Regensburg 2007 – wissenschaftliches Programm

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UP: Fachverband Umweltphysik

UP 13: Poster: Boden- und Agrarphysik

UP 13.1: Poster

Dienstag, 27. März 2007, 14:00–15:00, Poster C

Simulated annealing methods and ERT-Computertomography — •Hans Lustfeld¹ and Martin Reißel² — ¹Forschungszentrum Jülich, IFF, 52425 Jülich, e-mail: h.lustfeld@fz-juelich.de — ²Fachhochschule Aachen, Abteilung Jülich, 52428 Jülich, e-mail: reissel@fh-aachen.de

The Electrical Resistivity Tomography has become an advanced exploration tool for many near surface-investigations (e.g. mineral exploration). After placing electrodes inside and close to the surface, electric currents are injected at some electrodes and the electric potentials induced by those currents are measured at the others.

The success of such measurements depends on i) how much information is contained in the so-called cost function (always the key function in the inverse problem of tomography), ii) how satisfactorily the cost function can be minimized.

In the present work we concentrate on ii): We compare standard methods, such as Gauss-Newton-, Levenberg-Marquardt-, Powell’s Dog Leg procedure (1,2), with simulated annealing procedures. The last of these are most effective if the cost function contains many relative minima, because the detection of the global minimum becomes extremely difficult or even impossible when standard methods are applied.

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(1) A. Kleefeld, Diplomarbeit, Fachhochschule Aachen, Abteilung Juelich, 2005
(2) S. Jongen, Diplomarbeit, Fachhochschule Aachen, Abteilung Juelich, 2006