Statistical redundancy of instantaneous phases: Theory and application to the seismic ambient wavefield

Autor: Ianis Gaudot, M. Le Feuvre, Martin Schimmel, Eric Beucler, Antoine Mocquet
Přispěvatelé: Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Laboratoire Géophysique et évaluation non destructive (IFSTTAR/GERS/GeoEND), Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-PRES Université Nantes Angers Le Mans (UNAM)
Rok vydání: 2016
Předmět:
Zdroj: Digital.CSIC: Repositorio Institucional del CSIC
Consejo Superior de Investigaciones Científicas (CSIC)
Geophysical Journal International
Geophysical Journal International, Oxford University Press (OUP), 2016, 204 (2), pp.1159-1163. ⟨10.1093/gji/ggv501⟩
ISSN: 0956-540X
1365-246X
DOI: 10.1093/gji/ggv501
Popis: In order to detect possible signal redundancies in the ambient seismic wavefield, we develop a new method based on pairwise comparisons among a set of synchronous time-series. This approach is based on instantaneous phase coherence statistics. The first and second moments of the pairwise phase coherence distribution are used to characterize the phase randomness. For perfect phase randomness, the theoretical values of the mean and variance are equal to 0 and √1 - 2/π, respectively. As a consequence, any deviation from these values indicates the presence of a redundant phase in the rawcontinuous signal.Apreviously detected microseismic source in the Gulf of Guinea is used to illustrate one of the possible ways of handling phase coherence statistics. The proposed approach allows us to properly localize this persistent source, and to quantify its contribution to the overall seismic ambient wavefield. The strength of the phase coherence statistics relies in its ability to quantify the redundancy of a given phase among a set of time-series with various useful applications in seismic noise-based studies (tomography and/or source characterization). This works is funded by the VIBRIS project (Council of Pays de la Loire, France). EB thanks CNRS-INSU 2014-SYSTER. MS thanks MISTERIOS (CGL2013-48601-C2-1-R).
Databáze: OpenAIRE