f Monofrequency electromagnetic tomography

Seismic tomography between boreholes is now a well known method to investigate seismic wave velocities in the subsoil. It can also be applied to assess the anelastic properties of the ground after roversion of the received seismic signal amplitude. The technique is similar with RADAR tomography where the travel times and the amplitude of a short electromagnetic pulse can be inverted to recover the distribution of the velocity and of an attenuation coefficient of the e.m. waves in the ground between the boreholés . In both methods the reconstruction algorithms are used under the assumption that the energy propagates long raypaths (geometrical optics assumption) .