* <math>( \mathbf{ \hat{u}_{\|}, \hat{u}_{\perp}, \hat{k} } )</math> representing the incident parallel polarization vector, incident perpendicular polarization vector and incident propagation vector, respectively.
* <math>( \mathbf{ \hat{u}_{\|}'^{\prime}, \hat{u}_{\perp}', \hat{k}' } )</math> representing the reflected parallel polarization vector, reflected perpendicular polarization vector and reflected propagation vector, respectively.* <math>( \mathbf{ \hat{u}_{\|}''^{\prime\prime}, \hat{u}_{\perp}'', \hat{k}'' } )</math> representing the transmitted parallel polarization vector, transmitted perpendicular polarization vector and transmitted propagation vector, respectively.
The reflected ray is assumed to originate from a virtual image source point. The three triplets constitute three orthonormal basis systems. Below, it is assumed that the two dielectric media have permittivities ε<sub>1</sub> and ε<sub>2</sub>, and permeabilities μ<sub>1</sub> and μ<sub>2</sub>, respectively. A lossy medium with a conductivity σ can be modeled by a complex permittivity ε<sub>r</sub> = ε'<sub>r</sub> âjσ/ε<sub>0</sub>. Assuming '''n''' to be the unit normal to the interface plane between the two media, and Z<sub>0</sub> = 120Ω , the incident polarization vectors as well as all the reflected and transmitted vectors are found as: