Geodetic control represents a reference base for unequivocal spatial and temporal localization of spatial and physical information in geodetic reference systems with prescribed accuracy; they comprise the points of specialized national geodetic networks (National spatial network, National trigonometric network, National levelling network and National gravimetric network), the system of means and procedures defining their parameters with prescribed accuracy and documentation, reference models representing relation between the frames of geodetic reference systems and services allowing work in real time or post-processing, or data transformation between the systems.
Administrator of Slovakian geodetic control (GZ) is Geodetic and Cartographic Institute Bratislava (GKÚ), GZ department. The department fulfils tasks involving GZ complex administration. It carries out preparatory, reconnaissance, survey, checking, processing, analytical, updating, optimization, transformation, documentation, archival and administration work in the GZ section. It provides link of national geodetic systems and frames to international geodetic reference systems and their frames. It addresses the interoperability of geodetic measurements and services in cooperation with domestic partner organizations both within and outside the Geodesy, Cartography and Cadastre Authority (ÚGKK SR) scope and with foreign partners (especially with neighbouring countries) through agreements approved by expert groups and relevant contracts. The department ensures that the data and information are updated and modernized on the intranet and internet portals, and in data storages and also cooperation between the Institute departments providing the data. The department cooperates in developing technologies, rules, directions, conceptions, standards and legislation in the field of GZ. To provide the tasks, the department establishes specialized sections, whose work it coordinates and controls. GZ administration is described in detail also in the Regulation of ÚGKK SR No. 300/2009, Coll., implementing the Act of the National Council of the Slovak Republic No. 215/1995 on geodesy and cartography as amended by later regulations.
For the maintenance of the state geodetic network points is used Geodetic Control Information System (ISGZ), which is part of Geodesy, Cartography and Cadastre Information System.
Division of Geodetic Control
Under the current legislation (ÚGKK SR No. 300/2009 Coll. Regulation) implementing the Act of the National Council of the Slovak Republic No. 215/1995 Coll. on Geodesy and Cartography as amended by later regulations) GZ control is divided into:
- Active GZ – comprises Slovak real-time observation service,
- Passive GZ – comprises GZ survey control points, parameters of which are determined at least in one binding geodetic system and are incorporated in specialized national geodetic networks.
According to the type (character) of reference base, GZ can be divided also into:
- GZ services – included are e.g. SKPOS and transformation services within ÚGKK SR,
- GZ minor control – points of specialized national geodetic networks with determined parameters.
According to the way parameters are obtained, GZ can also be divided as follows:
- GZ for online use – included are mainly GZ services, by means of which the results or parameters in reference geodetic systems can be obtained in real time,GZ for post-processing – included are particularly points of specialized natinal geodetic networks and post-processing services of GZ, by means of which results or parameters in reference geodetic systems can be obtained only after the survey has been carried out.
- GZ for post-processing – included are particularly points of specialized natinal geodetic networks and post-processing services of GZ, by means of which results or parameters in reference geodetic systems can be obtained only after the survey has been carried out.