Modelling of radio tomography antennas using the finite-difference time-domain technique

Radio tomography is a geophysical technique that uses measurements of radio wave attenuation to produce images of rock conductivity between two boreholes. Accurate attenuation data is only available if the antenna performance is well characterized. This paper describes the use of a finite-difference time-domain model with body of revolution symmetry to model an insulated dipole antenna in a lossy dispersive earth. A subcell extension to the model is presented that allows the modelling of a thin layer of insulation around a thin conductive wire. The model allows the influence of the insulation thickness on system performance to be quantified.