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SLR-Mail No.102

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Date:1998-02-13 09:00:00
Sender:John J. Degnan <###FROM###>
Subject:[SLR-Mail] No. 102: Joint CSTG/IERS Call for Participation
Author:John J. Degnan
Content:********************************************************************************
SLR Electronic Mail 1998-02-13 09:00:00 UTC Message No. 102
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Author: John J. Degnan
Subject: Joint CSTG/IERS Call for Participation


The following is a Joint CSTG/IERS Call for Participation in the establishment
of an International Laser Ranging Service (ILRS) modelled in part after the
successful International GPS Service (IGS). Full details regarding the new
organization can be found at the following CSTG SLR/LLR Subcommission Web Site.

http://cddisa.gsfc.nasa.gov/cstg/slr_cstg.html

Standard forms to assist you in responding to the call by the March 31, 1998
proposal deadline can also be downloaded from the Web site.

Since at least three overlapping email server lists are being used to
announce this new organization, you may receive this notice more than once
and we apologize in advance.

Sincerely,


John J. Degnan
Chairperson, CSTG SLR/LLR Subcommission

Bob. E. Schutz
SLR Representative to IERS Directing Board

JOINT CSTG/IERS CALL FOR PARTICIPATION IN
SATELLITE AND LUNAR LASER RANGING

BACKGROUND

Laser ranging to the Moon and artificial satellites was initiated
in the 1960s and, during the 1970s and 1980s, matured into an
operational space geodetic technique supporting a variety of
scientific applications. Satellite laser ranging (SLR) was a
significant source of tracking information for early altimeter
satellites, such as GEOS-3 and SEASAT, and has provided a long
time series of data from the Starlette and LAGEOS satellites since
their launch in the mid-1970s.
In the early 1980s, the SLR and Lunar Laser Ranging (LLR)
communities participated in MERIT (Monitoring Earth Rotation and
Intercomparison of Techniques) to demonstrate the utility of modern
space techniques in determining Earth rotation parameters. Earth rotation
solutions, based on laser ranging to LAGEOS, have been delivered weekly
since 1981, and represent the longest, continuous Earth rotation series
obtained using modern space techniques.

In 1987, the newly formed International Earth Rotation Service (IERS)
issued a call requesting commitments from the geodetic community to
participate in the new IERS program. Since the inception of the IERS on
January 1, 1988, SLR, LLR and Very Long Baseline Interferometry
have been embraced by the IERS. Since 1988, the laser techniques
have not only contributed to the determination of Earth rotation
parameters but have become a significant component of the IERS
Terrestrial Reference Frame (ITRF) as well, especially in the
determination of Earth Center of Mass and scale, and contribute
significantly to precision orbit determination for current satellite
altimetry (TOPEX/POSEIDON AND ERS-2). Furthermore, SLR data,
collected from a variety of satellites, is the dominant contributor
to modern gravity field models, such as JGM-3, EGM96 and GRIM4. In
addition, LLR has been an important factor in the evaluation of
characteristics of Earth-Moon dynamics, including effects associated
with general relativity.

PURPOSE

The CSTG Satellite and Lunar Laser Ranging (SLR/LLR) Subcommission Steering
Committee and the IERS Directing Board jointly believe it is now
appropriate for supporting institutions to reaffirm their future
participation in the SLR/LLR effort and to cooperate in a more formal
structure designed to improve the operational efficiency of the laser
ranging community and to foster data product standardization and new
developments. In an era of diminishing resources, an equitable and
international distribution of responsibilities meeting the needs of the
global scientific community is needed. Toward this goal, the CSTG
SLR/LLR Subcommission has developed a ”Terms of Reference” document
which describes the needs and vision for this new organization, the
International Laser Ranging Service (ILRS). The CSTG SLR/LLR Subcommission
and IERS Directing Board have agreed to issue this joint ”Call for
Participation” as a first step in establishing the new ILRS to conduct the
operational support and analyses required by the scientific
community, including the results contributed to the IERS in support
of the International Terrestrial Reference Frame (ITRF).

