TY - JOUR

T1 - A method of extracting phase‐velocity curves from seismograms

AU - Abramovici, F.

AU - Gal‐Ezer, J.

AU - Baumgarten, J.

PY - 1981/6

Y1 - 1981/6

N2 - Summary. The Lanczos method of separating exponentials is applied to the Fourier transform of seismograms in order to separate the various modes that contribute to the given portion of the seismograms. Phase velocities and amplitudes are obtained as functions of the frequency. When applying the method to artificial seismograms, which are built as an exact superposition of a number of modes, the separation is very accurate. The method was also applied to the surface‐wave portion of numerical seismograms for a vertical point force in a layered medium. The phase velocity and amplitude of the fundamental mode are obtained. These functions were taken as the first guess in the Backus—Gilbert generalized inverse procedure and the process converged very rapidly. When a perturbation of the phases and amplitudes is taken as the first guess the process converges to the true model when enough data are available.

AB - Summary. The Lanczos method of separating exponentials is applied to the Fourier transform of seismograms in order to separate the various modes that contribute to the given portion of the seismograms. Phase velocities and amplitudes are obtained as functions of the frequency. When applying the method to artificial seismograms, which are built as an exact superposition of a number of modes, the separation is very accurate. The method was also applied to the surface‐wave portion of numerical seismograms for a vertical point force in a layered medium. The phase velocity and amplitude of the fundamental mode are obtained. These functions were taken as the first guess in the Backus—Gilbert generalized inverse procedure and the process converged very rapidly. When a perturbation of the phases and amplitudes is taken as the first guess the process converges to the true model when enough data are available.

UR - http://www.scopus.com/inward/record.url?scp=0019677501&partnerID=8YFLogxK

U2 - 10.1111/j.1365-246X.1981.tb04880.x

DO - 10.1111/j.1365-246X.1981.tb04880.x

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AN - SCOPUS:0019677501

SN - 0016-8009

VL - 65

SP - 727

EP - 739

JO - Geophysical Journal of the Royal Astronomical Society

JF - Geophysical Journal of the Royal Astronomical Society

IS - 3

ER -