Gps-based Volcano Deformation Monitoring: a Mixed-mode Network Processing Approach

Ground surface deformation at a volcano is recognised as a sure indicator of impending eruptive activity and can contribute to volcanic hazard mitigation and disaster risk management. The Global Positioning System (GPS) is ideally suited for detecting and monitoring such deformation. However, most volcanoes are located in the equatorial region where the highly disturbed ionosphere severely limits the accuracy achievable with low-cost, single-frequency GPS networks. This book reviews the characteristics of continuously operating GPS deformation monitoring networks and describes a mixed-mode GPS network approach used to optimise a low-cost deformation monitoring system on an active Indonesian volcano. A sparse network of GPS receivers surrounding the deformation zone models the regional ionosphere, and empirical corrections are applied to the inner deformation network in order to improve the achievable accuracy. This approach is suitable for a variety of applications, including both natural and man-made structures, and will be particularly useful for researchers and spatial professionals concerned with cost-effective and accurate deformation monitoring.