TY - GEN

T1 - Frequency-domain inversion using the amplitude of the derivative wavefield with respect to the angular frequency

AU - Choi, Yun Seok

AU - Alkhalifah, Tariq Ali

N1 - KAUST Repository Item: Exported on 2020-10-01

PY - 2014/12/3

Y1 - 2014/12/3

N2 - The instantaneous traveltime based inversion was developed to solve the phase wrapping problem, thus generating long-wavelength structures even for a high single-frequency. However, it required aggressive damping to insure proper convergence. A reason for that is the potential for unstable division in the calculation of the instantaneous traveltime for low damping factors. Thus, we propose an inversion algorithm using the amplitude of the derivative wavefield to avoid the unstable division process. Since the amplitude of the derivative wavefield contains the unwrapped-phase information, its inversion has the potential to provide robust inversion results. On the other hand, the damping term rapidly diminishes the amplitude of the derivative wavefield at far source-receiver offsets. As an alternative, we suggest using the logarithmic amplitude of the derivative wavefield. The gradient of this inversion algorithm is obtained by the back-propagation approach, based on the adjoint-state technique. Numerical examples show that the logarithmic-amplitude approach yields better convergent results than the instantaneous traveltime inversion, whereas the pure-amplitude approach does not show much convergence.

AB - The instantaneous traveltime based inversion was developed to solve the phase wrapping problem, thus generating long-wavelength structures even for a high single-frequency. However, it required aggressive damping to insure proper convergence. A reason for that is the potential for unstable division in the calculation of the instantaneous traveltime for low damping factors. Thus, we propose an inversion algorithm using the amplitude of the derivative wavefield to avoid the unstable division process. Since the amplitude of the derivative wavefield contains the unwrapped-phase information, its inversion has the potential to provide robust inversion results. On the other hand, the damping term rapidly diminishes the amplitude of the derivative wavefield at far source-receiver offsets. As an alternative, we suggest using the logarithmic amplitude of the derivative wavefield. The gradient of this inversion algorithm is obtained by the back-propagation approach, based on the adjoint-state technique. Numerical examples show that the logarithmic-amplitude approach yields better convergent results than the instantaneous traveltime inversion, whereas the pure-amplitude approach does not show much convergence.

UR - http://hdl.handle.net/10754/564512

UR - http://www.earthdoc.org/publication/publicationdetails/?publication=59628

U2 - 10.3997/2214-4609.20148731

DO - 10.3997/2214-4609.20148731

M3 - Conference contribution

SN - 9781629937908

BT - 74th EAGE Conference and Exhibition incorporating EUROPEC 2012

PB - EAGE Publications

ER -