Lietuvos teritorijos trianguliacijos tinklai. Istorija ir dabartis

Abstract

The first triangulation network on the Lithuanian area was established in 1816-1821. It was designed and measured by a tzarist Russian military officer K.Tenner. Weakly monumented stations of the network were soon destroyed, but the results of measurements were employed for determining parameters of the Bessel spheroid (ellipsoid) and used for about 100 years in many countries. In Lithuania between the World War First and Second, the first order triangulation networks connected with the Baltic chain were established. These works were organised and performed by Eng. M.Ratautas. In measuring procedures of this chain Lithuania took part together with other countries surrounding the Baltic Sea. These measurement results had not lost their importance until the development of the Global Positioning Systems GPS or the satellite geodesy approach. At the end of the World War Two, Soviet military services developed the triangulation networks of the second, third and fourth orders on the area of occupied territories of Lithuania. By using these networks a topographic map at scale of 1:25000 was compiled. The accuracy of this network was hot high. Since 1992 a State network has been created by means of methods and instruments of GPS. In some stations of the triangulation coordinate errors exceeding 0,3 - 0,4 m were made. At present State geodetic networks in Lithuania are being developed only by means of GPS. A large part of State geodetic reference stations are, however, not monumented by sufficiently stable or permanent markers.