Datums

As Fugro's GNSS augmentation services undergo continuous improvement, routine accuracies at centimetric level are becoming possible (with a subscription to an appropriate service) for our global PPP (orbit and clock) corrections, and at greater and greater distances from our reference stations, for our differential network (DGNSS) corrections.

In order to maintain consistency, all the stations in the network are coordinated with reference to the International Terrestrial Reference Frame (ITRF). The current datum for Fugro's reference station network is ITRF2014, effective as of 15 March 2017.

ETRS89, ITRF and WGS84

The ETRS89 (European Terrestrial Reference System of 1989) is based on ITRF89, epoch 1989.0 and monitored by a network of about 250 permanent GNSS tracking stations known as the EUREF Permanent Network (EPN). .

New WGS84 realisations (since G730, 1994) are coincident with ITRF at about 10-centimetre level. For these realisations there are no official transformation parameters. This means that one can consider that ITRF coordinates are also expressed in WGS84 at 10 cm level. However, the most recent G1674 realization adopted ITRF2008 coordinates for more than half of the reference stations and velocities of nearby sites for the others. Thus, ITRF2014, ITRF2008 and WGS84 (G1674) are likely to agree at the centimetre level, yielding conventional 0-transformation parameters.

Further reading: ITRF and QPS.