Total variation regularization of the -D gravity inverse problem using a randomized generalized singular value decomposition
arXiv:1709.08125 · doi:10.1093/gji/ggy014
Abstract
We present a fast algorithm for the total variation regularization of the -D gravity inverse problem. Through imposition of the total variation regularization, subsurface structures presenting with sharp discontinuities are preserved better than when using a conventional minimum-structure inversion. The associated problem formulation for the regularization is non linear but can be solved using an iteratively reweighted least squares algorithm. For small scale problems the regularized least squares problem at each iteration can be solved using the generalized singular value decomposition. This is not feasible for large scale problems. Instead we introduce the use of a randomized generalized singular value decomposition in order to reduce the dimensions of the problem and provide an effective and efficient solution technique. For further efficiency an alternating direction algorithm is used to implement the total variation weighting operator within the iteratively reweighted least squares algorithm. Presented results for synthetic examples demonstrate that the novel randomized decomposition provides good accuracy for reduced computational and memory demands as compared to use of classical approaches.
References in corpus (5)
- Hybrid and iteratively reweighted regularization by unbiased predictive risk and weighted GCV for projected systems
- 3-D Projected inversion of gravity data
- Application of the principle and unbiased predictive risk estimator for determining the regularization parameter in 3D focusing gravity inversion
- Automatic estimation of the regularization parameter in 2-D focusing gravity inversion: an application to the Safo manganese mine in northwest of Iran
- Compression Approaches for the Regularized Solutions of Linear Systems from Large-Scale Inverse Problems