A method for active polarization compensation for a scanning goniometer is presented. This is part of instrumentation constructed for measurements of light scattering by particulates in a high voltage spark. Individual optical element characterization is made using ellipsometry. Mueller matrix calculations are used to model the optical system. The inverse of the optical system is used to calculate the necessary input polarization state. A polarized source with angularly controlled halfwave and quarterwave retarders is used to introduce the necessary polarization state into the goniometer.