Background resistivity is fixed at 100 Ω·m. Blue = conductive (low ρₐ), red = resistive (high ρₐ).
This is a first-order teaching model: apparent resistivity is a sensitivity-weighted average of the true model around each measurement's focus point. It reproduces the characteristic smearing and the array differences, but it is not a full numerical solution. The real inversion problem is to recover the true model from a pseudosection like this.