Geodesy – the Challenge of the third Millenium

We take first reference to our book (eds. E.Grafarend/F.Krumm/V.S. Schwarze) “Geodesy The Challence of the Third Millenium”, a book of 500 pages published by Springer Verlag in  2003. It was written by the most important geodetic scientists  of our time, around the globe, written for E.Grafarend`s 60 birthday at 1999 . It included (i) J.Adam and (ii) P. Varga, for instance. Second we introduce the topics presented by the IAG/IUGG/ , namely the Global Geodetic Observing System in our Changing World. The third topic is VLBI Basics. General Relativity offers fourth new geodetic aspects by means of (i) clock networks, (ii) Heights and Time Systems, (iii)  in short Geodetic Relativity, a new topic indeed. The topic five is probably the most advanced one : (i) the Environment of our
Planet : is the mean equipotential surface , the GEOID, changing in time? (ii) Satellite Geodesy helps to determine the Water Level Rise (WLR) predicted for 4.8 cm/year by NASA. We conclude with our work with topic six : Sprace Gradiometry with respect to the International Reference Ellipsoid (in contrast to the widely accepted International Reference Sphere). even   recommended by the IAG/IUGG/ already in 1930 /International Gravity Formula/. The hightlights are Ellipsoidal Harmonics in contrast to spherical harmonics.