Abstract: The inverse scattering problem is converted to an operator equation F(Γ)=f, which consists of the far field operator F, the measured far field data f and the shape Γ of the unknown obstacle. Using the Levenberg-Marquardt method and the derivative of F on Γ, in-troduced by A. Kirsh, this equation is solved and the shape Γ is determined. The numerical results show that this algorithm is practical and efficient.

Key words: domain derivative, inverse scattering, Nyström method