GPS antrosios klasės tinklo sudarymo darbai

Abstract

Activities of the Institute of Geodesy, Vilnius Technical University on establishement of GPS second order network in 1995 are described. GPS second order network was densified from points of GPS first order network established in 1993. The establishement of network was perpormed following the technical conditions and regulations of Natonal Land Survey. Average distance between points of GPS second order network is 7-10 km. Points of GPS first and second order networks are forming homogenious network with density 1 point for 64 square kilometres. GPS second order network was started to establish in 1994. Design of network, preparation and GPS observation activities are described. Observations were performed with four Ashtech P-12 and four Ashtech M-XII GPS receivers. Adjusted coordinates of GPS second order network - geodetic latitude, geodetic longitude and errors of ellipsoidal heights respective to the GPS first order points are smaller than 4 mm. Largest relative error is 1.5 ppm and error of average lengh of baseline is 0.3 ppm. Catalogue of GPS second order network points was created. 376 points of GPS second order network have been established during 1995. GPS second order network was tied to the second order network, established by the Institute of Geodesy in 1994 in the North West of Lithuania. Total number of coordinated points of GPS second order network is 490. Establishment of GPS second order network is planned to end in 1996.