[IGSMAIL-6576] igs08_1685.atx: Update including reactivated Block IIA satellite SVN37/PRN24

[Robert Khachikyan]

Dear IGS colleagues!

The absolute IGS antenna correction file (igs08_wwww.atx) has been 
updated. The new release is called 'igs08_1685.atx'. It contains the 
following changes:

1) According to Stefan Schaer (CODE) BLOCK IIA satellite SVN37 is active 
utilizing PRN24 since today. Therefore, the following satellite has been 
added to igs08.atx:

G24 (G037)

The switch from SVN32 to SVN37 was announced in 'NANU 2012024':

NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2012024 NANU TYPE: GENERAL
*** GENERAL MESSAGE TO ALL GPS USERS ***
ON APPROXIMATELY 25 APR 2012 SVN37 WILL RESUME TRANSMITTING L-BAND 
UTILIZING PRN24.  AT L-BAND ACTIVATION, SVN37/PRN24 WILL BE UNUSABLE 
UNTIL FURTHER NOTICE.  ADDITIONALLY, NO BROADCAST ALMANACS WILL INCLUDE 
SVN37/PRN24.  FUTURE NANUS WILL INFORM USERS OF ANY CHANGES TO THE 
ABOVE-STATED STATUS.
http://cgls.uscg.mil/pipermail/nanu/2012-April/001406.html

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

G24 (G032): 25 April 2012


The updated antenna correction model is available at
ftp://igs.org/pub/station/general/igs08_1685.atx
or
ftp://igs.org/pub/station/general/igs08.atx

Many thanks to Stefan Schaer and Richard Langley for their help!

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