Imperial College London
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ProfessorMikeWarner

Faculty of Engineering, Department of Earth Science & Engineering

Professor
 
 
 
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Contact

 

+44 (0)20 7594 6535m.warner

 
 
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Assistant

 

Ms Daphne Salazar +44 (0)20 7594 7401

 
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Location

 

RSM 1.46CRoyal School of MinesSouth Kensington Campus

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Summary

 

Publications

Citation

BibTex format

@article{Da:2018:1361-6420/aade1f,
author = {Da, Silva NV and Yao, G and Warner, M},
doi = {1361-6420/aade1f},
journal = {Inverse Problems},
title = {Semi-global inversion of v<inf>p</inf> to v<inf>s</inf> ratio for elastic wavefield inversion},
url = {http://dx.doi.org/10.1088/1361-6420/aade1f},
volume = {34},
year = {2018}
}
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RIS format (EndNote, RefMan)

TY  - JOUR
AB  - © 2018 IOP Publishing Ltd. We introduce an approach to estimate the ratio between P- and S-wave velocities, v p/v s, in the scope of elastic full waveform inversion (FWI). Elastic FWI is generally implemented with local optimization methods relying on initial estimates of the long wavelengths of P- and S-wave models. However, successful inversions can be hindered if an accurate enough relation between v p and v s velocities is not used as a constraint. This relation can be estimated from empirical relations. Herein, we introduce an alternative approach based upon a semi-global inversion scheme. We observe that for a large number of cases, and particularly in the context of FWI, v p/v s can be represented on a sparse basis. This sparse basis has a much smaller dimension than that of the typical model space in elastic FWI. This creates the possibility of using global optimization methods. The optimal estimate of v p/v s is obtained with quantum particle swarm optimization (QPSO). This method probes a population of possible models. The assessment of each model of v p/v s in the population is obtained with nested local iterations updating for v p only. Conventional elastic FWI is then carried out for jointly estimating high-resolution models of v p and v s. We demonstrate with synthetic examples that the estimates of v p are relatively robust to errors in the estimated v p/v s, and that effectively a sparse representation of the model of v p/v s is feasible for the reconstruction of a model of v s. We also demonstrate that the proposed approach performs better than constraining elastic FWI with an empirical relation between v p and v s, leading to improved estimates of models of v p and v s from seismic data.
AU  - Da,Silva NV
AU  - Yao,G
AU  - Warner,M
DO  - 1361-6420/aade1f
PY  - 2018///
SN  - 0266-5611
TI  - Semi-global inversion of v<inf>p</inf> to v<inf>s</inf> ratio for elastic wavefield inversion
T2  - Inverse Problems
UR  - http://dx.doi.org/10.1088/1361-6420/aade1f
VL  - 34
ER  -
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