[IGSMAIL-6845] igs08_1771.atx: Update including reactivated Block IIR-M satellite SVN49/PRN30

[Ralf Schmid]

Dear IGS colleagues!

The absolute IGS antenna correction file (igs08_wwww.atx) has been 
updated. The new release is called 'igs08_1771.atx'. It contains the 
following changes:

1) According to NANU 2013080, Block IIR-M satellite SVN49 resumed 
transmitting L-band utilizing PRN30 on 19 December 2013. Therefore, the 
following satellite has been added to igs08.atx:

G30 (G049)

Source:
> NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2013080 NANU TYPE: GENERAL
> *** GENERAL MESSAGE TO ALL GPS USERS *** ON APPROXIMATELY 19 DEC 2013, SVN49 WILL RESUME TRANSMITTING L-BAND UTILIZING PRN30. AT L-BAND ACTIVATION, SVN49/PRN30 WILL BE UNUSABLE UNTIL FURTHER NOTICE. ADDITIONALLY, NO BROADCAST ALMANACS WILL INCLUDE SVN49/PRN30 UNTIL FURTHER NOTICE.
http://www.navcen.uscg.gov/?Do=gpsShowNanu&num=2013080

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

G30 (G027): 17 December 2013

According to the IGS tracking statistics as provided by CODE, G30 data 
is not available for DOY 352 (18 December 2013):
ftp://ftp.unibe.ch/aiub/igsdata/odata_gnss_day.txt


The updated antenna correction model is available at
ftp://igs.org/pub/station/general/igs08_1771.atx
or
ftp://igs.org/pub/station/general/igs08.atx

Thanks to Richard Langley for his help!

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