A preconditioned inexact newton method for nonlinear sparse electromagnetic imaging
Type
ArticleAuthors
Desmal, Abdulla
Bagci, Hakan

KAUST Department
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) DivisionCenter for Uncertainty Quantification in Computational Science and Engineering (SRI-UQ)
Electrical Engineering Program
Computational Electromagnetics Laboratory
Date
2015-03Permanent link to this record
http://hdl.handle.net/10754/564070
Metadata
Show full item recordAbstract
A nonlinear inversion scheme for the electromagnetic microwave imaging of domains with sparse content is proposed. Scattering equations are constructed using a contrast-source (CS) formulation. The proposed method uses an inexact Newton (IN) scheme to tackle the nonlinearity of these equations. At every IN iteration, a system of equations, which involves the Frechet derivative (FD) matrix of the CS operator, is solved for the IN step. A sparsity constraint is enforced on the solution via thresholded Landweber iterations, and the convergence is significantly increased using a preconditioner that levels the FD matrix's singular values associated with contrast and equivalent currents. To increase the accuracy, the weight of the regularization's penalty term is reduced during the IN iterations consistently with the scheme's quadratic convergence. At the end of each IN iteration, an additional thresholding, which removes small 'ripples' that are produced by the IN step, is applied to maintain the solution's sparsity. Numerical results demonstrate the applicability of the proposed method in recovering sparse and discontinuous dielectric profiles with high contrast values.Citation
Desmal, A., & Bagci, H. (2015). A Preconditioned Inexact Newton Method for Nonlinear Sparse Electromagnetic Imaging. IEEE Geoscience and Remote Sensing Letters, 12(3), 532–536. doi:10.1109/lgrs.2014.2349935ae974a485f413a2113503eed53cd6c53
10.1109/LGRS.2014.2349935