This paper describes a method for GPR Tomographic Inver-sion in three steps. The first step is the application of a Syn-thetic Aperture Radar (SAR) algorithm to detect the positions of anomalies in the subsurface. In a second step Algebraic Reconstruction Technique (ART) is used to solve the linear-ized inverse problem and come to a close approximation of the solution. In a third and last step the nonlinear solution is found using the Adjoint Method. Results are shown on simu-lated data.