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IAG - CDC

International Association of Geodesy - Committee for Developing Countries

(1999 – 2003)

D. Blitzkow and E. S. Fonseca Jr.

IAG - CDC (International Association of Geodesy/Committee for Developing Countries)

XXIII General Assembly of the International Union of Geodesy and Geophysics

Sapporo – Japan / June 30 – July 11, 2003

History

During the General Assembly in Vienna, August 1991, the IUGG (International Union of Geodesy and Geophysics) requested to each of its constituent associations to reinforce actions towards Developing Countries. For this reason the IAG Executive Committee, at its meeting in Columbus, March 1992, set up an IAG Committee for Developing Countries (IAG - CDC). The committee had several activities on the coordination of Michael Louis. With his retirement the activities have been discontinued. At the EC meeting in Como, November 1999, a proposal by the president has been approved to restart the activities of IAG - CDC under the coordination of Denizar Blitzkow.

Objectives

1. To encourage and to facilitate present participation of developing countries in geodetic activities with a significant contribution to their own development as well as to the development of geodesy in general.

2. To request all IAG bodies and organizations to take into account, in their activities, the needs and capabilities of developing countries in order to ensure a profitable participation of them.

IAG - CDC Membership

Denizar Blitzkow (Brazil) - Chairman

Edvaldo Simões da Fonseca Junior (Brazil)

J.Y. Chen (China)

Charles Merry (South Africa)

Salah Mahmoud (Egypt)

Salem Kahlouche (Algeria)

José Napoleon Hernandez (Venezuela)

John Manning (Australia).

General Information - Activities (1999 – 2003)

Many activities and happenings have occurred in different countries in the last four years with important contributions to developing countries.

South America

Gravity Surveys

Gravity activities related to the establishment of fundamental gravity network as well as densification surveys have been carried out in several countries during the last few years. The following countries have improved the gravity coverage due to these actions: Argentina, Brazil, Chile, Equator, and Paraguay.

This initiative has been coordinated by D. Blitzkow and supported by NIMA (USA), GETECH (University of Leeds – UK), and many national organizations in the different countries. As a consequence, several improved versions of the geoid have been derived for the continent as an effort of EPUSP/IBGE and with some particular cooperation like IGeS (International Geoid Service) and recently GFZ ( GeoForschungsZentrum). Some countries are carrying out particular efforts to compute their own geoid model, like Argentina, Brazil, Colombia, Uruguay and Venezuela.

TIGO Project

The TIGO (Transportable Integrated Geodetic Observatory) is a project of cooperation that involves the following organization in Germany and Chile: Bundesamt für Katographie und Geodäsie, Universidad de Conception, Universidad del Bio Bio, Universidad Catolica de la Santissima Conception and Instituto Geografico Militar (IGM). The following technologies or facilities are available at the site, in Conception, since 2000:

• VLBI
• SLR
• GPS
• Time-keeping
• Super conducting gravity meter
• Seismometer
• Meteorological station
• Water vapour radiometer.

More information can be obtained at the following site: www.wettzell.ifag.de/tigo/

Workshop: South America Geoid 2000

The South America Geoid 2000 workshop held at Escola Politécnica, Universidade de São Paulo, May 17 - 19, 2000, was organized by IGeS (International Geoid Service), SCGGSA (Sub-Commission for Gravity and Geoid in South America), CDC (Committee for Developing Countries) and was also supported by IAPSO (International Association of the Physical Science of the Ocean).

IAG-CDC Participation: D. Blitzkow, R. Barzaghi, O. Andersen and R. Forsberg.

IAG Symposium – Vertical Reference System (VeReS)

The VeReS Symposium was organized by the Instituto Geográfico Agustín Codazzi (IGAC), Bogotá and held in the city of Cartagena – Colombia, from February 20 to 23, 2001. Besides IAG and Pan-American Institute of Geography and History (PAIGH), the UNESCO Division of Earth Sciences and the German Carl Duisberg Gesellschaft sponsored the symposium.

SIRGAS Projet

In April, 2003 the Central Bureau of SIRGAS (Geocentric Reference System for the Americas) under the coordination of Luiz Paulo Souto Fortes as the president, presented the SIRGAS 2000 campaign final coordinates as well as their accuracy estimates. These results were generated by DGFI (Deutsche Geodätische Forschungsinstitut), from the individual results of the two processing centres: DGFI, in Munich, Germany, and IBGE, in Rio de Janeiro, Brazil. The results can be fund at: www.ibge.gov.br/sirgas

Africa

African Reference System (AFREF): Southern Africa

Representatives of 8 countries in Southern Africa met in Cape Town on the 13^th and 14^th of March 2001 to discuss a regional project within the broader ‘AFREF’ project to create a uniform geodetic reference system for Africa. The 8 countries present were: Botswana, Malawi, Mozambique, Namibia, South Africa, Swaziland, Zambia and Zimbabwe.

IAG Participation: Sansò, F., Neilan, R..

Organization of Africa gravity data for geoid computation

The purpose of this project is to carry out a determination of the geoid in Africa. A major part of the project will be to collate and merge gravity anomaly data sets for Africa. Because of the paucity of these data and their poor distribution, the geoid that will result won’t be very precise, but it should still be a substantial improvement over the global EGM96 model. An equally important part of the project will be to develop geoid computation expertise within Africa.

To do the African Geoid a working group was created with the following objectives:

• Identifying and acquiring data sets - gravity anomalies, DEM’s, GPS/leveling;
• Training African geodesists in geoid computation;
• Merging and validation of gravity data sets, producing 5’ gridded and mean Dg;
• Computation of African geoid, and evaluation using GPS/leveling data.
• A preliminary geoid model for Africa is prepared to be presented at XXIII General Assembly of IUGG, Sapporo – Japan.

IAG - CDC Coordination: C. Merry, D. Blitzkow.

2^nd Workshop on the definition of the North African Reference Frame (2° Atelier Nord Africain de Géodésie)

Representatives of the following countries participated to the workshop: Algeria, Libya, Morocco, Mauritania and Tunisia.

During the workshop a project was created to unify the Geodetic Reference Frame in North Africa (NAFREF).

To do the unification 3 working groups were set up:

1. WG I: Definition and establishment of a Terrestrial Reference System for North Africa.
2. WG II: Unified Geoid Determination.
3. WG III: Establishment of a General Committee for the realization of NAFREF. It was divided into two committees: Coordination Committee and Scientific Committee.

IAG - CDC Participation: F. Sansò, Z. Altamimi, M. Sarrailh, S. M. Alves Costa.