[IGSMAIL-1763] 8th IGS Governing Board Meeting

[G.]

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IGS Electronic Mail      Mon Dec 22  4:06:04 PST 1997      Message Number 1763
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Author: G. Beutler
Subject: 8th IGS Governing Board Meeting

Dear Colleagues

Two IGS-related events, the eighth Governing Board Meeting and the IGS
Retreat (announced in IGS Mail Message 1683), took place in December 1997.

The first part of the IGS Governing Board meeting took place in the
Moscone Conference Center in San Francisco on Thursday, December 11, 1997
(attached to the AGU Fall Meeting). The second part of the meeting took
place Sunday, December 14 during the IGS Retreat in Napa Valey.

The IGS Retreat was scheduled from Friday, December 12 (afternoon) -
Sunday, December 14 (morning) in the Napa Valley Marriot Hotel.
It was organized by Prof. Ivan I. Mueller and the IGS Central
Bureau. The retreat will be dealt with in a separate IGS-Mail Message.

Let me try to pick out and comment the essential agenda items of the
8th Governing Board Meeting.

IGS/BIPM Time Transfer Proposal
-------------------------------
At the 7th IGS Governing Board Meeting in Rio de Janeiro Dr. Dennis
McCarthy from US Naval Observatory presented the proposal "IGS Pilot
Project for Precise Time Comparisons" (IGS-Mail, Message 1683). The
IGS Governing Board viewed this proposal as a very positive and
constructive document in Rio and fully endorsed the project. It expressed
the hope that the experiment would include the entire "timing
community", in particular the BIPM in Paris.

USNO used the time-span between the 7th and the 8th IGS Governing Board
Meeting to develop draft "Terms of Reference" and "Call for Participation"
for what is now called

        "IGS/BIPM Project to Study Accurate Time and Frequency
         Comparisons using GPS Phase and Code Measurements".

This was done in close cooperation and continuous discussions with BIPM.

The latest versions of the two draft documents were presented by Dr. Jim
Ray at the 8th IGS Governing Board Meeting. They were approved by the
Board, and the hope was expressed that the project might soon start. The
two documents are now considered by the BIPM Governing Board. If the
project is approved by BIPM the project will start early in 1998. It is
proposed that Dr. Jim Ray from USNO and Dr. Claudine Thomas from BIPM
will co-chair the project.

GLONASS Project
---------------
At the 7th IGS Governing Board Meeting it was decided that the CSTG
Subcommission on "Precise Satellite Microwave Systems" should develop a
proposal for a joint CSTG/IGS Project, and present it to the IGS Governing
Board as soon as possible (IGS-Mail Message 1683). Pascal Willis from IGN
in Paris, chair of the mentioned CSTG Subcommission, was invited to inform
the Board about the status of the pilot project "International Glonass
Experiment (IGEX)". The Proposal could not yet be presented but the status
of the project was summarized by Pascal Willis as follows:

 - The ideas for the IGEX were presented and discussed at the 1997 ION
   Meeting in Kansas City (September 1997).
 - A steering committee consisting of Pascal Willis (chair), Gerhard
   Beutler, Werner Gurtner, Gunther Hein, Ruth Neilan, Jim Slater was
   formed.
 - This group organized a splinter meeting at the 1997 AGU Fall Meeting and
   agreed upon the principles of the experiment. It is expected that the
   draft "Call for Participation" will be available in time for the
   Business Meeting of the IGS Governing Board in February 1998 in
   Darmstadt.

IGS Infrastructure Committee Report
-----------------------------------
It was decided at the 7th Governing Board Meeting in Rio that an "IGS
Infrastructure Committee Report" consisting of Yehuda Bock (chair), Werner
Gurtner, Ruth Neilan, and a UNAVCO representative should study
infrastucture-related problems of the IGS network and prepare a report in
fall 1997 (IGS-Mail Message 1683). The group held a meeting on October 1,
1997 at JPL. Ulf Lindqwister (JPL) and Chuck Meertens (UNAVCO/UCAR) were
invited to join the committee.

The committee presented its first report at the 8th Governing Board
Meeting. The report summarizes the goals of the committee and gives an
overview of the work performed so far. The goals are to evaluate and
recommend improvements in the IGS infrastructure, specifically in the
areas

 - station instrumentation,
 - monumentation and long-term site stability,
 - accurate station reporting,
 - station performance,
 - data communications and data flow,
 - adherence to RINEX standards,
 - data quality control and reliability,
 - data archiving and dissemination,
 - adherence to IGS site standards for new sites,
 - adherence to IGS reporting standards for all centers, and
 - IGS home page.

Many independent institutions collaborate within the IGS. It is thus
difficult to "enforce" actions recommended by the committee. The IGS
Governing Board can and will, on the other hand, give the committee's
recommendations its approval and ask its components (Central Bureau,
Data Centers, Analysis Centers, etc.) to follow the recommendations to the
extent possible.

Such a step (approval of recommendations by the Governing Board) is
expected to take place at the next Governing Board Meeting. The chairman
thanked the committee for its work, encouraged it to continue its analysis
and expressed the hope that obvious problems, e.g., discrepancies in
coordinate results, would soon disappear.

