[IGSMAIL-4470]: Proposed single *change* to TRM33429.20+GP in igs_01.pcv

[Angelyn W. Moore]

******************************************************************************
IGS Electronic Mail      24 Jun 15:44:40 PDT 2003      Message Number 4470
******************************************************************************

Author: Angelyn Moore

Dear Colleagues,

The IGS typically does not change antenna calibration values once they
have appeared in the igs_01.pcv file.  However, it has become clear that
the values adopted for TRM33429.20+GP are in error.  (It was initially
reported back in 2000 that this antenna was electrically equivalent to the
TRM33429.00+GP; in actuality, it is electrically and physically different).

Therefore, it is proposed to take the rare decision to change a value in
igs_01.pcv to correct the values to the current best calibration available
from NGS.

Specifically, this will be removed:

TRIMBLE        TRM33429.20+GP                                 NGS (  8) 97/10/27 
       -.2       1.2      74.0
     .0   3.9   7.6  11.1  14.1  16.5  18.3  19.2  19.5  19.1
   18.1  16.6  14.9  13.0  11.5  10.4  10.2    .0    .0
         .6        .9      70.3
     .0    .6   1.4   2.4   3.4   4.4   5.1   5.6   5.8   5.7
    5.3   4.7   3.9   3.0   2.1   1.4    .9    .0    .0

and be replaced with this:

TRM33429.20+GP       L1/L2 microcentered Geodetic +GP         NGS (  3) 01/08/29
        -.4      -1.0      72.9
     .0   4.8   9.3  13.3  16.6  19.3  21.2  22.3  22.7  22.5
   21.8  20.6  19.3  18.0  16.9  16.4  16.7    .0    .0
        -.4      -1.3      75.0
     .0    .3    .9   1.6   2.2   2.9   3.4   3.8   4.0   4.1
    3.9   3.6   3.2   2.7   2.2   1.8   1.5    .0    .0

Accordingly, the offset values placed in igs.snx for IGS sites
GMAS (day 108 of 2002  to present) and SULP (days 161 to 286 of 2001)
would be changed.

Please send a comment to me and/or igscb at igscb.jpl.nasa.gov as
soon as possible if you realize any potential negative impact
from this proposed alteration.

Best regards,
Angie
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  Angelyn W. Moore, Ph.D.            Deputy Director, IGS Central Bureau
  JPL/Caltech                               Angelyn.W.Moore at jpl.nasa.gov
  4800 Oak Grove Dr. MS 238-540                   voice: +1 818 354 5434
  Pasadena CA 91109 USA  http://igscb.jpl.nasa.gov  fax: +1 818 393 6686