Full waveform inversion (FWI) of seismic or Ground Penetrating Radar data provides high-resolution quantitative images of the constitutive parameters of the rock/soil which control seismic/GPR wave propagation. We developed a 2D inversion tool in the frequency domain adapted to the multi-parameter physics controlling GPR propagation in isotropic non dispersive media, i.e. dielectric permittivit...

Introduction In brain perfusion measurements with Arterial Spin Labeling (ASL), blood is used as an endogenous tracer by inversion of the longitudinal magnetization of spins in blood. Because typical perfusion signal is low (1-2%) as compared to background signal, alternate images are acquired with and without labeling rendering perfusion images after subtraction. However, subtraction does not ...

MT2DInvMatlab is an open-source MATLAB software package for two-dimensional (2D) inversion of magnetotelluric (MT) data; it is written in mixed languages of MATLAB and FORTRAN. MT2DInvMatlab uses the finite element method (FEM) to compute 2D MTmodel responses, and smoothness-constrained least-squares inversion with a spatially variable regularization parameter algorithm to stabilize the inversi...

The problem of image reconstruction in thermoacoustic tomography requires inversion of a generalized Radon transform, which integrates the unknown function over circles in 2D or spheres in 3D. The paper investigates implementation of the recently discovered backprojection type inversion formulas for the case of spherical acquisition in 3D. A numerical simulation of the data acquisition with sub...

Background The border zone of myocardial scar after myocardial infarction (MI) plays an important role for arrhythmia formation. For this reason, high-resolution 3D information of scar tissue for planning of electrophysiological interventions after MI is highly desirable. This study evaluates sharpness of the borders (SB) of scar after MI by a self-navigated isotropic 3D free-breathing wholehea...

the radio magnetotelluric (rmt) method is one of the most widely used electromagnetic (em) methods which employs artificial time varying electric and magnetic fields at the surface of the earth for imaging conductivity. the radiomagnetotelluric method proposed by goldstein and strangway (1975) is based on measuring one set of horizontal electrical and perpendicular magnetic components. after th...

The theory of preconditioned multi-source waveform inversion is presented where many shot gathers are simultaneously back-propagated to form the multisource gradient of the misfit function. Synthetic tests on 2D Marmousi model data show that multi-source waveform inversion using an encoded multi-source deblurring filter as a preconditioner can provide a good inverted model but with less computa...