[IGSMAIL-6825] igs08_1758.atx: Update including reactivated Block IIA satellite SVN37/PRN30

[Ralf Schmid]

Dear IGS colleagues!

The absolute IGS antenna correction file (igs08_wwww.atx) has been 
updated. The new release is called 'igs08_1758.atx'. It contains the 
following changes:

1) According to NANU 2013054, Block IIA satellite SVN37 "will resume 
transmitting L-band utilizing PRN30 on approximately 19 SEP 2013". 
Therefore, the following satellite has been added to igs08.atx:

G30 (G037)

The date (currently 18 September 2013 in igs08_1758.atx) might be 
corrected with the next release.

Source:
> NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2013054 NANU TYPE: GENERAL
> *** GENERAL MESSAGE TO ALL GPS USERS *** On approximately 19 SEP 2013
> SVN37 will resume transmitting L-band utilizing PRN30. At L-band
> activation, SVN37/PRN30 will be unusable until further notice.
> Additionally, no broadcast almanacs will include SVN37/PRN30 until
> further notice.
http://cgls.uscg.mil/pipermail/nanu/2013-September/001525.html

2) A decommission date for the following satellite has been added:

G30 (G032): 16 September 2013

According to the IGS tracking statistics provided by CODE 
(ftp://ftp.unibe.ch/aiub/igsdata/odata_gnss_day.txt), SVN32 stopped 
signal transmission on 16 September 2013 (DOY 259).

The updated antenna correction model is available at
ftp://igs.org/pub/station/general/igs08_1758.atx
or
ftp://igs.org/pub/station/general/igs08.atx

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