Relations between the apparent resistivity and true resistivity in a homogeneous transversely-isotropic medium. If resistivities perpendicular and parallel to the bedding are ${\displaystyle \rho _{\perp }}$ and ${\displaystyle \rho _{\parallel }}$, respectively, the apparent resistivities in the transverse and longitudinal directions ${\displaystyle \rho _{aT}}$ and ${\displaystyle \rho _{aL}}$ are:
${\displaystyle \rho _{aT}=\rho _{\parallel }}$
${\displaystyle \rho _{aL}={\sqrt {(\rho _{\perp }\rho _{\parallel })}}}$