ITRF 2000 Reference Frame

The standing resolution on the use of geodetic datums in Antarctica requires

That members adopt the International Terrestrial Reference Frame 2000 (ITRF2000) at an epoch of 2000.0 together with the GRS80 ellipsoid, as the geodetic datum for all Antarctic activities.

(SCAR GSSG Standing Resolution since SCAR XXVII, Shanghai 2002)

The relationship of ITRF and WGS84

These days most research related mapping activities on the ground are carried out using GPS. In such activities it would be convenient to use the WGS84 datum including the WGS84 ellipsoid. So how does that fit to the recommended use of ITRF2000 and GRS80?

This question is mainly related to the absolute positional accuracy required. As long as you are fine with an absolute accuracy in the decimeter range you are safe to use WGS84.

The more recent realizations of WGS84 (such as WGS84 G730 or G873) are coincident with ITRF at about 10-centimeter level. Consequently one can consider that ITRF coordinates are also expressed in WGS84 at 10 cm level. The WGS84 ellipsoid can be regarded identical with the GRS80 ellipsoid. The only difference being the way of defining certain parameters is not of concern to mapping applications.

If you need more accurate absolute positions you should consider working in a geodetic network that is tied to an ITRF station. The SCAR GIANT programme is reponsible to establish and maintain a high precision geodetic infrastructure for Antarctica.

Read on for more on GIANT, ITRF and Antarctica, and the SCAR Epoch Crustal Movements Campaigns.