[IGSMAIL-6989] igs08_1816.atx: Update including Block IIF satellite G069

[Ralf Schmid]

Dear IGS colleagues!

The absolute IGS antenna correction file (igs08_wwww.atx) has been 
updated. The new release is called 'igs08_1816.atx'. It contains the 
following changes:

1) The eighth Block IIF satellite launched on 29 October 2014 has been 
added:

G03 (G069)

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

PCO_X =  39.4 cm
PCO_Y =   0.0 cm
PCO_Z = 160.0 cm

NANU message 2014082:
> NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2014082
> SUBJ: SVN69 (PRN03) LAUNCH JDAY 302
> 1. NANU TYPE: LAUNCH
> NANU NUMBER: 2014082
> NANU DTG: 291804Z OCT 2014
> SVN: 69
> PRN: 03
> LAUNCH JDAY: 302
> LAUNCH TIME ZULU: 1721
>
> 2. GPS SATELLITE SVN69 (PRN03) WAS LAUNCHED ON JDAY 302.
> A USABINIT NANU WILL BE SENT WHEN THE SATELLITE IS SET ACTIVE TO SERVICE.
http://www.navcen.uscg.gov/?Do=gpsShowNanu&num=2014082

spaceflightnow.com: 50th Atlas 5 rocket puts up new GPS satellite
http://spaceflightnow.com/2014/10/29/50th-atlas-5-rocket-puts-up-new-gps-satellite/

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

G03 (G035): 20 October 2014

3) The north reference point (NRP) of the following antenna has been 
updated from NRP=NOM to NRP=RXC:

JAV_GRANT-G3T   NONE

For more details see [IGSMAIL-6987]:
North reference point (NRP) definition added to antenna.gra
http://igscb.jpl.nasa.gov/pipermail/igsmail/2014/008177.html

4) The name of the following antenna has been updated according to the 
file rcvr_ant.tab:

STXS9PX001A     NONE


The updated antenna correction model is available at
ftp://ftp.igs.org/pub/station/general/igs08_1816.atx
or
ftp://ftp.igs.org/pub/station/general/igs08.atx

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