In optical belt sorting accurate predictions of the bulk material particles' motions are
required for high-quality results. By implementing a multitarget tracker tailored to the
scenario and deriving novel motion models the predictions are greatly enhanced. The tracker's
reliability is improved by also considering the particles' orientations. To this end new
estimators for directional quantities based on orthogonal basis functions are presented and
shown to outperform the state of the art.
