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dorismail               29-Apr-2015 13:45:21 Message No 0969
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Author: Couhert Alexandre <Alexandre.Couhert@cnes.fr>
Subject: Status of the GDR-E orbit standards



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Dear colleagues,

The first CryoSat-2 precise orbit (arc 260) in the new GDR-E standards
has been delivered today to the CDDIS/IGN data servers. It is flagged
with a version number VV=3D10 in the file name:

/pub/doris/products/orbits/ssa/cs2/ssacs210.b15087.e15095.D__.sp3.001.Z

(reminder of filename convention:
ssa<sss>VV.bXXDDD.eYYEEE.dgs.sp3.LLL.Z

 where :
      ssa fixed part (=3Dssa pour SSALTO)
      sss =3D satellite three-character abbreviation : cs2
      VV  =3D version number of the solution (=3D10 for GDR-E)
      b   =3D fixed part ("begin")
      XX  =3D last two digits of year of first position
      DDD =3D three-digit day of year of first position (2)
      e   =3D fixed part ("end")
      YY  =3D last two digits of year of last position
      EEE =3D three-digit day of year of last position (2)
      dgs =3D types of data used for the orbit determination
                d=3D "D" or "_" : if DORIS data are used or not
                g=3D "G" or "_" : if GPS data are used or not
                s=3D "S" or "_" : if SLR data are used or not
      sp3 =3D fixed part, referring to the SP3 format
      LLL =3D version number of the file)

The previous CryoSat-2 precise orbits (arcs < 260) have been reprocessed
and will be flagged with the same version number, when delivered to the
CDDIS/IGN data servers. The old GDR-C and GDR-D orbits (flagged with
version numbers 01 and 02) will then be moved to new separate directories
depending on their orbit standards. A readme file will be included in the
satellite directory and you will be kept informed by email of the update.

Jason-2 POE orbits will switch to the GDR-E standards from cycle 254.
Jason-3 POE orbits will be produced in GDR-E standards from cycle 1.

Saral POE orbits will switch to the GDR-E standards from cycle 25.

HY-2A POE orbits will switch to the GDR-E standards at a later stage.

Jason-1 POE orbits will be reprocessed by the beginning of June 2015.
Envisat POE orbits will be reprocessed at a later stage.

Spot-5 POE orbits will be kept in the GDR-D standards and the past Spot
satellites orbites will not be reprocessed.

Attached is a summary of the changes between the previous GDR-D and the
new GDR-E POD standards:


It can be found on the IDS web site on the page:
ftp://ftp.ids-doris.org/pub/ids/data/POD_configuration_GDRE.pdf

Please let me know if you need any clarification.

Best regards,

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Alexandre Couhert
Orbit Determination Department - Flight Dynamics Division
CNES - Centre Spatial de Toulouse
18 Av. Edouard Belin, 31401 Toulouse cedex 9, FRANCE
Tel.: +33 5 61 28 20 56 | Fax: +33 5 61 28 18 55
alexandre.couhert@cnes.fr<mailto:alexandre.couhert@cnes.fr> | http://www.cn=
es.fr<http://www.cnes.fr/>
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