******************************************************************************
dorisreport             01-Apr-2013 16:57:30 Message No 3295
******************************************************************************


Author: "Lemoine, Frank G. (GSFC-6980)" <frank.g.lemoine@nasa.gov>
Subject: GSCWD18, New SINEX Series (1992-2012) Delivered to IDS


This series represents a complete reprocessing of all
DORIS data from November 1992 to December 2012.
The gscwd18 series supercedes
the gscwd15 solution announced in DORISREPORT  3258 (28-Feb-2013).
This series constitutes an important step to the preparation of
the GSFC DORIS contribution for the next ITRF.

The major changes with respect to the previous series (gscwd15)
are as follows:

1.  Update of Envisat macromodel. Although the UCL model is
    used for solar radiation pressure modelling, the macromodel
    is still used for the drag and planetary radiation pressure
    calculations. An error associated with the orientation of
    the solar array has been corrected.

2.  The SPOT-2, SPOT-3 macromodels have been retuned, based on
    analysis of the gscwd15 results, in particular of the
    recovered empirical accelerations.

3.  A new version of GEODYN is used (1212) that applies new code
    to properly handle the change in the station beacon frequency
    from the nominal value.  This change has a substantial effect
    on the scale, the Tz and the WRMS of the solutions. Herein
    we summarize briefly the changes:

    wd15: Previous series (See DORISReport 3258, 28-Feb-2013)
    wd17: Internal series (Application of macromodel improvements
          only on Envisat, SPOT-2, SPOT-3)
    wd18: wd17 + new version of GEODYN applying correction
          for frequency bias at DORIS stations.

    Weekly solutions were computed and Helmert transformations
    were evaluated wrt. DPOD2008.

    Average Scale (2002-2008) wrt. DPOD2008
      wd15: -1.32 mm
      wd17: -1.69 mm
      wd18:  2.50 mm
 Average Scale (2008-2012) wrt. DPOD2008
      wd15:  -3.21 mm
      wd17:  -3.51 mm
      wd18    1.35 mm

    Avg. WRMS (2002-2008)
      wd15:  11.62 mm
      wd17:  11.59 mm
      wd18:  10.05 mm

    Avg. WRMS (2008-2012)
      wd15:  12.33 mm
      wd17:  12.32 mm
      wd18:  10.08 mm

   Avg. Tz (2002-2008)
      wd15:   -7.49 mm
      wd17:   -6.75 mm
      wd18:  -11.06 mm
   Avg. Tz (2008-2012)
      wd15:  -4.63 mm
      wd17:  -4.62 mm
      wd18:  -9.37 mm

The initial delivery (March 30 2013)  includes files
from November 1992  to December 2012.  The delivery includes
weekly SINEX files in Normal Equation (NEQ) format.

The satellites included in this series, when data are available,
include TOPEX/Poseidon, SPOT-2, SPOT-3, SPOT-4, SPOT-5,
Envisat, Jason-2 and Cryosat-2.

This series represents the first step in the preparation of solutions
to be submitted for the  next ITRF (cf ITRF2013).

For the other major force and measurement models, with the
exception of the changes for SPOT-2, SPOT-3, Envisat, the
reader is referred to DORISReport 3258 (28-Feb-2013) as all
other models in wd18 are the same as in gscwd15.


                           Cliquez sur l'url suivante 
https://www.mailcontrol.com/sr/PD7OKZkybh!GX2PQPOmvUkjDae7bB5Iguwn3zx6rCZuAcm!YSahw08jjqV90TzlEhXd4!OUc0YaMQcgptJ50Pg==  
                    si ce message est indésirable (pourriel).



Please do not reply directly to this message, but send 
comments and suggestions to IDS.central.bureau@cls.fr