Abstract
Greece has always been an interesting study area for the geodesists due to its intense geodynamic behaviour. Especially, the exploitation of a modern geodetic velocity field using GNSS becomes a crucial requirement for geodetic purposes. The main aim of the present study is the assessment of a modern geodetic velocity model. This procedure is based on the unification of various reference frames, implemented from individual extended GNSS campaigns in different epochs with the effective involvement of the Hellenic Military Geographic Service. The implementation of geodetic velocities in the inhomogeneous Greek velocity field improves significantly the reliability of transformations, more than 60% with respect to the horizontal component, applying a vice versa time shift to a common epoch. We also emphasise the necessity to adopt a velocity model in order to process regional GNSS networks and therefore to establish a modern semi-kinematic reference frame in Greece.
Acknowledgements
The authors are indebted to the two anonymous reviewers and the editor for their helpful suggestions. We would like also to thank all data providers: METRICA S.A., National Observatory of Athens and National Cadastre and Mapping Agency S.A. Figures in this paper were plotted with the public domain Generic Mapping Tools (GMT) software (Wessel et al. Citation2013).
ORCID
S. Bitharis http://orcid.org/0000-0003-3799-2149
N. Papadopoulos http://orcid.org/0000-0003-1940-995X