International Association of Geodesy (IAG)

The International Association of Geodesy (IAG) was created in 1864 under the name of Europäische Gradmessung. In 1886 it became the Association Géodésique Internationale. At the first General Assembly of IUGG (Rome, 2-10 May 1922) it became one of the five constituent sections of the Union. It took its present name at the Stockholm General Assembly of IUGG (1930).

IAG works to promote the study of all problems of geodesy through geodetic research especially involving international cooperation and activities in developing countries. The main permanent activity is to monitor positions of points at the surface of the Earth through a global system of satellite tracking stations. The data collection is coordinated by services such as the International GPS Service. The products support scientific activities such as improving and extending the International Earth Rotation Service (IERS) Terrestrial Reference Frame (ITRF); monitoring deformations of the solid Earth; monitoring variations in the liquid Earth e.g., sea level, ice sheets; monitoring variations in the Earth's rotation; determining orbits of scientific satellites; and monitoring the ionosphere. Other services support mapping the gravity field and its variations over time. Through its meetings and publications, IAG provides the basis for discussion of the latest research results. Activities are organized into the following Sections:

Section I : Positioning and Reference Frames
Section II : Advanced Space Geodesy
Section III : Determination of the Gravity Field
Section IV : General Theory and Methodology
Section V : Geodynamics