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Subject: [IGSSTATION-1733]: IGS05 Review - MAC1 - OHI2
Date: Tue, 21 Aug 2007 11:14:58 -0400
Message-ID: <159FD28F03D76E468EE6650EB50072D004F7FCD2@S0-OTT-X2.nrn.nrcan.gc.ca>
Thread-Topic: IGS05 Review - MAC1 - OHI2
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From: =?iso-8859-1?Q?Ferland=2C_R=E9mi?= <RFerland@NRCan.gc.ca>
To: <igsstation@igscb.jpl.nasa.gov>
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IGS Station Mail          21 Aug 08:15:01 PDT 2007      Message Number 1733
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Author: Remi Ferland

Dear IGS Colleagues,

        Starting with the IGS sinex combination of GPS week 1439,
station MAC1 and OHI2 will not be used for the IGS realization of
ITRF2005 in the weekly SINEX combination.

MAC1:
=====

        The difference between the weekly solutions and the
IGS realization at the epoch of the weekly, has gradually degraded
in the North component. It has recently reached ~12-15mm
for all Acs using that station.
The gradual degradation suggest a potential problem with the
estimated velocity. However, for that station, the IGS realization
of ITRF2005 and the most recent IGS cumulative solution agree in
velocity at the mm/y level. There is also a small bias (~5mm)
in the north component between the IGS realization and the
recent cumulative.

IGS05 -   IGS07P30.snx (at 2005.0):
 Code Pt Soln d  d. Lat  d. Lon  d. Hei  d.VLat  d.VLon  d.VHei
                   (mm)    (mm)    (mm)   (mm/y)  (mm/y)   (mm/y)
 MAC1  A    4 D     5.2     0.9    -0.5     -0.1     0.6     0.4

So for those requiring the best IGS realization accuracy,
I suggest not to use this station in IGS05.snx for IGS
realization purposes.

OHI2:
=====
        The difference between the weekly solutions and the
IGS realization at the epoch of the weekly, have been different
in the East component at about 16-18mm for a few weeks. Based
on long time series, this may be a temporary situation. I suggest,
at least for now, not to use this station for IGS realization.
It may be reintroduced if the situation changes.

Note: the nearby OHI3 station, which is also part of the IGS
realization, is currently better behaved.


Best Regards,
Remi,