The supporting operational elements of the new ILRS organization, for
which proposals are being sought, are:

Central Bureau - provides overall coordination of global laser
ranging activities; maintains documentation and electronic databases;
organizes meetings and workshops

Laser Tracking Stations and Subnetworks - acquire and transmit lunar and
satellite data to an Operations Center and/or Data Center. Individual
stations may submit their proposals separately or as part of a Subnetwork

Operations Centers -provide for the collection and merging of data from the
subnetwork, initial data quality checks, data reformatting into a uniform
format, compression of data files if requested, maintenance of a local
archive of the tracking data, electronic transmission of data to a
designated ILRS Data Center; provide sustaining engineering, communications
links, and other technical support to a subnetwork.

Regional and Global Data Centers - collect, archive and distribute the
data acquired by the stations on behalf of the user community. Global
centers archive and provide electronic access to the entire SLR/LLR dataset
often in cooperation with Regional or other Global Centers.

Analysis and Associate Analysis Centers - Analysis Centers generate
precision ephemerides for the approved satellite constellation and
regularly submit Earth rotation results and station coordinates and
velocities for ITRF in strict accordance with IERS standards and delivery
schedules. Associate Analysis Centers generate products of a specific or
specialized nature, provide quality control of the products generated
by the various Analysis Centers, and/or generate combination
products. Analysis Centers (or Associates) are asked to indicate in their
proposal their interest in routinely performing intercomparisons and quality
checks of different Center solutions, prior to submission to the IERS, and
perhaps even providing ”combined solutions” to the IERS.

The duties and functions of the various supporting organizations are
described in more detail in the ILRS Terms of Reference which can be
accessed via the CSTG SLR/LLR Subcommission Home Page at the following address:

http://cddisa.gsfc.nasa.gov/cstg/slr_cstg.html

It is highly recommended that all organizations responding to this call
review the Terms of Reference document before submitting their proposal.

Policy guidelines for the new ILRS will be set by the ILRS Governing Board,
an international elective body which is expected to supplant the current
CSTG Satellite and Lunar Laser Ranging Subcommission but retain its CSTG
affilliation. The ILRS Governing Board will elect from among its members an
Analysis Coordinator who will also serve as the ILRS representative to the
IERS Directing Board and, as part of a reciprocal arrangement, the
IERS will appoint a representative to the ILRS Governing Board.

CALL FOR PARTICIPATION

The CSTG Satellite and Lunar Laser Ranging Subcommission and the IERS
requests proposals for participation in the new International Laser
Ranging Service (ILRS). Qualified institutions, or collaborating groups
of institutions, are encouraged to submit proposals to serve in
one or more of the following areas:

o Central Bureau
o Laser Ranging Station or Subnetwork
o Operations Center
o Regional or Global Data Center
o Analysis or Associate Analysis Center

Participants must provide their own financial resources in carrying out
their proposed duties . The proposal should clearly address the services and
capabilities being offered by the institution (or institutions), its (their)
financial ability to carry them out, and appropriate points of contact.
Proposal lengths of one to four pages should be adequate for all
organization types. Further suggestions on proposal format and content for
each type of organization will be placed on our CSTG SLR/LLR Subcommission
website by January 30, 1998.

PROPOSAL DEADLINE

Detailed proposals must be submitted in writing by March 31, 1998, to:

Dr. John J. Degnan
Chairperson, CSTG Satellite and Lunar Laser Ranging Subcommission
Code 920.3
NASA Goddard Space Flight Center
Greenbelt, MD 20771 USA

The proposals will be jointly reviewed by a special session of the CSTG
SLR/LLR Subcommission Steering Committee to be held in advance of the 23rd
General Assembly of the European Geophysical Society (EGS) in Nice, France
during the week of April 20-24, 1998.and by the IERS Directing Board at its
19 April 1998 meeting. Successful proposers will be notified by early June
with a goal of fully implementing the new ILRS organization by November 1, 1998.





_________________________________ __________________________________

John J. Degnan, Chairperson Bob E. Schutz, SLR Representative
CSTG Satellite and Lunar Laser Ranging Subcommission IERS Directing Board

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