2. Key Activities
  3. Geodesy
  4. Very Long Baseline Interferometry (VLBI)

Very Long Baseline Interferometry (VLBI)

Very Long Baseline Interferometry (VLBI)
  • Geodetic origin point
  • Triangulation
  • Measurement of Unified Control Point
  • Leveling
  • Gravity Surveying
  • Geomagnetism Surveying
  • Very Long Baseline Interferometry (VLBI)
Very Long Baseline Interferometry (VLBI)
When multiple telescopes (antennas) simultaneously receive radio waves from quasars billions of light years away, VLBI in land surveying can obtain precise measurements of the time differences between the arrivals of radio waves. By analyzing such measurements, VLBI can obtain a highly precise configuration of observational stations.
  • How VLBI works
  • How VLBI works
  • How VLBI works
National Geographic Information Institute has started the basic planning and implementation design project for introducing the geodetic VLBI from 2006 to improve the precision of the national geodetic control point of Korea and to study the crustal displacement. From 2008 to 2011, the geodetic VLBI observation equipment and observatory building construction completed.
Geodetic VLBI is operated in 15 countries (about 30 antenna operation) around the world, and Korea has introduced geodetic VLBI as the 16th (3rd of Asia) in the world
In February 2012, we successfully conducted the geodetic VLBI test observation, participated in the 7th International VLBI Organization (IVS) General Assembly, and made a presentation on the current state of construction of the Geodetic VLBI system, future observation plan, linkage between VLBI observation performance and ground control point. In addition, by submitting an application for joining IVS's formal member countries and Network Station of Geodetic VLBI Observation Station (Sejong-si Space Geodetic Observation Center), IVS Board of Directors approved the formal membership at the regular general meeting.
On March 27, 2012, the completion ceremony of Sejong Space Geodetic Observation Center was successfully held with more than 250 people attending, such as the Minister of Land, Transport and Maritime Affairs, the Chief Executive Officer, Chungnam Administrative Governor, Survey Association President, Children’s Map Drawing Contest winners and officials and etc. Sejong Space Geodetic Observation Center consists of 22 meters in diameter of the main observation equipment such as the geodetic VLBI antenna and the receiver, and the advanced observatory building of 2 floors above ground and 1 underground floor. The observatory building has a land area of 7,412㎡ and the building floor area is 1,026㎡, and it has various facilities such as observation office, data analysis office, and public relations centers.
Through the introduction of the geodetic VLBI and fully operation of the Space Geodetic Observation Center, it is expected to contribute to the prevention of natural disasters such as earthquakes by precisely observing long distance survey between countries and intercontinental crustal fluctuations.
  • Bird’s-eye view of VLBI observatory in Sejong City Bird´s-eye view of VLBI observatory in Sejong City
The operation of the VLBI system for geodesy will enable the creation and management of precise measurements of the Korean geodetic horizontal datum, which serves as the basis for all surveying efforts, and improve the accuracy of surveying. The system will also help Korea participate in joint observations, such as intercontinental research on diastrophism, to prepare for natural disasters that can affect the entire planet, thereby contributing to international society and heightening Korea’s role on the global stage. Moreover, Korea will gain advanced technology for surveying the universe, thanks to the techniques of highly precise measurements (within a few millimeters of error per 1,000km).