[IGSMAIL-6418] Update: igs08.atx: z-offset update for GLONASS-K1 satellite R04/R801

[Robert Khachikyan]

Dear IGS colleagues!

The absolute IGS antenna correction file (igs08_wwww.atx) has been
updated. The new release is called 'igs08_1643.atx' and should be used
starting with GPS week 1643 (3 July 2011). It contains the following
changes:

1) The z-offset of GLONASS-K1 satellite R04/R801 has been changed from
0.00 cm to 175.00 cm using an initial estimate provided by Stefan Schaer
(CODE). As only few data are available so far, the new z-offset value is
still preliminary and might be updated once more in a few months.

All GLONASS AC results starting with GPS week 1643 will be based on the
new z-offset value. Sorry for any inconvenience this may cause!

2) Two robot calibrations provided by Trimble Navigation Ltd. and
performed by the University of Hannover:

TRM59900.00     NONE
TRM59900.00     SCIS

Although not valid before 3 July 2011, the updated antenna correction
model is already available at
ftp://igs.org/pub/station/general/igs08_1643.atx
or
ftp://igs.org/pub/station/general/igs08.atx

With best regards,
Ralf Schmid and Robert Khachikyan
on behalf of the IGS Antenna Working Group