Subject: [IGSMAIL-374] Network Operations Workshop
From: Ruth Neilan
Date: 19 NOV 1993 20:23:44

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IGS Electronic Mail       19-NOV-1993 20:23:44       Message Number 374
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From: Ruth Neilan 
Subj: Network Operations Workshop
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From: Ruth Neilan <[email-masked]>

                       Subject:                               Time:6:28 PM
  OFFICE MEMO          Network Operations Workshop Summary    Date:11/18/93
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   Summary Recommendations of the Network Operations Workshop 
                      October 118-20, 1993,
                     Silver Spring, Maryland, USA

      Submitted by the IGS Central Bureau (Neilan and Zumberge) and  
                 With assistance from Dow, Noll, Chin, Mader
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The IGS Network Operations Workshop was held at the NOAA facilities in 
Silver Spring, Maryland from October 18 - 20.  On the final day of the 
workshop, summary resolutions were completed and are listed below.  

Many thanks to John Dow, Carey Noll, Miranda Chin, Gerry Mader, and 
Werner Gurtner for their assistance in guiding the sessions and focusing 
on the key issues.

IGS STATIONS:
Much discussion was generated concerning what is the definition of an 
IGS station and how to coordinate the data flow of all IGS stations so 
that the data is easily available to everyone.  In terms of the amount 
of data that is currently flowing to the Global Data Centers, a scheme 
is being developed to direct the flow of data to an appropriate data 
center and to list the location of all IGS data as a distributed data 
archive system.

The group also responded to the Analysis Workshop request for data 
delivery to the Data Centers within one day after observation. There was 
discussion as to why the data was needed in such a short time if the 
Analysis Centers still had up to two weeks to process the data.  
However, it was agreed that this request would be approved wherever 
possible, especially for the list of stations prepared by the Analysis 
Centers (see Analysis Center Workshop Summary notes.). 

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Resolution 1: IGS STATION LISTS and DATA HOLDINGS

The Global Data Centers must contain as a MINIMUM the data from the 
following list of stations. This station list was determined according 
to three criteria: 
           1) Current use by the IGS Analysis Centers
           2) Redundancy of the Network
           3) Geographic distribution 
The following 28 stations must be maintained at an IGS Global Data 
Center:
*      Algonquin
*    x Fairbanks
*    x Goldstone
*    x Hartebeesthoek
       Hobart
       JPL
*    x Kokee
*      Kootwijk
       Kourou
*    x Madrid
       Mas Palomas
       Matera
       McMurdo
       Metsahovi
       Onsala
*    x Pamatai
       Penticton
       Richmond
*    x Santiago
       St. John's
       Taiwan
*      Tidbinbilla
*      Tromso
       Usuda
       Westford
*      Wettzell
*      Yarragadee
*      Yellowknife

* designated stations that are 'fixed' or constrained by four or more 
analysis centers.  

x  Station information reports from these stations are requested to be 
submitted as soon as possible.

Data must be held on line for a MINIMUM of 30 days.

The list will be reviewed as new stations are implemented and/or at 
least twice yearly.

New IGS stations will be assigned which data center to send their data 
to by the Central Bureau.

The Central Bureau in turn will list the location of each station, the 
location(s) of the data for the stations, and the contact agency and 
person responsible for each IGS station.

A catalog of all holdings of data will be developed to ensure access to 
interested parties.  

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Resolution 2:  STATION REPORT FORMS AND REPORTING

Station Report forms must be submitted documenting the CURRENT status by 
December 15, 1993.
It is important to track past configuration changes of the stations, 
directions on how to do this will follow in the future. 

ANY CHANGE IN STATION CONFIGURATION SHOULD BE NOTED AND AN ADVISORY MUST 
BE TRANSMITTED BY IGSMAIL TO ALERT THE CB, DATA AND ANALYSIS CENTERS TO 
THE CHANGE OR PROBLEM (e.g., receiver change, antenna relocation, 
receiver failure , etc.)

New stations must submit the station information reports to the Central 
Bureau at the time they propose to submit the data to the IGS.  

Requested hardcopy information for the station book is due by January 1, 
1994.  This includes,: picture of the monument, pictures from the 
monument of the surrounding facilities, map of station and area, horizon 
mask plot, 
These will be duplicated (including color copies of the photos) and 
distributed as an IGS publication, the IGS Station Information Book.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Resolution 3: RINEX 2 COMPLIANCE

Summary of RINEX conventions and missing information was sent to each 
agency by Werner Gurtner. 

It was agreed that Gurtner would monitor the compliance of the data 
exchange format for the IGS Central Bureau. 

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Resolution 4: RINEX QUALITY CHECKS

Analysis Centers continue to discover problems with the data that should 
be discovered at the operational centers or at the stations.  It was 
agreed that a common program would be developed that would use the RINEX 
files as input to determining the quality of the data and the health of 
the stations.   The results of such a program must serve two ways:
            1) Feed-back to the stations concerning the status of the 
receivers and tracking data
            2) Alerts and advisories to the analysis centers to assist 
in improving the efficiency of data processing.

It was recognized that all Operational Centers have some method for 
quality assurance and the measures used and existing program will be 
exchanged and evaluated to develop this common software.

Analysis Centers and Operational Centers have been requested to submit 
their ideas on this point to Werner Gurtner.  Please do so as soon as 
possible.  Specific directions will follow in the near future.

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Resolution 5: NET OPS CENTER ISSUES

Automation of the data downloading, RINEXING, checking and transmission 
of data to data centers must be implemented.  Techniques and procedures 
will be documented for each center.

Network configuration will be documented (also see Resolution 6 below).

Formatted summary reports (daily, weekly, monthly, ...) will be 
developed for the operations.

It is necessary to reduce the duplication in data flow, but yet allow 
for back-up routing of data in the event of a problem at an operational 
center.

Only ONE agency will be responsible for RINEXing a given stations data.

Alternative communication links must be studied (Internet, X.25, 
INMARSAT, Iridium, etc.)

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Resolution 6: DATA CENTER ISSUES

IGS must continue to optimize data flow from the station to the Global 
Data Center:
             NOAA will cease delivery of the European data to the CDDIS.  
This data will be transferred to the CDDIS through the IGN Global Data 
Center in France.

Replacement data must be clearly identified to analysis centers as well 
as to data centers.  E-MAIL WILL BE ISSUED BY THE OPERATIONAL CENTER TO 
IGSMAIL WHEN RE-SUBMITTING DATA.  This procedure may be reviewed in the 
future.

Automation in all areas is necessary.  Data Centers will implement (when 
practical) execution of data processing routines every 6 hours.

Back-up data flow capabilities need to be developed and tested.

A table (diagram) detailing flow of data from each station to the 
operational, regional and global data centers will be developed.  

+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Resolution 7: DATA AND PRODUCT HOLDINGS

Products must be held on line for a MINIMUM of 12 months will be in the 
following formats:
          1) in standard SP3 files for a MINIMUM of 6 months.  
          2) in compressed OR standard SP3 format for data more than 6 
months old.

Note that these are MINIMUM standards, data centers can hold as much 
data as they can maintain, but must follow at least these minimum 
guidelines.