Compare: ITRF, IGS08, WGS84 and NAD83 Print

For every reference system, specify the datum tag (also called frame tag), and epoch time

For example for the reference frame NAD83(2011) epoch 2010.00 these are –

Reference system: NAD83

Datum/frame tag: (2011), year adjustment completed

Epoch time: 2010.00, control station position at midnight Jan 1, 2010

While not specified, the antennae calibration value is attached to each particular reference frame and distinguishes these frames as well.


Reference frame definitions

·         ITRF frame (global): multi-technique (vlbi, slr, foris, gnss)

·         IGS frame (global): GNSS only

·         NAD83 frame (plate fixed): related to ITRF/IGS

   Frame name                                          Epoch                  Antennae PCV

   ITRF2000                                             1997.00                    Rel

   ITRF2000 (NGS)                                   1997.00                    Rel NGS

   NAD83(CORS96)                                  2002.00                     Rel NGS  

   NAD83(PacP00)                                    2002.00                     Rel NGS  

   NAD83(MarP00)                                    2002.00                     Rel NGS 

   IGS08                                                   2005.00                     Abs IGS08

    IGS08 (NGS)                                        2005.00                     Abs IGS08

   NAD83(2011)                                     2010.00                     Abs NGS

   NAD83(PA11)                                     2010.00                     Abs NGS

   NAD83(MA11)                                    2010.00                     Abs NGS

* Standard Antennae Calibration Value (phase center value - PCV)

   moved from Relative (Rel) to Absolute (Abs).

Source for above chart