449 citations · 848 across the 29 of their papers we have counts for
28 papers
Multistatic anisotropic travel-time as a tensor tomography problem
Naeem Desai, Oliver Graham, Sean Holman +1
Travel-time imaging problems seek to reconstruct an image of reflectivity of a scene by measuring travel time (and amplitude, phase) of electromagnetic or acoustic signals, such as…
On Regularisation of Coherent Imagery with Proximal Methods
F. M. Watson, W. R. B. Lionheart, J. Hellier
In complex-valued coherent inverse problems such as synthetic aperture radar (SAR), one may often have prior information only on the magnitude image which shows the features of int…
Resolving Full-Wave Through-Wall Transmission Effects in Multi-Static Synthetic Aperture Radar
Francis Watson, Daniel Andre, William Robert Breckon Lionheart
Through-wall synthetic aperture radar (SAR) imaging is of significant interest for security purposes, in particular when using multi-static SAR systems consisting of multiple distr…
Direct inversion of the Longitudinal Ray Transform for 2D residual elastic strain fields
C. M. Wensrich, S. Holman, M. Courdurier +3
We examine the problem of Bragg-edge elastic strain tomography from energy resolved neutron transmission imaging. A new approach is developed for two-dimensional plane-stress and p…
Properties of Generalised Magnetic Polarizability Tensors
P. D. Ledger, W. R. B. Lionheart
We present new alternative complete asymptotic expansions for the time harmonic low--frequency magnetic field perturbation caused by the presence of a conducting permeable object a…
Recovering the second moment of the strain distribution from neutron Bragg edge data
Kyle Fogarty, Evelina Ametova, Genoveva Burca +4
Point by point strain scanning is often used to map the residual stress (strain) in engineering materials and components. However, the gauge volume and hence spatial resolution is…
Minimal Object Characterisations using Harmonic Generalised Polarizability Tensors and Symmetry Groups
P. D. Ledger, W. R. B. Lionheart
We introduce a new type of object characterisation, which is capable of accurately describing small isolated inclusions for potential field inverse problems such as in electrostati…
Identification of Metallic Objects using Spectral Magnetic Polarizability Tensor Signatures: Object Classification
B. A. Wilson, P. D. Ledger, W. R. B. Lionheart
The early detection of terrorist threat objects, such as guns and knives, through improved metal detection, has the potential to reduce the number of attacks and improve public saf…
A polarization tensor approximation for the Hessian in iterative solvers for non-linear inverse problems
F. M. Watson, M. G. Crabb, W. R. B. Lionheart
For many inverse parameter problems for partial differential equations in which the domain contains only well-separated objects, an asymptotic solution to the forward problem invol…
Crystalline phase discriminating neutron tomography using advanced reconstruction methods
Evelina Ametova, Genoveva Burca, Suren Chilingaryan +8
Time-of-flight neutron imaging offers complementary attenuation contrast to X-ray computed tomography (CT), coupled with the ability to extract additional information from the vari…
Core Imaging Library -- Part II: Multichannel reconstruction for dynamic and spectral tomography
Evangelos Papoutsellis, Evelina Ametova, Claire Delplancke +7
The newly developed Core Imaging Library (CIL) is a flexible plug and play library for tomographic imaging with a specific focus on iterative reconstruction. CIL provides building…
Core Imaging Library -- Part I: a versatile Python framework for tomographic imaging
Jakob S. Jørgensen, Evelina Ametova, Genoveva Burca +8
We present the Core Imaging Library (CIL), an open-source Python framework for tomographic imaging with particular emphasis on reconstruction of challenging datasets. Conventional…
Scanning electron diffraction tomography of strain
Robert Tovey, Duncan N. Johnstone, Sean M. Collins +4
Strain engineering is used to obtain desirable materials properties in a range of modern technologies. Direct nanoscale measurement of the three-dimensional strain tensor field wit…
Lipschitz stability at the boundary for time-harmonic diffuse optical tomography
Olga Doeva, Romina Gaburro, William R. B. Lionheart +1
We study the inverse problem in Optical Tomography of determining the optical properties of a medium , with , under the so-called diffusion approxima…
The Spectral Properties of the Magnetic Polarizability Tensor for Metallic Object Characterisation
P. D. Ledger, W. R. B. Lionheart
The measurement of time-harmonic perturbed field data, at a range of frequencies, is beneficial for practical metal detection where the goal is to locate and identify hidden target…
Polarimetric Neutron Tomography of Magnetic Fields: Uniqueness of Solution and Reconstruction
Naeem M. Desai, William R. B. Lionheart, Morten Sales +2
We consider the problem of determination of a magnetic field from three dimensional polarimetric neutron tomography data. We see that this is an example of a non-Abelian ray transf…
Histogram Tomography
William R. B. Lionheart
In many tomographic imaging problems the data consist of integrals along lines or curves. Increasingly we encounter "rich tomography" problems where the quantity imaged is higher d…
Non-linearity in monochromatic transmission tomography
William R. B. Lionheart, Bjørn Tore Hjertaker, Rachid Maad +3
While it is well known that X-ray tomography using a polychromatic source is non-linear, as the linear attenuation coefficient depends on the wavelength of the X-rays, tomography u…
Generalised Magnetic Polarizability Tensors
P. D. Ledger, W. R. B. Lionheart
We present a new complete asymptotic expansion for the low frequency time-harmonic magnetic field perturbation caused by the presence of a conducting (permeable) object as its size…
Three dimensional Compton scattering tomography
James Webber, William Lionheart
We propose a new acquisition geometry for electron density reconstruction in three dimensional X-ray Compton imaging using a monochromatic source. This leads us to a new three dime…
Three Dimensional Polarimetric Neutron Tomography of Magnetic Fields
Morten Sales, Markus Strobl, Takenao Shinohara +6
Through the use of Time-of-Flight Three Dimensional Polarimetric Neutron Tomography (ToF 3DPNT) we have for the first time successfully demonstrated a technique capable of measurin…
An explicit reconstruction algorithm for the transverse ray transform of a second rank tensor field from three axis data
Naeem M. Desai, William R. B. Lionheart
We give an explicit plane-by-plane filtered back-projection reconstruction algorithm for the transverse ray transform of symmetric second rank tensor fields on Euclidean 3-space, u…
Understanding the Magnetic Polarizability Tensor
P. D. Ledger, W. R. B. Lionheart
The aim of this paper is provide new insights into the properties of the rank 2 polarizability tensor proposed in (P.D. Ledger and W.R.B. Lionheart Cha…
Direct high-order edge-preserving regularization for tomographic image reconstruction
Daniil Kazantsev, Evgueni Ovtchinnikov, William R. B. Lionheart +2
In this paper we present a new two-level iterative algorithm for tomographic image reconstruction. The algorithm uses a regularization technique, which we call edge-preserving Lapl…