International Network of Global Fiducial Stations: Science and Implementation Issues (1991)

February 1, 1991

Dear Colleague:

This IAG Call for Participation solicits support in the establishment of a permanent international service under IAG auspices for the purpose of providing precision ephemerides and associated products derived from observations of the Global Positioning System (GPS). These products are considered fundamental for the proper use of GPS in global and regional geodesy and in geodynamics during the next decade and may contribute to other areas of geophysical research.

Participation in this International GPS Geodynamics Service—IGS—is open to government agencies, educational institutions and other organizations whose financial resources allow a firm commitment to be made in support of the service. Proposals may be submitted at any time during the period ending May 31, 1991.

Based on the proposals received, a plan will be submitted to the IUGG General Assembly in Vienna in August, 1991, for endorsement and approval. This plan will be for a test campaign to be conducted during the International Space Year in 1992, followed by the establishment of the Service in 1993, provided all goes well.

The enclosed document provides program information on the IGS, outlining its roles, responsibilities, and functional areas for which proposals are sought. Proposals may address any aspect of IGS activity for which the proposing organization has the capability and capacity to support.

Those organizations interested in participating in the IGS should submit a letter of intent by March 29, 1991, expressing their interest in the Service. Those organizations which respond will receive a second document providing additional details on the Service such as the standards to be followed and proposal submission information. For this reason an early letter of intent may be advisable.

The IAG is aware of already existing successful global international GPS scientific efforts such as CIGNET for orbit determination or GIG '91 for Earth rotation monitoring. IGS will offer full cooperation to these groups and thus enhance their effectiveness. For this reason, participants in these current activities are strongly encouraged to respond to this solicitation.

Your interest and cooperation in participating in this international effort are welcomed and appreciated. Please feel free to contact any member of the Steering Committee with questions or comments regarding the IGS.