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

IAG Scientific Assembly - Budapest, September 2 - 8, 2001.


1. 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.


2. Objectives

2.1 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.

2.2 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.


3. 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).


4. Activities

IAG - CDC has been involved directly or indirectly with different projects in South America and Africa.


4.1 South America

4.1.1 Gravity surveys for densification of national network have been carried out in several countries for the last few years. The following countries have improved the gravity coverage due to this action: Argentina, Brazil, Chile, 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 in a joint cooperation of EPUSP and IGeS.


4.1.2 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 it was also supported by IAPSO (International Association of the Physical Science of the Ocean). The workshop had the following objectives:

·            To assemble as many countries as possible from South America to compute a geoid model.

·            To encourage every country to cooperate with SCGGSA for data delivery.

·            To encourage every country to compute a local geoid model with the data available.

·            To discuss different efforts for data acquisition in the continent.

The countries that participated to the activities were the following: Argentina, Brazil, Chile, Ecuador, Paraguay and Uruguay.

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


4.2 Africa

4.2.1 African Reference System (AFREF): Southern Africa

Representatives of 8 countries in Southern Africa met in Cape Town on the 13th and 14th 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 - CDC Participation: Sansò, F., Neilan, R..


4.2.2 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 was created a working group 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.

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


4.2.3 2nd 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 created:

WG I: Definition and establishment of a Terrestrial Reference System for North Africa.

WG II: Unified Geoid Determination.

WG III: Establishment of a General Committee for the realization of NAFREF. It was created two committees: Coordination Committee and Scientific Committee.

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



(Report prepared by D. Blitzkow and E.S. Fonseca Junior)


Denizar Blitzkow




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