Prism effects on total station measurements: steps towards computational correction

Systematic effects on total station measurements arising from solid glass corner cube prisms can lead to deviations at the mm-level. We show that these deviations can be mitigated by forward modeling based on geometrical optics and assumed properties of the reflectors, or by empirical modeling based on calibration measurements with a variety of reflector poses. Establishing the forward model is less costly, but some empirical modeling is required to derive necessary pa-rameters which are not disclosed by the manufacturers. Empirical modeling can better account for specific deviations of individual prisms and for deviations related to the particular data pro-cessing within a total station. Corrections obtained by modeling are applicable to measurements of moving prisms, e.g., for tracking drones or construction machines, and to geodetic network measurements where differences exceeding 5 mm could result from uncorrected prism effects even when using high-precision single prisms.