Since taking over the position of president of the International Association of Geodesy (IAG – http:// www.iag-aig.org) on the 6th July 2011, I have had on occasion mused on what geodesy “is” and how to explain this arcane field to those who are not acquainted with it. For example, how do I tell the Dean of the Faculty of Engineering, at the University of New South Wales, Sydney (Australia), that I, the head of a department within his faculty which has its primary objective the education of undergraduate students in “surveying” (or more broadly in “geomatics”), now occupy an important position in the geoscience field of “Geodesy and Geophysics”? (This is not an idle exercise, as the Dean will be asked to approve my increased travel commitments over the next four years

The year 1978 saw the launch of the first Global Positioning System (GPS) satellite. Today, GPS, as the first and currently only operational global navigation satellite system (GNSS), is widely used and is a vital technology for many of society’s economic, scientific and social activities. Applications can be found everywhere, such as spacecraft navigation, geodesy, surveying and mapping, precision navigation, machine guidance, vehicle fleet management and “intelligent transport systems” (ITS), emergency services and “location based services” (LBS). Clearly the development of GPS has revolutionised what are now termed “positioning, navigation and timing” (PNT) activities.

There are some countries trying to develop their own GNSS system. Is there any race? If yes, how appropriate and where would it lead to? Here are some views
“Well first of all there is the issue of robustness and putting all your eggs in one basket – that is one aspect and a major legitimate concern. The other, is a matter of national pride. In Europe there is a feeling that GPS dominates things…

Although Global Navigation Satellite Systems (GNSS) technology is developing rapidly, the major disadvantage of GNSS will still exist even when the European Galileo system is fully operational, that is, signal blockage due to obstructions and the low power of the signals. The combination of GNSS with a self-contained inertial navigation system (INS) provides an ideal solution, which can not only address the weakness of GNSS and but also bound…