co-chairs:      U. Marti (Urs.Marti@swisstopo.ch)
                I. Tziavos (tziavos@olimpia.topo.auth.gr)

This session will focus on the practical solution of various formulations of geodetic boundary-value problems to yield continental, regional and local geoid models. A main part will be the status reports of the projects for the accurate determination of the geoid on the continental scale. Contributions are welcomed that describe recent developments in theory, processing methods, downward continuation of satellite and airborne data, terrain modeling, software development and the combination of gravity data with GPS/leveling for an accurate local gravity field determination. Further topics are the comparison of methods and results, the interpretation of residuals as well as geoid applications to satellite altimetry, oceanography, vertical datums and local geospatial height registration.