[IGS-DCWG-73] Charter part 2

[Carey Noll]

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IGS-DCWG Mail      12 May 18:33:06 PDT 2010      Message Number 73
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Author: Carey Noll/CDDIS

I of course forgot that attachments would not go through the
exploder.  Here is a text version of the charter. Comments
welcome!

Regards,
Carey.
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IGS Data Center Working Group
Charter

The IGS Data Center Working Group (DCWG) will tackle many of the problems facing the IGS data centers as well as develop new ideas to aid users both internal and external to the
IGS.  The direction of the IGS has changed since its start in 1992 and many new working groups, projects, data sets, and products have been created and incorporated into the
service since that time. The DCWG was formed to revisit the requirements of data centers within the IGS and to address issues relevant to effective operation of all IGS data
centers, operational, regional, and global.

The DCWG will continue to review the current structure for data dissemination, identifying data currently archived, the mechanisms for delivering and archiving the data (from
operational data center to global/regional data center).  This process will identify both strengths and weaknesses in the current data flow. Mapping the topology will allow the
group to identify where improvements can be made and redundant data flow paths can be recommended.  The group will also identify/clarify existing procedures for communications
between the various levels of data centers, particularly in the area of replacement data sets. The DCWG will work closely with the IGS Infrastructure Committee (IC) on
requirements for data center within the IGS.

Some of the topics to be addressed by the DCWG over the upcoming years include:

- Support of the IGS Infrastructure Committee: A major focus of the DCWG will be to support the IC in its various activities to coordinate the resolution of issues related to the
IGS components. These activities will address recommendations from IGS Workshops including assessment and monitoring of station performance and data quality, generating metrics
on these data.

- Data QC and validation: The DCWG will work with the IC to develop guidelines and coordinate implementation at the data centers.

- High-rate GNSS data handling: Transfer of high-rate data to data centers is currently performed via traditional file transfer and through accumulation of real-time data
streams. IGS data centers must ensure that files generated from these streams are sufficiently reliable. The DCs must also coordinate to ensure consistent copies of high-rate
files are archived.

- Daily GPS data status files: The WG will coordinate implementation of software to generate daily status files at all GDCs. The software, developed at CDDIS, creates a daily
file that summarizes the daily data holdings and extracts key metadata and data quality information from all files. The IC has requested that these daily summary files be made
available at all GDCs since data holdings vary among data centers.

- Broadcast ephemeris files: The daily and hourly concatenated broadcast ephemeris files (BRDC and HOUR files) are generated each day at the CDDIS and are made available to all
GDCs. At the request of the IC, the DCWG will coordinate the implementation of the software at the GDCs to provide redundant creation of these files thus precluding missing BRDC
and HOUR files should the CDDIS be unavailable.

- Data center harmonization: The working group will consider methodologies for ensuring key data sets are available at all GDCs. The process should not only address data holdings
but update of files and their proper distribution to all data centers.

- Compression scheme: The working group will review the current compression software used within the IGS and recommend adoption of alternate methods to ensure efficiency within
the IGS infrastructure.

The membership of the working group is:

Carey Noll (NASA GSFC/USA), Chair
Yehuda Bock (SIO/USA)
Giovanni Sella (NOAA/USA)
Ludwig Combrinck (HRAO/South Africa)
Bruno Garayt (IGN/France)
Roman Galas (GFZ/Germany)
Paul Jamason (SIO/USA)
Heinz Habrich (BKG/Germany)
Ruth Neilan (JPL/USA), ex-officio
Jim Ray (NOAA/USA), ex-officio
Ignacio.Romero (ESA/Germany)
Mike Schmidt (NRCan/Canada)
Grigory Steblov (RDAAC/Russia)
Dave Stowers (JPL/USA)
Bob Twilley (GA/Australia)