International Association of Geodesy

Under the umbrella of the IAG (International Association of Geodesy) the symposium ‘Multi-sensor Systems for Engineering Geodesy’ was held at the XXV General Assembly of the International Union of Geodesy and Geophysics (IUGG) at the end of June, early July 2011 in Melbourne, Australia. The convenors of this symposium were Dorota Grejner-Brzezinska and Hans-Joerg Kutterer. The symposium included two oral sessions with in total ten presentations and one poster session with seven posters. In this issue of the journal four revised papers from the conference are presented, namely the first, fourth, fifth and sixth paper. In addition, two papers were selected which deal with the topic of the use, and their integration, of GNSS and multi-sensors in engineering geodesy and navigation applications. Many applications in engineering geodesy and navigation nowadays rely on GNSS positioning. Due to its limitations the use of multi-sensors as an alternative and/or backup to GNSS positioning has become an increasingly important field of research. In the coming years the IAG Sub-Commission 4.1 ‘Alternatives and Backups to GNSS’ under Commission 4 ‘Positioning and Applications’ will place special emphasis on research and other activities that address multi-sensor system theory and applications. Important topics include integrated guidance, navigation, positioning and orientation of airborne and land-based platforms. The primary sensors of interest will be inertial navigation systems (INS); however, the important role of other emerging techniques, such as pseudolites, vision-based sensors, ultrasonic and magnetic sensors etc., used in navigation, engineering geodesy and environmental monitoring is also recognised. New concepts and innovations in navigation algorithms, sensor calibration, synchronization and inter-calibration, real-time sensor information processing, sensor and data fusion, and automation techniques for information extraction from multi-sensor systems using expert systems continue to be investigated. Furthermore the progress in new applications (not limited to conventional engineering geodesy and navigation) of multi-sensor systems (e.g., in transportation, engineering, car navigation, environmental monitoring personal navigation, indoor navigation) is an important research focus in the years to come.

Fifty years or so ago, the geosynthetic installation industry was in its infancy, and people were experimenting with materials and ways to join them. Just about anybody with a roll of plastic and a welding system could line a dam or toxic waste facility. How things have changed! Innovation upon innovation occurred, and it soon became evident that the highly engineered materials and installation demands required a significant degree of experience and expertise, combined with strict quality control.