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From: heinz.habrich@bkg.bund.de
To: igs-dcwg@igscb.jpl.nasa.gov
Subject: [IGS-DCWG-10] Resupplied Data, Comments from BKG
Date: Mon, 16 Jun 2003 14:55:33 +0200
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IGS-DCWG Mail      16 Jun 05:55:54 PDT 2003      Message Number 10
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Author: Heinz Habrich/BKG

Dear Colleagues,

some remarks to the discussion about resupplied data:

1) It is practical to distinguish

   Case a) Data flow between various data centers (operational, local, 
   ======= regional and global)

   and

   Case b) Data flow between a data center and an analysis center
   =======

2) If all data centers follow the "put approach", resubmitted files 
   could easily and correctly be handled. As soon as an updated file 
   occurs in the "incoming" directory of a data center it will be 
   forwarded to the next level, e.g., from local to regional data center.
   "Case a)" could thus be satisfied. The mirror between the 
   global data centers has to be arranged diffenrently.

3) The announcement of a file resubmission by IGS-Mail is meaningful, but
   not reliable enough from the analysis center's point of view.

4) More difficult to handle is "Case b)". The analysis centers need to 
   know about new submissions. The GSAC (GPS Seamless Archive Center)
   initiative stores the file creation date and the corresponding providers
   into the "data holding file (*.dhf)". GSAC could serve as the 
   "central information source" for analysis centers to check for
   resupplied data (provided all data centers participate in GSAC.

Perhaps my remarks could contribute to the discussion.

With kind regards,

Heinz

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  Dr. Heinz Habrich

  Bundesamt fuer Kartographie und Geodasie
  Richard-Strauss-Allee 11, 60598 Frankfurt am Main, Germany

    Phone  +49 69 6333267      E-Mail  heinz.habrich@bkg.bund.de
      Fax    +49 69 6333425      URL     http://www.bkg.bund.de
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