SINBAD Consortium Meeting - 2013 Spring - Abstracts
Curt Da Silva, Felix J. Herrmann, "Hierarchical {Tucker} tensor optimization - applications to {4D} seismic data interpolation"
In this work, we develop optimization algorithms on the manifold of Hierarchical Tucker (HT) tensors, an extremely efficient format for representing high-dimensional tensors exhibiting particular low-rank structure. With some minor alterations to existing theoretical developments, we develop an optimization framework based on the geometric understanding of HT tensors as a...
Rajiv Kumar, Hassan Mansour, Aleksandr Y. Aravkin, Felix J. Herrmann, "Seismic data interpolation via low-rank matrix factorization in the hierarchical semi-separable representation"
Recent developments in matrix rank optimization have allowed for new computational approaches in the field of seismic data interpolation. One of the main requirements of exploiting rank-minimization approaches is that the target data set should...
Ning Tu, Aleksandr Y. Aravkin, Tristan van Leeuwen, Felix J. Herrmann, "Fast imaging with multiples and source estimation"
Multiples are usually treated as unwanted components in seismic data. However, if correctly used, they can provide valuable information about the subsurface. In this presentation, I will talk about how to make use of multiples in ℓ1 regularized least-squares imaging, and how to estimate the source wavelet on the fly using multiples. Synthetic...
Felix J. Herrmann, "Mitigating local minima in full-waveform inversion by expanding the search space with the penalty method"
Wave-equation based inversions, such as full-waveform inversion, are challenging because of their computational costs, memory requirements, and reliance on accurate initial models. To confront these issues, we propose a novel formulation of full-waveform inversion based on a penalty method. In this formulation, the objective function consists of a data-misfit term and a penalty term which measures how...
Felix J. Herrmann, "Frugal {FWI}"
Seismic waveform inversion aims at obtaining detailed estimates of subsurface medium parameters, such as soundspeed, from seismic data. A formulation in the frequency-domain leads to an optimization problem constrained by a Helmholtz equation with many right-hand- sides. Application of this technique in 3D precludes the use of factorization techniques to solve the Helmholtz equation due the large number of gridpoints and the bandwidth of the matrix. While many sophisticated pre-conditioned iterative techniques have been developed for the Helmholtz equation, they often...
Haneet Wason, Felix J. Herrmann, "Time-jittered ocean bottom seismic acquisition"
Leveraging ideas from the field of compressed sensing, we show how simultaneous or blended acquisition can be setup as a – compressed sensing problem. This helps us to design a pragmatic time-jittered marine acquisition scheme where multiple source vessels sail across an ocean-bottom array firing airguns at – jittered source locations and instances in time, resulting in better spatial sampling, and speedup acquisition. Furthermore, we can significantly...
Felix J. Herrmann, "Extended images in action"
Image gathers as a function of subsurface offset are an important tool for migration-velocity and amplitude-versus-angle analysis in areas of complex geology. Traditionally, these gathers are thought of as multidimensional correlations of the source and receiver wavefields. The bottleneck in computing the gathers lies in the fact that one needs to store and compute these wavefields and in correlating the wavefields to obtain the desired image gathers. Therefore, the image gathers are typically only computed for a limited number of subsurface...
Felix J. Herrmann, "Latest developments on the {Chevron} {GOM} and other datasets"
During this talk, we will give a brief overview on our imaging and FWI results on various synthetic and field datasets we have been working on. This is joint work with Andrew Calvert, Brendan R. Smithyman, and the SLIM team.
Ning Tu, Felix J. Herrmann, "Controlling linearization errors with rerandomization"
Least squares migration aims to fit the observed seismic data with data predicted by linearized modelling, by solving an PDE-constrained optimization problem. This problem is challenging mostly because of its prohibitive computational cost. To address the issue, dimensionality reduction techniques were proposed in the literature. However, the solution of the reduced problem can deviate from that of the full problem when there are components in the...
Tim T.Y. Lin, Felix J. Herrmann, "Cosparse seismic data interpolation"
Over the years we have investigated seismic data interpolation and redatuming algorithms rely on on the assumption that seismic records and images permit sparse approximations under certain representations, such as Curvelet coefficients. Recent findings have suggested that for redundant representations (of which Curvelet is an example), the analysis operator that maps the physical signal to coefficients may also play a crucial role in recovering data from incomplete...