[IGSMAIL-7082] igs08_1840.atx: Update including reactivated GLONASS-M satellite R714

[Ralf Schmid]

Dear IGS colleagues!

The absolute IGS antenna correction file (igs08_wwww.atx) has been 
updated. The new release is called 'igs08_1840.atx'. It contains the 
following changes:

1) According to the Information-Analytical Centre, GLONASS-M satellite 
R714 was reactivated utilizing almanac slot 17. Therefore, the following 
satellite has been added:

R17 (R714)

NAGU message 012-150415:
> NOTICE ADVISORY TO GLONASS USERS (NAGU) 012-150415
> SUBJ: 17/-6 (714) PUT INTO OPERATION 15.04/0825 MT
> 1.CONDITION: 17/-6 (714) PUT INTO OPERATION 15.04/0825 MT (UTC+0300)
http://glonass-iac.ru/en/CUSGLONASS/index.php

According to CODE analyses, the switch from R746 to R714 already took 
place on 12/13 April 2015 (DOY 102/103).

2) Decommission dates for the following satellites have been added:

G08 (G038): 13 April 2015
R17 (R746): 12 April 2015

Although officially removed from the GPS constellation on 26 March 2015, 
Block IIA satellite SVN38/PRN08 didn't stop signal transmission before 
13 April 2015 (DOY 103) according to the IGS tracking statistics 
provided by CODE (ftp://ftp.unibe.ch/aiub/igsdata/odata_gnss_day.txt).

NANU message 2015021:
> NOTICE ADVISORY TO NAVSTAR USERS (NANU) 2015021 NANU TYPE: GENERAL
> *** GENERAL MESSAGE TO ALL GPS USERS ***
> SUBJ: SVN38 (PRN08) DECOMMISSIONING JDAY 085/2200
> 1. NANU TYPE: GENERAL
> NANU NUMBER: 2015021
> NANU DTG: 262242Z MAR 2015
> REFERENCE NANU: 2015003
> REF NANU DTG: 021712Z JAN 2015
> SVN: 38
> PRN: 08
> UNUSABLE START JDAY: 303
> UNUSABLE START TIME ZULU: 1500
> UNUSABLE START CALENDAR DATE: 30 OCT 2014
> DECOMMISSIONING JDAY: 085
> DECOMMISSIONING TIME ZULU: 2200
> DECOMMISSIONING CALENDAR DATE: 26 MAR 2015
>
> 2. CONDITION: GPS SATELLITE SVN38 (PRN08) WAS UNUSABLE AS OF JDAY 303 (30 OCT 2014)
> AND REMOVED FROM THE GPS CONSTELLATION ON JDAY 085 (26 MAR 2015).
http://www.navcen.uscg.gov/?Do=gpsShowNanu&num=2015021

NAGU message 011-150415:
> NOTICE ADVISORY TO GLONASS USERS (NAGU) 011-150415
> REF: 010-150413
> SUBJ: 17/04 (746) UNDER CHECK BY THE SPC SINCE 15.04/0825 MT
> 1.CONDITION: 17/04 (746) UNDER CHECK BY THE SPC SINCE 15.04/0825 MT (UTC+0300)
http://glonass-iac.ru/en/CUSGLONASS/index.php

3) One robot calibration provided by Javad GNSS Inc. has been added:

JAV_RINGANT_G3T JAVC


The updated antenna correction model is available at
ftp://ftp.igs.org/pub/station/general/igs08_1840.atx
or
ftp://ftp.igs.org/pub/station/general/igs08.atx

Thanks to Stefan Schaer and Richard Langley for their help!

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