Patent ID: 7769572

Claim:
A method of imaging a subsurface formation, comprising the steps of: computing the inner and outer radii of a grounded electromagnetic concentric ring source focused on the formation; using the radii to compute the length of a radial electric bipole corresponding to the ring source; using the length of the radial electric bipole to determine the length of a radial dipole source; positioning the radial dipole source at a first position along a radius of the ring source; energizing the radial dipole source; measuring an electromagnetic signal at one or more receiver locations; repeating steps d, e, and f for one or more additional positions of the radial dipole source along the radius; using the measured electromagnetic signals to compute the signal of a virtual radial bipole corresponding to the radius; repeating steps d, e, f, g, and h for at least five additional radii of the ring source; and using the signals of the virtual radial bipoles to image the formation.