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EUREF Electronic Mail      14-Jan-1998 13:10:03 CET        Message Number 0082
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Author: W. Gurtner
Subject: Introducton of the Hatanaka compression



        Hatanaka RINEX Compression: Use as Primary Tool in IGS
        ******************************************************

                             Werner Gurtner
                         Astronomical Institute
                          University of Berne

Since April 1997 the RINEX compression scheme developed by Yuki Hatanaka, GSI
Japan (IGSMail 1525)  has been extensively tested between various IGS data
centers (IGMails 1686, 1726). At the most recent IGS Governing Board Meeting
the decision was taken to introduce this compression scheme as primary
tool for the exchange of RINEX observation files within the IGS community
(IGSMail 1763).

The "compact" RINEX files, which are generated by a two-step procedure (actual
Hatanaka compression plus standard UNIX compression), are nearly 8 times
smaller than the original ASCII RINEX files, yielding a gain of about 2.5
in disk space and transmission times compared to standard compressed files.

The schedule for the implementation was fixed as follows:

1) Before December 31, 1997
   - Hatanaka compression software available at CBIS
   - GB decision made public through IGSMail and other mail exploders
     (= this mail).

2) Till February 1st, 1998
   - Introduction of the compact RINEX files for data distribution at and
     between all IGS Data Centers (Global and Regional)

3) Till March 1st, 1998
   - Introduction of the compact RINEX files for the data transfer between the
     individual stations or Operational Centers and the assigned IGS Data
     Centers according to bilateral coordination

4) May 1st, 1998
   - Availability of the standard RINEX files at the IGS Data Centers may be
     discontinued if no special user interests have to be regarded.
     Regional or Local Data Centers can of course continue to also provide
     to their users RINEX files compressed with standard UNIX compression.

The software for various platforms is available now at the Information System
of the IGS Central Bureau:

     Internet :  igscb.jpl.nasa.gov
     User     :  anonymous
     Directory: /igscb/software/rnxcmp

as well as at the European mirror site

     Internet :  igs.ensg.ign.fr
     User     :  anonymous
     Directory: /pub/igscb/software/rnxcmp

There you find the directories for DOS-, Unix- and VMS-specific command
files, a docs directory with documentations and installation guides, and
the source directory with the C-coded source files.

Questions about the compression programs can be directed to Yuki Hatanaka
(hatanaka@unavco.ucar.edu).

All the IGS Data Centers are asked to coordinate the necessary changes directly
with their partners according to the IGS network structure and to update the
data center description files at CBIS, if necessary. Please contact me
(gurtner@aiub.unibe.ch) if you have questions about this procedure.

We would like to thank Yuki Hatanaka for the development and documentations
of the programs.

                                                             Werner Gurtner


[Mailed from: werner.gurtner@aiub.unibe.ch]