[IGSMAIL-7843] igs14_2076.atx: Update including reactivated BLOCK IIA satellite SVN74/PRN04 and 5 new BeiDou satellites

[arturo.villiger at aiub.unibe.ch]

Dear IGS colleagues,
 
The absolute IGS antenna correction file (igs14_wwww.atx) has been updated. 
The new release is called 'igs14_2076.atx'. It contains the following changes:

1) According CODE Block IIA satellite SVN36 has stopped transmitting L-band utilizing PRN04
     on approximately 8. October 2019.  Following decommission date has been added:
     G04 (G036): 8. October 2019	

2) According to NANU 2019159 (https://www.navcen.uscg.gov/?Do=gpsShowNanu&num=2019159) , Block IIIA satellite SVN74 will resume transmitting L-band utilizing PRN04. CODE observed that the satellite became active on approximately 21 October 2019.  Following satellite entry has been added
    G18 (G074): 21. October 2019

3) According to the MGEX metadata information file (http://mgex.igs.org/igs_metadata_2076.snx) GLONASS-M satellites R716 resumed transmitting L-band utilizing PRN27.
    Following satellite entry date has been added:
    R27 (R716): 3. August 2019

3) Five new BeiDou satellites have been launched this year and are added according to the IGS MGEX metadata  (see http://mgex.igs.org/igs_metadata_2076.snx).
    C18 (C020, 2019-023A, BEIDOU-2G) starting from 5. May 2019
    C38 (C220, 2019-023A, BEIDOU-3I) starting from 20. April 2019
    C39 (C221, 2019-035A, BEIDOU-3I) starting from 24. June 2019
    C45 (C222, 2019-061A, BEIDOU-3I) starting from 7. October 2019
    C46 (C223, 2019-061B, BEIDOU-3I) starting from 7. October 2019

4) According to the MGEX metadata information BEIDOU-3SI-CAST C104 satellite has resumed transmitting L-band utilizing C56  (see http://mgex.igs.org/igs_metadata_2076.snx).
     Following satellite entry has been added 
    C56 (C104): 2019 04 25 00 00 00

4) According to DLR BEIDOU-3SI-CAST C104 has stopped transmitting (C18) on 24. April 2019 at 02:00 (see http://mgex.igs.org/igs_metadata_2076.snx).
    Following decommission date has been added:
    C18 (C104): 2019 04 24 02 00 00


Many thanks to Peter Steigenberger for the information about the BeiDou satellites!

The updated antenna correction model is available at
ftp://ftp.igs.org/pub/station/general/igs14_2076.atx
or
ftp://ftp.igs.org/pub/station/general/igs14.atx

With best regards,
Arturo