ITRF combination - status and recommendations for the future

In its function as ITRS Combination Center and IERS Combination Research Center, DGFI is involved in the combination of space geodetic observations. Based on the latest space geodetic solutions provided by individual analysis centers and/or technique centers, DGFI has computed a combined solution for station positions and velocities. Major goals are: (1) a validation of the various components of the ITRS Combination Center; (2) a verification and enhancement of the combination strategy; (3) an external comparison with ITRF2000; (4) the identification of still existing deficiencies; and (5) proposals for future ITRF realisations.