The new IAG structure - The new structure of the International Association of Geodesy (IAG) viewed from the perspective of history

The IAG Executive Committee and the IAG Council decided to invoke a thorough review of the IAG and its structure with the goal to create a new, hopefully simpler structure, meeting the needs of the 21st century, at the IAG General Assembly in Birmingham in 1999. The new structure was implemented in 2003 at the XXIII-rd IUGG General Assembly in Sapporo. The new structure should - have a focus - be based on the three pillars of modern geodesy, namely the geometric shape of the Earth, the orientation of the Earth in space, and the Earth's gravity field, and - better incorporate the IAG services The new structure may be viewed as an attempt to go back to the roots of the IAG, as they were designed and realized by the eminent geodesists and practitioners of the 19th century. There are remarkable parallels between this first IAG structure and that of 2003: The focus of IAG in the 19th century was the Central European Arc Measurement, in the 21st century it is the Integrated Global Geodetic Observing System (IGGOS). The creation of the International Latitude Service (ILS) was a proud achievement of the "old'' IAG, today's IAG services are the modern counterpart. The goals of the 19th century IAG were technically achieved by optical (astrometric) observations and politically by international collaboration. The modern tools are the space geodetic techniques ( geometric and gravitational), nothing changed on the political level: Only international coordination and collaboration and long-lasting institutional commitments promise satisfactory results.