Assessment of gravity and height anomaly changes due to a possible transition of UCS-2000 to the GRS80 ellipsoid

Although the UCS-2000 system has been in operation for nearly 20 years, it is still not fully complete — particularly in terms of its vertical component. Currently, the system is based on the Krasovsky ellipsoid and uses the Baltic Height System. The development trend of modern geodetic systems is oriented toward the creation and implementation of a unified global system, such as the various realizations of the ITRS/ITRF, which provide a coordinate framework along with the ability to determine geodetic heights.

The potential transition of the UCS-2000 system to the GRS80 ellipsoid would bring about numerous changes. However, in this article, we aim to focus specifically on the impact of such a transition on the transformants of the gravitational potential, which are widely used in geodesy, particularly in work related to height determination — namely, gravity anomalies and height anomalies (quasigeoid heights).

This study presents the differences in gravity anomalies and height anomalies calculated on the GRS80 and Krasovsky ellipsoids. The resulting height anomaly differences indicate that, in the event of transitioning the UCS-2000 system to the GRS80 ellipsoid, the values would change by approximately 0.5 to 1 meter. These are significant differences that must be taken into account in all works related to height determination.