A two - step approach to analyze European

Since 1990 the European xed station geodetic Very Long Baseline Interferometry (VLBI) network has been observing on a regular basis in order to determine crustal motion in Europe. Usually the analyses of geodetic VLBI data are set up in two diierent ways: a) to produce station coordinates for each observation epoch from independent parameter adjustments and b) to compute station coordinates at a reference epoch together with drift rate components simultaneously from solutions where station drifts are modeled directly using vector representation. In this paper we present an alternative analysis strategy which uses a two step approach. In a rst step all station coordinates are estimated as independent parameters for each session. Then in a second step topocentric drift rate vectors are computed from the individual series of station coordinates and their covariance matrices.