Establishment of Geodetic Coordinate Systems - Geodesy: Introduction to Geodetic Datum and Geodetic Systems - page 357

Table 7.3 Datum definition adopted by ITRFyy
ITRF
solutions Origin

Time evolution of the
orientation Scale Orientation

ITRF0 BTS87 BTS87 BIH EOP -

ITRF88 ITRF0 ITRF0 ITRF0 Recommended

AMO-2

ITRF89 SLR[SSC(CSR)] SLR[SSC(CSR)] ITRF88 Recommended

AMO-2

ITRF90 SLR[SSC(CSR)] SLR[SSC(CSR)] ITRF89 Recommended

AMO-2

ITRF91 SLR[SSC(CSR)] SLR[SSC(CSR)] ITRF90 NNR wrt

NNR-NUVEL1

ITRF92 SLR[SSC(CSR)] SLR[SSC(CSR)] ITRF91 NNR wrt

NNR-NUVEL1A

ITRF93 SLR SLR IERS EOP IERS EOP series

ITRF94 SLR +GPS SLR +GPS +VLBI ITRF92 NNR wrt

NNR-NUVEL1A

ITRF96 SLR +GPS SLR +GPS +VLBI ITRF94 NNR wrt ITRF94

ITRF97 SLR +GPS SLR +GPS +VLBI ITRF96 NNR wrt ITRF96

ITRF2000 SLR (origin rate def-
inition included)

SLR +VLBI (scale rate
definition included)

ITRF97 NNR wrt

NNR-NUVEL1A

ITRF2005 SLR VLBI ITRF2000 NNR wrt ITRF2000

ITRF2008 SLR VLBI + SLR ITRF2005 NNR wrt ITRF2005

increasing. Hence, new computational results of coordinates and velocities are
regularly published.
The maintenance of CTRF, namely the retention of its dynamic features, pri-
marily depends on the velocity field in actual measurement; for instance, the GPS
Continuously Operating Reference System (CORS) network has a large amount of
continuous observational data, which can be used to compute the station velocities
and to provide observational data for maintenance of the TRF.

7.4.4 International Terrestrial Reference Frame and The

World Geodetic System 1984

ITRF

The Establishment of ITRF

The International Terrestrial Reference Frame (ITRF) is a realization of the Inter-
national Terrestrial Reference System (ITRS). The definition of ITRS is coincident
with that of CTRS. The ITRF was established through a set of station coordinates
(SSC) and station velocities derived from observations using space geodetic