An interwell tomography method for guided drilling, the method comprising: casing a first borehole with a casing tubular lining a wall of the first bore hole and having at least one transmission crossover arrangement, each transmission crossover arrangement having an internal adapter in communication with an external coil antenna that encircles an exterior of the casing tubular; deploying, inside the casing tubular, a conductive path that extends from a surface interface to the at least one transmission crossover arrangement, wherein the adapter enables coupling of the transmission crossover arrangement to the conductive path; drilling a second borehole with a steerable drillstring having antennas to transmit or receive signals from the at least one transmission crossover arrangement of the first bore hole; acquiring measurements of the antenna responses to signals received at the steerable drillstring from the at least one transmission crossover arrangement of the first bore hole; processing the acquired measurements to improve the signal-to-noise ratio of the measurements; inverting the acquired measurements to match the measurements with synthetic measurements from a tomographic formation model to derive model parameter values; displaying a representation of the derived model parameters; determining a position of the steerable drillstring by triangulation using distance or direction measurements acquired from the antenna responses and deriving, in combination with previous measurements, a trajectory of the steerable drillstring; and steering the steerable drillstring along a course relative to the first bore hole in response to the determined position and derived trajectory. casing a first borehole with a casing tubular lining a wall of the first bore hole and having at least one transmission crossover arrangement, each transmission crossover arrangement having an internal adapter in communication with an external coil antenna that encircles an exterior of the casing tubular; deploying, inside the casing tubular, a conductive path that extends from a surface interface to the at least one transmission crossover arrangement, wherein the adapter enables coupling of the transmission crossover arrangement to the conductive path; drilling a second borehole with a steerable drillstring having antennas to transmit or receive signals from the at least one transmission crossover arrangement of the first bore hole; acquiring measurements of the antenna responses to signals received at the steerable drillstring from the at least one transmission crossover arrangement of the first bore hole; processing the acquired measurements to improve the signal-to-noise ratio of the measurements; inverting the acquired measurements to match the measurements with synthetic measurements from a tomographic formation model to derive model parameter values; displaying a representation of the derived model parameters; determining a position of the steerable drillstring by triangulation using distance or direction measurements acquired from the antenna responses and deriving, in combination with previous measurements, a trajectory of the steerable drillstring; and steering the steerable drillstring along a course relative to the first bore hole in response to the determined position and derived trajectory.