This volume is based on an international symposium held in Rio de Janeiro. It gives a progress report on geodetic positioning with GPS. The maintenance and the densification of reference frames are treated for the purpose of establishing global and regional GPS networks. The scientific achievements of the South American Geocentric Reference System project (SIRGAS) are described. Several contributions review the state of the art of GPS analysis techniques, ambiguity resolution methods, as well as GPS antenna and site problems. Novel applications of kinematic GPS positioning and quality control issues of real-time GPS positioning are discussed.
WGS 84: Past, Present and Future.- ITRF Densification and Continuous Realization by the IGS.- The Use of the EUREF Permanent GPS Network for the Maintenance of the European Terrestrial Reference Frame.- The European Vertical GPS Reference Network Campaign 1997: Concept and Status.- The Brazilian Network for Continuous Monitoring of GPS.- Towards an Austrian GPS Reference Network.- Processing Strategies for Regional GPS Networks.- An Overview of the SIRGAS Project.- The Definition and Realization of the Reference System in the SIRGAS Project.- GPS Ambiguity Resolution for Navigation, Rapid Static Surveying, and Regional Networks.- GPS Antenna and Site Effects.- High Precision GPS Kinematic Positioning: Progress and Outlook.