T. Ito, International Space University, Strasbourg Central Campus, 1 Rue Jean Dominique Cassini, Parc d'Innovation, 67400 lllkirch-Graffenstaden, France e-mail: ito@isu. isunet. edu M. J. Rycroft, CAESAR Consultancy, 35 Millington Road, Cambridge CB3 9HW, UK e-mail: Michael. J. Rycroft®ukgateway. net As Symposium Committee Chair for the 2003 International Space University (ISU) Symposium, and Editor of this Proceedings volume, respectively, we write this introduction. The success of previous ISU symposia suggests that the ISU has developed a unique and winning formula for a novel type of symposium. The characteristics of ISU symposia are that they: • Adopt a broad, and interdisciplinary, perspective • Address all aspects of the subject, ranging from policy, business, organisational, and legal issues to technical and scientific topics • Foster a constructive dialogue among very different sectors of the space community, and • Allow ample time for interactive discussions. The present Symposium is no exception. It considers the very timely topic of space-based systems for global positioning and navigation, ranging from the GPS system developed by the US military to the Russian GLONASS system, and on to the future European Galileo system. Other nations are planning regional augmentation systems.

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A Brief Summary of Four Keynote Addresses.- Galileo: Status and Way Forward.- At the Crossroads: Civil and Security Issues Concerning Navigation Satellites in Japan.- The Future of the GPS Local Area Augmentation System (LAAS).- Complement and Augmentation of GPS from a Quasi-Zenith Orbit.- A GNSS Literature Review and a Navigation System for Future Space Vehicles.- Galileo System Architecture Status and Concepts.- Europe's Challenges in Developing its Own Satellite Navigation System.- Cislunar Navigation.- Compatibility and Interoperability of GPS and Galileo: A Continuum of Time, Geodesy, and Signal Structure Options for Civil GNSS Services.- Galileo The Essentials of Interoperability.- Inmarsat: An Approach for Integration of EGNOS and Galileo.- A Software Perspective on GNSS Receiver Integration and Operation.- GNSS Safety of Life Services: Towards a Safer and More Effective Use of European Transport Networks.- Testing the Dubai Virtual Reference System (DVRS) National GPS-RTK Network.- Network-based RTK-GPS for Nationwide High-accuracy Positioning and Navigation in Japan.- Measuring Galileo's Channel The Pedestrian Satellite Channel.- A Challenging Navigation Environment Indoor Applications.- Evaluation of EGNOS (GNSS-1) for Application in a Vehicle Driving Support System.- The Use of Global Navigation Systems in the Aviation Industry.- The Advent of Galileo in the European Air Navigation System.- The Need for, and Benefits of, Galileo Local Services.- ISAGNSS: Infrastructure for Spanish GNSS Activities.- Session 6 Discussion Groups.- A Combined Localisation/Communications System for Mountain Rescue Applications.- Automatic Guidance of Farm Vehicles.- Algorithms of a Complex Inertial and Satellite Navigation System for Aircraft.- GPS-based ClockSynchronization for Precision Time Management for LEO Remote Sensing Satellites.- Space Radiation Environment and its Effects on Satellite Navigation Systems.- Navigation Support through Intelligent Agents.- A Novel Signal Processing Scheme for a Next Generation GNSS Receiver.- Damage Caused by GNSS Signals in the Light of the Liability Convention of 1972.- Galileo System Test Bed Validation Algorithms.- Potential Criteria for the Assessment of a Future Public-Private Partnership for Galileo.- Qualification of EGNOS for Routine Operation.- Solutions to Increasing the Availability of GPS and Future Upgrades of the Satellite Navigation System.- Symposium Summary.