REFGR on Greenland

Between 1996 and 2001, the National Survey and Cadastre established the Greenlandic reference network REFGR. This network consists of 258 GPS-surveyed points, most of which are located along the more populated west coast. However, reference points have also been established on the east coast at Illoqqortoormiut (Scoresbysund) and Tasiilaq (Ammassalik).

The REFGR reference network is the foundation for the GR96 reference system. Its component reference points are illustrated on the map below. 

Prior to the use of GPS satellites and the development of REFGR, a triangulated survey network was used to determine Greenland’s geodesy. This network was developed over a 60-year period that ended with the launch of GPS-based surveying. Theodolites were used to measure the angles between the component triangles in a network of 6000 reference points.

With the advent of Doppler satellite technology in the 1970s, Greenland’s triangulated reference network was supplemented with approximately 350 readings from the TRANSIT navigation system.  All 6000 points were subsequently updated when GPS technology came online in the 1990s. They were also assigned coordinates within the GR96  reference system.