The availability of GPS observations via the telemetry during GOCE's (Gravity Field and Steady-State Ocean Circulation Explorer) entire re-entry campaign enabled the generation of high quality orbit products which can be used as input to re-entry predictions. These high precision orbits can be used as reference to assess the quality of orbits generated from other sources. Here we verify the accuracy of orbits based on radar tracking data, obtained by dedicated observations with the Tracking & Imaging Radar system from the Fraunhofer High Frequency Physics and Radar Techniques institute, with respect to the a post-processed GPS based reference orbit. This leads to time-depended quantification of the orbit determination uncertainties on the re-entry predictions. Furthermore, the ballistic coefficient determined by the orbit determination and its time dependent evolution can be used to a priori estimate the attitude behaviour of GOCE, which can be compared to the telemetry. The attitude behaviour can be analysed by the use of inverse synthetic aperture radar (ISAR) images, also obtained by dedicated observation by TIRA. The effect of adding this knowledge on the attitude evolution to the re-entry predictions is evaluated.