Glacsweb: an environmental sensor network

Environmental sensor networks provide an exciting opportunity to remotely study and monitor a range of environments. This is particularly important in remote or hazardous environments where many studies are hampered by inaccessibility. In addition, more accessible environments could be monitored on an unprecedented scale. The potential advances to environmental sciences could be as great as the revolution produced by the development of remote sensing during the 1970's. The aim of the GlacsWeb project is to build an environmental sensor network to understand glacier dynamics in response to climate change. This was undertaken to collect data from sensor nodes (probes) within the ice and the till (subglacial sediment). The wireless probes were designed to move freely like natural stones. Data is also collected from the surface of the glacier (position, weather, image). The data is sent to the Sensor Network Server where it is combined with large scale data from maps and satellites. In this way, specific data from the unique sensor nodes (which reflect point data) are combined with larger scale data to understand the glacier as a whole. The data was collected from within the ice by radio communications specifically designed for this environment; with increased power and using a 433Mhz frequency. The GlacsWeb system is composed of custom-built probes, a Base Station on the ice surface, a Reference Station (2.5 km from the glacier with mains electricity) and the Server based in Southampton. A differential GPS is used to track the base station's movement and recordings are made each day. The whole system operates automatically and data is fetched daily and sent to a web server for analysis. An initial system was installed in 2003 and an improved system was built and deployed in Jostedalsbreen, Norway in 2004. Advances were made in miniaturisation, low power design, networking and autonomous behaviour. Extra sensors were also added which measure probe stress and external conductivity. The results from the most recent system will be presented and discussed.