctuations for the noise. The technique consists of combining time-frequency reassign-ment with multitapering. The principle of the method is outlined, its implementation based on Hermite functions is justified and discussed, and some examples are provided for supporting the efficiency of the approach, both qualitatively and quantitatively. 1