Domain reconstruction using photothermal techniques

  • Authors:
  • Ana Carpio;María-Luisa Rapún

  • Affiliations:
  • Dep. Matemática Aplicada, Fac. Matemáticas, Universidad Complutense de Madrid, 28040 Madrid, Spain;Dep. Fundamentos Matemáticos, ETSI Aeronáuticos, Universidad Politécnica de Madrid, 28040 Madrid, Spain

  • Venue:
  • Journal of Computational Physics
  • Year:
  • 2008

Quantified Score

Hi-index 31.45

Visualization

Abstract

A numerical method to detect objects buried in a medium by surface thermal measurements is presented. We propose a new approach combining the use of topological derivatives and Laplace transforms. The original optimization problem with time-dependent constraints is replaced by an equivalent problem with stationary constraints by means of Laplace transforms. The first step in the reconstruction scheme consists in discretizing the inversion formula to produce an approximate optimization problem with a finite set of constraints. Then, an explicit expression for the topological derivative of the approximate shape functional is given. This formula is evaluated at low cost using explicit expressions of the forward and adjoint fields involved. We apply this technique to a simple shape reconstruction problem set in a half space. Good approximations of the number, location and size of the obstacles are obtained. The description of their shapes can be improved by more expensive hybrid methods combining time averaging with topological derivative based iterative schemes.