title: Single frequency inverse obstacle scattering: a sparsity constrained linear sampling method approach.
abstract: The linear sampling method (LSM) offers a qualitative image reconstruction approach, which is known as a viable alternative for obstacle support identification to the well-studied filtered backprojection (FBP), which depends on a linearized forward scattering model. Of practical interest is the imaging of obstacles from sparse aperture far-field data under a fixed single frequency mode of operation. Under this scenario, the Tikhonov regularization typically applied to LSM produces poor images that fail to capture the obstacle boundary. In this paper, we employ an alternative regularization strategy based on constraining the sparsity of the solution's spatial gradient. Two regularization approaches based on the spatial gradient are developed. A numerical comparison to the FBP demonstrates that the new method's ability to account for aspect-dependent scattering permits more accurate reconstruction of concave obstacles, whereas a comparison to Tikhonov-regularized LSM demonstrates that the proposed approach significantly improves obstacle recovery with sparse-aperture data.
authors.affiliation: Department of Electrical and Computer Engineering, University of Cincinnati, Cincinnati, OH 45221, USA. alqadahf@mail.uc.edu
authors.forename: Hatim F
authors.initials: HF
authors.lastname: Alqadah
authors.forename: Matthew
authors.initials: M
authors.lastname: Ferrara
authors.forename: Howard
authors.initials: H
authors.lastname: Fan
authors.forename: Jason T
authors.initials: JT
authors.lastname: Parker
mesh_terms: D000465:Algorithms; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D016014:Linear Models; D009716:Numerical Analysis, Computer-Assisted; D015203:Reproducibility of Results; D018401:Sample Size; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted