together there are 77 components representing 30 Member Organizations
in 15 countries and more than 230 individual Associate Members. IVS
has 31 Member organizations, and 6 Affiliated Member organizations.
1. Overview of the distribution of the IVS components
1st Directing Board meeting was held in Wettzell on
February 11, 1999 in order to establish the Service and to initiate
activities under the flag of the IVS. As of the inauguration date of
IVS, on March 1, 1999, its web site was available at http://ivs.gsfc.nasa.gov.
thereafter, a solicitation for IVS data and analysis was released to
obtain proposals from the Operation and Analysis Centers on the
provision of products such as correlation results, EOPs, and combined
analysis. Those products derived by the Analysis Centers were designed
to become official IVS products. In the same solicitation the
call for an Analysis Coordinator was released.
IVS Annual Report 1999 was
published in August 1999 (electronically) and September 1999 (printed)
. The intention of the Analysis Report was to provide a document on
the status of all components. A procedure was created to standardize
the layout, which supported and accelerated the publication of the
Annual Report 1999.
2000 IVS General Meeting
was organized and held in Kötzting, Germany, during February 21-24,
2000. It was a successful meeting with more than 120 participants
registered. The goals of the meeting were determined by a program
committee. The main character of the 1st General Meeting
was addressed towards young researchers. Overview talks and tutorials
were held before the sessions, in order to introduce the session topic
to those who work in different areas. It has to be mentioned that the
proceedings of 2000 IVS General Meeting  were published in June
2000. The proceedings published nearly all the papers and tutorials
and are a very valuable tool, especially for people starting to work
the 3rd Directing Board Meeting, held in Wettzell before
the General Meeting, slight modifications to the Terms of References
were made in order to clarify the status of the Analysis Centers and
to include Affiliated Members. Affiliated Members will be informed
about IVS activities without having obligations to IVS.
the IVS 2000 General Meeting, a first meeting was held of the IVS Working group on "GPS phase centers Mapping"
, which is a joint Working Group of the International GPS Service
(IGS) and International Laser Ranging Service (ILRS). The objectives
were "to study the feasibility equipment, time required, and if
it could be done with accuracy sufficient to make it worthwhile".
The members of the WG are Brian Corey/ MIT-Haystack, Ed Himwich/NVI,
Inc./GSFC for the IVS, Tom Herring/MIT-Boston, Tim Springer/AIUB for
the IGS and Graham Appleby/ and Richard Biancale/CNES for the ILRS.
The activity and the status of the work could be seen on the
the last day of the 2000 General Meeting, February 24, the first Analysis Workshop has been held. Axel Nothnagel, who became
IVS Analysis Coordinator on October 1, 1999, invited to the meeting.
Standards, analysis models and contributions of the various Analysis
Centers were discussed, five Working groups have been established in
order to share the workload. Access to all the information is made
available via http://ivs.gsfc.nasa.gov and its link to the Analysis
regular combination procedure
for the VLBI derived EOP series, provided from the four Analysis
Centers, NASA Goddard Space Flight Center/Greenbelt, USA, Bundesamt
fuer Kartographie und Geodäsie/Leipzig, Germany, Institut for Applied
Astronomie /St. Petersburg, Russia and University of St. Petersburg,
Russia has been developed by Axel Nothnagel and Christoph Steinforth
of the Geodetic Institute of the University of Bonn. The combined
results have been released as IVS products and are now used from IERS
for further combination with the other techniques.
2000 the first Analysis Pilot
Project has been started by the Analysis Coordinator in order to
encourage more Analysis Centers to perform data analysis. A common set
of data covering a period of one year has been released for the pilot
project which allows to compare the results of the individual
analyses, to unify the data reduction procedures and to exchange
experience. In addition to the 4 global Analysis Centers, 9 more
Analysis Centers participated in the Pilot Project. 17 different
solutions have been derived using 6 different analysis software
packages. The results have been discussed at the
Second VLBI Analysis Workshop held at the Goddard Space Flight
Center/Greenbelt, USA in the period from February 12-14, 2001. These
activities are very encouraging and a second pilot project is going to
be started soon.
September 2000 the hardware VLBI
Standard Interface (VSI-H) specification has been released (more
detailed information: http://ivs.gsfc.nasa.gov). VSI-H specification
was developed by an international committee of experts in VLBI
instrumentation, led by Alan Whitney/MIT-Haystack, IVS Technology
Coordinator, in a concerted effort to standardize interfaces to/from
VLBI data recording and playback systems. Adherence to the VSI-H
specification will allow data collected on heterogeneous VLBI data
systems to be processed directly on VLBI correlators. A standardized
software interface, VSI-S, is expected to follow within the next year.
Thanks to the committee especially Alan Whitney/MIT-Haystack-USA as
the chair, Wayne Cannon and Richard Worsfold/CRESTech-Canada, Ralph
Spencer/ Jodrell Bank Observatory-UK, Richard Ferris/CSIRO Telescope
National Facility-Australia, John Romney, George Peck/NRAO-USA, Brent
Carlson/Herzberg Institut of Astrophysics NRCC-Canada, Tetsuro Kondo,
Junichi Nakajima, Yasuhiro Koyama, Mamorou Sekido and Hitoshi Kiuchi/CRL-Japan
and Mickael Popov/Astro Space Center of Lebedev Physical Institute
Moscow-Russia the specification have been set up in a short period of
time with a broad international acceptance.
4th Directing Board meeting was held on September 17, 2001
in Paris-F and the 5th Directing Board Meeting was held in
Greenbelt-USA. In order to improve the IVS products and to optimize
the resources within IVS a Working Group for the evaluation of the existing observing programs
was created with the following task :
Review the usefulness and appropriateness of the current definition of
IVS products and suggest modifications.
Recommend guidelines for accuracy, timeliness, and redundancy of
Review the quality and appropriateness of existing observing programs
with respect to the desired products.
Suggest a realistic set of observing programs which should result in
achieving the desired products, taking into account existing agency
Set goals for improvements in IVS products and suggest how these may
possibly be achieved in the future.
Present a written report to the IVS Directing Board at its next meeting.
Schuh is the chair of this group and experienced members are invited
First IVS Technology and
Operations Workshop (TOW) was held at Haystack Observatory during
March 12-14, 2001. The program committee for the meeting was lead by
Ed Himwich, NVI Inc/GSFC. The workshop provided detailed training on
VLBI technology and operations and was attended by over 60 people.
This meeting will be repeated every two years. The material covered
was adapted to meet people's interests as well as important issues. A
notebook covering details of the training sessions and talks were
provided to all attendees. This notebook should prove to be useful a
reference for all involved.
Personal fluctuations in the Directing Board
personal fluctuations in the Directing Board (DB) have to be
mentioned. The representative of the IAG, Gerhard Beutler, when he was
elected as Vice President of IAG, withdrew from the board after the 2nd
DB meeting, held in Birmingham, July 19, 1999. He was the initiator of
the IVS and we have to express our thanks to him. James Campbell, one
of the most experienced VLBI experts, was nominated by IAG to be the
new IAG representative. Axel Nothnagel, representing the Analysis
Centers on the DB, started his work as Analysis Coordinator (AC) as of
October 1, 1999. Up to October, 1999 the function of the AC was
jointly carried out by Marshall Eubanks, Chopo Ma and Nancy Vandenberg.
Marshall Eubanks, representative of the Operations Centers and
Correlators, has founded a new e-business, which demands his full
attention. He withdrew from the DB and was replaced by Kerry Kingham.
accordance with the ToR, elections have carried out for the positions
of the Analysis and Data Center representative and of the Technology
Development Center representative. Both positions have been occupied
for the first two years term only, starting at the initiation date of
the IVS. Since Axel Nothnagel became the Analysis Coordinator in
October 1999 the position of the Analysis Representative became
vacant. The position of the representative for the Technology
Development Centers was held by Tesuro Kondo, CRL-Japan. In addition
one of the At Large positions, that position held by Wayne Cannon, was
set for a two years term only. The election has been held in December
2000. Harald Schuh, Austria was elected as the representative for the
Analysis and Data Centers, Arthur Neill, USA was elected to represent
the Technology Development Centers and Yasuhiro Koyama, Japan was
elected as AT Large Member. After the election, it turns out that the
Directing Board is strongly dominated by US and European
representatives and improvements for the balance of representatives
from different agencies, nations and groups have been discussed at the
5th Directing Board meeting. The enlargement of the board
by a 3rd At Large Member was decided and the ToR have been
current members of the DB and their functions are: