Integration of the Lithuanian vertical network into united European leveling network

Abstract

The geodetic height systems adoption is crucial in development of national geodetic reference. Successful solution of this questions guarantees the reliable determination of geopotential heights, usage of modern geodetic space techniques, maintenance of the navigation, geodetic and cartographic works, solution of geodynamic tasks, support the relations between the similar systems of other countries, participation in the international projects. The gravity and height systems should be related with the geocentric geodetic coordinate system. In Lithuania such a system was adopted in 1994 as a Lithuanian Coordinate System (LKS 94). It is consist with European Terrestrial Reference System 1989 (ETRS 89). In 1994 with adoption of LKS 94 the normal gravity field GRS 80 was introduced. It was recommend by the International Association of Geodesy (IAG). To introduce the new gravity system instead of Potsdam system the absolute gravity measurements were carried out in 1994. The 5 µGal precision of the gravity acceleration was derived. From 1998 to 2001 the National first order gravimetric network was observed. There are 51 gravimetric points in the National first order gravimetric network, evenly distributed in the territory of country. The Baltic Sea height system defined by Kronshtadt datum is still in use in Lithuania. Therefore Lithuania is participating in the United European Levelling Network (UELN) and European Vertical Network (EUVN) project, and is planning to adopt the common European Vertical System. Lithuania participates in the all main European projects related to gravity and heights system development. The works on development of the Lithuanian National Geodetic Vertical Network were finished in 2007. That creates the strong premises for the Lithuanian gravity and height systems adoption.