The EUREF (International Association of Geodesy (IAG) Reference Frame
Sub-Commission for Europe) network of continuously operating GPS stations (EPN)
was primarily established for reference frame maintenance, and also plays an
important role for geodynamical research in Europe. The main goal of this paper
is to obtain an independent homogeneous time-series of the EPN station
coordinates, which is also available in SINEX format. A new combined solution
of the EPN station coordinates was computed. The combination was performed
independently for every week, in three steps: 1. the stated constraints on the
coordinates were removed from the individual solutions of the Analysis Centers;
2. the de-constrained solutions were aligned to ITRF2000; 3. the resulting
solutions were combined using the Helmert block-ing technique. All the data
from GPS week 900 to week 1302 (April 1997 - December 2004) were used. We
investigated in detail the behavior of the transformation parameters aligning
the new combined solution to ITRF2000. In general, the time-series of the
transformation parameters show a good stability in time although small
systematic effects can be seen, most likely caused by station instabilities. A
comparison of the new combined solution to the official EUREF weekly combined
solution is also presented