The SCAR GPS Campaigns have been carried out since 1995. Based on these data a densification of the Terrestrial Reference Frame (ITRF) in Antarctica has been performed. The results can be used for precise positioning, navigation and validation purposes. Furthermore, the station velocities were obtained. Based on these vectors the kinematics of the Antarctic plate could be determined and an active rifting of 7 mm/year across the Bransfield Strait was measured. Vertical rates are important for the validation of models on glacial isostatic adjustment. The activities are being continued and extended during the International Polar Year within the POLENET project.