Unification Of Polish Local Vertical Datum With Global Vertical Datum

The aim of this study is to determine the gravity potential difference Delta W between the Kronsztadt86 local vertical datum in Poland and the global vertical datum. The computation is based on the use of ellipsoidal heights from satellite observations, normal heights obtained from the levelling campaign and quasigeoid/ellipsoid separations computed from the EGM2008 geopotential model. This study is revised version of previous computations by taking into account the influence of vertical movements of Earth's crust, and unification of the tide systems in satellite and levelling networks. Computed value of potential difference between the local and global vertical datum vary from 0.158 m(2)s(-2) to 0.606 m(2)s(-2) which correspond to 2 cm and 6 cm respectively. The results indicate that there are still unexpected differences in the estimated value of the parameter Delta W, computed from three different satellite networks: POLREF, EUVN-DA and ASG-EUPOS.