[IGSMAIL-3605]: Towards ITRF2000

[Weber Robert]

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IGS Electronic Mail      20 Nov 12:22:49 PST 2001      Message Number 3605
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Author: AC Coordinator


Dear IGS colleagues,

Pleased be informed that IGS Analysis Centers will begin to use the IGS
realization of ITRF2000 (IGS00) with GPS week 1143, which starts on 
December 2, 2001. This implies that simultaneously all IGS products 
will be based on ITRF2000. 

At the same time the set of reference stations (RF) will be slightly
enhanced from 51 to 54 sites.

Included below is preliminary information from the IGS Reference Frame 
Coordinator, Remi Ferland, on the transformation parameters between 
IGS97 and IGS00.

    best regards,

          Robert Weber 

ps: The complete set of ITRF2000 coordinates may be found at:
    ftp://lareg.ensg.ign.fr/pub/itrf/itrf2000



               -----------------------------------
The current station changes between IGS97 and IGS00 are:
	
	Removed :	BRAZ, AREQ
	Added	:	ASC1, CEDU, DGAR, LPGS, RIOG

The estimated transformation parameters between IGS97 and IGS00
are given below. For consistency, they were estimated as the previous
one (IGS96 - IGS97). The parameters are estimated without using
the covariance info. 


Transformation from IGS(ITRF97) to IGS(ITRF2000) at epoch 01-JAN-1998:
====================================================================
         TX     TY     TZ    RX      RY      RZ       D
         mm     mm     mm    mas     mas     mas     ppb
Offset  -6.0   -5.6   20.1 -0.040   0.001  -0.043  -1.403
+/-      2.5    3.3    5.1   .053    .060    .036    .12
--------------------------------------------------------------------
        dTX    dTY    dTZ    dRX     dRY     dRZ     dD
        mm/y   mm/y   mm/y   mas/y   mas/y   mas/y   ppb/y
Drift    0.4    0.8    1.5  0.004  -0.001  -0.030  -0.012
+/-      1.7    1.9    2.8   .038    .040    .034    .12
--------------------------------------------------------------------
* The IERS convention for the transformation parameters was followed.
* The equivalent changes in polar motion, in the sense
  (ITRF2000 - ITRF97), may be obtained using PMx = RY and PMy = RX.

When propagated at epoch 02-DEC-2001:
Transformation from IGS(ITRF97) to IGS(ITRF2000)
====================================================================
         TX     TY     TZ    RX      RY      RZ       D
         mm     mm     mm    mas     mas     mas     ppb
Offset  -4.5   -2.4   26.0 -0.024  -0.004  -0.159  -1.451
+/-      4.1    5.0    7.5   .092    .099    .076    .27
--------------------------------------------------------------------
        dTX    dTY    dTZ    dRX     dRY     dRZ     dD
        mm/y   mm/y   mm/y   mas/y   mas/y   mas/y   ppb/y
Drift    0.4    0.8    1.5  0.004  -0.001  -0.030  -0.012
+/-      1.7    1.9    2.8   .038    .040    .034    .12
--------------------------------------------------------------------

The sigmas in the second table were only a propagation of
the ones in the first table.

There are two files 

   IGS01P37_RS54.snx  and IGS01P37_RS54.notes

with the necessary information available at 
         macs.geod.emr.ca
         cd /pub/requests/sinex/rfwg


--
___________________________________________________________________________
Robert Weber                           Tel:    ++43-1-58801-12865               
Department of Advanced Geodesy         Fax:    ++43-1-58801-12896              
University of Technology, Vienna       E-Mail: rweber at luna.tuwien.ac.at
Gusshausstrasse 27-29                          robert.weber at aiub.unibe.ch
A-1040 Vienna, Austria                         
___________________________________________________________________________