[IGSMAIL-6445] repro1 product files finalized

Jim.Ray jim.ray at noaa.gov
Thu Aug 4 05:19:25 PDT 2011


Authors: Jim Ray, Analysis Center Coordinator
          Bruno Garayt, Reference Frame Coordinator

Gerd Gendt and Remi Ferland announced the release of the IGS 1st
reprocessing campaign (repro1) in IGS Mail 6136 (26 Apr 2010), which
covered the interval from GPS week 730 thru 1459; please see
http://igscb.jpl.nasa.gov/mail/igsmail/2010/msg00084.html.  At that
time, there were a few unresolved details, which have now been finalized:

* Contrary to earlier plans, the time scale of the repro1 clock products
will not be realigned to IGST version 2.0, which was implemented starting
week 1632 (see IGS Mail 6384).  Instead, v. 2 will be used in the future
repro2.

* Contrary to earlier discussions, the Global Data Center (GDC) products
directory structure will not be modified from the current configuration.
That is, the established convention will be retained indefinitely, where
the original operational products stay in the main weekly directories and
subsequent reprocessed products are kept in lower "./reproN/" directories
for each reprocessing N = 1, 2, ...  Any attempts to change the main
product directories to always contain the latest, "best" products would
cause the holdings to be time-dependent, which could lead to serious user
confusion and inconsistencies.  Users should always consult the precise
directory configuration for each GDC.

* All original repro1 *.sp3 and *.clk files have been replaced in order to
correct and harmonize reference frame and antenna calibration information
in the headers.  The data contents of these files have not changed.  Pierre
Tetreault is acknowledged for pointing out metadata errors and Jake
Griffiths for updating the files.

* In addition to the official repro1 period from wks 730 thru 1459, there
are some later repro1 subdirectories.  Some individual AC solutions were
submitted for wks 1460 thru 1511, which were never used, as well as ig1*
combined solutions for wks 1460 thru 1566.  The latter were updates of the
official operational combinations that were submitted for ITRF2008 with
improved discontinuity detection, etc.  All these files have been retained
for historical reasons.

* The accumulated daily repro1 ERP values are posted in the GDC products
directory as ig110p01.erp.Z.

* As described by Paul Rebischung in IGS Mail 6401 (see:
http://igscb.jpl.nasa.gov/pipermail/igsmail/2011/006393.html), new
combinations of the AC repro1 SINEX solutions for weeks 0730-1459 and of
the AC operational SINEX solutions for weeks 1460-1631 have been derived
at IGN and have been added to the repro1 product directories with the
prefix "igb".  These files are at the GDCs and also available at:
    ftp://igs-rf.ign.fr/pub/igb
    ftp://igs-rf.ensg.eu/pub/igb
The "igb" products form a consistent set from wks 0730 thru 1631, after
which the IGS08/igs08.atx framework was adopted.  But please note that
the original "ig1*" products are retained; those were used for the
repro1 orbit and clock combinations and for ITRF2008.  The recombined
weekly "igb" solutions are the basis for the current IGS cumulative frame
since wk 1632 (after applying station-specific corrections for earlier
weeks to account for igs05 -> igs08 antenna calibration changes).  These
newer products are recommended for the most precise work involving the IGS
reference frame.


As a reminder, please recall that the reference framework for repro1 was
IGS05/igs05.atx.  The available data range is from GPS weeks 0730 thru
1459 for the reprocessed products plus consistent operational products
from weeks 1460 thru 1631.  Details of the repro1 campaign are at
acc.igs.org/reprocess.html.

Many thanks to Carey Noll for coordinating the archiving tasks with the
GDCs.  Please note that the holdings of the GDCs might not have fully
equalized yet.

For your information, the ACs have begun deliberating plans for repro2,
which will probably begin in earnest in 2012.



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