Hatanaka Compression
--------------------
The Board decided to follow Werner Gurtner's proposal (presented at the 7th
GB Meeting, IGS-Mail Message 1683) to switch to the Hatanaka compression
scheme within the IGS in 1998. It seems that all the concerns raised at the
7th GB Meeting in Rio were addressed and could be successfully removed.
The following schedule will be observed:

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

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 provide standard
     RINEX files to their users.

The chairman thanked Werner Gurtner (who presented his proposal to the
Board) and Yuki Hatanaka for their excellent work.

Densification Project Status
----------------------------
Geoff Blewitt presented the status of the densification project. He was
very pleased with the progress made and the results obtained. The RNAACs
and the three GNAACs are in essence ready to switch over to a routine
operation in the near future. The GNAACs were asked by the Board (in
September 1997) whether they would committ themselves for the operational
phase of the densification, as well. The answer was positive in all three
cases.

Before actually switching to routine operations, the following steps have
to be performed:

 - the RNAACs have to be asked to continue delivering their contributions
   in the operational phase (committment for the operational phase),
 - the exact procedure to come up with the weekly official IGS solution
   has to be defined,
 - the coordinate discrepancies published each week by Jan Kouba
   have to be removed.

It was agreed on the other hand that the project should go into the
operational phase as soon as possible, and that there should be an official
IGS set of coordinates and velocities.

The Board is very pleased that the densification soon will lead to a
coherent series of IGS station-coordinates and -velocities in the ITRF.
It also interprets this development as a sign of a good and close
cooperation with the IERS, the International Earth Rotation Service.

Central Bureau Activities
-------------------------
Many activities had to be organized in 1997 by the Central Bureau, among
others two Governing Board Meetings, a Business Meeting of the Board,
the 1997 IGS Analysis Center Workshop, and the Sea Level Workshop.
Moreover, all major conferences in 1997, where GPS was an issue, e.g., the
AGU meetings, the IAG Scientific Assembly, the ION-Meetings, etc., had IGS
booths. In addition, the written information about the IGS (foulders in
English and Spanish, Colleague directory, e.t.c) was updated and
distributed in 1997. The workload for the Central Bureau in this area
should not be underestimated.

The 1996 IGS Annual Report could be distributed to the Board Members at the
GB Meeting, it is in the mail right now. With 446  pages it is probably
the most complete and comprehensive description of the IGS available today.
I personally believe that the 1996 Report will be used as a reference for a
long time. The Chairman congratulated the editors, J.F. Zumberge, D.E. Fulton
and R.E. Neilan for their fine work.

In view of the time it took to publish the 1996 Report and in view of the
costs involved, it seems clear that it does not make sense publish such a
document every year. The attempt will be made in 1998 to make the 1997 IGS
Annual Report shorter and more rapidly available -- the contributors will
be soon notified by the Central Bureau. Ruth Neilan also announced that
the Proceedings of the 1997 IGS Analysis Center Workshop (held in March
1997 at JPL) and of the 1997 Sea Level Workhop (also held at JPL) will soon
be in the mail.

Wayne Shiver from UNAVCO was invited to inform the Board concerning
UNAVCO's involvement in IGS matters. Wayne Shiver explained that, as part
of a contract (between JPL and UNAVCO), UNAVCO will take over some
responsibilties related to "network monitoring and engineering" for the IGS
Central Bureau. From the point of view of the IGS such activities will be
considered Central Bureau activities.

AC Coordinator Report
---------------------
Kouba presented his AC report (on Dec 11/97) in two parts:

1) All ACs:  A selection of about 50, globally well distributed, stations
with good performance and quality track records was made, as potential
candidates to replace the current, ailing set of the 13 ITRF stations.
After 7 parameter transformation, the combination of all 3 GNAAC station
solutions (1.5 years) for the newly selected 50 ITRF stations, compared (at
epoch 1997.0) with the preliminary (Sep97) ITRF96 solution with an rms of
about 3 mm and 8mm in the horizontal and vertical direction, resp.  With
the help of the CODE and NCL ACs and the CB, a new & official SINEX Header
Template was developed which should mitigate the ANT/SITE SINEX header
conflicts.

2) The research/improvements in the IGS combinations:
New AC LOD weights (proportional to the LOD calibration rms^2) improved the
IGR combined UT sigmas from 96 to 85 us. Using LOD derived from EMR Rapid
UT, resulted in further sigma decrease down to about 70 us (for a 20 week
test period). This new weighting was introduced on Wk0829/d0 and Wk0831/d0
for the IGS Final(IGS) and Rapid(IGR) UT combinations. The EMR derived LOD
are used only in IGR, since Wk0933/d0. Improved combined sv clocks is to
be soon realized due to more realistic and robust AC clock weights
(derived from comparisons to a chosen AC clock solutions). The clock
rms decreased from about 1 ns down to about .2-.4 ns (now in use since
Wk0936/d1 and Wk0935/d0 for  the IGR and IGS combinations, respectively).
Improvements in the combined clock/orbit consistency now has a high
priority due to point positioning applications and the imminent timing pilot
project. The methology has been developed and coded more than a year ago,
but, due to a relatively low precision of most AC clock submissions
(1-3 ns) and other, more urgent, matters (e.g., IGS orbit prediction and/or
LOD/UT combinations) it had to be repetitively postponed till now.

