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Subject: [IGSMAIL-5456]: RE: IGS05 Fine Tuning
Date: Fri, 3 Nov 2006 13:13:27 -0500
Message-ID: <159FD28F03D76E468EE6650EB50072D001CFB1D9@S0-OTT-X2.nrn.nrcan.gc.ca>
Thread-Topic: IGS05 Fine Tuning
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From: =?iso-8859-1?Q?Ferland=2C_R=E9mi?= <RFerland@NRCan.gc.ca>
To: =?iso-8859-1?Q?Ferland=2C_R=E9mi?= <RFerland@NRCan.gc.ca>,
  <igsmail@igscb.jpl.nasa.gov>
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IGS Electronic Mail      03 Nov 10:13:29 PST 2006      Message Number 5456
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Author:  R. Ferland

Dear colleagues,

	Please note that I have just reposted an updated IGT05.snx.
Thanks to Stefan Schaer for pointing out a problem.

Sorry for the inconveniences,
Best Regards,
Remi,

> -----Original Message-----
> From: Ferland, Rimi
> Sent: November 3, 2006 10:51
> To: 'igsmail@igscb.jpl.nasa.gov'
> Subject: IGS05 Fine Tuning
>
> Author:  R. Ferland
>
> Dear colleagues,
>
> 	Following several feedbacks received the last couple of
> weeks, I am proposing minor last minute "fine tuning" to the
> IGS realization of ITRF2005. 4 stations are affected:
>
> Addition:
> =========
>
> CORD:	This station was in earlier proposed realizations. It had
> 	been removed because the station was decommissioned.
> 	The station will be recommissioned and the same equipment
> 	will be reinstalled! (D. Stowers).
> 	This is conditional to the coordinates time series resumes
> 	without discontinuity.
>
> LHAZ	To replace LHAS (a few meters away) suggested by R. Stoeger.
> 	At the site all ACs have been using one or the other.
> 	2 ACs have been using LHAZ regularly.
>
> Deletion:
> =========
>
> GOUG	Data problems. Likely difficult to improve in the
> 	short term due to the remoteness of the station.
>
> FAIR	Due to the gradual degradation of the residuals (mainly in
> 	the North/South component). The cause is likely related to
> 	non-linear motion due to post-seismic effects caused by the
> 	Delani earthquake.
>
> 	Those deletions are very unfortunate as the two
> stations have some very desirable characteristics.
>
> Other Stations:
> ===============
>
> 	The coordinates & velocity changes of the other
> stations between the current and updated proposed realization
> are unchanged (<< 0.1mm & << 0.1mm/y). This applies to both
> versions of the realization IGS05 & IGT05.
> The total number of stations in remains 132.
>
> The update can be found at the usual location:
>
> ftp	macs.geod.nrcan.gc.ca
> cd	/pub/requests/sinex/IGS05
>
>
> Transformations:
> ================
>
> 	For those of you who may want the transformation from
> IGS05 (with absolute antenna phase center) and IGb00
> (relative antenna phase center) they are (at epoch 2000.0):
>
>    R X (mas)   :              -0.0070
>    R Y (mas)   :               0.0340
>    R Z (mas)   :              -0.0069
>    T X (m)     :              -0.0003
>    T Y (m)     :              -0.0015
>    T Z (m)     :              -0.0061
>    SCL (ppb)   :               0.7125
>  d R X (mas/y) :               0.0033
>  d R Y (mas/y) :              -0.0001
>  d R Z (mas/y) :              -0.0161
>  d T X (m/y)   :              -0.0004
>  d T Y (m/y)   :               0.0007
>  d T Z (m/y)   :              -0.0018
>  d SCL (ppb/y) :               0.1748
>
> 	Note that the transformation of the IGS realization,
> using relative phase center only, they have been provided in
> the earlier e-mail (Sect. 4-1):
> http://igscb.jpl.nasa.gov/mail/igsmail/2006/msg00170.html
>
> A comparison of the two sets of transformations indicates
> that the phase center change causes variations in the
> transformations:
> 	Rotations	< 0.02mas,
> 	Translation	< 1mm,
> 	Scale		< 0.2ppb
> The effect on the rates is negligible.
>
> 	Starting with GPS week 1400, the "parallel" solutions
> using the absolute phase center provided by the ACs will
> become the official solutions. This imply that there won't be
> any combination for those parallel solutions posted at the usual ftp.
>
> The cooperation of all those that have been contributing to
> this long transition phase is very much appreciated!
> Thanks also to all of those that have been providing feedback
> on the various versions of the proposed realization!
>
> Sorry for any inconveniences,
> Best Regards,
> Remi,
>