[IGSMAIL-7154] igs08_1861.atx: Update including reactivated Block IIA satellite SVN36/PRN10

[Ralf Schmid]

Dear IGS colleagues!

The absolute IGS antenna correction file (igs08_wwww.atx) has been 
updated. The new release is called 'igs08_1861.atx'. It contains the 
following changes:

1) According to NANU 2015080, Block IIA satellite SVN36 (one of the two 
satellites equipped with laser retroreflector arrays) will resume 
transmitting L-band utilizing PRN10 on approximately 16 September 2015. 
Therefore, the following satellite has been added to igs08.atx:

G10 (G036)

Source:
> NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2015080 NANU TYPE: GENERAL
> *** GENERAL MESSAGE TO ALL GPS USERS ***
> ON APPROXIMATELY 16 SEPT 2015 SVN36 WILL RESUME TRANSMITTING L-BAND UTILIZING PRN10. AT L-BAND ACTIVATION, SVN36/PRN10 WILL BE UNUSABLE UNTIL FURTHER NOTICE. ADDITIONALLY, NO BROADCAST ALMANACS WILL INCLUDE SVN36/PRN10 UNTIL FURTHER NOTICE.
http://www.navcen.uscg.gov/?Do=gpsShowNanu&num=2015080

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

G10 (G040): 3 August 2015

Although officially removed from the GPS constellation on 16 July 2015, 
Block IIA satellite SVN40/PRN10 didn't stop signal transmission before 3 
August 2015 (DOY 215) according to the IGS tracking statistics provided 
by CODE (ftp://ftp.unibe.ch/aiub/igsdata/odata_gnss_day.txt).

Source:
> NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2015069
> SUBJ: SVN40 (PRN10) DECOMMISSIONING JDAY 197/2228
> 1. NANU TYPE: DECOM
> NANU NUMBER: 2015069
> NANU DTG: 162217Z JUL 2015
> REFERENCE NANU: 2015066
> REF NANU DTG: 071852Z JUL 2015
> SVN: 40
> PRN: 10
> UNUSABLE START JDAY: 197
> UNUSABLE START TIME ZULU: 1624
> UNUSABLE START CALENDAR DATE: 16 JUL 2015
> DECOMMISSIONING JDAY: 197
> DECOMMISSIONING TIME ZULU: 2228
> DECOMMISSIONING CALENDAR DATE: 16 JUL 2015
>
> 2. CONDITION: GPS SATELLITE SVN40 (PRN10) WAS UNUSABLE AS OF JDAY 197 (16 JUL 2015)
> AND REMOVED FROM THE GPS CONSTELLATION ON JDAY 197 (16 JUL 2015).
http://www.navcen.uscg.gov/?Do=gpsShowNanu&num=2015069


The updated antenna correction model is available at
ftp://ftp.igs.org/pub/station/general/igs08_1861.atx
or
ftp://ftp.igs.org/pub/station/general/igs08.atx

Those who don't cope with the MGEX extension can use the following model 
instead:
ftp://ftp.igs.org/pub/station/general/igs08_1861_woMGEX.atx

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