Choisir la langue :

The sound of silence — Recovering signals from time-frequency zeros

Disentangling multicomponent nonstationary signals into coherent AM-FM modes is usually achieved by identifying « loud » time-frequency trajectories where energy is locally maximum. We will here present an alternative perspective that relies on « silent » points, namely spectrogram zeros. Based on the theory of Gaussian analytic functions, a number of results will be presented regarding the distribution of such zeros considered as a point process in the plane, with repulsive properties. The rationale and the implementation of the zeros-based approach for recovering signals embedded in noise will then be discussed, with an application to the extraction and characterization of actual gravitational wave chirps.

 

Dates: 
Thursday, March 23, 2017 - 14:00 to 15:15
Location: 
Grand amphithéâtre, Ecole centrale
Speaker(s): 
Patrick Flandrin
Affiliation(s): 
CNRS & École normale supérieure de Lyon, France