We consider the two-dimensional version of Calderòn’s problem. When the Dirichlet-to-Neumann map is assumed to be known up to an error level ε_0, we investigate how the resolution in the determination of the unknown conductivity deteriorates the farther one goes from the boundary. We provide explicit formulas for the resolution, which apply to conductivities which are perturbations, concentrated near an interior point q, of the homogeneous conductivity.
