[IGSMAIL-6433] igs08_1645.atx: Update including Block IIF-2 satellite SVN63/PRN01

[Robert Khachikyan]

Dear IGS colleagues!

The absolute IGS antenna correction file (igs08_wwww.atx) has been
updated. The new release is called 'igs08_1645.atx'. It contains the
following changes:

The second Block IIF satellite launched on 16 July 2011 has been added:

G01 (G063)

The following PRELIMINARY phase center offset (PCO) values were assigned:

PCO_X =  39.4 cm
PCO_Y =   0.0 cm
PCO_Z = 165.0 cm

The z-offset of 165 cm is a "rounded" value, derived from the z-offset
estimate of CODE and ESOC for the first Block IIF satellite (G25). Also
the phase center variations were adopted from Block IIF-1.

NANU message 2011047:

> >  NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2011047
> >  SUBJ: SVN63 (PRN01) LAUNCH JDAY 197
> >  1.     NANU TYPE: LAUNCH
> >          NANU NUMBER: 2011047
> >          NANU DTG: 160718Z JUL 2011
> >          SVN: 63
> >          PRN: 01
> >          LAUNCH JDAY: 197
> >          LAUNCH TIME ZULU: 0641
> >  
> >  2. GPS SATELLITE SVN63 (PRN1) WAS LAUNCHED ON JDAY 197
> >      THIS SATELLITE WILL UNDERGO EXTENSIVE ON-ORBIT CHECK OUT PRIOR TO BEING SET HEALTHY.
> >      A USABINIT NANU WILL BE SENT WHEN THE SATELITTE IS SET ACTIVE TO SERVICE.
http://cgls.uscg.mil/pipermail/nanu/2011-July/001320.html

The updated antenna correction model is available at
ftp://igs.org/pub/station/general/igs08_1645.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