[IGSMAIL-7894] igs14_2019.atx: Update including four new BEIDOU-3M-CAST/SECM (C225-C228)

[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_2091.atx'. It contains the 
following changes:


1) Four new Beidou satellites have been added (two BEIDOU-3M-CAST and two BEIDOU-3M-SECM).
     According to the metadata provided by the DLR (http://mgex.igs.org/igs_metadata_2091.snx) for
     satellites have been launched by the end of 2019.
     Following entries have been added (valid from the launching date):
    C41 (C227): BEIDOU-3M-CAST , valid from 2019 12 16
    C42 (C228): BEIDOU-3M-CAST , valid from 2019 12 16
    C43 (C226): BEIDOU-3M-SECM, valid from 2019 11 23
    C44 (C225): BEIDOU-3M-SECM, valid from 2019 11 23

3) Two additional antenna type calibrations habe been added that were performed by Geo++:

     - One robot calibration provided by Geomax AG has been added:
       GMXZENITH16     NONE

     - One robot calibration provided by Trimble Inc has been added:
       TRMR12          NONE

3) One antenna calibration has been withdrawn by Geo++. The withdrawn antenna was NOT used 
     within the IGS network.
     - TRM115000.00+S    SCIT

The updated antenna correction model is available at
ftp://ftp.igs.org/pub/station/general/igs14_2091.atx
or
ftp://ftp.igs.org/pub/station/general/igs14.atx
 
With best regards,
Arturo Villiger
on behalf of the IGS Antenna Working Group