National Reference Frame
The NRF provides the connection between national geodetic and vertical datums, and international reference systems.
The following table summarises the main characteristics of the network.
| Purpose | To enable the link between official geodetic and vertical datums and international reference systems to be determined and monitored |
|---|---|
| Density | At least one geodetic datum reference mark (GDRM) on the stable part of each tectonic plate (Pacific, Australian, Antarctic) Vertical datum reference mark (VDRM) to be co-located with each GDRM |
| Accuracy | Order: 0 Tier: Horiz A (0.05 m), Vert A (0.05 m) Class: Horiz II (0.003 m, 3x10-8m/m), Vert II (0.003 m, 3x10-8m/m) Class evaluation radius: all NRF marks |
| Mark characteristics | GDRM normally continuous GNSS VDRM normally absolute gravity May co-locate with other observation systems (VLBI, DORIS) |
| Location | To enable GNSS collection (GDRM) To enable absolute gravity collection (VDRM) |
| Mark Access | Data available from LINZ website No physical access to mark |