On the precision of noise correlation interferometry

Richard L. Weaver (1) , Céline Hadziioannou (2) , Éric Larose (3) , Michel Campillo (3)

1 Departement of Physics
2 ISTerre - Institut des Sciences de la Terre
3 Ondes et Structures

Long duration noisy-looking waveforms such as those obtained in randomly multiply scattering and reverberant media are complex; they resist direct interpretation. Nevertheless, such waveforms are sensitive to small changes in the source of the waves or in the medium in which they propagate. Monitoring such waveforms, whether obtained directly or obtained indirectly by noise correlation, is emerging as a technique for detecting changes in media. Interpretation of changes is in principle problematic; it is not always clear whether a change is due to sources or to the medium. Of particular interest is the detection of small changes in propagation speeds. An expression is derived here for the apparent, but illusory, waveform dilation due to a change of source. The expression permits changes in waveforms due to changes in wavespeed to be distinguished with high precision from changes due to other reasons. The theory is successfully compared with analysis of a laboratory ultrasonic data set and a seismic data set from Parkfield California.

Mots clés: Time series analysis; Coda waves; Theoretical seismology; Wave scattering and diffraction; Rheology: crusts and lithosphere

Domaines: Acoustique [physics.class-ph]; Acoustique [physics.class-ph]; Géophysique [physics.geo-ph]; Géophysique [physics.geo-ph]; Milieux et Changements globaux

Richard L. Weaver, Céline Hadziioannou, Éric Larose, Michel Campillo. On the precision of noise correlation interferometry. Geophysical Journal International, 2011, 185 (3), pp.1384-1392. ⟨10.1111/j.1365-246X.2011.05015.x⟩. ⟨hal-00598830⟩