Least-squares reverse-time migration with sparsity constraints
File(s)
Published version
Author(s)
Wu, Di
Wang, Yanghua
Cao, Jingjie
da Silva, Nuno V
Yao, Gang
Type
Journal Article
Abstract
Least-squares reverse-time migration (RTM) works with an inverse operation, rather than an adjoint operation in a conventional RTM, and thus produces an image with a higher resolution and more balanced amplitude than the conventional RTM image. However, least-squares RTM introduces two side effects: sidelobes around reflectors and high-wavenumber migration artifacts. These side effects are caused mainly by the limited bandwidth of seismic data, the limited coverage of receiver arrays and the inaccuracy of the modeling kernel. To mitigate these side effects and to further boost resolution, we employed two sparsity constraints in the least-squares inversion operation, namely the Cauchy and L1-norm constraints. For solving the Cauchy-constrained least-squares RTM, we used a preconditioned nonlinear conjugate-gradient method. For solving the L1-norm constrained least-squares RTM, we modified the iterative soft thresholding method. While adopting these two solution methods, the Cauchy-constrained least-squares RTM converged faster than the L1-norm constrained least-squares RTM. Application examples with synthetic data and laboratory modeling data demonstrated that the constrained least-squares RTM methods can mitigate the side effects and promote image resolution.
Date Issued
2021-05-07
Date Acceptance
2021-03-31
Citation
Journal of Geophysics and Engineering, 2021, 18 (2), pp.304-316
ISSN
1742-2132
Publisher
Oxford University Press (OUP)
Start Page
304
End Page
316
Journal / Book Title
Journal of Geophysics and Engineering
Volume
18
Issue
2
Copyright Statement
© The Author(s) 2021. Published by Oxford University Press on behalf of the Sinopec Geophysical Research Institute.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
License URL
Identifier
https://academic.oup.com/jge/article/18/2/304/6272111
Subjects
0404 Geophysics
0905 Civil Engineering
Geochemistry & Geophysics
Publication Status
Published
Date Publish Online
2021-05-07