In the second GB meeting (on Dec 14/97) Kouba stressed the fundamental role
of the ACs and the importance of the long term AC commitments. He used the
VLBI analogy to demonstrate the fundamental role of the AC global product
(orbits/EOP/station coordinates) and pointed out the need for redundancy,
robustness and security of the IGS reference system.  Eliminating or
redirecting some ACs could potentially lead to serious consequences and
might in the worst case render IGS a big data collector only, with GPS data
as its only product!  That is why he suggested that IGS writes to each and
every AC acknowledging their significant contributions and the utmost
importance of their long term commitments and continuation in IGS.

Governing Board Elections
-------------------------
The IGS Terms of Reference specify that 6 of the 15 Governing Board Members
are elected by the IGS Associates. Three positions, those currently held
by Geoff Blewitt, Bjorn Engen and Carey Noll, were up for election in 1997.
Prof. Ivan Mueller conducted these elections by e-mail in fall 1997. All
three candidates were re-elected. The chairman congratulated them for
at the December Board Meeting.

Four Governing Board members are elected by the Governing Board upon
recommendations from the Central Bureau. The candidates have four year
terms. Two positions, those currently held by Bob Schutz and Gerry Mader,
were up for election at the 8th GB Meeting. This interesting agenda item
was actually dealt with in two steps:  on Thursday, December 11, general
principles were discussed, candidates were presented, and a broad
discussion took place. Final discussions and the actual elections took
place on Sunday, December 14.

It became clear that the Central Bureau and the Board wished to account for
the importance of ground-based and space-borne atmospheric research. It
therefore seemed advisable to consider new candidates. After extensive
discussions

 - Dr. Robert J. Serafin, National Center for
                          Atmospheric Research (NCAR)
and

 - Dr. Michael Bevis, University of Hawaii

were elected for the time period 1 January, 1998 - 31 December, 2001. Mike
Bevis is well known in the IGS-community as a pioneer and a protagonist of
GPS ground-based meteorolgy. Bob Serafin, as Director of NCAR, is deeply
involved in upcoming space missions related to GPS-meteorology.

The Board is convinced that with these new IGS Governing Board members the
IGS is well prepared to meet the challenges of the upcoming GPS space
missions using the occultation technique and to make the best possible use
of the IGS network for research in meteorology.

AC Coordinator Succession -- "Habemus Papam"
--------------------------------------------
After having been informed in July 1997 that Dr. Jan Kouba would retire
from NRCan by the end of March 1998 (see IGS-Mail, Message 1683), the
procedure to elect a new IGS Analysis Center Coordinator had to be invoked.
A call for proposals was sent out in September 1997 to all seven IGS
Analysis Centers, proposals were due by 21. November 1997.

Only one proposal, from the CODE Analysis Center, was received.
Essentially, CODE proposes that Tim Springer, currently responsible for the
CODE operational solutions for the IGS, will succeed Jan Kouba on
January 1, 1999 for a time period of four years. The proposal, which
received the full support of all IGS Analysis Centers, was discussed and
accepted by the Governing Board at its 8th Meeting.

The Board gratefully acknowledged that NRCan will continue to act as IGS
Analysis Coordinating Center till the end of the year 1998. Details for the
transition phase in 1998 are currently discussed with the parties involved.

The 1998 IGS AC Workshop in Darmstadt
-------------------------------------
The workshop will take place at the ESOC facilities in Darmstadt from
February 9 to 11, 1998. The workshop will focus on

 - The IGS Analysis Products and the
   Consistency of the Combination Solutions,
 - Orbit Prediction and Rapid Products,
 - IGS Reference Frame Realization and Contributions to ITRF,
 - IGS products for Troposphere and Ionosphere.

The workshop agenda and the invitations are sent out in December 1997. The
Board thanked Dr. John Dow for hosting the 1998 IGS Anaylsis Center
Workshop, the Scientific Program Committee (John M Dow, Jan Kouba and Tim
Springer) and the IGS Central Bureau for taking care of the organization
of the workshop. We are all looking forward to interesting presentations
and discussions in Darmstadt.

At the end of a very long Governing Board Meeting the chairman cordially
thanked the IGS Central Bureau for organizing the 8th Governing Board
Meeting and the IGS Retreat. The discussions in the Board Meeting and at
the Retreat were very stimulating, indeed. With all the new activities
initiated in December 1997 the IGS will continue to be one of the most
active and successful organizations in (space) geodesy.

Let me conclude by thanking all organizations and individuals contributing
to the IGS in the name of the Governing Board. The Board also wishes to
thank those organizations and researchers using IGS products for their
confidence in our organization.

                                     Merry Christmas and a Happy New Year

                                               Gerhard Beutler
                                          Chair, IGS Governing Board


[Mailed From: GERHARD BEUTLER <BEUTLER at aiub.unibe.ch>]