[IGSMAIL-5151]: GLONASS MW antenna offset values

[Stefan Schaer]

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IGS Electronic Mail      20 May 07:39:40 PDT 2005      Message Number 5151
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Author: Stefan Schaer


Dear IGLOS colleagues,

The X-component of the GLONASS-M MW antenna offset vector is, with
nominally -0.545 m, remarkably big. See also:

   http://igscb.jpl.nasa.gov/mail/igsmail/2005/msg00027.html

Note that the axis notation used for GLONASS SVs differs from that used
for GPS (specifically Y_GLONASS corresponds to -X_GPS).

The mentioned X-offset value could be verified on the basis of CODE
GNSS analysis results. Furthermore, our test computations showed that
disregarding the nominal GLONASS Z-offset value (of 1.620 and 2.183 m,
respectively) is still advisable (at least when relying on "relative"
receiver antenna PCV calibration models). Also, comparisons with SLR
range measurements to GLONASS SVs indicated that this is an adequate
approach.

Starting with GPS week 1321, BKG, ESA, and CODE will start to refer
their GLONASS orbit products to the following satellite antenna offset
(SAO) values:

   X/Y/Z =  0.000/0.000/0.000 m for GLONASS and
   X/Y/Z = -0.545/0.000/0.000 m for GLONASS-M SVs.

The SAO values specified above may be considered "recommended to be
adopted for use with IGS/IGLOS GNSS/GLONASS orbit products" (until the
expected change to "absolute" GPS/GLONASS SAO and SAP calibration
models).

Best regards,

The CODE AC Team