The Bulgarian Academy of Sciences’ (BAS) Central Laboratory of Geodesy (CLG) is the architect of the permanent Global Navigation Satellite System (GNSS) installations in Bulgaria for controlling the Geodic networks of the state and also for a wide range of scientific applications, such as studies related to seismic danger in Bulgaria’s territory and geodynamics, sea-level monitoring, and GPS meteorology. The first CLG network stations were installed in Southwest during May 2007.
The NATO ‘Science for Peace’ program is supported financially by Bulgaria as per a project’s agenda. The CLG network stations have been installed in the BAS’ infrastructure in meteorological and seismic stations basically and are stabilized through reinforced concrete pillars having forced centering devices. Every moment data obtained via permanent observations is transmitted using Internet connections to two servers located in CLG and the BAS’ Telematics laboratory in real time. This data is stored, archived for subsequent processing and analysis at the CLG’s computing center that is accessible for all users through registrations. The QOCA scientific research, Bernese 5.0, and GAMIT/GLOBK software products help to process the results.
Currently CLG-BAS has constructed 30 stations, 15 of NAVITEC and 15 of CLG, in the National permanent GSS stations network, with 8 additional stations under construction. In this manner, the network will be able to cover the Bulgarian territory by 2010, for providing data for a broad range of scientific-practical and scientific applications in real time.
The European Terrestrial Reference Frame 89 (ÅÒRS89) of the European terrestrial reference coordinate system is created by GNSS’s very precise velocities and coordinates geodetics points network. In Europe, national GPS networks are built, maintained and controlled by respective European states, which function as a base for cartographic, geodetic and a wide range of various practical activities.
The NAVITEC Company, based on a contract between the SB Group and the CLG, provides its permanent locations’ 30 s data to CLG that subsequently ensures the process, analysis, along with offering the NAVITEC stations’ precise velocities and coordinates to the Coordinating Systems of the state, besides monitoring the station stability.