Geophysical tomography.

Estimating Uncertainties for Geophysical Tomography

We present statistical and interval techniques for evaluating the uncertainties associated with geophysical tomographic inversion problems, including estimation of data errors, model errors, and total solution uncertainties. These techniques are applied to the inversion of traveltime data collected in a cross well seismic experiment. The inversion method uses the conjugate gradient technique, i...

Electrical Impedance Tomography for Geophysical Applications

We report on the development of a new software package for image reconstruction in threedimensional Electrical Impedance Tomography (EIT). Designed for large-scale computations, the software includes mesh generation utilities, a simulator of the quasi-static electrical potential fields based on finite elements and regularized inversion algorithms. We describe in brief some of its main functions...

Geophysical Tomography for Imaging Water Movement in Welded Tuff-

Alterant tomography h*s been evaluated for its ability to de­ lineate itfsitu water flow paths in a fractured welded-tuff rock mass, The evaluation involved a field experiment in which tomographs of electromagnet attenuation factor (or attenuation rate) at 300 MHz were made before, during, and after the introduc­ tion to the rock of two different water-based tracers: a plain water and dye solut...

Geophysical Turbulence Geophysical Turbulence

The generalized cross validation method for the selection of regularization parameter in geophysical diffraction tomography

Inverse problems are usually ill-posed in such a way that it is necessary to use some method to reduce their deficiencies. The method that we choose is the regularization by derivative matrices. There is a crucial problem in regularization, which is the selection of the regularization parameter λ. In this work we use generalized cross validation (GCV) as a tool for the selection of λ. GCV was p...