ELECTROMAGNETIC MODELING WITH WAVE TILT AND REFLECTION COEFFICIENT

This work aims at formulating models based on the Maxwell equations, using earth parameters such as conductivity, permeability, permittivity and surface wave impedance. Three measurable field parameters; Amplitude of the correction factor to the wave tilt, Q; phase of Q,and reflection coefficient were calculated from the model with various conductivity contrasts over a layered media. Two cases of a top layer overlying a more resistive basement and a conductive top layer overlying a resistive basement were considered with a radio frequency of 125kHz and a VLF of 20kHz, which are within the range of the far field and quasi-static approximations. The model was tested using data from existing models and was then applied to homogeneous and layered earth media. The results from the models reveal among others, that the phase of the Amplitude of the correction to the wave tilt is the most diagnostic of the changes in the layer parameters. It was also observed that the two modes of reflection coefficient (TM and TE) are always a mirror image of each other, for the two frequencies considered. The variation in the dielectric constant of the layers also reveal some facts worthy of note.