05-29   Berichtsreihe des Mathematischen Seminars der Universität Kiel

Helmut Harbrecht, Thorsten Hohage:

Fast Methods for Three-Dimensional Inverse Obstacle Scattering Problems

We study the inverse problem to reconstruct the shape of a three-dimensional sound-soft obstacle from measurements of scattered acoustic waves. To solve the forward problem we use a wavelet based boundary element method and prove 4th order accuracy both for the evaluation of the forward solution operator and its Fr\'echet derivative. Moreover, we discuss the characterization and implementation of the adjoint of the Fr\'echet derivative. For the solution of the inverse problem we use a regularized Newton method. The boundaries are represented by a class of parametrizations, which include non star-shaped domains and which are not uniquely determined by the obstacle. To prevent degeneration of the parametrizations during the Newton iteration, we introduce an additional penalty term. Numerical examples illustrate the performance of our method.


Mail an Jens Burmeister
[Thu Feb 19 18:56:37 2009]
Impressum