Colloquium d'informatique

2012-2013 - Campus Jussieu

Séminaire de prestige en recherche informatique. Invitation de grands noms du domaine, visant un public large.

"Chirps" everywhere


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Résumé

Chirps — i.e., transient waveforms that are modulated in both amplitude and frequency—are ubiquitous in Nature. Birds are chirping, bats and whales too, and even coalescing black holes are, as it has been recently evidenced by the first direct detection of gravitational waves. Chirps can also be found in some mathematical functions (such as Riemann’s) and they are extensively used in engineering (active radar and sonar, non-destructive evaluation). Because of their highly nonstationary structure, chirps call for description tools that go beyond Fourier, with « time-frequency » as a natural paradigm for their analysis and processing. Basics of such approaches will be first recalled and complemented by recent advances aimed at adaptively disentangling multicomponent chirp signals into coherent constitutive waveforms. Two case studies will then be detailed, dealing namely with the bat biosonar system and the interferometric detection of gravitational waves.


Orateur(s) : Patrick Flandrin
Public : Tous
Date : Thursday 16 June 2016
Lieu : Jussieu Amphi 24