International Service for the Geoid


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International Service for the Geoid

President: Mirko Reguzzoni (Italy)
Director: Giovanna Sona (Italy)

ISG has been founded in 1992 (as International Geoid Service - IGeS) as a working arm of International Geoid Commission (IGeC), and it is actually an official Service of the International Association of Geodesy (IAG).

Since 1999 the process of reviewing statutes of IAG has deeply involved also the IAG Services and those Services which are related to the determination of the gravity field.
In 2003, a new unified IAG Service for the Gravity Field has been created: the International Gravity Field Service (IGFS), to coordinate and integrate broad gravity field activities.
IGFS centres are: International Gravimetric Bureau (BGI), International Service for the Geoid (ISG), International Center for Earth Tides (ICET), International Centre for Global Earth Models (ICGEM) and International DEM Service (IDEMS). In IGFS, ISG is one of the operative arms of the International Commission for the Gravity Field.

ISG' activities are on educational, research, and data distribution sides: principal purposes of ISG are the collection and distribution of geoid models, the collection and distribution of software for geoid computation, and the organization of technical schools on geoid determinations.

The Service is provided by two Centres, one at Politecnico di Milano, and one at NGA

Main tasks of ISG are:

• to collect geoid data on a worldwide scale (geoid repository)
• to collect and distribute software for geoid determination (software download)
• to conduct researches on procedure for geoid determination (projects)
• to organize Geoid schools
• to edit and distribute the Newton's Bulletin

Moreover, as regards the research activity, ISG takes part in:

• the European Gravity Geoid Project
• the GOCE satellite mission
• the Global Geodetic Observing System project (GGOS) for the height datum unification
For other details about ISG projects please click here

At present the following scientists are ISG advisors:
N. Pavlis (USA), M. Sideris, J. Huang (Canada), R. Forsberg (Denmark), U. Marti (Switzerland), H. Denker, L. Sanchez (Germany), I. Tziavos (Greece), W. Kearsley (Australia), D. Blitzkow (Brazil)

Within the structure of ISG, Working Groups can be established for specific purposes, limited in time.

Neither ISG nor any of its staff accept any liability in connection with the use of data and models provided here. Neither ISG nor any of its staff make any warranty of fitness, completeness, usefulness and accuracy of the data and models for any intented or unintended purpose.

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