Geodesy
Geodesy is a very old industry of science and practice. Its origins have to date before our era in ancient Egyptian countries. As a science sector, it was and is closely linked to both astronomy and physics, geophysics, mathematics, but today it is not conceivable without cosmic research and links with other sciences. It can be said that geodesy is the basis for all modern life. We cannot today imagine our lives without residential, cultural and recreational buildings, without our jobs, without travelling. All of this is based, both directly and indirectly, on geodesy.
Planet Earth is in the process of evolution. The Earth's crust, along with the upper mantle, is in continuous motion: horizontal and vertical direction. The Earth's crust movements move lithosphere plates, creating mountains and valleys, changing shorelines, changing sea and ocean levels, etc.
The operation of the internal and external forces of the earth (Sun and Moon) results in various deformation of the surface of the earth over time, which is of great practical importance. Geodesy is a science industry that studies the shape and size of planet Earth, its gravitational field, as well as practicing measurements on the surface of the earth for its display in the form of plans, maps and data acquisition for various tasks. Geodetic, gravimetric and magnetometric measurements shall be performed to address practical and scientific tasks. For reducing measurements in a single coordinate system, geodetic networks are created. Geodetic networks shall consist of a set of geodesic points with one type of characteristics determined as a result of cross-measurement.
By January 1, 2006, the State geodesy functions were taken over by the State Agency's “Latvian Geospatial Information Agency” (LGIA) Geodesy Department from the State Land Service. By May 5, 2010, in the process of optimizing the structure of LGIA, a Geography and Cartography Department was established, consisting of the Geodesy Division, and the Geodesy Department was again separately distributed by September 29, 2018.
Main functions in the field of geodesy:
- create, maintain and realize a geodetic reference system consisting of a coordinate reference system, a height reference system, gravimetric systems and a geo-magnetic network, defined in theory and in nature by a national geodesic network;
- ensure interlinking of the geodetic reference system with international reference systems;
- monitor the Geodetic Network Information System, including store and update data in the National Geodetic Network database and monitor the Local Geodetic Network database;
- manage the geodesic circle of Struve in Latvia;
- create and maintain the Global Positioning Base Station System “Latvian Positioning System”;
- measurement of the country border - determine the geodetic coordinates of the country border lines and landmarks.
Main tasks in the field of geodesy:
- carry out the maintenance work of the National Geodetic Network – identification, assessment, development (including the installation of geodesic points), measurements, monitoring and ensuring the circulation of information on points of the National Geodetic Network;
- perform processing and analysis of the measurement data of the National Geodetic Network;
- maintain and develop a national quasi-geoid model;
- accumulate and update the information of the National Geodetic Network in the National Geodetic Network database;
- supervise the operation of the Local Geodetic Network Database and, in accordance with regulatory enactments, administer the Local Geodetic Network Database and approve the improved coordinates and heights of the Local Geodetic Network points;
- provide methodological support to local authorities in developing a Local Geodetic Network, updating geodetic data and circulating geodetic information, and preparing Agency opinions on Local Geodetic Network documentation;
- to create, maintain and improve LatPos, including storage, processing, systematization and analysis of LatPos base station information;
- carry out surveys and demarcation of the country border.