“…Furthermore, because of the small amount of data available we shall assume a constant anisotropic conductivity. With these simplifying assumptions, the problem is analytically tractable and, for the full‐space case, the electrical potential at an electrode r e produced by a unit current source point r s reads (Das & Li 1996), where is the electrical resistivity tensor with components ρ αβ =σ −1 αβ . In practice, the resistivity tensor is often given in terms of both its principal values, (ρ 1 , ρ 2 , ρ 3 ), expressed in Ω.…”